Merge remote-tracking branch 'origin/Development' into Development

* Ackermann added.

* Ackermann updated

.classpath

@@ -1,7 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<classpath>
-	<classpathentry excluding="data_structures/" kind="src" path=""/>
-	<classpathentry kind="src" path="data_structures"/>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
-	<classpathentry kind="output" path="bin"/>
-</classpath>

.github/workflows/gradle.yml

@@ -0,0 +1,41 @@
+name: Java gradle CI
+
+on:
+  push:
+    branches:
+      - Development
+  pull_request:
+    branches:
+      - Development
+
+jobs:
+  test:
+    name: Test algorithms
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        java-version: [1.8, 11]
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - name: Checkout project
+        uses: actions/checkout@v2
+        with:
+          ref: Development
+      - name: Set up jdk
+        uses: actions/setup-java@v1
+        with:
+          java-version: ${{ matrix.java-version }}
+      - name: JUnit5 tests on ubuntu
+        if: startsWith(matrix.os, 'ubuntu')
+        run: |
+          chmod +x gradlew
+          ./gradlew clean test
+      - name: JUnit5 tests on macos
+        if: startsWith(matrix.os, 'macos')
+        run: |
+          chmod +x gradlew
+          ./gradlew clean test
+      - name: JUnit5 tests on windows
+        if: startsWith(matrix.os, 'windows')
+        run: gradle clean test

.gitignore

@@ -1 +1,15 @@
-/bin/
+.settings
+
+.classpath
+.project
+
+Java.iml
+.idea/*
+out/
+*.iml
+
+.gradle
+
+bin
+target
+build

.project

@@ -1,17 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<projectDescription>
-	<name>Java</name>
-	<comment></comment>
-	<projects>
-	</projects>
-	<buildSpec>
-		<buildCommand>
-			<name>org.eclipse.jdt.core.javabuilder</name>
-			<arguments>
-			</arguments>
-		</buildCommand>
-	</buildSpec>
-	<natures>
-		<nature>org.eclipse.jdt.core.javanature</nature>
-	</natures>
-</projectDescription>

ClosestPair/ClosestPair.java

@@ -1,211 +0,0 @@
-import java.io.*;
-import java.util.*;
-
-public class ClosestPair {
-	static int count = 0;// array length
-	static int secondCount = 0;// array length
-	static Location array[] = new Location[10000];
-	static Location point1 = null; // Minimum point coordinate
-	static Location point2 = null; // Minimum point coordinate
-	static double minNum = Double.MAX_VALUE;// Minimum point length
-
-	private static class Location { // Location class
-		double x = 0, y = 0;
-
-		public Location(double x, double y) { //Save x, y coordinates
-			this.x = x;
-			this.y = y;
-		}
-	}
-
-	public static int xPartition(Location[] a, int first, int last) { // x-axis Quick Sorting
-		Location pivot = a[last]; // pivot
-		int pIndex = last;
-		int i = first - 1;
-		Location temp; // Temporarily store the value for position transformation
-		for (int j = first; j <= last - 1; j++) {
-			if (a[j].x <= pivot.x) { // Less than or less than pivot
-				i++;
-				temp = a[i]; // array[i] <-> array[j]
-				a[i] = a[j];
-				a[j] = temp;
-			}
-		}
-		i++;
-		temp = a[i];// array[pivot] <-> array[i]
-		a[i] = a[pIndex];
-		a[pIndex] = temp;
-		return i;// pivot index
-	}
-	public static int yPartition(Location[] a, int first, int last) { //y-axis Quick Sorting
-		Location pivot = a[last]; // pivot
-		int pIndex = last;
-		int i = first - 1;
-		Location temp; // Temporarily store the value for position transformation
-		for (int j = first; j <= last - 1; j++) {
-			if (a[j].y <= pivot.y) { // Less than or less than pivot
-				i++;
-				temp = a[i]; // array[i] <-> array[j]
-				a[i] = a[j];
-				a[j] = temp;
-			}
-		}
-		i++;
-		temp = a[i];// array[pivot] <-> array[i]
-		a[i] = a[pIndex];
-		a[pIndex] = temp;
-		return i;// pivot index
-	}
-
-	public static void xQuickSort(Location[] a, int first, int last) { //x-axis Quick Sorting
-		if (first < last) {
-			int q = xPartition(a, first, last); // pivot
-			xQuickSort(a, first, q - 1); // Left
-			xQuickSort(a, q + 1, last); // Right
-		}
-	}
-
-	public static void yQuickSort(Location[] a, int first, int last) { //y-axis Quick Sorting
-		if (first < last) {
-			int q = yPartition(a, first, last); // pivot
-			yQuickSort(a, first, q - 1); // Left
-			yQuickSort(a, q + 1, last); // Right
-		}
-	}
-
-	public static double closestPair(Location[] a, int indexNum, int first, int last) {// closestPair
-		Location divideArray[] = new Location[indexNum]; // array stored before divide
-		System.arraycopy(a, 0, divideArray, 0, indexNum); // Copy from previous array
-
-		int totalNum = indexNum; // number of coordinates in the divideArray array
-		int divideX = indexNum / 2; // Intermediate value for divide
-		Location leftArray[] = new Location[divideX]; //divide - left array
-		Location rightArray[] = new Location[totalNum - divideX]; //divide - right array
-
-		if (indexNum <= 3) { // If the number of coordinates is 3 or less
-			return bruteForce(divideArray);
-		}
-		System.arraycopy(divideArray, 0, leftArray, 0, divideX); //divide - left array
-		System.arraycopy(divideArray, divideX, rightArray, 0, totalNum - divideX); //divide - right array
-
-		double minLeftArea = 0; //Minimum length of left array
-		double minRightArea = 0; //Minimum length of right array
-		double minValue = 0; //Minimum lengt
-
-		minLeftArea = closestPair(leftArray, divideX, 0, divideX - 1); // recursive closestPair
-		minRightArea = closestPair(rightArray, totalNum - divideX, divideX, totalNum - divideX - 1);
-		minValue = Math.min(minLeftArea, minRightArea);// window size (= minimum length)
-
-		// Create window
-		for (int i = 0; i < totalNum; i++) { // Set the size for creating a window and creating a new array for the coordinates in the window
-			double xGap = Math.abs(divideArray[divideX].x - divideArray[i].x);
-			if (xGap < minValue) {
-				secondCount++; // size of the array
-			} else {
-				if (divideArray[i].x > divideArray[divideX].x) {
-					break;
-				}
-			}
-		}
-		Location firstWindow[] = new Location[secondCount]; // new array for coordinates in window
-		int k = 0;
-		for (int i = 0; i < totalNum; i++) {
-			double xGap = Math.abs(divideArray[divideX].x - divideArray[i].x);
-			if (xGap < minValue) { // if it's inside a window
-				firstWindow[k] = divideArray[i]; // put in an array
-				k++;
-			} else {
-				if (divideArray[i].x > divideArray[divideX].x) {
-					break;
-				}
-			}
-		}
-		yQuickSort(firstWindow, 0, secondCount - 1);// Sort by y coordinates
-		/ * Coordinates in Window * /
-		double length = 0; 
-		for (int i = 0; i < secondCount - 1; i++) { // size comparison within window
-			for (int j = (i + 1); j < secondCount; j++) {
-				double xGap = Math.abs(firstWindow[i].x - firstWindow[j].x);
-				double yGap = Math.abs(firstWindow[i].y - firstWindow[j].y);
-				if (yGap < minValue) {
-					length = (double) Math.sqrt(Math.pow(xGap, 2) + Math.pow(yGap, 2));
-					if (length < minValue) { // If the measured distance is less than the current minimum distance
-						minValue = length;// Change minimum distance to current distance
-						if (length < minNum) { // Conditional statement for registering final coordinate
-							minNum = length;
-							point1 = firstWindow[i];
-							point2 = firstWindow[j];
-						}
-					}
-				} 
-				else
-					break;
-			}
-		}
-		secondCount = 0;
-		return minValue;
-	}
-
-	public static double bruteForce(Location[] array) { // When the number of coordinates is less than 3
-		double minValue = Double.MAX_VALUE; // minimum distance
-		double length = 0; 
-		double xGap = 0, yGap = 0; // Difference between x, y coordinates
-		if (array.length == 2) { // When there are two coordinates
-			xGap = (array[0].x - array[1].x); // Difference between x coordinates
-			yGap = (array[0].y - array[1].y); // Difference between y coordinates
-			length = (double) Math.sqrt(Math.pow(xGap, 2) + Math.pow(yGap, 2)); // distance between coordinates
-			if (length < minNum) { // Conditional statement for registering final coordinate
-				minNum = length;
-				point1 = array[0];
-				point2 = array[1];
-			}
-			return length;
-		} else if (array.length == 3) { // When there are 3 coordinates
-			for (int i = 0; i < array.length - 1; i++) {
-				for (int j = (i + 1); j < array.length; j++) {
-					xGap = (array[i].x - array[j].x); // Difference between x coordinates
-					yGap = (array[i].y - array[j].y); // Difference between y coordinates
-					length = (double) Math.sqrt(Math.pow(xGap, 2) + Math.pow(yGap, 2));  // distance between coordinates
-					if (length < minValue) { // If the measured distance is less than the current minimum distance
-						minValue = length; // Change minimum distance to current distance
-						if (length < minNum) { // Conditional statement for registering final coordinate
-							minNum = length;
-							point1 = array[i];
-							point2 = array[j];
-						}
-					}
-				}
-			}
-			return minValue;
-		}
-		return minValue;
-	}
-
-	public static void main(String[] args) throws IOException {
-		// TODO Auto-generated method stub
-		StringTokenizer token;
-
-		BufferedReader in = new BufferedReader(new FileReader("closest_data.txt"));
-		//Input data consists of one x-coordinate and one y-coordinate
-		String ch;
-
-		System.out.println("Input data");
-		while ((ch = in.readLine()) != null) {
-			token = new StringTokenizer(ch, " "); 
-
-			array[count] = new Location(Double.parseDouble(token.nextToken()), Double.parseDouble(token.nextToken())); // put in an array
-			count++; // the number of coordinates actually in the array
-			System.out.println("x: "+array[count - 1].x + ", y: " + array[count - 1].y);
-		}
-
-		xQuickSort(array, 0, count - 1); // Sorting by x value
-
-		double result; // minimum distance
-		result = closestPair(array, count, 0, count - 1); // ClosestPair start
-		System.out.println("Output Data");// minimum distance coordinates and distance output
-		System.out.println("(" + point1.x + ", " + point1.y + ")");
-		System.out.println("(" + point2.x + ", " + point2.y + ")");
-		System.out.println("Minimum Distance : " + result);
-
-	}
-}

ClosestPair/closest_data.txt

@@ -1,12 +0,0 @@
-2 3
-2 16
-3 9
-6 3
-7 7
-9 12
-10 11
-15 2
-15 19
-16 11
-17 13
-19 4

Compression/src/HEncoder.java

@@ -1,108 +0,0 @@
-import java.util.ArrayList;
-import java.util.Comparator;
-import java.util.HashMap;
-
-public class HEncoder {
-
-	public HashMap<Character, String> encoder = new HashMap<>(); // in order to encode
-	public HashMap<String, Character> decoder = new HashMap<>(); // in order to decode
-
-	private static class Node {
-
-		Character ch;
-		Integer freq;
-		Node left;
-		Node right;
-
-		public static final Nodecomparator Ctor = new Nodecomparator();
-
-		public static class Nodecomparator implements Comparator<Node> {
-
-			@Override
-			public int compare(Node o1, Node o2) {
-				return o2.freq - o1.freq;
-			}
-
-		}
-	}
-
-	public HEncoder(String feeder) {
-		// 1. freq map
-		HashMap<Character, Integer> freqmap = new HashMap<>();
-		for (int i = 0; i < feeder.length(); ++i) {
-			char ch = feeder.charAt(i);
-			if (freqmap.containsKey(ch)) {
-				freqmap.put(ch, freqmap.get(ch) + 1);
-			} else {
-				freqmap.put(ch, 1);
-			}
-		}
-
-		// 2. prepare the heap from keyset
-		genericheap<Node> heap = new genericheap<Node>(Node.Ctor);
-		ArrayList<Character> k = new ArrayList<>(freqmap.keySet());
-		for (Character c : k) {
-			Node n = new Node();
-			n.ch = c;
-			n.left = null;
-			n.right = null;
-			n.freq = freqmap.get(c);
-			heap.add(n);
-		}
-
-		// 3.Prepare tree, remove two , merge, add it back
-		Node fn = new Node();
-		while (heap.size() != 1) {
-			Node n1 = heap.removeHP();
-			Node n2 = heap.removeHP();
-			fn = new Node();
-
-			fn.freq = n1.freq + n2.freq;
-			fn.left = n1;
-			fn.right = n2;
-
-			heap.add(fn);
-		}
-
-		// 4. traverse
-
-		traverse(heap.removeHP(), "");
-	}
-
-	private void traverse(Node node, String osf) {
-
-		if (node.left == null && node.right == null) {
-			encoder.put(node.ch, osf);
-			decoder.put(osf, node.ch);
-			return;
-		}
-		traverse(node.left, osf + "0");
-		traverse(node.right, osf + "1");
-
-	}
-
-	// compression work done here
-	public String compress(String str) {
-		String rv = "";
-		for (int i = 0; i < str.length(); ++i) {
-			rv += encoder.get(str.charAt(i));
-		}
-		return rv;
-	}
-	
-
-	//in order to decompress
-	public String decompress(String str) {
-		String s = "";
-		String code = "";
-		for (int i = 0; i < str.length(); ++i) {
-			code += str.charAt(i);
-			if (decoder.containsKey(code)) {
-				s += decoder.get(code);
-				code = "";
-			}
-		}
-
-		return s;
-	}
-}

Compression/src/compressclient.java

@@ -1,11 +0,0 @@
-
-public class compressclient {
-
-	public static void main(String[] args) {
-
-		HEncoder h= new HEncoder("aaaabbbcccccccccccdddd");
-		System.out.println(h.compress("aabccd"));
-		System.out.println(h.decompress("101011000111"));
-	}
-
-}

Compression/src/genericheap.java

@@ -1,93 +0,0 @@
-
-
-import java.util.ArrayList;
-import java.util.Comparator;
-
-public class genericheap<T> { // create a generic heap class <T> , where T can be of any type.
-
-	private ArrayList<T> data = new ArrayList<>();
-	private Comparator<T> ctor;
-
-	public genericheap(Comparator<T> ctor) { // constructor to initialize the generic comparator 
-		this.ctor=ctor;
-	}	
-
-	public int size() { // returns the size of the arraylist data
-		return data.size();
-	}
-
-	public boolean isEmpty() { // checks whether the list is empty or not :: return true or false for the same
-		return data.isEmpty();
-	}
-
-	public void display() { //displays the list
-		System.out.println(this.data);
-	}
-
-	public void add(T integer) { // in this function we have added the <t> type object into the arraylist and called upheapify 
-		data.add(integer);
-		upheapify(data.size() - 1);
-	}
-
-	private void upheapify(int ci) {
-		if (ci == 0) {
-			return;
-		}
-		int pi = (ci - 1) / 2;
-		if (isLarger(ci,pi) == true) {
-			swap(ci, pi);
-			upheapify(pi);
-		}
-	}
-
-	private boolean isLarger(int i, int j) {
-		T ith = data.get(i);
-		T jth = data.get(j);
-		if(ctor.compare(ith,jth)>0)
-		{
-			return true;
-		}
-		else
-		{
-			return false;
-		}
-	}
-
-	private void swap(int ci, int pi) { // swap function  written like this because of the generic property
-		T ith = data.get(ci);
-		T jth=data.get(pi);
-		data.set(ci, jth);
-		data.set(pi, ith);
-	}
-
-	public T getHP() {
-		return data.get(0);
-	}
-
-	public T removeHP() {
-	
-		swap(0, data.size() - 1);
-		T rv=data.remove(data.size()-1);
-		downheapify(0);
-		return rv;
-	}
-
-	private void downheapify(int pi) {
-		int lci = 2 * pi + 1;
-		int rci = 2 * pi + 2;
-
-		int max = pi;
-
-		if (lci < data.size() && isLarger(lci, max) == true) {
-			max = lci;
-		}
-		if (rci < data.size() && isLarger(rci, max) == true) {
-			max = rci;
-		}
-		if (max != pi) {
-			swap(pi, max);
-			downheapify(max);
-		}
-	}
-
-}

Conversions/AnyBaseToAnyBase.java

@@ -1,130 +0,0 @@
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.InputMismatchException;
-import java.util.Scanner;
-
-/**
- * Class for converting from "any" base to "any" other base, when "any" means from 2-36.
- * Works by going from base 1 to decimal to base 2. Includes auxiliary method for 
- * determining whether a number is valid for a given base.
- * 
- * @author Michael Rolland
- * @version 2017.10.10
- *
- */
-public class AnyBaseToAnyBase {
-	
-	// Smallest and largest base you want to accept as valid input
-	static final int MINIMUM_BASE = 2;
-	static final int MAXIMUM_BASE = 36;
-	
-	// Driver
-	public static void main(String[] args) {
-		Scanner in = new Scanner(System.in);
-		String n;
-		int b1=0,b2=0;
-		while (true) {
-			try {
-				System.out.print("Enter number: ");
-				n = in.next();
-				System.out.print("Enter beginning base (between "+MINIMUM_BASE+" and "+MAXIMUM_BASE+"): ");
-				b1 = in.nextInt();
-				if (b1 > MAXIMUM_BASE || b1 < MINIMUM_BASE) {
-					System.out.println("Invalid base!");
-					continue;
-				}
-				if (!validForBase(n, b1)) {
-					System.out.println("The number is invalid for this base!");
-					continue;
-				}
-				System.out.print("Enter end base (between "+MINIMUM_BASE+" and "+MAXIMUM_BASE+"): ");
-				b2 = in.nextInt();
-				if (b2 > MAXIMUM_BASE || b2 < MINIMUM_BASE) {
-					System.out.println("Invalid base!");
-					continue;
-				}
-				break;
-			} catch (InputMismatchException e) {
-				System.out.println("Invalid input.");
-				in.next();
-			}
-		}
-		System.out.println(base2base(n, b1, b2));
-	}
-	
-	/**
-	 * Checks if a number (as a String) is valid for a given base.
-	 */
-	public static boolean validForBase(String n, int base) {
-		char[] validDigits = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E',
-				'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
-				'W', 'X', 'Y', 'Z'};
-		// digitsForBase contains all the valid digits for the base given
-		char[] digitsForBase = Arrays.copyOfRange(validDigits, 0, base);
-		
-		// Convert character array into set for convenience of contains() method
-		HashSet<Character> digitsList = new HashSet();
-		for (int i=0; i<digitsForBase.length; i++)
-			digitsList.add(digitsForBase[i]);
-		
-		// Check that every digit in n is within the list of valid digits for that base.
-		for (char c : n.toCharArray()) 
-			if (!digitsList.contains(c))
-				return false;
-		
-		return true;
-	}
-	
-	/**
-	 * Method to convert any integer from base b1 to base b2. Works by converting from b1 to decimal,
-	 * then decimal to b2.
-	 * @param n The integer to be converted.
-	 * @param b1 Beginning base.
-	 * @param b2 End base.
-	 * @return n in base b2.
-	 */
-	public static String base2base(String n, int b1, int b2) {
-		// Declare variables: decimal value of n, 
-		// character of base b1, character of base b2,
-		// and the string that will be returned.
-		int decimalValue = 0, charB2;
-		char charB1;
-		String output="";
-		// Go through every character of n
-		for (int i=0; i<n.length(); i++) {
-			// store the character in charB1
-			charB1 = n.charAt(i);
-			// if it is a non-number, convert it to a decimal value >9 and store it in charB2
-			if (charB1 >= 'A' && charB1 <= 'Z') 
-				charB2 = 10 + (charB1 - 'A');
-			// Else, store the integer value in charB2
-			else 
-				charB2 = charB1 - '0';
-			// Convert the digit to decimal and add it to the
-			// decimalValue of n
-			decimalValue = decimalValue * b1 + charB2;
-		}
-		
-		// Converting the decimal value to base b2:
-		// A number is converted from decimal to another base
-		// by continuously dividing by the base and recording 
-		// the remainder until the quotient is zero. The number in the
-		// new base is the remainders, with the last remainder
-		// being the left-most digit.
-		
-		// While the quotient is NOT zero:
-		while (decimalValue != 0) {
-			// If the remainder is a digit < 10, simply add it to
-			// the left side of the new number.
-			if (decimalValue % b2 < 10) 
-				output = Integer.toString(decimalValue % b2) + output;
-			// If the remainder is >= 10, add a character with the
-			// corresponding value to the new number. (A = 10, B = 11, C = 12, ...)
-			else
-				output = (char)((decimalValue % b2)+55) + output;
-			// Divide by the new base again
-			decimalValue /= b2;
-		}
-		return output;
-	}
-}

Conversions/AnyBaseToDecimal.java

@@ -1,59 +0,0 @@
-import java.io.BufferedReader;
-import java.io.InputStreamReader;
-
-/**
- *
- * @author Varun Upadhyay (https://github.com/varunu28)
- *
- */
-
-// Driver program
-public class AnyBaseToDecimal {
-    public static void main (String[] args) throws Exception{
-        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
-        
-        String inp = br.readLine();
-        int base =  Integer.parseInt(br.readLine());
-
-        System.out.println("Input in base " + base + " is: " + inp);
-        System.out.println("Decimal value of " + inp + " is: " + convertToDecimal(inp, base));
-
-        br.close();
-    }
-
-    /**
-     * This method produces a decimal value of any given input number of any base
-     * @param inp_num String of which we need the decimal value and base in integer format
-     * @return string format of the decimal value
-     */
-
-    public static String convertToDecimal(String inp_num, int base) {
-        int len = inp_num.length();
-        int num = 0;
-        int pow = 1;
-
-        for (int i=len-1; i>=0; i--) {
-            if (valOfChar(inp_num.charAt(i)) >= base) {
-                return "Invalid Number";
-            }
-            num += valOfChar(inp_num.charAt(i))*pow;
-            pow *= base;
-        }
-        return String.valueOf(num);
-    }
-
-    /**
-     * This method produces integer value of the input character and returns it
-     * @param c Char of which we need the integer value of
-     * @return integer value of input char
-     */
-
-    public static int valOfChar(char c) {
-        if (c >= '0' && c <= '9') {
-            return (int)c - '0';
-        }
-        else {
-            return (int)c - 'A' + 10;
-        }
-    }
-}

Conversions/AnytoAny.java

@@ -1,29 +0,0 @@
-package Java.Conversions;
-
-import java.util.Scanner;
-//given a source number , source base, destination base, this code can give you the destination number.
-//sn ,sb,db ---> ()dn  .   this is what we have to do    .
-
-public class AnytoAny {
-
-    public static void main(String[] args) {
-        Scanner scn = new Scanner(System.in);
-        int sn = scn.nextInt();
-        int sb = scn.nextInt();
-        int db = scn.nextInt();
-        int m = 1, dec = 0, dn = 0;
-        while (sn != 0) {
-            dec = dec + (sn % 10) * m;
-            m *= sb;
-            sn /= 10;
-        }
-        m = 1;
-        while (dec != 0) {
-            dn = dn + (dec % db) * m;
-            m *= 10;
-            dec /= db;
-        }
-        System.out.println(dn);
-    }
-
-}

Conversions/BinaryToDecimal.java

@@ -1,33 +0,0 @@
-import java.util.Scanner;
-
-/**
- * This class converts a Binary number to a Decimal number
- * 
- * @author Unknown
- *
- */
-class BinaryToDecimal
-{
-	
-	/**
-	 * Main Method
-	 * 
-	 * @param args Command line arguments
-	 */
-  public static void main(String args[])
-  {
-    Scanner sc=new Scanner(System.in);
-    int n,k,d,s=0,c=0;
-    System.out.print("Binary number: ");
-    n=sc.nextInt();
-    k=n;
-    while(k!=0)
-    {
-      d=k%10;
-      s+=d*(int)Math.pow(2,c++);
-      k/=10;
-    }
-    System.out.println("Decimal equivalent:"+s);
-    sc.close();
-  }
-}

Conversions/BinaryToHexadecimal.java

@@ -1,57 +0,0 @@
-import java.util.*;
-/**
- * Converts any Binary Number to a Hexadecimal Number
- * 
- * @author Nishita Aggarwal
- *
- */
-public class BinaryToHexadecimal {
-   
-	/**
-	 * This method converts a binary number to
-	 * a hexadecimal number.
-	 * 
-	 * @param binary The binary number
-	 * @return The hexadecimal number
-	 */ 
-	static String binToHex(int binary)
-	{
-		//hm to store hexadecimal codes for binary numbers within the range: 0000 to 1111 i.e. for decimal numbers 0 to 15
-		HashMap<Integer,String> hm=new HashMap<>();	
-		//String to store hexadecimal code
-		String hex="";
-		int i;
-		for(i=0 ; i<10 ; i++)
-		{
-			hm.put(i, String.valueOf(i));
-		}
-		for(i=10 ; i<16 ; i++)	hm.put(i,String.valueOf((char)('A'+i-10)));
-		int currbit;
-		while(binary != 0)
-		{
-			int code4 = 0;	//to store decimal equivalent of number formed by 4 decimal digits
-			for(i=0 ; i<4 ; i++)
-			{
-				currbit = binary % 10;
-				binary = binary / 10;
-				code4 += currbit * Math.pow(2, i);
-			}
-			hex= hm.get(code4) + hex;
-		}
-		return hex; 
-	}
-	
-	/**
-	 * Main method
-	 * 
-	 * @param args Command line arguments
-	 */
-	public static void main(String[] args) {
-		Scanner sc = new Scanner(System.in);
-		System.out.println("Enter binary number:");
-		int binary = sc.nextInt();
-		String hex = binToHex(binary);
-		System.out.println("Hexadecimal Code:" + hex);
-		sc.close();
-	}
-}

Conversions/BinaryToOctal.java

@@ -1,43 +0,0 @@
-import java.util.Scanner;
-
-/**
- * Converts any Binary number to an Octal Number
- * 
- * @author Zachary Jones
- *
- */
-public class BinaryToOctal {
-	
-	/**
-	 * Main method
-	 * 
-	 * @param args Command line arguments
-	 */
-	public static void main(String args[]) {
-		Scanner sc = new Scanner(System.in);
-		int b = sc.nextInt();
-		System.out.println("Octal equivalent: " + convertBinaryToOctal(b));
-		sc.close();
-		
-	}
-	
-	/**
-	 * This method converts a binary number to
-	 * an octal number.
-	 * 
-	 * @param b The binary number
-	 * @return The octal number
-	 */
-	public static int convertBinaryToOctal(int b) {
-		int o = 0, r=0, j =1 ;
-		while(b!=0)
-		{
-			r = b % 10;
-        		o = o + r * j;
-       			j = j * 2;
-        		b = b / 10;
-		}
-		return o;
-	}
-
-}

Conversions/DecimalToAnyBase.java

@@ -1,65 +0,0 @@
-import java.io.BufferedReader;
-import java.io.InputStreamReader;
-import java.util.ArrayList;
-
-/**
- *
- * @author Varun Upadhyay (https://github.com/varunu28)
- *
- */
-
-// Driver Program
-public class DecimalToAnyBase {
-    public static void main (String[] args) throws Exception{
-        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
-        System.out.println("Enter the decimal input below: ");
-        int decInput = Integer.parseInt(br.readLine());
-        System.out.println();
-
-        System.out.println("Enter the base below: ");
-        int base =  Integer.parseInt(br.readLine());
-        System.out.println();
-
-        System.out.println("Decimal Input" + " is: " + decInput);
-        System.out.println("Value of " + decInput + " in base " + base + " is: " + convertToAnyBase(decInput, base));
-
-        br.close();
-    }
-
-    /**
-     * This method produces a String value of any given input decimal in any base
-     * @param inp Decimal of which we need the value in base in String format
-     * @return string format of the converted value in the given base
-     */
-
-    public static String convertToAnyBase(int inp, int base) {
-        ArrayList<Character> charArr = new ArrayList<>();
-
-        while (inp > 0) {
-            charArr.add(reVal(inp%base));
-            inp /= base;
-        }
-
-        StringBuilder str = new StringBuilder(charArr.size());
-
-        for(Character ch: charArr)
-        {
-            str.append(ch);
-        }
-
-        return str.reverse().toString();
-    }
-
-    /**
-     * This method produces character value of the input integer and returns it
-     * @param num integer of which we need the character value of
-     * @return character value of input integer
-     */
-
-    public static char reVal(int num) {
-        if (num >= 0 && num <= 9)
-            return (char)(num + '0');
-        else
-            return (char)(num - 10 + 'A');
-    }
-}

Conversions/DecimalToBinary.java

@@ -1,57 +0,0 @@
-import java.util.Scanner;
-
-/**
- * This class converts a Decimal number to a Binary number
- * 
- * @author Unknown
- *
- */
-class DecimalToBinary {
-
-    /**
-     * Main Method
-     * 
-     * @param args Command Line Arguments
-     */
-    public static void main(String args[]) {
-        conventionalConversion();
-        bitwiseConversion();
-    }
-
-    /**
-     * This method converts a decimal number 
-     * to a binary number using a conventional
-     * algorithm.
-     */
-    public static void conventionalConversion() {
-        int n, b = 0, c = 0, d;
-        Scanner input = new Scanner(System.in);
-        System.out.printf("Conventional conversion.\n\tEnter the decimal number: ");
-        n = input.nextInt();
-        while (n != 0) {
-            d = n % 2;
-            b = b + d * (int) Math.pow(10, c++);
-            n /= 2;
-        } //converting decimal to binary
-        System.out.println("\tBinary number: " + b);
-    }
-
-    /**
-     * This method converts a decimal number 
-     * to a binary number using a bitwise
-     * algorithm
-     */
-    public static void bitwiseConversion() {
-        int n, b = 0, c = 0, d;
-        Scanner input = new Scanner(System.in);
-        System.out.printf("Bitwise conversion.\n\tEnter the decimal number: ");
-        n = input.nextInt();
-        while (n != 0) {
-            d = (n & 1);
-            b += d * (int) Math.pow(10, c++);
-            n >>= 1;
-        }
-        System.out.println("\tBinary number: " + b);
-    }
-
-}

Conversions/DecimalToHexaDecimal.java

@@ -1,30 +0,0 @@
-
-class DecimalToHexaDecimal {
-	private static final int sizeOfIntInHalfBytes = 8;
-	private static final int numberOfBitsInAHalfByte = 4;
-	private static final int halfByte = 0x0F;
-	private static final char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E',
-			'F' };
-
-	// Returns the hex value of the dec entered in the parameter.
-	public static String decToHex(int dec) {
-		StringBuilder hexBuilder = new StringBuilder(sizeOfIntInHalfBytes);
-		hexBuilder.setLength(sizeOfIntInHalfBytes);
-		for (int i = sizeOfIntInHalfBytes - 1; i >= 0; --i) {
-			int j = dec & halfByte;
-			hexBuilder.setCharAt(i, hexDigits[j]);
-			dec >>= numberOfBitsInAHalfByte;
-		}
-		return hexBuilder.toString().toLowerCase();
-	}
-
-	// Test above function.
-	public static void main(String[] args) {
-		System.out.println("Test...");
-		int dec = 305445566;
-		String libraryDecToHex = Integer.toHexString(dec);
-		String decToHex = decToHex(dec);
-		System.out.println("Result from the library : " + libraryDecToHex);
-		System.out.println("Result decToHex method : " + decToHex);
-	}
-}

Conversions/DecimalToOctal.java

@@ -1,33 +0,0 @@
-import java.util.Scanner;
-
-/**
- * This class converts Decimal numbers to Octal Numbers
- * 
- * @author Unknown
- *
- */
-class Decimal_Octal
-{
-	/**
-	 * Main Method
-	 * 
-	 * @param args Command line Arguments
-	 */
-  public static void main(String[] args)
-  {
-    Scanner sc=new Scanner(System.in);
-    int n,k,d,s=0,c=0;
-    System.out.print("Decimal number: ");
-    n=sc.nextInt();
-    k=n;
-    while(k!=0)
-    {
-      d=k%8;
-      s+=d*(int)Math.pow(10,c++);
-      k/=8;
-    }
-   
-    System.out.println("Octal equivalent:"+s);
-    sc.close();
-  }
-}

Conversions/HexToOct.java

@@ -1,74 +0,0 @@
-/**
- + * Converts any Hexadecimal Number to Octal 
- + * 
- + * @author Tanmay Joshi
- + *
- + */
-import java.util.Scanner;
-
-public class HexToOct
-{ 
-	/**
- +	 * This method converts a Hexadecimal number to
- +	 * a decimal number
- +	 * 
- +	 * @param The Hexadecimal Number
- +	 * @return The Decimal number
- +	 */ 
-    public static int hex2decimal(String s)
-    {
-             String str = "0123456789ABCDEF";  
-             s = s.toUpperCase();
-             int val = 0;
-             for (int i = 0; i < s.length(); i++)
-             {
-                 char a = s.charAt(i);
-                 int n = str.indexOf(a);
-                 val = 16*val + n;
-             }
-             return val;
-    } 
-	
-	/**
- +	 * This method converts a Decimal number to
- +	 * a octal number
- +	 * 
- +	 * @param The Decimal Number
- +	 * @return The Octal number
- +	 */ 
-	public static int decimal2octal(int q)
-	{
-		int now;
-		int i=1;
-		int octnum=0;
-		while(q>0)
-		{
-			now=q%8;
-			octnum=(now*(int)(Math.pow(10,i)))+octnum;
-			q/=8;
-			i++;
-		}
-		octnum/=10;
-		return octnum;
-	}
-	// Main method that gets the hex input from user and converts it into octal.
-    public static void main(String args[])
-    {
-        String hexadecnum;
-        int decnum,octalnum;
-        Scanner scan = new Scanner(System.in);
-		
-        System.out.print("Enter Hexadecimal Number : ");
-        hexadecnum = scan.nextLine();      
-        
-        // first convert hexadecimal to decimal
-        
-        decnum = hex2decimal(hexadecnum);       //Pass the string to the hex2decimal function and get the decimal form in variable decnum
-		
-        // convert decimal to octal
-        octalnum=decimal2octal(decnum);
-	System.out.println("Number in octal: "+octalnum);
- 
-        
-    }
-}

Conversions/HexaDecimalToBinary.java

@@ -1,37 +0,0 @@
-import java.lang.StringBuilder;
-import java.util.*;
-import java.util.Scanner;
-import javax.swing.*;
-
-public class HexaDecimalToBinary {
- 
-    private final int LONG_BITS = 8;
-
-    public void convert(String numHex) {
-        //String a HexaDecimal:
-        int conHex = Integer.parseInt(numHex, 16);
-        //Hex a Binary:
-        String binary = Integer.toBinaryString(conHex);
-        //Presentation:
-        System.out.println(numHex + " = " + completeDigits(binary));
-    }
-
-    public String completeDigits(String binNum) {
-        for (int i = binNum.length(); i < LONG_BITS; i++) {
-            binNum = "0" + binNum;
-        }
-        return binNum;
-    }
-
-    public static void main(String[] args) {
-
-        //Testing Numbers:
-        String[] hexNums = {"1", "A1", "ef", "BA", "AA", "BB",
-            "19", "01", "02", "03", "04"};
-        HexaDecimalToBinary objConvert = new HexaDecimalToBinary();
-
-        for (String num : hexNums) {
-            objConvert.convert(num);
-        }
-    }
-}

Conversions/HexaDecimalToDecimal.java

@@ -1,42 +0,0 @@
-package Conversions;
-
-import java.util.Scanner;
-
-public class HexaDecimalToDecimal {
-
-    // convert hexadecimal to decimal
-    public static int getHexaToDec(String hex){
-        String digits = "012345678910ABCDEFF";
-        hex = hex.toUpperCase();
-        int val = 0;
-        for (int i = 0; i < hex.length(); i++)
-        {
-            int d = digits.indexOf(hex.charAt(i));
-            val = 16*val + d;
-        }
-        return val;
-    }
-
-    // Main method gets the hexadecimal input from user and converts it into Decimal output.
-
-    public static void main(String args[])
-    {
-        String hexa_Input;
-        int dec_output;
-        Scanner scan = new Scanner(System.in);
-
-        System.out.print("Enter Hexadecimal Number : ");
-        hexa_Input = scan.nextLine();
-
-        // convert hexadecimal to decimal
-
-        dec_output = getHexaToDec(hexa_Input);
-        /*
-        Pass the string to the getHexaToDec function
-        and it returns the decimal form in the variable dec_output.
-        */
-        System.out.println("Number in Decimal: "+dec_output);
-
-
-    }
-}

Conversions/OctalToBinary.java

@@ -1,49 +0,0 @@
-import java.util.Scanner;
-
-/**
- * Converts any Octal number to a Binary number
- * 
- * @author Zachary Jones
- *
- */
-public class OctalToBinary {
-
-	/**
-	 * Main method
-	 * 
-	 * @param args Command line arguments
-	 */
-	public static void main(String args[]) {
-		Scanner sc = new Scanner(System.in);
-		int o = sc.nextInt();
-		System.out.println("Binary equivalent: " + convertOctalToBinary(o));
-		sc.close();
-	}
-	
-	/**
-	 * This method converts an octal number
-	 * to a binary number.
-	 * 
-	 * @param o The octal number
-	 * @return The binary number
-	 */
-	public static int convertOctalToBinary(int o) {
-		Scanner scan;
-		int num;
-	
-		void getVal() {
-		
-			System.out.println("Octal to Binary");
-			scan = new Scanner(System.in);
-			// Entering the needed number
-			System.out.println("\nEnter the number : ");
-			num = Integer.parseInt(scan.nextLine(), 8);
-		}
-		
-		void convert() {
-		
-			String binary = Integer.toBinaryString(num);		
-			System.out.println("Binary Value is : " + binary);
-		}
-	}
-}

Conversions/OctalToDecimal.java

@@ -1,47 +0,0 @@
-import java.util.Scanner;
-
-/**
- * Converts any Octal Number to a Decimal Number
- * 
- * @author Zachary Jones
- *
- */
-public class OctalToDecimal {
-
-	/**
-	 * Main method
-	 * 
-	 * @param args
-	 *            Command line arguments
-	 */
-	public static void main(String args[]) {
-		Scanner sc = new Scanner(System.in);
-		System.out.print("Octal Input: ");
-		String inputOctal = sc.nextLine();
-		int result = convertOctalToDecimal(inputOctal);
-		if (result != -1)
-			System.out.println("Result convertOctalToDecimal : " + result);
-		sc.close();
-	}
-
-	/**
-	 * This method converts an octal number to a decimal number.
-	 * 
-	 * @param inputOctal
-	 *            The octal number
-	 * @return The decimal number
-	 */
-	public static int convertOctalToDecimal(String inputOctal) {
-
-		try {
-			// Actual conversion of Octal to Decimal:
-			Integer outputDecimal = Integer.parseInt(inputOctal, 8);
-			return outputDecimal;
-		} catch (NumberFormatException ne) {
-			// Printing a warning message if the input is not a valid octal
-			// number:
-			System.out.println("Invalid Input, Expecting octal number 0-7");
-			return -1;
-		}
-	}
-}

Conversions/OctalToHexadecimal.java

@@ -1,63 +0,0 @@
-/**
- + + * Converts any Octal Number to HexaDecimal 
- + + * 
- + + * @author Tanmay Joshi
- + + *
- + + *
- **/
-import java.util.Scanner;
-
-public class OctalToHexadecimal {
-	
-  /**
- + +	 * This method converts a Octal number to
- + +	 * a decimal number
- + +	 * 
- + +	 * @param The Octal Number
- + +	 * @return The Decimal number
- + +	 */ 
- public static int OctToDec(String s)
- {
-	 int i =0;
-	 for(int j =0;j<s.length();j++)
-	 {
-		 char num = s.charAt(j);
-		 num-='0';
-		 i*=8;
-		 i+=num;
-	 }
-	 return i;
-}
-
-/**
- + +	 * This method converts a Decimal number to
- + +	 * a Hexadecimal number
- + +	 * 
- + +	 * @param The Decimal Number
- + +	 * @return The Hexadecimal number
- + +	 */ 
-public static String DecimalToHex(int d) {
-    String digits = "0123456789ABCDEF";
-    if (d <= 0) 
-		return "0";  
-    String hex = "";
-    while (d > 0) {
-        int digit = d % 16;              
-        hex = digits.charAt(digit) + hex;
-        d = d / 16;
-    }
-    return hex;
-}
-
-           //Driver Program
-public static void main ( String args[]) {
-		
-     Scanner input = new Scanner(System.in);
-     System.out.print("Enter the Octal number: ");
-     String oct  = input.next();                     //Take octal number as input from user in a string
-     int decimal = OctToDec(oct);                    //Pass the octal number to function and get converted deciaml form
-     String hex = DecimalToHex(decimal);             //Pass the decimla number to function and get converted Hex form of the number
-     System.out.println("The Hexadecimal equivalant is: "+hex);
- }
-}
-

DataStructures/Bags/Bag.java

@@ -1,126 +0,0 @@
-package Bags;
-
-import java.util.Iterator;
-import java.util.NoSuchElementException;
-
-/**
- * Collection which does not allow removing elements (only collect and iterate)
- * 
- * @param <Element> - the generic type of an element in this bag
- */
-public class Bag<Element> implements Iterable<Element> {
-
-	private Node<Element> firstElement; // first element of the bag
-	private int size; // size of bag
-
-	private static class Node<Element> {
-		private Element content;
-		private Node<Element> nextElement;
-	}
-
-	/**
-	 * Create an empty bag
-	 */
-	public Bag() {
-		firstElement = null;
-		size = 0;
-	}
-
-	/**
-	 * @return true if this bag is empty, false otherwise
-	 */
-	public boolean isEmpty() {
-		return firstElement == null;
-	}
-
-	/**
-	 * @return the number of elements
-	 */
-	public int size() {
-		return size;
-	}
-
-	/**
-	 * @param element - the element to add
-	 */
-	public void add(Element element) {
-		Node<Element> oldfirst = firstElement;
-		firstElement = new Node<>();
-		firstElement.content = element;
-		firstElement.nextElement = oldfirst;
-		size++;
-	}
-	
-	/**
-	 * Checks if the bag contains a specific element
-	 * 
-	 * @param element which you want to look for
-	 * @return true if bag contains element, otherwise false
-	 */
-	public boolean contains(Element element) {
-		Iterator<Element> iterator = this.iterator();
-		while(iterator.hasNext()) {
-			if (iterator.next().equals(element)) {
-				return true;
-			}
-		}
-		return false;
-	}
-
-	/**
-	 * @return an iterator that iterates over the elements in this bag in arbitrary order
-	 */
-	public Iterator<Element> iterator() {
-		return new ListIterator<>(firstElement);
-	}
-
-	@SuppressWarnings("hiding")
-	private class ListIterator<Element> implements Iterator<Element> {
-		private Node<Element> currentElement;
-
-		public ListIterator(Node<Element> firstElement) {
-			currentElement = firstElement;
-		}
-
-		public boolean hasNext() {
-			return currentElement != null;
-		}
-
-		/**
-		 * remove is not allowed in a bag
-		 */
-		@Override
-		public void remove() {
-			throw new UnsupportedOperationException();
-		}
-
-		public Element next() {
-			if (!hasNext())
-				throw new NoSuchElementException();
-			Element element = currentElement.content;
-			currentElement = currentElement.nextElement;
-			return element;
-		}
-	}
-
-	/**
-	 * main-method for testing
-	 */
-	public static void main(String[] args) {
-		Bag<String> bag = new Bag<>();
-
-		bag.add("1");
-		bag.add("1");
-		bag.add("2");
-
-		System.out.println("size of bag = " + bag.size());
-		for (String s : bag) {
-			System.out.println(s);
-		}
-		
-		System.out.println(bag.contains(null));
-		System.out.println(bag.contains("1"));
-		System.out.println(bag.contains("3"));
-	}
-
-}

DataStructures/Buffers/CircularBuffer.java

@@ -1,124 +0,0 @@
-import java.util.Random;
-import java.util.concurrent.atomic.AtomicInteger;
-
-public class CircularBuffer {
-    private char[] _buffer;
-    public final int _buffer_size;
-    private int _write_index = 0;
-    private int _read_index = 0;
-    private AtomicInteger _readable_data = new AtomicInteger(0);
-
-    public CircularBuffer(int buffer_size) {
-        if(!IsPowerOfTwo(buffer_size)) {
-            throw new IllegalArgumentException();
-        }
-        this._buffer_size = buffer_size;
-        _buffer = new char[buffer_size];
-    }
-
-    private boolean IsPowerOfTwo(int i) {
-        return (i & (i - 1)) == 0;
-    }
-
-    private int getTrueIndex(int i) {
-        return i % _buffer_size;
-    }
-
-    public Character readOutChar() {
-        Character result = null;
-
-        //if we have data to read
-        if(_readable_data.get() > 0) {
-            result = new Character(_buffer[getTrueIndex(_read_index)]);
-            _readable_data.decrementAndGet();
-            _read_index++;
-        }
-
-        return result;
-    }
-
-    public boolean writeToCharBuffer(char c) {
-        boolean result = false;
-
-        //if we can write to the buffer
-        if(_readable_data.get() < _buffer_size) {
-            //write to buffer
-            _buffer[getTrueIndex(_write_index)] = c;
-            _readable_data.incrementAndGet();
-            _write_index++;
-            result = true;
-        }
-
-        return result;
-    }
-
-    private static class TestWriteWorker implements Runnable {
-        String _alphabet = "abcdefghijklmnopqrstuvwxyz0123456789";
-        Random _random = new Random();
-        CircularBuffer _buffer;
-        public TestWriteWorker(CircularBuffer cb) {
-            this._buffer = cb;
-        }
-
-        private char getRandomChar() {
-            return _alphabet.charAt(_random.nextInt(_alphabet.length()));
-        }
-
-        public void run() {
-            while(!Thread.interrupted()) {
-                if(!_buffer.writeToCharBuffer(getRandomChar())){
-                    Thread.yield();
-                    try{
-                        Thread.sleep(10);
-                    } catch (InterruptedException e) {
-                        return;
-                    }
-                }
-            }
-        }
-    }
-
-    private static class TestReadWorker implements Runnable {
-        CircularBuffer _buffer;
-        public TestReadWorker(CircularBuffer cb) {
-            this._buffer = cb;
-        }
-
-        public void run() {
-            System.out.println("Printing Buffer:");
-            while(!Thread.interrupted()) {
-                Character c = _buffer.readOutChar();
-                if(c != null) {
-                    System.out.print(c.charValue());
-                } else {
-                    Thread.yield();
-                    try {
-                        Thread.sleep(10);
-                    } catch (InterruptedException e) {
-                        System.out.println();
-                        return;
-                    }
-                }
-            }
-        }
-    }
-
-    public static void main(String[] args) throws InterruptedException {
-        int buffer_size = 1024;
-        //create circular buffer
-        CircularBuffer cb = new CircularBuffer(buffer_size);
-
-        //create threads that read and write the buffer.
-        Thread write_thread = new Thread(new TestWriteWorker(cb));
-        Thread read_thread = new Thread(new TestReadWorker(cb));
-        read_thread.start();
-        write_thread.start();
-
-        //wait some amount of time
-        Thread.sleep(10000);
-
-        //interrupt threads and exit
-        write_thread.interrupt();
-        read_thread.interrupt();
-    }
-}

DataStructures/CSVFile/src/CSVFile.java

@@ -1,692 +0,0 @@
-/*
- * author: Christian Bender
- * class: CSVFile
- * 
- * This class implements a data structure for handling of 
- * CSV-files.
- * 
- * Overview
- * 
- * CSVFile(path : string, seperator : char)
- * 	compiles the CSV-file in the inner data structure.
- * 
- * CSVFile (file : File, seperator : char)
- * CSVFile (seperator : char)
- * 
- * compile (row : string, seperator : char) : string
- * 	compiles row in its columns.
- * 
- * isPunctuation (ch : char) : boolean
- * 	check whether ch is a punctuation character.
- * 
- * getElementString(row : int, column : int) : string
- * 	returns the specified element.
- * 
- * getElementDouble(row : int, column : int) : double
- * 	returns the specified element as double.
- * 
- * addRow(row : string) : void
- * 	adds a row to the inner data structure.
- * 	without writing into the CSV-file.
- * 
- * set (row : int, column : int, item : string) : void
- * 	replaces the specified item with a newer.
- * 
- * commit() : void 
- * 	writes the added data into CSV-file.
- * 
- * commit(path : String) : void
- * commit(file : File ) : void
- * 
- * findRow(key : string) : ArrayList<String>
- * 	returns the searched row otherwise null.
- * 
- * contains(key : string) : boolean
- * 	returns true if a row contains 'key' otherwise false.
- * 
- * getColumn(column : int) : ArrayList<String>
- * 	returns the specified column as ArrayList.
- * 
- * getColumn(key : string) : ArrayList<String>
- * 
- * removeRow(key : string) : void 
- * 	purpose removes the specified row at the inner data structure.
- * 
- * removeRow(column : int) : void
- * 
- * updateFile() : void
- * 	overwrites the CSV-file with the current inner data structure.
- * 	removed rows are remove in the CSV-file, too.
- * 
- * updateFile(file : File) : void
- * 
- * getNumberOfRows() : int
- * 	returns the number of rows in CSV-File
- * 	it counts only rows that in the table.
- * 
- */
-
-import java.io.BufferedReader;
-import java.io.BufferedWriter;
-import java.io.File;
-import java.io.FileReader;
-import java.io.FileWriter;
-import java.io.IOException;
-import java.io.PrintWriter;
-import java.nio.file.Files;
-import java.nio.file.Paths;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.regex.Pattern;
-
-public class CSVFile {
-
-	// the actual CSV-content
-	private ArrayList<ArrayList<String>> table;
-	// to tracking added rows. 
-	private ArrayList<Integer> trackList;
-	// notice the seperator
-	private char seperator;
-	// notice the path of the CSV-File.
-	private String pathCSVFile;
-
-	
-	/**
-	 * Constructor
-	 * 
-	 * @param path
-	 * @param seperator
-	 * @purpose loads the CSV-file and fills the inner table with the data
-	 */
-	public CSVFile(String path, char seperator) {
-		this(new File(path),seperator);
-	}
-	
-	
-	/**
-	 * 
-	 * @param file
-	 * same constructor different arguments.
-	 */
-	public CSVFile(File file, char seperator) {
-		table = new ArrayList<ArrayList<String>>();
-		trackList = new ArrayList<Integer>();
-		pathCSVFile = file.getPath();
-		this.seperator = seperator;
-		ArrayList<String> colums = new ArrayList<String>();
-		if (!file.canRead() || !file.isFile()) {
-			System.out.println("unable to open file");
-			System.exit(1);
-		}
-
-		try (BufferedReader br = Files.newBufferedReader(Paths.get(file.getAbsolutePath()))) {
-			br.lines().forEach(line -> table.add(compile(line, seperator)));
-		} catch (IOException e) {
-			e.printStackTrace();
-		}
-	}
-	
-	
-	/**
-	 * 
-	 * @param separator
-	 * @purpose Constructor for empty CSV-File.
-	 */
-	public CSVFile(char separator) {
-		table = new ArrayList<ArrayList<String>>();
-		trackList = new ArrayList<Integer>();
-		pathCSVFile = "";
-		this.seperator = seperator;
-	}
-
-	
-	/**
-	 * 
-	 * @param row
-	 * @param sep
-	 *            the seperator
-	 * @return ArrayList<String> that contains each column of row.
-	 * @purpose compiles row in its columns.
-	 * 
-	 */
-	public static ArrayList<String> compile(String row, char sep) {
-		ArrayList<String> columns = new ArrayList<String>();
-		int state = 0;
-		char ch = ' ';
-		String column = "";
-		int countQuotes = 0;
-		for (int i = 0; i < row.length(); i++) {
-			// fetch next character
-			ch = row.charAt(i);
-			switch (state) {
-
-			// state 0
-			case 0:
-				if (Character.isLetter(ch) || Character.isDigit(ch)) {
-					state = 1;
-					column += ch;
-				} else if (ch == '"') { // catch "
-					state = 2;
-					column += ch;
-				} else if (Character.isWhitespace(ch)) {
-					state = 0;
-				}
-				break;
-			// state 1
-			case 1:
-				if ((Character.isLetter(ch) || Character.isDigit(ch) 
-						|| isPunctuation(ch) || Character.isWhitespace(ch))
-						&& (ch != sep)) {
-					state = 1;
-					column += ch;
-				} else if (ch == sep || ch == '\n') {
-					state = 0;
-					column = column.trim();
-					columns.add(column);
-					column = "";
-				} else { // error case
-					throw new RuntimeException("compile: invalid"
-							+ " character " + ch);
-				}
-				break;
-
-			// state 2
-			case 2:
-				if ((Character.isLetter(ch) || Character.isDigit(ch)
-						|| Character.isWhitespace(ch) || isPunctuation(ch))
-						&& (ch != '"')) {
-					state = 2;
-					column += ch;
-				} else if (ch == '"') {
-					state = 3;
-					column += ch;
-				} else { // error case
-					throw new RuntimeException("compile: invalid"
-							+ " character " + ch);
-				}
-				break;
-
-			// state 3
-			case 3:
-				if ((Character.isLetter(ch) || Character.isDigit(ch)
-						|| Character.isWhitespace(ch) || isPunctuation(ch))
-						&& (ch != '"') && (ch != sep)) {
-					state = 2;
-					column += ch;
-				} else if (ch == ',') {
-					state = 0;
-					column = column.trim();
-					columns.add(column);
-					column = "";
-				} else { // error case
-					throw new RuntimeException("compile: invalid"
-							+ " character " + ch);
-				}
-
-			}
-
-		}
-		// for adding the remaining column
-		columns.add(column);
-		column = "";
-		return columns;
-	}
-
-	private static Pattern PATTERN_PUNCTUATION = Pattern.compile("\\p{Punct}");
-	/**
-	 * 
-	 * @param ch
-	 * @returns true if ch is punctuation character otherwise false.
-	 */
-	public static boolean isPunctuation(char ch) {
-		return PATTERN_PUNCTUATION.matcher("" + ch).matches();
-	}
-
-	
-	/**
-	 * 
-	 * @param row
-	 * @param column
-	 * @return the specific element as string
-	 */
-	public String getElementString(int row, int column) {
-		// check arguments
-		if (row < table.size() && column < table.get(0).size()) {
-			return table.get(row).get(column);
-		} else { // error case
-			throw new RuntimeException("getElementString: "
-					+ " arguments out of bound.");
-		}
-		
-	}
-
-	
-	/**
-	 * 
-	 * @param row
-	 * @param column
-	 * @return the specific element as double
-	 * @throws NumberFormatException
-	 */
-	public double getElementDouble(int row, int column) 
-			throws NumberFormatException {
-		// check arguments
-		if (row < table.size() && column < table.get(0).size()) {
-			return Double.parseDouble(table.get(row).get(column));
-		} else { // error case
-			throw new RuntimeException("getElementString: "
-					+ " arguments out of bound.");
-		}
-	}
-
-	
-	/**
-	 * 
-	 * @param row
-	 * @purpose adds a row to the inner data structure.
-	 * 			without writing into the CSV-file.
-	 */
-	public void addRow(String row) {
-		table.add(compile(row, seperator));
-		// tracking the last item.
-		trackList.add(table.size() - 1);
-	}
-
-	
-	/**
-	 * @purpose: writes the added data into CSV-file.
-	 */
-	public void commit() {
-		String row = "";
-		PrintWriter pWriter = null;
-		try {
-			pWriter = new PrintWriter(new BufferedWriter(new FileWriter(
-					pathCSVFile, true)));
-
-			// writes the tracked rows into CSV-file.
-			for (int index : trackList) {
-				for (int i = 0; i < table.get(index).size(); i++) {
-					if (i != 0) {
-						row += ",";
-						row += table.get(index).get(i);
-					} else {
-						row += table.get(index).get(i);
-					}
-				}
-				// add newline for next row
-				row += "\n"; 
-				pWriter.write(row);
-				// clear row for the next one
-				row = ""; 
-			}
-		} catch (IOException ioe) {
-			ioe.printStackTrace();
-		} finally {
-			if (pWriter != null) {
-				pWriter.flush();
-				pWriter.close();
-			}
-		}
-		
-		// remove tracked rows.
-		trackList.clear();
-	}
-	
-	
-	/**
-	 * @param path
-	 * @purpose: writes the added data into CSV-file (given path).
-	 */
-	public void commit(String path) {
-		String row = "";
-		pathCSVFile = path;
-		PrintWriter pWriter = null;
-		try {
-
-			pWriter = new PrintWriter(new BufferedWriter(new FileWriter(
-					pathCSVFile, true)));
-
-			// writes the tracked rows into CSV-file.
-			for (int index : trackList) {
-				for (int i = 0; i < table.get(index).size(); i++) {
-					if (i != 0) {
-						row += ",";
-						row += table.get(index).get(i);
-					} else {
-						row += table.get(index).get(i);
-					}
-				}
-				// add newline for next row
-				row += "\n"; 
-				pWriter.write(row);
-				// clear row
-				row = ""; 
-			}
-		} catch (IOException ioe) {
-			ioe.printStackTrace();
-		} finally {
-			if (pWriter != null) {
-				pWriter.flush();
-				pWriter.close();
-			}
-		}
-		
-		// remove tracked rows.
-		trackList.clear();
-	}
-	
-	/**
-	 * 
-	 * @param file
-	 * @purpose: writes the added data into CSV-file (given path).
-	 */
-	public void commit(File file) {
-		String row = "";
-		pathCSVFile = file.getPath();
-		PrintWriter pWriter = null;
-		try {
-
-			pWriter = new PrintWriter(new BufferedWriter(new FileWriter(
-					file, true)));
-
-			// writes the tracked rows into CSV-file.
-			for (int index : trackList) {
-				for (int i = 0; i < table.get(index).size(); i++) {
-					if (i != 0) {
-						row += ",";
-						row += table.get(index).get(i);
-					} else {
-						row += table.get(index).get(i);
-					}
-				}
-				// add newline for next row
-				row += "\n"; 
-				pWriter.write(row);
-				// clear row
-				row = ""; 
-			}
-		} catch (IOException ioe) {
-			ioe.printStackTrace();
-		} finally {
-			if (pWriter != null) {
-				pWriter.flush();
-				pWriter.close();
-			}
-		}
-		
-		// remove tracked rows.
-		trackList.clear();
-	}
-
-
-	/**
-	 * 
-	 * @param key
-	 * @returns the searched row otherwise null.
-	 */
-	public ArrayList<String> findRow(String key) {
-		ArrayList<String> ans = null;
-		key = key.trim();
-		for (int i = 0; i < table.size(); i++) {
-			for (String item : table.get(i)) {
-				item = item.trim();
-				if (item.equals(key)) {
-					ans = table.get(i);
-					break;
-				}
-			}
-		}
-		return ans;
-	}
-	
-	
-	/**
-	 * 
-	 * @param key
-	 * @returns true if a row contains 'key' otherwise false.
-	 */
-	public boolean contains(String key) {
-		key = key.trim();
-		for (int i = 0; i < table.size(); i++) {
-			for (String item : table.get(i)) {
-				item = item.trim();
-				if (item.equals(key)) {
-					return true;
-				}
-			}
-		}
-		return false;
-	}
-	
-	
-	/**
-	 * 
-	 * @param n of type integer
-	 * @returns the specified column as ArrayList.
-	 */
-	public ArrayList<String> getColumn(int column) {
-		ArrayList<String> ans = new ArrayList<String>();
-		if (column < table.get(0).size()) {
-			for (int i = 0; i < table.size(); i++) {
-				ans.add(table.get(i).get(column));
-			}
-		} else { // error case
-			throw new RuntimeException("getColumn: column is too large");
-		}
-		return ans;
-	}
-	
-	
-	/**
-	 * 
-	 * @param label of type string
-	 * @returns the specified column at label.
-	 */
-	public ArrayList<String> getColumn(String label) {
-		ArrayList<String> ans = new ArrayList<String>();
-		int n = table.get(0).indexOf(label);
-		// check whether label exists.
-		if (n != -1) {	
-			for (int i = 1; i < table.size(); i++) {
-				ans.add(table.get(i).get(n));
-			}
-		} else { // error case
-			throw new RuntimeException("getColumn: label " + label
-					+ " don't exists.");
-		}
-		return ans;
-	}
-	
-	
-	/**
-	 * 
-	 * @param key of type string
-	 * @purpose removes the specified row at the inner data structure.
-	 */
-	public void removeRow(String key) {
-		for (int i = 0; i < table.size(); i++) {
-			if (table.get(i) != null) {
-				for (String item : table.get(i)) {
-					if (item.equals(key)) {
-						table.set(i,null);
-						// updates the track list
-						if (trackList.indexOf(i) != -1) {
-							trackList.remove(i);
-						}
-					}
-				}
-			}
-		}
-		// removes all null-elements
-		table.removeAll(Collections.singleton(null));
-	}
-	
-	
-	/**
-	 * 
-	 * @param n of type integer
-	 * @purpose removes the specified row at the inner data structure.
-	 */
-	public void removeRow(int column) {
-		if (column < table.size()) {
-			table.set(column, null);
-			// removes all null-elements
-			table.removeAll(Collections.singleton(null));
-			// updates the track list
-			if (trackList.indexOf(column) != -1) {
-				trackList.remove(column);
-			}
-		} else {
-			throw new RuntimeException("removeRow: column is too large");
-		}
-	}
-	
-	
-	/**
-	 * overwrites the CSV-file with the current inner data structure.
-	 * removed rows are remove in the CSV-file, too.
-	 */
-	public void updateFile() {
-		String row = "";
-		PrintWriter pWriter = null;
-		try {
-			pWriter = new PrintWriter(new BufferedWriter(new FileWriter(
-					pathCSVFile)));
-
-			// writes the table rows into CSV-file.
-			for (int i = 0; i < table.size(); i++) {
-				for (int j = 0; j < table.get(i).size(); j++) {
-					if (j != 0) {
-						row += ",";
-						row += table.get(i).get(j);
-					} else {
-						row += table.get(i).get(j);
-					}
-				}
-				// add newline for next row
-				row += "\n"; 
-				pWriter.write(row);
-				// clear row
-				row = ""; 
-			}
-			
-			// writes the tracked rows into CSV-file.
-			for (int index : trackList) {
-				for (int i = 0; i < table.get(index).size(); i++) {
-					if (i != 0) {
-						row += ",";
-						row += table.get(index).get(i);
-					} else {
-						row += table.get(index).get(i);
-					}
-				}
-				// add newline for next row
-				row += "\n"; 
-				pWriter.write(row);
-				// clear row for the next one
-				row = ""; 
-			}
-		} catch (IOException ioe) {
-			ioe.printStackTrace();
-		} finally {
-			if (pWriter != null) {
-				pWriter.flush();
-				pWriter.close();
-			}
-		}
-		
-		// remove tracked rows.
-		trackList.clear();
-	}
-	
-	
-	/**
-	 * 
-	 * @param file
-	 * overwrites the CSV-file with the current inner data structure.
-	 * removed rows are remove in the CSV-file, too.
-	 */
-	public void updateFile(File file) {
-		String row = "";
-		PrintWriter pWriter = null;
-		try {
-			pWriter = new PrintWriter(new BufferedWriter(new FileWriter(
-					file)));
-
-			// writes the table rows into CSV-file.
-			for (int i = 0; i < table.size(); i++) {
-				for (int j = 0; j < table.get(i).size(); j++) {
-					if (j != 0) {
-						row += ",";
-						row += table.get(i).get(j);
-					} else {
-						row += table.get(i).get(j);
-					}
-				}
-				// add newline for next row
-				row += "\n"; 
-				pWriter.write(row);
-				// clear row
-				row = ""; 
-			}
-			
-			// writes the tracked rows into CSV-file.
-			for (int index : trackList) {
-				for (int i = 0; i < table.get(index).size(); i++) {
-					if (i != 0) {
-						row += ",";
-						row += table.get(index).get(i);
-					} else {
-						row += table.get(index).get(i);
-					}
-				}
-				// add newline for next row
-				row += "\n"; 
-				pWriter.write(row);
-				// clear row
-				row = ""; 
-			}
-		} catch (IOException ioe) {
-			ioe.printStackTrace();
-		} finally {
-			if (pWriter != null) {
-				pWriter.flush();
-				pWriter.close();
-			}
-		}
-		
-		// remove tracked rows.
-		trackList.clear();
-	}
-	
-	
-	/**
-	 * 
-	 * @returns the number of rows in CSV-File
-	 * it counts only rows that in the table.
-	 */
-	public int getNumberOfRows() {
-		return table.size();
-	}
-	
-	
-	/**
-	 * 
-	 * @param row
-	 * @param column
-	 * @param item
-	 * @purpose replaces the specified item with a newer.
-	 */
-	public void set(int row, int column, String item) {
-		if (row < table.size()) {
-			if (column < table.get(row).size()) {
-				table.get(row).set(column, item);
-			} else {
-				throw new RuntimeException("set: column is too large!");
-			}
-		} else {
-			throw new RuntimeException("set: row is too large!");
-		}
-	}
-	
-}

DataStructures/CSVFile/src/TestCSVFile.java

@@ -1,133 +0,0 @@
-import static org.junit.Assert.*;
-
-import org.junit.Before;
-import org.junit.Test;
-
-import java.io.File;
-import java.util.ArrayList;
-
-public class TestCSVFile {
-
-	
-	@Test
-	public void testConstructor1() {
-		CSVFile testObj = new CSVFile("testData.csv",',');
-		assertEquals(testObj.getElementDouble(1, 1),65.78331, 0.001);
-		assertEquals(testObj.getElementString(1, 1),"65.78331");
-		assertEquals(testObj.getElementString(0, 1),"\"Height(Inches)\"");
-		assertEquals(testObj.getNumberOfRows(),25029);
-	}
-	
-	@Test
-	public void testConstructor2() {
-		CSVFile testObj = new CSVFile(',');
-		testObj.addRow("1, 65.78331, 112.9925");
-		testObj.addRow("12, 67.62333, 114.143");
-		testObj.addRow("6, 68.69784, 123.3024");
-//		testObj.commit("testData2.csv");
-//		testObj.commit(new File("testData2.csv"));
-	}
-	
-	@Test
-	public void testConstructor3() {
-		CSVFile testObj = new CSVFile(new File("testData.csv"),',');
-		assertEquals(testObj.getElementDouble(1, 1),65.78331, 0.001);
-		assertEquals(testObj.getElementString(1, 1),"65.78331");
-		assertEquals(testObj.getElementString(0, 1),"\"Height(Inches)\"");
-	}
-	
-	@Test
-	public void testIsPunctuation() {
-		assertTrue(CSVFile.isPunctuation(':'));
-	}
-	
-	@Test
-	public void testCompile() {
-		ArrayList<String>  columns = new ArrayList<String>();
-		columns.add("2");
-		columns.add("71.51521");
-		columns.add("136.4873");
-		
-		
-		assertEquals(CSVFile.compile("2, 71.51521, 136.4873", ','),columns);
-		columns.clear();
-
-		// test successful
-		columns.add("\"Index\"");
-		columns.add("\"Height(Inches)\"");
-		columns.add("\"Weight(Pounds)\"");
-		
-		assertEquals(CSVFile.compile("\"Index\", \"Height(Inches)\", "
-				+ "\"Weight(Pounds)\"", ','),columns);
-		
-		
-	}
-	
-	@Test
-	public void testAddRowCommit() {
-//		CSVFile testObj = new CSVFile("testData.csv",',');
-//		testObj.addRow("1,1,1");
-//		testObj.addRow("1,2,3");
-//		testObj.commit();
-		// test successful
-	}
-	
-	@Test
-	public void testFindRow() {
-		CSVFile testObj = new CSVFile("testData.csv",',');
-		ArrayList<String>  columns = new ArrayList<String>();
-		columns.add("2");
-		columns.add("71.51521");
-		columns.add("136.4873");
-		assertEquals(testObj.findRow("71.51521"),columns);
-	}
-	
-	@Test
-	public void testContains() {
-		CSVFile testObj = new CSVFile("testData.csv",',');
-		ArrayList<String>  columns = new ArrayList<String>();
-		columns.add("2");
-		columns.add("71.51521");
-		columns.add("136.4873");
-		assertTrue(testObj.contains("71.51521"));
-		assertFalse(testObj.contains("9889678"));
-	}
-	
-	
-	@Test
-	public void testGetColumn() {
-		CSVFile testObj = new CSVFile("testData2.csv",',');
-		CSVFile testObj2 = new CSVFile("testData3.csv",',');
-		ArrayList<String>  columns = new ArrayList<String>();
-		columns.add("height");
-		columns.add("65.78331");
-		columns.add("67.62333");
-		assertEquals(testObj.getColumn(1),columns);
-		columns.clear();
-		columns.add("65.78331");
-		columns.add("67.62333");
-		assertEquals(testObj.getColumn("height"),columns);
-		columns.clear();
-		assertEquals(testObj2.getColumn("height"),columns);
-	}
-	
-	
-	@Test
-	public void testRemoving() {
-		CSVFile testObj = new CSVFile("testData4.csv",',');
-		//testObj.removeRow("68.69784");
-//		testObj.removeRow(0);
-//		testObj.updateFile(new File("testData4.csv"));
-		// test successful
-	}
-	
-	@Test
-	public void testSet() {
-//		CSVFile testObj = new CSVFile("testData4.csv",',');
-//		testObj.set(6, 2, "80");
-//		testObj.updateFile();
-		// test succesfull
-	}
-	
-
-}

DataStructures/CSVFile/testData2.csv

@@ -1,3 +0,0 @@
-id, height, width
-1, 65.78331, 112.9925
-12, 67.62333, 114.143

DataStructures/CSVFile/testData3.csv

@@ -1 +0,0 @@
-id, height, width

DataStructures/CSVFile/testData4.csv

@@ -1,7 +0,0 @@
-1,65.78331,112.9925
-2,71.51521,136.4873
-3,69.39874,153.0269
-4,68.2166,142.3354
-5,67.78781,144.2971
-7,69.80204,141.4947
-8,70.01472,80

DataStructures/Graphs/BFS.java

@@ -1,62 +0,0 @@
-import java.util.*;
-
-/**
- * Implementation of a Breadth First Search
- *
- * @author Unknown
- *
- */
-public class BFS{
-
-	/**
-	 * The BFS implemented in code to use.
-	 *
-	 * @param a Structure to perform the search on a graph, adjacency matrix etc.
-	 * @param vertices The vertices to use
-	 * @param source The Source
-	 */
-	public static void bfsImplement(byte [][] a,int vertices,int source){  //passing adjacency matrix and no of vertices
-		byte []b=new byte[vertices];    //flag container containing status of each vertices
-		Arrays.fill(b,(byte)-1);   //status initialization
-		/*       code   status
-				 -1  =  ready
-				  0  =  waiting
-				  1  =  processed       */
-
-		Stack st = new Stack(vertices);     //operational stack
-		st.push(source);                                                 //assigning source
-		while(!st.isEmpty()){
-			b[st.peek()]=(byte)0;                                   //assigning waiting status
-			System.out.println(st.peek());
-			int pop=st.peek();
-			b[pop]=(byte)1;               //assigning processed status
-			st.pop();                  //removing head of the queue
-			for(int i=0;i<vertices;i++){
-				if(a[pop][i]!=0 && b[i]!=(byte)0 && b[i]!=(byte)1 ){
-					st.push(i);
-					b[i]=(byte)0;                        //assigning waiting status
-				}}}
-	}
-
-
-	/**
-	 * The main method
-	 *
-	 * @param args Command line arguments
-	 */
-		public static void main(String args[]){
-		Scanner in=new Scanner(System.in);
-		int vertices=in.nextInt(),source=in.nextInt();
-		byte [][]a=new byte [vertices][vertices];
-		//initially all elements of a are initialized with value zero
-
-		for(int i=0;i<vertices;i++){
-			int size =in.nextInt();
-			for(int j=0;j<size;j++){
-				a[i][in.nextInt()]=1;      //taking adjacency entries by assigning 1
-			}
-		}
-		bfsImplement(a,vertices,source);         //function call
-		in.close();
-	}
-}

DataStructures/Graphs/BellmanFord.java

@@ -1,158 +0,0 @@
-import java.util.*;
-class BellmanFord
-/*Implementation of Bellman ford to detect negative cycles. Graph accepts inputs in form of edges which have 
-start vertex, end vertes and weights. Vertices should be labelled with a number between 0 and total number of vertices-1,both inclusive*/
-{
-    int vertex,edge;
-    private Edge edges[];
-    private int index=0;
-    BellmanFord(int v,int e)
-    {
-        vertex=v;
-        edge=e;
-        edges=new Edge[e];
-    }
-    class Edge
-    {
-        int u,v;
-        int w;
-        /**
-        *@param u Source Vertex
-        * @param v End vertex
-        * @param c Weight
-        */
-        Edge(int a,int b,int c)
-        {
-            u=a;
-            v=b;
-            w=c;
-        }    
-    }
-    /**
-     * @param p[] Parent array which shows updates in edges
-     * @param  i Current vertex under consideration
-     */
-    void printPath(int p[],int i)
-    {
-        if(p[i]==-1)//Found the path back to parent
-            return;
-        printPath(p,p[i]);
-        System.out.print(i+" ");
-    }
-    public static void main(String args[])
-    {    
-        BellmanFord obj=new BellmanFord(0,0);//Dummy object to call nonstatic variables
-        obj.go();
-    }
-    public void go()//Interactive run for understanding the class first time. Assumes source vertex is 0 and shows distaance to all vertices
-    {
-        Scanner sc=new Scanner(System.in);//Grab scanner object for user input
-        int i,v,e,u,ve,w,j,neg=0;
-        System.out.println("Enter no. of vertices and edges please");
-        v=sc.nextInt();
-        e=sc.nextInt();
-        Edge arr[]=new Edge[e];//Array of edges 
-        System.out.println("Input edges");
-        for(i=0;i<e;i++)
-        {
-            u=sc.nextInt();
-            ve=sc.nextInt();
-            w=sc.nextInt();
-            arr[i]=new Edge(u,ve,w);
-        }
-        int dist[]=new int[v];//Distance array for holding the finalized shortest path distance between source and all vertices
-        int p[]=new int[v];//Parent array for holding the paths
-        for(i=0;i<v;i++)
-            dist[i]=Integer.MAX_VALUE;//Initializing distance values
-        dist[0]=0;
-        p[0]=-1;
-        for(i=0;i<v-1;i++)
-        {
-            for(j=0;j<e;j++)
-            {
-                if((int)dist[arr[j].u]!=Integer.MAX_VALUE&&dist[arr[j].v]>dist[arr[j].u]+arr[j].w)
-                {
-                    dist[arr[j].v]=dist[arr[j].u]+arr[j].w;//Update
-                    p[arr[j].v]=arr[j].u;
-                }
-            }
-        }
-        //Final cycle for negative checking
-        for(j=0;j<e;j++)
-        if((int)dist[arr[j].u]!=Integer.MAX_VALUE&&dist[arr[j].v]>dist[arr[j].u]+arr[j].w)
-        {
-            neg=1;
-            System.out.println("Negative cycle");
-            break;
-        }
-        if(neg==0)//Go ahead and show results of computaion
-        {
-            System.out.println("Distances are: ");
-            for(i=0;i<v;i++)
-            System.out.println(i+" "+dist[i]);
-            System.out.println("Path followed:");
-            for(i=0;i<v;i++)
-            { 
-                System.out.print("0 ");
-                printPath(p,i);
-                System.out.println();
-            }
-        }
-    }
-    /**
-     * @param source Starting vertex
-     * @param end Ending vertex
-     * @param Edge Array of edges 
-    */
-    public void show(int source,int end, Edge arr[])//Just shows results of computation, if graph is passed to it. The graph should
-    //be created by using addEdge() method and passed by calling getEdgeArray() method
-    {
-        int i,j,v=vertex,e=edge,neg=0;
-        double dist[]=new double[v];//Distance array for holding the finalized shortest path distance between source and all vertices
-        int p[]=new int[v];//Parent array for holding the paths
-        for(i=0;i<v;i++)
-            dist[i]=Integer.MAX_VALUE;//Initializing distance values
-        dist[source]=0;
-        p[source]=-1;
-        for(i=0;i<v-1;i++)
-        {
-            for(j=0;j<e;j++)
-            {
-                if((int)dist[arr[j].u]!=Integer.MAX_VALUE&&dist[arr[j].v]>dist[arr[j].u]+arr[j].w)
-                {
-                    dist[arr[j].v]=dist[arr[j].u]+arr[j].w;//Update
-                    p[arr[j].v]=arr[j].u;
-                }
-            }
-        }
-        //Final cycle for negative checking
-        for(j=0;j<e;j++)
-        if((int)dist[arr[j].u]!=Integer.MAX_VALUE&&dist[arr[j].v]>dist[arr[j].u]+arr[j].w)
-        {
-            neg=1;
-            System.out.println("Negative cycle");
-            break;
-        }
-        if(neg==0)//Go ahead and show results of computaion
-        {
-            System.out.println("Distance is: "+dist[end]);
-            System.out.println("Path followed:");
-            System.out.print(source+" ");
-            printPath(p,end);
-            System.out.println();
-        }
-    }
-    /**
-     *@param x Source Vertex
-     * @param y End vertex
-     * @param z Weight 
-    */
-    public void addEdge(int x,int y,int z)//Adds unidirectionl Edge
-    {
-        edges[index++]=new Edge(x,y,z);
-    }
-    public Edge[] getEdgeArray()
-    {
-       return edges;
-    }
-}

DataStructures/Graphs/ConnectedComponent.java

@@ -1,150 +0,0 @@
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.Set;
-
-/**
- * A class that counts the number of different connected components in a graph
- * 
- * @author Lukas Keul, Florian Mercks
- *
- */
-class Graph<E extends Comparable<E>> {
-
-	class Node {
-		E name;
-
-		public Node(E name) {
-			this.name = name;
-		}
-	}
-
-	class Edge {
-		Node startNode, endNode;
-
-		public Edge(Node startNode, Node endNode) {
-			this.startNode = startNode;
-			this.endNode = endNode;
-		}
-	}
-
-	ArrayList<Edge> edgeList;
-	ArrayList<Node> nodeList;
-
-	public Graph() {
-		edgeList = new ArrayList<Edge>();
-		nodeList = new ArrayList<Node>();
-	}
-
-	/**
-	 * Adds a new Edge to the graph. If the nodes aren't yet in nodeList, they
-	 * will be added to it.
-	 * 
-	 * @param startNode
-	 *            the starting Node from the edge
-	 * 
-	 * @param endNode
-	 *            the ending Node from the edge
-	 */
-	public void addEdge(E startNode, E endNode) {
-		Node start = null, end = null;
-		for (Node node : nodeList) {
-			if (startNode.compareTo(node.name) == 0) {
-				start = node;
-			}
-			else if (endNode.compareTo(node.name) == 0) {
-				end = node;
-			}
-		}
-		if (start == null) {
-			start = new Node(startNode);
-			nodeList.add(start);
-		}
-		if (end == null) {
-			end = new Node(endNode);
-			nodeList.add(end);
-		}
-
-		edgeList.add(new Edge(start, end));
-	}
-
-	/**
-	 * Main method used for counting the connected components. Iterates through
-	 * the array of nodes to do a depth first search to get all nodes of the
-	 * graph from the actual node. These nodes are added to the array
-	 * markedNodes and will be ignored if they are chosen in the nodeList.
-	 * 
-	 * @return returns the amount of unconnected graphs
-	 * 
-	 */
-	public int countGraphs() {
-		int count = 0;
-		Set<Node> markedNodes = new HashSet<Node>();
-
-		for (Node n : nodeList) {
-			if (!markedNodes.contains(n)) {
-				markedNodes.add(n);
-				markedNodes.addAll(depthFirstSearch(n, new ArrayList<Node>()));
-				count++;
-			}
-		}
-
-		return count;
-	}
-
-	/**
-	 * Implementation of depth first search.
-	 * 
-	 * @param n
-	 *            the actual visiting node
-	 * 
-	 * @param visited
-	 *            A list of already visited nodes in the depth first search
-	 * 
-	 * @return returns a set of visited nodes
-	 *
-	 */
-	public ArrayList<Node> depthFirstSearch(Node n, ArrayList<Node> visited) {
-		visited.add(n);
-		for (Edge e : edgeList) {
-			if (e.startNode.equals(n) && !visited.contains(e.endNode)) {
-				depthFirstSearch(e.endNode, visited);
-			}
-		}
-		return visited;
-	}
-}
-
-public class ConnectedComponent {
-
-	public static void main(String[] args) {
-		Graph graphChars = new Graph();
-
-		// Graph 1
-		 graphChars.addEdge('a', 'b');
-		 graphChars.addEdge('a', 'e');
-		 graphChars.addEdge('b', 'e');
-		 graphChars.addEdge('b', 'c');
-		 graphChars.addEdge('c', 'd');
-		 graphChars.addEdge('d', 'a');
-		 
-		 graphChars.addEdge('x', 'y');
-		 graphChars.addEdge('x', 'z');
-		 
-		 graphChars.addEdge('w', 'w');
-
-		Graph graphInts = new Graph();
-		
-		// Graph 2
-		graphInts.addEdge(1, 2);
-		graphInts.addEdge(2, 3);
-		graphInts.addEdge(2, 4);
-		graphInts.addEdge(3, 5);
-		
-		graphInts.addEdge(7, 8);
-		graphInts.addEdge(8, 10);
-		graphInts.addEdge(10, 8);
-
-		System.out.println("Amount of different char-graphs: " + graphChars.countGraphs());
-		System.out.println("Amount of different int-graphs: " + graphInts.countGraphs());
-	}
-}

DataStructures/Graphs/DFS.java

@@ -1,63 +0,0 @@
-import java.util.*;
-
-/**
- * Implementation of a Depth First Search
- * 
- * @author Unknown
- *
- */
-
-public class DFS{
-	
-	/**
-	 * Implementation in code of a DFS
-	 * 
-	 * @param a structure to be DFS'ed
-	 * @param vertices The vertices
-	 * @param source The source
-	 */
-	public static void dfsImplement(byte [][] a,int vertices,int source){            //passing adjacency matrix and no of vertices
-		byte []b=new byte[vertices];               //flag container containing status of each vertices
-		Arrays.fill(b,(byte)-1);                  //status initialization
-		/*       code   status 
-		          -1  =  ready
-		           0  =  waiting
-		           1  =  processed       */
-		
-		
-		Stack st=new Stack(vertices);         //operational stack
-		st.push(source);                          //assigning source
-		while(!st.isEmpty()){
-			b[st.peek()]=(byte)0;                 //assigning waiting status
-			System.out.println(st.peek());
-			int pop=st.pop();
-			b[pop]=(byte)1;                       //assigning processed status
-			for(int i=0;i<vertices;i++){
-				if(a[pop][i]!=0 && b[i]!=(byte)0 && b[i]!=(byte)1 ){
-					st.push(i);
-					b[i]=(byte)0;                  //assigning waiting status
-				}}}
-		
-	}
-	
-	/**
-	 * The main method
-	 * 
-	 * @param args Command line arguments
-	 */
-	public static void main(String args[]){
-		Scanner in=new Scanner(System.in);
-		int vertices=in.nextInt(),source=in.nextInt();
-		byte [][]a=new byte [vertices][vertices];
-		//initially all elements of a are initialized with value zero
-		
-		for(int i=0;i<vertices;i++){
-			int size =in.nextInt(); 
-			for(int j=0;j<size;j++){
-				a[i][in.nextInt()]=1;      //taking adjacency entries by assigning 1
-			}
-		}
-		dfsImplement(a,vertices,source);         //function call
-		in.close();
-	}
-}

DataStructures/Graphs/FloydWarshall.java

@@ -1,78 +0,0 @@
-    import java.util.Scanner;
-    public class FloydWarshall
-    {
-        private int DistanceMatrix[][];
-        private int numberofvertices;//number of vertices in the graph
-        public static final int INFINITY = 999;
-        public FloydWarshall(int numberofvertices)
-        {
-            DistanceMatrix = new int[numberofvertices + 1][numberofvertices + 1];//stores the value of distance from all the possible path form the source vertex to destination vertex
-            Arrays.fill(DistanceMatrix, 0);
-            this.numberofvertices = numberofvertices;
-        }
-        public void floydwarshall(int AdjacencyMatrix[][])//calculates all the distances from source to destination vertex
-        {
-            for (int source = 1; source <= numberofvertices; source++)
-            {
-                for (int destination = 1; destination <= numberofvertices; destination++)
-                {
-                    DistanceMatrix[source][destination] = AdjacencyMatrix[source][destination];
-                }
-            }
-            for (int intermediate = 1; intermediate <= numberofvertices; intermediate++)
-            {
-                for (int source = 1; source <= numberofvertices; source++)
-                {
-                    for (int destination = 1; destination <= numberofvertices; destination++)
-                    {
-                        if (DistanceMatrix[source][intermediate] + DistanceMatrix[intermediate][destination]
-                             < DistanceMatrix[source][destination])//if the new distance calculated is less then the earlier shortest calculated distance it get replaced as new shortest distance
-                            DistanceMatrix[source][destination] = DistanceMatrix[source][intermediate] 
-                                + DistanceMatrix[intermediate][destination];
-                    }
-                }
-            }
-            for (int source = 1; source <= numberofvertices; source++)
-                System.out.print("\t" + source);
-            System.out.println();
-            for (int source = 1; source <= numberofvertices; source++)
-            {
-                System.out.print(source + "\t");
-                for (int destination = 1; destination <= numberofvertices; destination++)
-                {
-                    System.out.print(DistanceMatrix[source][destination] + "\t");
-                }
-                System.out.println();
-            }
-        }
-        public static void main(String... arg)
-        {
-            int Adjacency_Matrix[][];
-            int numberofvertices;
-            Scanner scan = new Scanner(System.in);
-            System.out.println("Enter the number of vertices");
-            numberofvertices = scan.nextInt();
-            Adjacency_Matrix = new int[numberofvertices + 1][numberofvertices + 1];
-            System.out.println("Enter the Weighted Matrix for the graph");
-            for (int source = 1; source <= numberofvertices; source++)
-            {
-                for (int destination = 1; destination <= numberofvertices; destination++)
-                {
-                    Adjacency_Matrix[source][destination] = scan.nextInt();
-                    if (source == destination)
-                    {
-                        Adjacency_Matrix[source][destination] = 0;
-                        continue;
-                    }
-                    if (Adjacency_Matrix[source][destination] == 0)
-                    {
-                        Adjacency_Matrix[source][destination] = INFINITY;
-                    }
-                }
-            }
-            System.out.println("The Transitive Closure of the Graph");
-            FloydWarshall floydwarshall = new FloydWarshall(numberofvertices);
-            floydwarshall.floydwarshall(adjacency_matrix);
-            scan.close();
-        }
-    }

DataStructures/Graphs/Graphs.java

@@ -1,129 +0,0 @@
-import java.util.ArrayList;
-import java.lang.StringBuilder;
-
-class AdjacencyListGraph<E extends Comparable<E>> {
-	
-    ArrayList<Vertex> verticies;
-
-    public AdjacencyListGraph() {
-        verticies = new ArrayList<>();
-    }
-
-    private class Vertex {
-        E data;
-        ArrayList<Vertex> adjacentVerticies;
-
-        public Vertex(E data) {
-            adjacentVerticies = new ArrayList<>();
-            this.data = data;
-        }
-
-        public boolean addAdjacentVertex(Vertex to) {
-            for (Vertex v: adjacentVerticies) {
-                if (v.data.compareTo(to.data) == 0) {
-                    return false; // the edge already exists
-                }
-            }
-            return adjacentVerticies.add(to); // this will return true;
-        }
-
-        public boolean removeAdjacentVertex(E to) {
-            // use indexes here so it is possible to 
-            // remove easily without implementing 
-            // equals method that ArrayList.remove(Object o) uses
-            for (int i = 0; i < adjacentVerticies.size(); i++) {
-                if (adjacentVerticies.get(i).data.compareTo(to) == 0) {
-                    adjacentVerticies.remove(i);
-                    return true;
-                }
-            }
-            return false;
-        }
-    }
-
-    /**
-     * this method removes an edge from the graph between two specified
-     * verticies
-     *
-     * @param from the data of the vertex the edge is from
-     * @param to the data of the vertex the edge is going to
-     * @return returns false if the edge doesn't exist, returns true if the edge exists and is removed
-     */
-    public boolean removeEdge(E from, E to) {
-        Vertex fromV = null;
-        for (Vertex v: verticies) {
-            if (from.compareTo(v.data) == 0) {
-                fromV = v;
-                break;
-            }
-        }
-        if (fromV == null) return false;
-        return fromV.removeAdjacentVertex(to);
-    }
-    /**
-     * this method adds an edge to the graph between two specified
-     * verticies 
-     *
-     * @param from the data of the vertex the edge is from
-     * @param to the data of the vertex the edge is going to
-     * @return returns true if the edge did not exist, return false if it already did
-     */
-    public boolean addEdge(E from, E to) {
-        Vertex fromV = null, toV = null;
-        for (Vertex v: verticies) {
-            if (from.compareTo(v.data) == 0) { // see if from vertex already exists
-                fromV = v;
-            } else if (to.compareTo(v.data) == 0) { // see if to vertex already exists
-                toV = v;
-            }
-            if (fromV != null && toV != null) break; // both nodes exist so stop searching
-        }
-        if (fromV == null) {
-            fromV = new Vertex(from);
-            verticies.add(fromV);
-        }
-        if (toV == null) {
-            toV = new Vertex(to);
-            verticies.add(toV);
-        }
-        return fromV.addAdjacentVertex(toV);
-    }
-
-    /**
-     * this gives a list of verticies in the graph and their adjacencies
-     * 
-     * @return returns a string describing this graph
-     */
-    public String toString() {
-        StringBuilder sb = new StringBuilder();
-        for (Vertex v: verticies) {
-            sb.append("Vertex: ");
-            sb.append(v.data);
-            sb.append("\n");
-            sb.append("Adjacent verticies: ");
-            for (Vertex v2: v.adjacentVerticies) {
-                sb.append(v2.data);
-                sb.append(" ");
-            }
-            sb.append("\n");
-        }
-        return sb.toString();
-    }
-}
-
-public class Graphs {
-	
-	public static void main(String args[]) {
-		AdjacencyListGraph<Integer> graph = new AdjacencyListGraph<>();
-        assert graph.addEdge(1, 2);
-        assert graph.addEdge(1, 5);
-        assert graph.addEdge(2, 5);
-	    assert !graph.addEdge(1, 2);
-        assert graph.addEdge(2, 3);
-        assert graph.addEdge(3, 4);
-        assert graph.addEdge(4, 1);
-        assert !graph.addEdge(2, 3);
-        System.out.println(graph);
-    }
-	
-}

DataStructures/Graphs/KruskalsAlgorithm.java

@@ -1,174 +0,0 @@
-// Java program for Kruskal's algorithm to find Minimum Spanning Tree
-// of a given connected, undirected and weighted graph
-import java.util.*;
-import java.lang.*;
-import java.io.*;
- 
-class Graph
-{
-    // A class to represent a graph edge
-    class Edge implements Comparable<Edge>
-    {
-        int src, dest, weight;
- 
-        // Comparator function used for sorting edges based on
-        // their weight
-        public int compareTo(Edge compareEdge)
-        {
-            return this.weight-compareEdge.weight;
-        }
-    };
- 
-    // A class to represent a subset for union-find
-    class subset
-    {
-        int parent, rank;
-    };
- 
-    int V, E;    // V-> no. of vertices & E->no.of edges
-    Edge edge[]; // collection of all edges
- 
-    // Creates a graph with V vertices and E edges
-    Graph(int v, int e)
-    {
-        V = v;
-        E = e;
-        edge = new Edge[E];
-        for (int i=0; i<e; ++i)
-            edge[i] = new Edge();
-    }
- 
-    // A utility function to find set of an element i
-    // (uses path compression technique)
-    int find(subset subsets[], int i)
-    {
-        // find root and make root as parent of i (path compression)
-        if (subsets[i].parent != i)
-            subsets[i].parent = find(subsets, subsets[i].parent);
- 
-        return subsets[i].parent;
-    }
- 
-    // A function that does union of two sets of x and y
-    // (uses union by rank)
-    void Union(subset subsets[], int x, int y)
-    {
-        int xroot = find(subsets, x);
-        int yroot = find(subsets, y);
- 
-        // Attach smaller rank tree under root of high rank tree
-        // (Union by Rank)
-        if (subsets[xroot].rank < subsets[yroot].rank)
-            subsets[xroot].parent = yroot;
-        else if (subsets[xroot].rank > subsets[yroot].rank)
-            subsets[yroot].parent = xroot;
- 
-        // If ranks are same, then make one as root and increment
-        // its rank by one
-        else
-        {
-            subsets[yroot].parent = xroot;
-            subsets[xroot].rank++;
-        }
-    }
- 
-    // The main function to construct MST using Kruskal's algorithm
-    void KruskalMST()
-    {
-        Edge result[] = new Edge[V];  // Tnis will store the resultant MST
-        int e = 0;  // An index variable, used for result[]
-        int i = 0;  // An index variable, used for sorted edges
-        for (i=0; i<V; ++i)
-            result[i] = new Edge();
- 
-        // Step 1:  Sort all the edges in non-decreasing order of their
-        // weight.  If we are not allowed to change the given graph, we
-        // can create a copy of array of edges
-        Arrays.sort(edge);
- 
-        // Allocate memory for creating V ssubsets
-        subset subsets[] = new subset[V];
-        for(i=0; i<V; ++i)
-            subsets[i]=new subset();
- 
-        // Create V subsets with single elements
-        for (int v = 0; v < V; ++v)
-        {
-            subsets[v].parent = v;
-            subsets[v].rank = 0;
-        }
- 
-        i = 0;  // Index used to pick next edge
- 
-        // Number of edges to be taken is equal to V-1
-        while (e < V - 1)
-        {
-            // Step 2: Pick the smallest edge. And increment the index
-            // for next iteration
-            Edge next_edge = new Edge();
-            next_edge = edge[i++];
- 
-            int x = find(subsets, next_edge.src);
-            int y = find(subsets, next_edge.dest);
- 
-            // If including this edge does't cause cycle, include it
-            // in result and increment the index of result for next edge
-            if (x != y)
-            {
-                result[e++] = next_edge;
-                Union(subsets, x, y);
-            }
-            // Else discard the next_edge
-        }
- 
-        // print the contents of result[] to display the built MST
-        System.out.println("Following are the edges in the constructed MST");
-        for (i = 0; i < e; ++i)
-            System.out.println(result[i].src+" -- "+result[i].dest+" == "+
-                               result[i].weight);
-    }
- 
-    // Driver Program
-    public static void main (String[] args)
-    {
- 
-        /* Let us create following weighted graph
-                 10
-            0--------1
-            |  \     |
-           6|   5\   |15
-            |      \ |
-            2--------3
-                4       */
-        int V = 4;  // Number of vertices in graph
-        int E = 5;  // Number of edges in graph
-        Graph graph = new Graph(V, E);
- 
-        // add edge 0-1
-        graph.edge[0].src = 0;
-        graph.edge[0].dest = 1;
-        graph.edge[0].weight = 10;
- 
-        // add edge 0-2
-        graph.edge[1].src = 0;
-        graph.edge[1].dest = 2;
-        graph.edge[1].weight = 6;
- 
-        // add edge 0-3
-        graph.edge[2].src = 0;
-        graph.edge[2].dest = 3;
-        graph.edge[2].weight = 5;
- 
-        // add edge 1-3
-        graph.edge[3].src = 1;
-        graph.edge[3].dest = 3;
-        graph.edge[3].weight = 15;
- 
-        // add edge 2-3
-        graph.edge[4].src = 2;
-        graph.edge[4].dest = 3;
-        graph.edge[4].weight = 4;
- 
-        graph.KruskalMST();
-    }
-}

DataStructures/Graphs/MatrixGraphs.java

@@ -1,145 +0,0 @@
-public class MatrixGraphs {
-
-	public static void main(String args[]) {
-		AdjacencyMatrixGraph graph = new AdjacencyMatrixGraph(10);
-		graph.addEdge(1, 2);
-		graph.addEdge(1, 5);
-		graph.addEdge(2, 5);
-		graph.addEdge(1, 2);
-		graph.addEdge(2, 3);
-		graph.addEdge(3, 4);
-		graph.addEdge(4, 1);
-		graph.addEdge(2, 3);
-		System.out.println(graph);
-	}
-
-}
-
-class AdjacencyMatrixGraph {
-	private int _numberOfVertices;
-	private int _numberOfEdges;
-	private int[][] _adjacency;
-
-	static final int EDGE_EXIST = 1;
-	static final int EDGE_NONE = 0;
-
-	public AdjacencyMatrixGraph(int givenNumberOfVertices) {
-		this.setNumberOfVertices(givenNumberOfVertices);
-		this.setNumberOfEdges(0);
-		this.setAdjacency(new int[givenNumberOfVertices][givenNumberOfVertices]);
-		for (int i = 0; i < givenNumberOfVertices; i++) {
-			for (int j = 0; j < givenNumberOfVertices; j++) {
-				this.adjacency()[i][j] = AdjacencyMatrixGraph.EDGE_NONE;
-			}
-		}
-	}
-
-	private void setNumberOfVertices(int newNumberOfVertices) {
-		this._numberOfVertices = newNumberOfVertices;
-	}
-
-	public int numberOfVertices() {
-		return this._numberOfVertices;
-	}
-
-	private void setNumberOfEdges(int newNumberOfEdges) {
-		this._numberOfEdges = newNumberOfEdges;
-	}
-
-	public int numberOfEdges() {
-		return this._numberOfEdges;
-	}
-
-	private void setAdjacency(int[][] newAdjacency) {
-		this._adjacency = newAdjacency;
-	}
-
-	private int[][] adjacency() {
-		return this._adjacency;
-	}
-
-	private boolean adjacencyOfEdgeDoesExist(int from, int to) {
-		return (this.adjacency()[from][to] != AdjacencyMatrixGraph.EDGE_NONE);
-	}
-
-	public boolean vertexDoesExist(int aVertex) {
-		if (aVertex >= 0 && aVertex < this.numberOfVertices()) {
-			return true;
-		} else {
-			return false;
-		}
-	}
-
-	public boolean edgeDoesExist(int from, int to) {
-		if (this.vertexDoesExist(from) && this.vertexDoesExist(to)) {
-			return (this.adjacencyOfEdgeDoesExist(from, to));
-		}
-
-		return false;
-	}
-
-	/**
-     * This method adds an edge to the graph between two specified
-     * vertices 
-     *
-     * @param from the data of the vertex the edge is from
-     * @param to the data of the vertex the edge is going to
-     * @return returns true if the edge did not exist, return false if it already did
-     */
-	public boolean addEdge(int from, int to) {
-		if (this.vertexDoesExist(from) && this.vertexDoesExist(to)) {
-			if (!this.adjacencyOfEdgeDoesExist(from, to)) {
-				this.adjacency()[from][to] = AdjacencyMatrixGraph.EDGE_EXIST;
-				this.adjacency()[to][from] = AdjacencyMatrixGraph.EDGE_EXIST;
-				this.setNumberOfEdges(this.numberOfEdges() + 1);
-				return true;
-			}
-		}
-
-		return false;
-	}
-
-	 /**
-     * this method removes an edge from the graph between two specified
-     * vertices 
-     *
-     * @param from the data of the vertex the edge is from
-     * @param to the data of the vertex the edge is going to
-     * @return returns false if the edge doesn't exist, returns true if the edge exists and is removed
-     */
-	public boolean removeEdge(int from, int to) {
-		if(!this.vertexDoesExist(from) || !this.vertexDoesExist(to)) {
-			if (this.adjacencyOfEdgeDoesExist(from, to)) {
-				this.adjacency()[from][to] = AdjacencyMatrixGraph.EDGE_NONE;
-				this.adjacency()[to][from] = AdjacencyMatrixGraph.EDGE_NONE;
-				this.setNumberOfEdges(this.numberOfEdges() - 1);
-				return true;
-			}
-		}
-		return false;
-	}
-
-    /**
-     * this gives a list of vertices in the graph and their adjacencies
-     * 
-     * @return returns a string describing this graph
-     */
-	public String toString() {
-		String s = new String();
-		s = "    ";
-		for (int i = 0; i < this.numberOfVertices(); i++) {
-			s = s + String.valueOf(i) + " ";
-		}
-		s = s + " \n";
-
-		for (int i = 0; i < this.numberOfVertices(); i++) {
-			s = s + String.valueOf(i) + " : ";
-			for (int j = 0; j < this.numberOfVertices(); j++) {
-				s = s + String.valueOf(this._adjacency[i][j]) + " ";
-			}
-			s = s + "\n";
-		}
-		return s;
-	}
-
-}

DataStructures/Graphs/PrimMST.java

@@ -1,114 +0,0 @@
-// A Java program for Prim's Minimum Spanning Tree (MST) algorithm.
-//adjacency matrix representation of the graph
-
-import java.lang.*;
- 
-class PrimMST
-{
-    // Number of vertices in the graph
-    private static final int V=5;
- 
-    // A utility function to find the vertex with minimum key
-    // value, from the set of vertices not yet included in MST
-    int minKey(int key[], Boolean mstSet[])
-    {
-        // Initialize min value
-        int min = Integer.MAX_VALUE, min_index=-1;
- 
-        for (int v = 0; v < V; v++)
-            if (mstSet[v] == false && key[v] < min)
-            {
-                min = key[v];
-                min_index = v;
-            }
- 
-        return min_index;
-    }
- 
-    // A utility function to print the constructed MST stored in
-    // parent[]
-    void printMST(int parent[], int n, int graph[][])
-    {
-        System.out.println("Edge   Weight");
-        for (int i = 1; i < V; i++)
-            System.out.println(parent[i]+" - "+ i+"    "+
-                               graph[i][parent[i]]);
-    }
- 
-    // Function to construct and print MST for a graph represented
-    //  using adjacency matrix representation
-    void primMST(int graph[][])
-    {
-        // Array to store constructed MST
-        int parent[] = new int[V];
- 
-        // Key values used to pick minimum weight edge in cut
-        int key[] = new int [V];
- 
-        // To represent set of vertices not yet included in MST
-        Boolean mstSet[] = new Boolean[V];
- 
-        // Initialize all keys as INFINITE
-        for (int i = 0; i < V; i++)
-        {
-            key[i] = Integer.MAX_VALUE;
-            mstSet[i] = false;
-        }
- 
-        // Always include first 1st vertex in MST.
-        key[0] = 0;     // Make key 0 so that this vertex is
-                        // picked as first vertex
-        parent[0] = -1; // First node is always root of MST
- 
-        // The MST will have V vertices
-        for (int count = 0; count < V-1; count++)
-        {
-            // Pick thd minimum key vertex from the set of vertices
-            // not yet included in MST
-            int u = minKey(key, mstSet);
- 
-            // Add the picked vertex to the MST Set
-            mstSet[u] = true;
- 
-            // Update key value and parent index of the adjacent
-            // vertices of the picked vertex. Consider only those
-            // vertices which are not yet included in MST
-            for (int v = 0; v < V; v++)
- 
-                // graph[u][v] is non zero only for adjacent vertices of m
-                // mstSet[v] is false for vertices not yet included in MST
-                // Update the key only if graph[u][v] is smaller than key[v]
-                if (graph[u][v]!=0 && mstSet[v] == false &&
-                    graph[u][v] <  key[v])
-                {
-                    parent[v]  = u;
-                    key[v] = graph[u][v];
-                }
-        }
- 
-        // print the constructed MST
-        printMST(parent, V, graph);
-    }
- 
-    public static void main (String[] args)
-    {
-        /* Let us create the following graph
-           2    3
-        (0)--(1)--(2)
-        |    / \   |
-        6| 8/   \5 |7
-        | /      \ |
-        (3)-------(4)
-             9          */
-        PrimMST t = new PrimMST();
-        int graph[][] = new int[][] {{0, 2, 0, 6, 0},
-                                    {2, 0, 3, 8, 5},
-                                    {0, 3, 0, 0, 7},
-                                    {6, 8, 0, 0, 9},
-                                    {0, 5, 7, 9, 0},
-                                   };
- 
-        // Print the solution
-        t.primMST(graph);
-    }
-}

DataStructures/HashMap/HashMap.java

@@ -1,283 +0,0 @@
-<<<<<<< HEAD:Data Structures/HashMap/HashMap.java
-
-
-import java.util.ArrayList;
-import java.util.LinkedList;
-
-public class HashMap<K,V> {
-	public class hmnodes{ //HashMap nodes 
-		K key;
-		V value;
-	}
-	
-	private int size=0; //size of hashmap
-	private LinkedList<hmnodes> buckets[];  //array of addresses of list
-	
-	public HashMap(){
-		buckets=new LinkedList[4]; //initially create bucket of any size 
-		for(int i=0;i<4;i++)
-			buckets[i]=new LinkedList<>(); 
-	}
-	
-	public void put(K key,V value) throws Exception{
-		int bi=bucketIndex(key); //find the index,the new key will be inserted in linklist at that index
-		int fountAt=find(bi,key); //check if key already exists or not 
-		if(fountAt==-1){
-			hmnodes temp=new hmnodes(); //if doesn't exist create new node and insert 
-			temp.key=key;
-			temp.value=value;
-			buckets[bi].addLast(temp);
-			this.size++;
-		}else{
-			buckets[bi].get(fountAt).value=value;//if already exist modify the value
-		}
-		
-		double lambda = (this.size*1.0)/this.buckets.length;
-		if(lambda>2.0){
-			rehash();  //rehashing function which will increase the size of bucket as soon as lambda exceeds 2.0
-		}
-		
-		return;
-	}
-	
-
-	public V get(K key) throws Exception{
-		int bi=bucketIndex(key);
-		int fountAt=find(bi,key);
-		if(fountAt==-1){
-			return null;
-		}else{
-			return buckets[bi].get(fountAt).value;
-		}
-	}
-	
-	public V remove(K key) throws Exception{
-		int bi=bucketIndex(key);
-		int fountAt=find(bi,key);
-		if(fountAt==-1){
-			return null;
-		}else{
-			this.size--;
-			return buckets[bi].remove(fountAt).value;
-		}
-	}
-	
-	public boolean containskey(K key) throws Exception{
-		int bi=bucketIndex(key);
-		int fountAt=find(bi,key);
-		if(fountAt==-1){
-			return false;
-		}else{
-			return true;
-		}
-	}
-	
-	public int size(){
-		return this.size;
-	}
-	
-	
-	public boolean isempty(){
-		return this.size==0;
-	}
-	
-	public ArrayList<K> keyset() throws Exception{
-		ArrayList<K> arr=new ArrayList<>();
-		for(int i=0;i<buckets.length;i++){
-			for(int j=0;j<buckets[i].size();j++){
-				arr.add(buckets[i].get(j).key);
-			}
-		}
-		return arr;
-	}
-	
-	public ArrayList<V> valueset() throws Exception{
-		ArrayList<V> arr=new ArrayList<>();
-		for(int i=0;i<buckets.length;i++){
-			for(int j=0;j<buckets[i].size();j++){
-				arr.add(buckets[i].get(j).value);
-			}
-		}
-		return arr;
-	}
-	
-	public void display() throws Exception{
-		for(int i=0;i<buckets.length;i++){
-			System.out.print("Bucket: "+i+" ");
-			for(int j=0;j<buckets[i].size();j++){
-				hmnodes temp=buckets[i].get(j);
-				System.out.print("["+temp.key+"->"+temp.value+"]");
-			}
-			System.out.println();
-		}
-	}
-	
-	public int find(int bi,K key) throws Exception{
-		for(int i=0;i<buckets[bi].size();i++){
-			if(key.equals(buckets[bi].get(i).key))
-				return i;
-		}
-		return -1;
-	}
-	
-	public int bucketIndex(K key) throws Exception{
-		int bi=key.hashCode();
-		return Math.abs(bi%buckets.length);
-	}
-
-	private void rehash() throws Exception{
-		LinkedList<hmnodes> ob[]= buckets;
-		buckets=new LinkedList[ob.length*2];
-		for(int i=0;i<ob.length*2;i++)
-			buckets[i]=new LinkedList<>();
-		
-		size = 0;
-		for(int i=0;i<ob.length;i++){
-			for(int j=0;j<ob[i].size();j++){
-				put(ob[i].get(j).key,ob[i].get(j).value);
-			}
-		}
-		
-	}
-}
-=======
-import java.util.ArrayList;
-import java.util.LinkedList;
-
-public class HashMap<K,V> {
-	public class hmnodes{ //HashMap nodes 
-		K key;
-		V value;
-	}
-	
-	private int size=0; //size of hashmap
-	private LinkedList<hmnodes> buckets[];  //array of addresses of list
-	
-	public HashMap(){
-		buckets=new LinkedList[4]; //initially create bucket of any size 
-		for(int i=0;i<4;i++)
-			buckets[i]=new LinkedList<>(); 
-	}
-	
-	public void put(K key,V value) throws Exception{
-		int bi=bucketIndex(key); //find the index,the new key will be inserted in linklist at that index
-		int fountAt=find(bi,key); //check if key already exists or not 
-		if(fountAt==-1){
-			hmnodes temp=new hmnodes(); //if doesn't exist create new node and insert 
-			temp.key=key;
-			temp.value=value;
-			buckets[bi].addLast(temp);
-			this.size++;
-		}else{
-			buckets[bi].get(fountAt).value=value;//if already exist modify the value
-		}
-		
-		double lambda = (this.size*1.0)/this.buckets.length;
-		if(lambda>2.0){
-			rehash();  //rehashing function which will increase the size of bucket as soon as lambda exceeds 2.0
-		}
-		
-		return;
-	}
-	
-
-	public V get(K key) throws Exception{
-		int bi=bucketIndex(key);
-		int fountAt=find(bi,key);
-		if(fountAt==-1){
-			return null;
-		}else{
-			return buckets[bi].get(fountAt).value;
-		}
-	}
-	
-	public V remove(K key) throws Exception{
-		int bi=bucketIndex(key);
-		int fountAt=find(bi,key);
-		if(fountAt==-1){
-			return null;
-		}else{
-			this.size--;
-			return buckets[bi].remove(fountAt).value;
-		}
-	}
-	
-	public boolean containskey(K key) throws Exception{
-		int bi=bucketIndex(key);
-		int fountAt=find(bi,key);
-		if(fountAt==-1){
-			return false;
-		}else{
-			return true;
-		}
-	}
-	
-	public int size(){
-		return this.size;
-	}
-	
-	
-	public boolean isempty(){
-		return this.size==0;
-	}
-	
-	public ArrayList<K> keyset() throws Exception{
-		ArrayList<K> arr=new ArrayList<>();
-		for(int i=0;i<buckets.length;i++){
-			for(int j=0;j<buckets[i].size();j++){
-				arr.add(buckets[i].get(j).key);
-			}
-		}
-		return arr;
-	}
-	
-	public ArrayList<V> valueset() throws Exception{
-		ArrayList<V> arr=new ArrayList<>();
-		for(int i=0;i<buckets.length;i++){
-			for(int j=0;j<buckets[i].size();j++){
-				arr.add(buckets[i].get(j).value);
-			}
-		}
-		return arr;
-	}
-	
-	public void display() throws Exception{
-		for(int i=0;i<buckets.length;i++){
-			System.out.print("Bucket: "+i+" ");
-			for(int j=0;j<buckets[i].size();j++){
-				hmnodes temp=buckets[i].get(j);
-				System.out.print("["+temp.key+"->"+temp.value+"]");
-			}
-			System.out.println();
-		}
-	}
-	
-	public int find(int bi,K key) throws Exception{
-		for(int i=0;i<buckets[bi].size();i++){
-			if(key.equals(buckets[bi].get(i).key))
-				return i;
-		}
-		return -1;
-	}
-	
-	public int bucketIndex(K key) throws Exception{
-		int bi=key.hashCode();
-		return Math.abs(bi%buckets.length);
-	}
-
-	private void rehash() throws Exception{
-		LinkedList<hmnodes> ob[]= buckets;
-		buckets=new LinkedList[ob.length*2];
-		for(int i=0;i<ob.length*2;i++)
-			buckets[i]=new LinkedList<>();
-		
-		size = 0;
-		for(int i=0;i<ob.length;i++){
-			for(int j=0;j<ob[i].size();j++){
-				put(ob[i].get(j).key,ob[i].get(j).value);
-			}
-		}
-		
-	}
-}
->>>>>>> 7e3a8c55c865471a33f6932a022a1059c5243fc3:data_structures/HashMap/HashMap.java

DataStructures/HashMap/Hashing/HashMap.java

@@ -1,39 +0,0 @@
-class HashMap {
-	private int hsize;
-	private LinkedList[] buckets;
-
-	public HashMap(int hsize) {
-		buckets = new LinkedList[hsize];
-		for (int i = 0; i < hsize ; i++ ) {
-			buckets[i] = new LinkedList();
-			// Java requires explicit initialisaton of each object 
-		}
-		this.hsize = hsize;
-	}
-
-	public int hashing(int key) {
-		int hash = key % hsize;
-		if(hash < 0)
-			hash += hsize;
-		return hash;
-	}
-	
-	public void insertHash(int key) {
-		int hash = hashing(key);
-		buckets[hash].insert(key);
-	}
-
-
-	public void deleteHash(int key) {
-		int hash = hashing(key);
-
-		buckets[hash].delete(key);
-	}
-	public void displayHashtable() {
-		for (int i = 0;i < hsize ; i++) {
-			System.out.printf("Bucket %d :",i);
-			buckets[i].display();
-		}
-	}
-
-}

DataStructures/HashMap/Hashing/LinkedList.java

@@ -1,62 +0,0 @@
-class LinkedList {
-
-	private Node Head;
-	private int size;
-
-	public LinkedList() {
-		Head = null;
-		size = 0;
-	}
-
-	public void insert(int data) {
-
-		Node temp = Head;
-		Node newnode = new Node(data);
-	
-		size++;
-
-		if(Head == null) {
-			Head = newnode;
-		}
-		else {
-			newnode.next = Head;
-			Head = newnode;
-		}
-	}
-
-	public void delete(int data) {
-		if(size == 0) {
-			System.out.println("UnderFlow!");
-			return;
-		}
-
-		else {
-			Node curr = Head;
-			if (curr.data == data) {
-				Head = curr.next;
-				size--;
-				return;
-			}
-			else {
-				
-				while(curr.next.next != null) {
-					if(curr.next.data == data){
-							curr.next = curr.next.next;
-							return;
-						}
-				}
-
-				System.out.println("Key not Found");
-			}
-		}
-	}
-
-	public void display() {
-		Node temp = Head;
-		while(temp != null) {
-			System.out.printf("%d ",temp.data);
-			temp = temp.next;
-		}
-		System.out.println();
-	}
-}

DataStructures/HashMap/Hashing/Main.java

@@ -1,45 +0,0 @@
-import java.util.Scanner;
-
-public class Main {
-	public static void main(String[] args) {
-
-		int choice, key;
-
-		HashMap h = new HashMap(7);
-
-		while (true) {
-			System.out.println("Enter your Choice :");
-			System.out.println("1. Add Key");
-			System.out.println("2. Delete Key");
-			System.out.println("3. Print Table");
-			System.out.println("4. Exit");
-
-			Scanner In = new Scanner(System.in);
-
-			choice = In.nextInt();
-
-			switch (choice) {
-				case 1: {
-					System.out.println("Enter the Key: ");
-					key = In.nextInt();
-					h.insertHash(key);
-					break;
-				}
-				case 2: {
-					System.out.println("Enter the Key delete:  ");
-					key = In.nextInt();
-					h.deleteHash(key);
-					break;
-				}
-				case 3: {
-					System.out.println("Print table");
-					h.displayHashtable();
-					break;
-				}
-				case 4: {
-					return;
-				}	
-			}
-		}
-	}
-}

DataStructures/HashMap/Hashing/Node.java

@@ -1,9 +0,0 @@
-class Node {
-	int data;
-	Node next;
-
-	public Node(int data) {
-		this.data = data;
-		this.next = null;
-	}
-}

DataStructures/Heaps/EmptyHeapException.java

@@ -1,18 +0,0 @@
-/**
- * 
- */
-package heaps;
-
-/**
- * @author Nicolas Renard
- * Exception to be thrown if the getElement method is used on an empty heap.
- *
- */
-@SuppressWarnings("serial")
-public class EmptyHeapException extends Exception {
-    
-    public EmptyHeapException(String message) {
-        super(message);
-    }
-
-}

DataStructures/Heaps/Heap.java

@@ -1,41 +0,0 @@
-package heaps;
-
-/**
- * Interface common to heap data structures.<br>
- * <p>Heaps are tree-like data structures that allow storing elements in a specific
- * way. Each node corresponds to an element and has one parent node (except for the root) and
- * at most two children nodes. Every element contains a key, and those keys
- * indicate how the tree shall be built. For instance, for a min-heap, the key of a node shall
- * be greater than or equal to its parent's and lower than or equal to its children's (the opposite rule applies to a
- * max-heap).</p>
- * <p>All heap-related operations (inserting or deleting an element, extracting the min or max) are performed in
- * O(log n) time.</p>
- * @author Nicolas Renard
- * 
- * 
- */
-public interface Heap {
-    
-    /**
-     * 
-     * @return the top element in the heap, the one with lowest key for min-heap or with
-     * the highest key for max-heap
-     * @throws Exception if heap is empty
-     */
-    public abstract HeapElement getElement() throws EmptyHeapException;
-    /**
-     * Inserts an element in the heap. Adds it to then end and toggle it until it finds its
-     * right position.
-     * 
-     * @param element an instance of the HeapElement class.
-     */
-    public abstract void insertElement(HeapElement element);
-    
-    /**
-     * Delete an element in the heap.
-     * 
-     * @param elementIndex int containing the position in the heap of the element to be deleted.
-     */
-    public abstract void deleteElement(int elementIndex);
-
-}

DataStructures/Heaps/HeapElement.java

@@ -1,132 +0,0 @@
-/**
- * 
- */
-package heaps;
-
-import java.lang.Double;
-import java.lang.Object;
-
-/**
- * Class for heap elements.<br>
- * <p>A heap element contains two attributes: a key which will be used to build the tree (int
- * or double, either primitive type or object) and any kind of IMMUTABLE object the user sees fit
- * to carry any information he/she likes. Be aware that the use of a mutable object might
- * jeopardize the integrity of this information. </p>
- * @author Nicolas Renard
- *
- */
-public class HeapElement {
-    private final double key;
-    private final Object additionalInfo;
-    
-    // Constructors
-
-    /**
-     * 
-     * @param key : a number of primitive type 'double'
-     * @param info : any kind of IMMUTABLE object. May be null, since the purpose is only to carry
-     * additional information of use for the user
-     */
-    public HeapElement(double key, Object info) {
-        this.key = key;
-        this.additionalInfo = info;
-    }
-    
-    /**
-     * 
-     * @param key : a number of primitive type 'int'
-     * @param info : any kind of IMMUTABLE object. May be null, since the purpose is only to carry
-     * additional information of use for the user
-     */
-    public HeapElement(int key, Object info) {
-        this.key = key;
-        this.additionalInfo = info;
-    }
-    
-    /**
-     * 
-     * @param key : a number of object type 'Integer'
-     * @param info : any kind of IMMUTABLE object. May be null, since the purpose is only to carry
-     * additional information of use for the user
-     */
-    public HeapElement(Integer key, Object info) {
-        this.key = key;
-        this.additionalInfo = info;
-    }
-    
-    /**
-     * 
-     * @param key : a number of object type 'Double'
-     * @param info : any kind of IMMUTABLE object. May be null, since the purpose is only to carry
-     * additional information of use for the user
-     */
-    public HeapElement(Double key, Object info) {
-        this.key = key;
-        this.additionalInfo = info;
-    }
-    
-    /**
-     * 
-     * @param key : a number of primitive type 'double'
-     */
-    public HeapElement(double key) {
-        this.key = key;
-        this.additionalInfo = null;
-    }
-    
-    /**
-     * 
-     * @param key : a number of primitive type 'int'
-     */
-    public HeapElement(int key) {
-        this.key = key;
-        this.additionalInfo = null;
-    }
-    
-    /**
-     * 
-     * @param key : a number of object type 'Integer'
-     */
-    public HeapElement(Integer key) {
-        this.key = key;
-        this.additionalInfo = null;
-    }
-    
-    /**
-     * 
-     * @param key : a number of object type 'Double'
-     */
-    public HeapElement(Double key) {
-        this.key = key;
-        this.additionalInfo = null;
-    }
-    
-    // Getters
-    /**
-     * @return the object containing the additional info provided by the user.
-     */
-    public Object getInfo() {
-        return additionalInfo;
-    }
-    /**
-     * @return the key value of the element
-     */
-    public double getKey() {
-        return key;
-    }
-    
-    // Overridden object methods
-    
-    public String toString() {
-        return "Key: " + key + " - " +additionalInfo.toString();
-    }
-    /**
-     * 
-     * @param otherHeapElement
-     * @return true if the keys on both elements are identical and the additional info objects
-     * are identical.
-     */
-    public boolean equals(HeapElement otherHeapElement) {
-        return (this.key == otherHeapElement.key) && (this.additionalInfo.equals(otherHeapElement.additionalInfo));
-    }
-}

DataStructures/Heaps/MaxHeap.java

@@ -1,115 +0,0 @@
-package heaps;
-
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * Heap tree where a node's key is higher than or equal to its parent's and lower than or equal
- * to its children's.
- * @author Nicolas Renard
- *
- */
-public class MaxHeap implements Heap {
-    
-    private final List<HeapElement> maxHeap;
-    
-    public MaxHeap(List<HeapElement> listElements) throws Exception {
-        maxHeap = new ArrayList<HeapElement>();
-        for (HeapElement heapElement : listElements) {
-            if (heapElement != null) insertElement(heapElement);
-            else System.out.println("Null element. Not added to heap");
-        }
-        if (maxHeap.size() == 0) System.out.println("No element has been added, empty heap.");
-        }
-    
-    // Get the element at a given index. The key for the list is equal to index value - 1
-    public HeapElement getElement(int elementIndex) {
-        if ((elementIndex <= 0) && (elementIndex > maxHeap.size())) throw new IndexOutOfBoundsException("Index out of heap range");
-        return maxHeap.get(elementIndex - 1);
-    }
-    
-    // Get the key of the element at a given index
-    private double getElementKey(int elementIndex) {
-        return maxHeap.get(elementIndex - 1).getKey();
-    }
-    
-    // Swaps two elements in the heap
-    private void swap(int index1, int index2) {
-        HeapElement temporaryElement = maxHeap.get(index1 - 1);
-        maxHeap.set(index1 - 1, maxHeap.get(index2 - 1));
-        maxHeap.set(index2 - 1, temporaryElement);
-    }
-    
-    // Toggle an element up to its right place as long as its key is lower than its parent's 
-    private void toggleUp(int elementIndex) {
-        double key = maxHeap.get(elementIndex - 1).getKey();
-        while (getElementKey((int) Math.floor(elementIndex/2)) < key) {
-            swap(elementIndex, (int) Math.floor(elementIndex/2));
-            elementIndex = (int) Math.floor(elementIndex/2);
-        }
-    }
-    
-    // Toggle an element down to its right place as long as its key is higher
-    // than any of its children's 
-    private void toggleDown(int elementIndex) {
-        double key = maxHeap.get(elementIndex - 1).getKey();
-        boolean wrongOrder = (key < getElementKey(elementIndex*2)) || (key < getElementKey(Math.min(elementIndex*2, maxHeap.size())));
-        while ((2*elementIndex <= maxHeap.size()) && wrongOrder) {
-            // Check whether it shall swap the element with its left child or its right one if any.
-            if ((2*elementIndex < maxHeap.size()) && (getElementKey(elementIndex*2 + 1) > getElementKey(elementIndex*2))) {
-                swap(elementIndex, 2*elementIndex + 1);
-                elementIndex = 2*elementIndex + 1;
-            }
-            else {
-                swap(elementIndex, 2*elementIndex);
-                elementIndex = 2*elementIndex;
-            }
-            wrongOrder = (key < getElementKey(elementIndex*2)) || (key < getElementKey(Math.min(elementIndex*2, maxHeap.size())));
-            
-        }
-    }
-
-    private HeapElement extractMax() {
-        HeapElement result = maxHeap.get(0);
-        deleteElement(0);
-        return result;
-    }
-
-    @Override
-    public void insertElement(HeapElement element) {
-        maxHeap.add(element);
-        toggleUp(maxHeap.size());
-
-    }
-
-    @Override
-    public void deleteElement(int elementIndex) {
-		if (maxHeap.isEmpty())
-			try {
-				throw new EmptyHeapException("Attempt to delete an element from an empty heap");
-			} catch (EmptyHeapException e) {
-				e.printStackTrace();
-			}
-        if ((elementIndex > maxHeap.size()) && (elementIndex <= 0)) throw new IndexOutOfBoundsException("Index out of heap range");
-        // The last element in heap replaces the one to be deleted
-        maxHeap.set(elementIndex - 1, getElement(maxHeap.size()));
-        maxHeap.remove(maxHeap.size());
-        // Shall the new element be moved up...
-        if (getElementKey(elementIndex) > getElementKey((int) Math.floor(elementIndex/2))) toggleUp(elementIndex);
-        // ... or down ?
-        else if (((2*elementIndex <= maxHeap.size()) && (getElementKey(elementIndex) < getElementKey(elementIndex*2))) ||
-                ((2*elementIndex < maxHeap.size()) && (getElementKey(elementIndex) < getElementKey(elementIndex*2)))) toggleDown(elementIndex);
-    }
-
-    @Override
-    public HeapElement getElement() throws EmptyHeapException {
-        try {
-            return extractMax();
-        } catch (Exception e) {
-            throw new EmptyHeapException("Heap is empty. Error retrieving element");
-        }
-    }
-
-}
-
-

DataStructures/Heaps/MinHeap.java

@@ -1,115 +0,0 @@
-/**
- * 
- */
-package heaps;
-
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * Heap tree where a node's key is higher than or equal to its parent's and lower than or equal
- * to its children's.
- * @author Nicolas Renard
- *
- */
-public class MinHeap implements Heap {
-    
-    private final List<HeapElement> minHeap;
-    
-    public MinHeap(List<HeapElement> listElements) throws Exception {
-        minHeap = new ArrayList<HeapElement>();
-        for (HeapElement heapElement : listElements) {
-            if (heapElement != null) insertElement(heapElement);
-            else System.out.println("Null element. Not added to heap");
-        }
-        if (minHeap.size() == 0) System.out.println("No element has been added, empty heap.");
-    }
-    
-    // Get the element at a given index. The key for the list is equal to index value - 1
-    public HeapElement getElement(int elementIndex) {
-        if ((elementIndex <= 0) && (elementIndex > minHeap.size())) throw new IndexOutOfBoundsException("Index out of heap range");
-        return minHeap.get(elementIndex - 1);
-    }
-    
-    // Get the key of the element at a given index
-    private double getElementKey(int elementIndex) {
-        return minHeap.get(elementIndex - 1).getKey();
-    }
-    
-    // Swaps two elements in the heap
-    private void swap(int index1, int index2) {
-        HeapElement temporaryElement = minHeap.get(index1 - 1);
-        minHeap.set(index1 - 1, minHeap.get(index2 - 1));
-        minHeap.set(index2 - 1, temporaryElement);
-    }
-    
-    // Toggle an element up to its right place as long as its key is lower than its parent's 
-    private void toggleUp(int elementIndex) {
-        double key = minHeap.get(elementIndex - 1).getKey();
-        while (getElementKey((int) Math.floor(elementIndex/2)) > key) {
-            swap(elementIndex, (int) Math.floor(elementIndex/2));
-            elementIndex = (int) Math.floor(elementIndex/2);
-        }
-    }
-    
-    // Toggle an element down to its right place as long as its key is higher
-    // than any of its children's 
-    private void toggleDown(int elementIndex) {
-        double key = minHeap.get(elementIndex - 1).getKey();
-        boolean wrongOrder = (key > getElementKey(elementIndex*2)) || (key > getElementKey(Math.min(elementIndex*2, minHeap.size())));
-        while ((2*elementIndex <= minHeap.size()) && wrongOrder) {
-            // Check whether it shall swap the element with its left child or its right one if any.
-            if ((2*elementIndex < minHeap.size()) && (getElementKey(elementIndex*2 + 1) < getElementKey(elementIndex*2))) {
-                swap(elementIndex, 2*elementIndex + 1);
-                elementIndex = 2*elementIndex + 1;
-            }
-            else {
-                swap(elementIndex, 2*elementIndex);
-                elementIndex = 2*elementIndex;
-            }
-            wrongOrder = (key > getElementKey(elementIndex*2)) || (key > getElementKey(Math.min(elementIndex*2, minHeap.size())));
-            
-        }
-    }
-
-    private HeapElement extractMin() {
-        HeapElement result = minHeap.get(0);
-        deleteElement(0);
-        return result;
-    }
-
-    @Override
-    public void insertElement(HeapElement element) {
-        minHeap.add(element);
-        toggleUp(minHeap.size());
-
-    }
-
-    @Override
-    public void deleteElement(int elementIndex) {
-		if (minHeap.isEmpty())
-			try {
-				throw new EmptyHeapException("Attempt to delete an element from an empty heap");
-			} catch (EmptyHeapException e) {
-				e.printStackTrace();
-			}
-        if ((elementIndex > minHeap.size()) && (elementIndex <= 0)) throw new IndexOutOfBoundsException("Index out of heap range");
-        // The last element in heap replaces the one to be deleted
-        minHeap.set(elementIndex - 1, getElement(minHeap.size()));
-        minHeap.remove(minHeap.size());
-        // Shall the new element be moved up...
-        if (getElementKey(elementIndex) < getElementKey((int) Math.floor(elementIndex/2))) toggleUp(elementIndex);
-        // ... or down ?
-        else if (((2*elementIndex <= minHeap.size()) && (getElementKey(elementIndex) > getElementKey(elementIndex*2))) ||
-                ((2*elementIndex < minHeap.size()) && (getElementKey(elementIndex) > getElementKey(elementIndex*2)))) toggleDown(elementIndex);
-    }
-    
-    @Override
-    public HeapElement getElement() throws EmptyHeapException {
-        try {
-            return extractMin();
-        } catch (Exception e) {
-            throw new EmptyHeapException("Heap is empty. Error retrieving element");
-        }
-    }
-}

DataStructures/Lists/CircleLinkedList.java

@@ -1,54 +0,0 @@
-public class CircleLinkedList<E>{
-     private static class Node<E>{
-         Node<E> next;
-         E value;
-         private Node(E value, Node<E> next){
-              this.value = value;
-              this.next = next;
-         }
-     }
-     //For better O.O design this should be private allows for better black box design
-     private int size; 
-     //this will point to dummy node;
-     private Node<E> head; 
-     //constructer for class.. here we will make a dummy node for circly linked list implementation with reduced error catching as our list will never be empty;
-     public CircleLinkedList(){ 
-          //creation of the dummy node
-         head = new Node<E>(null,head); 
-         size = 0;
-     }
-      // getter for the size... needed because size is private.
-     public int getSize(){ return size;} 
-     // for the sake of simplistiy this class will only contain the append function or addLast other add functions can be implemented however this is the basses of them all really.
-     public void append(E value){ 
-         if(value == null){
-          // we do not want to add null elements to the list.
-         	throw new NullPointerException("Cannot add null element to the list"); 
-         }
-          //head.next points to the last element;
-         head.next = new Node<E>(value,head); 
-         size++;}
-     public E remove(int pos){
-     	if(pos>size || pos< 0){
-               //catching errors
-     		throw new IndexOutOfBoundsException("position cannot be greater than size or negative"); 
-     	}
-     	Node<E> iterator = head.next; 
-          //we need to keep track of the element before the element we want to remove we can see why bellow.
-     	Node<E> before = head;
-     	for(int i = 1; i<=pos; i++){
-            iterator = iterator.next;
-            before = before.next;   
-     	}
-     	E saved = iterator.value;
-          // assigning the next referance to the the element following the element we want to remove... the last element will be assigned to the head.
-     	before.next = iterator.next; 
-          // scrubbing 
-     	iterator.next = null; 
-     	iterator.value = null; 
-     	return saved;
-
-     	}
-
-     }
-

DataStructures/Lists/DoublyLinkedList.java

@@ -1,214 +0,0 @@
-/**
- * This class implements a DoublyLinkedList. This is done using the classes
- * LinkedList and Link.
- * 
- * A linked list is simplar to an array, it holds values. However,
- * links in a linked list do not have indees. With a linked list
- * you do not need to predetermine it's size as it grows and shrinks
- * as it is edited. This is an example of a double ended, doubly
- * linked list. Each link references the next link and the previous
- * one.
- * 
- * @author Unknown
- *
- */
-
-class DoublyLinkedList{
-	/** Head refers to the front of the list */
-	private Link head;
-	/** Tail refers to the back of the list */
-	private Link tail;
-
-	/**
-	 * Constructor
-	 */
-	public DoublyLinkedList(){
-		head = null;
-		tail = null;
-	}
-
-	/**
-	 * Insert an element at the head
-	 * 
-	 * @param x Element to be inserted
-	 */
-	public void insertHead(int x){
-		Link newLink = new Link(x); //Create a new link with a value attached to it
-		if(isEmpty()) //Set the first element added to be the tail
-			tail = newLink;
-		else
-			head.previous = newLink; // newLink <-- currenthead(head)
-		newLink.next = head; // newLink <--> currenthead(head)
-		head = newLink; // newLink(head) <--> oldhead
-	}
-
-	/**
-	 * Insert an element at the tail
-	 * 
-	 * @param x Element to be inserted
-	 */
-	public void insertTail(int x){
-		Link newLink = new Link(x);
-		newLink.next = null; // currentTail(tail)     newlink -->
-		tail.next = newLink; // currentTail(tail) --> newLink -->
-		newLink.previous = tail; // currentTail(tail) <--> newLink -->
-		tail = newLink; // oldTail <--> newLink(tail) -->
-	}
-
-	/**
-	 * Delete the element at the head
-	 * 
-	 * @return The new head
-	 */
-	public Link deleteHead(){
-		Link temp = head;
-		head = head.next; // oldHead <--> 2ndElement(head)
-		head.previous = null; // oldHead --> 2ndElement(head) nothing pointing at old head so will be removed
-		if(head == null)
-			tail = null;
-		return temp;
-	}
-
-	/**
-	 * Delete the element at the tail
-	 * 
-	 * @return The new tail
-	 */
-	public Link deleteTail(){
-		Link temp = tail;
-		tail = tail.previous; // 2ndLast(tail) <--> oldTail --> null
- 		tail.next = null; // 2ndLast(tail) --> null
-		return temp;
-	}
-
-	/**
-	 * Delete the element from somewhere in the list
-	 * 
-	 * @param x element to be deleted
-	 * @return  Link deleted
-	 */
-	public Link delete(int x){
-		Link current = head;
-
-		while(current.value != x) //Find the position to delete
-			current = current.next;
-
-		if(current == head)
-			deleteHead();
-
-		else if(current == tail)
-			deleteTail();
-
-		else{ //Before: 1 <--> 2(current) <--> 3
-			current.previous.next = current.next;  // 1 --> 3
-			current.next.previous = current.previous; // 1 <--> 3
-		}
-		return current;
-	}
-
-	/**
-	 * Inserts element and reorders
-	 * 
-	 * @param x Element to be added
-	 */
-	public void insertOrdered(int x){
-		Link newLink = new Link(x);
-		Link current = head;
-		while(current != null && x > current.value) //Find the position to insert
-			current = current.next;
-
-		if(current == head)
-			insertHead(x);
-
-		else if(current == null)
-			insertTail(x);
-
-		else{ //Before: 1 <--> 2(current) <--> 3
-			newLink.previous = current.previous; // 1 <-- newLink
-			current.previous.next = newLink; // 1 <--> newLink
-			newLink.next = current; // 1 <--> newLink --> 2(current) <--> 3
-			current.previous = newLink; // 1 <--> newLink <--> 2(current) <--> 3
-		}
-	}
-
-	/**
-	 * Returns true if list is empty
-	 * 
-	 * @return true if list is empty
-	 */
-	public boolean isEmpty(){
-		return(head == null);
-	}
-
-	/**
-	 * Prints contents of the list
-	 */
-	public void display(){ //Prints contents of the list
-		Link current = head;
-		while(current!=null){
-			current.displayLink();
-			current = current.next;
-		}
-		System.out.println();
-	}
-}
-
-/**
- * This class is used to implement the nodes of the
- * linked list.
- * 
- * @author Unknown
- *
- */
-class Link{
-	/** Value of node */
-	public int value;
-	/** This points to the link in front of the new link */
-	public Link next;
-	/** This points to the link behind the new link */
-	public Link previous;
-
-	/**
-	 * Constructor
-	 * 
-	 * @param value Value of node
-	 */
-	public Link(int value){
-		this.value = value;
-	}
-
-	/**
-	 * Displays the node
-	 */
-	public void displayLink(){
-		System.out.print(value+" ");
-	}
-
-	/**
-	 * Main Method
-	 * 
-	 * @param args Command line arguments
-	 */
-	public static void main(String args[]){
-		DoublyLinkedList myList = new DoublyLinkedList();
-
-		myList.insertHead(13);
-		myList.insertHead(7);
-		myList.insertHead(10);
-		myList.display(); // <-- 10(head) <--> 7 <--> 13(tail) -->
-
-		myList.insertTail(11);
-		myList.display(); // <-- 10(head) <--> 7 <--> 13 <--> 11(tail) -->
-
-		myList.deleteTail();
-		myList.display(); // <-- 10(head) <--> 7 <--> 13(tail) -->
-
-		myList.delete(7);
-		myList.display(); // <-- 10(head) <--> 13(tail) -->
-
-		myList.insertOrdered(23);
-		myList.insertOrdered(67);
-		myList.insertOrdered(3);
-		myList.display(); // <-- 3(head) <--> 10 <--> 13 <--> 23 <--> 67(tail) -->
-	}
-}

DataStructures/Lists/SinglyLinkedList.java

@@ -1,151 +0,0 @@
-/**
- * This class implements a SinglyLinked List. This is done
- * using SinglyLinkedList class and a LinkForLinkedList Class.
- * 
- * A linked list is implar to an array, it hold values.
- * However, links in a linked list do not have indexes. With
- * a linked list you do not need to predetermine it's size as
- * it gorws and shrinks as it is edited. This is an example of
- * a singly linked list. Elements can only be added/removed
- * at the head/front of the list.
- * 
- * @author Unknown
- *
- */
-class SinglyLinkedList{
-	/**Head refered to the front of the list */
-	private Node head;
-
-	/**
-	 * Constructor of SinglyLinkedList
-	 */
-	public SinglyLinkedList(){
-		head = null;
-	}
-
-	/**
-	 * This method inserts an element at the head
-	 * 
-	 * @param x Element to be added
-	 */
-	public void insertHead(int x){
-		Node newNode = new Node(x); //Create a new link with a value attached to it
-		newNode.next = head; 		//Set the new link to point to the current head
-		head = newNode; 			//Now set the new link to be the head
-	}
-
-
-	/**
-     * Inserts a new node at a specified position
-     * @param head     head node of the linked list
-     * @param data     data to be stored in a new node
-     * @param position position at which a new node is to be inserted
-     * @return  reference of the head of the linked list
-     */
-
-    Node InsertNth(Node head, int data, int position) {
-        
-        Node newNode = new Node();
-        newNode.data = data;
-        
-        if (position == 0) {
-            newNode.next = head;
-            return newNode;
-        }
-
-        Node current = head;
-
-        while (--position > 0) {
-            current = current.next;
-        }
-        
-        newNode.next = current.next;
-        current.next = newNode;
-        return head;
-    }
-    
-	/**
-	 * This method deletes an element at the head
-	 * 
-	 * @return The element deleted
-	 */
-	public Node deleteHead(){
-		Node temp = head;
-		head = head.next; //Make the second element in the list the new head, the Java garbage collector will later remove the old head
-		return temp;
-	}
-
-	/**
-	 * Checks if the list is empty
-	 * 
-	 * @return true is list is empty
-	 */
-	public boolean isEmpty(){
-		return(head == null);
-	}
-
-	/**
-	 * Prints contents of the list
-	 */
-	public void display(){
-		Node current = head;
-		while(current!=null){
-			System.out.print(current.getValue()+" ");
-			current = current.next;
-		}
-		System.out.println();
-	}
-	
-	/**
-	 * Main method
-	 * 
-	 * @param args Command line arguments
-	 */
-	public static void main(String args[]){
-		SinglyLinkedList myList = new SinglyLinkedList();
-
-		System.out.println(myList.isEmpty()); //Will print true
-
-		myList.insertHead(5);
-		myList.insertHead(7);
-		myList.insertHead(10);
-
-		myList.display(); // 10(head) --> 7 --> 5
-
-		myList.deleteHead();
-
-		myList.display(); // 7(head) --> 5
-	}
-}
-
-/**
- * This class is the nodes of the SinglyLinked List.
- * They consist of a vlue and a pointer to the node
- * after them.
- * 
- * @author Unknown
- *
- */
-class Node{
-	/** The value of the node */
-	public int value;
-	/** Point to the next node */
-	public Node next; //This is what the link will point to
-
-	/**
-	 * Constructor
-	 * 
-	 * @param valuein Value to be put in the node
-	 */
-	public Node(int valuein){
-		value = valuein;
-	}
-
-	/**
-	 * Returns value of the node
-	 */
-	public int getValue(){
-		return value;
-	}
-
-}

DataStructures/Matrix/Matrix.java

@@ -1,259 +0,0 @@
-/**
-* Matrix data-type.
-*
-* @author Kyler Smith, 2017
-*/
-
-
-public class Matrix {
-
-	public static void main(String[] args) {
-
-		int[][] data1 = new int[0][0];
-        int[][] data2 = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
-        int[][] data3 = {{1, 4, 7}, {2, 5, 8}, {3, 6, 9}};
-
-        Matrix m1 = new Matrix(data1);
-        Matrix m2 = new Matrix(data2);
-        Matrix m3 = new Matrix(data3);
-
-        System.out.println("m1 --> Rows: " + m1.getRows() + " Columns: " + m1.getColumns());
-        System.out.println("m2 --> Rows: " + m2.getRows() + " Columns: " + m2.getColumns());
-        System.out.println("m3 --> Rows: " + m3.getRows() + " Columns: " + m3.getColumns());
-
-        //check for reference issues
-        System.out.println("m2 -->\n" + m2);
-        data2[1][1] = 101;
-        System.out.println("m2 -->\n" + m2);
-
-        //test equals
-        System.out.println("m2==null: " + m2.equals(null));             //false
-        System.out.println("m3==\"MATRIX\": " + m2.equals("MATRIX"));   //false
-        System.out.println("m2==m1: " + m2.equals(m1));                 //false
-        System.out.println("m2==m2: " + m2.equals(m2));                 //true
-        System.out.println("m2==m3: " + m2.equals(m3));                 //false
-
-        //test operations (valid)
-        System.out.println("2 * m2:\n" + m2.scale(2));
-        System.out.println("m2 / 2:\n" + m2.divide(2));
-        System.out.println("m2 + m3:\n" + m2.plus(m3));
-        System.out.println("m2 - m3:\n" + m2.minus(m3));
-        System.out.println("m2 * m3: \n"+m2.multiply(m3));
-	}
-
-
-    /**
-     *  Data needs to be a deep copy as not to change the original state.
-     */
-    private int[][] data;
-
-    /**
-    * Constructor for the matrix takes in a 2D array
-    *
-    * @param pData
-    */
-    public Matrix(int[][] pData) {
-
-        /** Make a deep copy of the data */
-        if(pData.length != 0) {
-            int[][] newData = new int[pData.length][pData[0].length];
-
-            for(int i = 0; i < pData.length; i++)
-                for(int j = 0; j < pData[0].length; j++)
-                    newData[i][j] = pData[i][j];
-
-            this.data = newData;
-        } else {
-            this.data = null;
-        }
-    }
-
-    /**
-    * Returns the element specified by the given location
-    *
-    * @param x : x cooridinate
-    * @param y : y cooridinate
-    * @return int : value at location
-    */
-    public int getElement(int x, int y) {
-        return data[x][y];
-    }
-
-    /**
-    * Returns the number of rows in the Matrix
-    *
-    * @return rows
-    */
-    public int getRows() {
-    	if(this.data == null)
-    		return 0;
-
-        return data.length;
-    }
-
-    /**
-    * Returns the number of rows in the Matrix
-    *
-    * @return columns
-    */
-    public int getColumns() {
-    	if(this.data == null)
-    		return 0;
-        return data[0].length;
-    }
-
-    /**
-	* Returns this matrix scaled by a factor. That is, computes sA where s is a
-	* constant and A is a matrix (this object).
-	*
-	* @param scalar : value to scale by
-	* @return A new matrix scaled by the scalar value
-	*/
-    public Matrix scale(int scalar) {
-
-    	int[][] newData = new int[this.data.length][this.data[0].length];
-
-		for (int i = 0; i < this.getRows(); ++i)
-			for(int j = 0; j < this.getColumns(); ++j)
-				newData[i][j] = this.data[i][j] * scalar;
-
-		return new Matrix(newData);
-    }
-    
-    /**
-	* Returns this matrix divided by a factor. That is, computes sA where s is a
-	* constant and A is a matrix (this object).
-	*
-	* @param scalar : value to divide by
-	* @return A new matrix scaled by the scalar value
-	*/
-    public Matrix divide(int scalar) {
-
-    	int[][] newData = new int[this.data.length][this.data[0].length];
-
-		for (int i = 0; i < this.getRows(); ++i)
-			for(int j = 0; j < this.getColumns(); ++j)
-				newData[i][j] = this.data[i][j] / scalar;
-
-		return new Matrix(newData);
-    }
-
-    /**
-    * Adds this matrix to another matrix.
-    *
-    * @param other : Matrix to be added
-    * @return addend
-    */
-    public Matrix plus(Matrix other) throws RuntimeException {
-
-    	int[][] newData = new int[this.data.length][this.data[0].length];
-
-    	if(this.getRows() != other.getRows() || this.getColumns() != other.getColumns())
-			throw new RuntimeException("Not the same size matrix.");
-
-    	for (int i = 0; i < this.getRows(); ++i)
-			for(int j = 0; j < this.getColumns(); ++j)
-				newData[i][j] = this.data[i][j] + other.getElement(i, j);
-
-        return new Matrix(newData);
-    }
-
-    /**
-    * Subtracts this matrix from another matrix.
-    *
-    * @param other : Matrix to be subtracted
-    * @return difference
-    */
-    public Matrix minus(Matrix other) throws RuntimeException {
-
-    	int[][] newData = new int[this.data.length][this.data[0].length];
-
-    	if(this.getRows() != other.getRows() || this.getColumns() != other.getColumns())
-			throw new RuntimeException("Not the same size matrix.");
-
-    	for (int i = 0; i < this.getRows(); ++i)
-			for(int j = 0; j < this.getColumns(); ++j)
-				newData[i][j] = this.data[i][j] - other.getElement(i, j);
-
-        return new Matrix(newData);
-    }
-    
-    /**
-     * Multiplies this matrix with another matrix.
-     *
-     * @param other : Matrix to be multiplied with
-     * @return product
-     */
-     public Matrix multiply(Matrix other) throws RuntimeException {
-
-     	int[][] newData = new int[this.data.length][other.getColumns()];
-
-     	if(this.getColumns() !=other.getRows())
- 			throw new RuntimeException("The two matrices cannot be multiplied.");
-     	int sum;
-     	for (int i = 0; i < this.getRows(); ++i)
- 			for(int j = 0; j < other.getColumns(); ++j){
- 				sum = 0;
- 				for(int k=0;k<this.getColumns();++k){
- 					sum += this.data[i][k] * other.getElement(k, j);
- 				}
- 				newData[i][j] = sum; 
- 			}
- 				
-
-         return new Matrix(newData);
-     }
-
-    /**
-    * Checks if the matrix passed is equal to this matrix
-    *
-	* @param other : the other matrix
-	* @return boolean
-    */
-    public boolean equals(Matrix other) {
-        return this == other;
-    }
-
-    /**
-    * Returns the Matrix as a String in the following format
-    *
-    * [ a b c ] ...
-    * [ x y z ] ...
-    * [ i j k ] ...
-    *    ...
-    *
-    * @return Matrix as String
-	* TODO: Work formatting for different digit sizes
-    */
-    public String toString() {
-        String str = "";
-
-        for(int i = 0; i < this.data.length; i++) {
-        	str += "[ ";
-            for(int j = 0; j < this.data[0].length; j++) {
-            	str += data[i][j];
-            	str += " ";
-            }
-            str += "]";
-            str += "\n";
-        }
-
-        return str;
-    }
-	
-	/**
-    * Returns transposed matrix of this matrix.
-    *
-    * @return transposed Matrix. 
-    */
-	public Matrix transpose() {
-		
-		int[][] newData = new int[this.data[0].length][this.data.length];
-
-		for (int i = 0; i < this.getColumns(); ++i)
-			for(int j = 0; j < this.getRows(); ++j)
-				newData[i][j] = this.data[j][i];
-
-		return new Matrix(newData);
-	}		
-}

DataStructures/Queues/GenericArrayListQueue.java

@@ -1,42 +0,0 @@
-import java.util.ArrayList;
-
-public class GenericArrayListQueue<T> {
-    ArrayList<T> _queue = new ArrayList<T>();
-
-    private boolean hasElements() {
-        return !_queue.isEmpty();
-    }
-
-    public T peek() {
-        T result = null;
-        if(this.hasElements()) { result = _queue.get(0); }
-        return result;
-    }
-
-    public boolean add(T element) {
-        return _queue.add(element);
-    }
-
-    public T poll() {
-        T result = null;
-        if(this.hasElements()) { result = _queue.remove(0); }
-        return result;
-    }
-
-    public static void main(String[] args) {
-        GenericArrayListQueue<Integer> queue = new GenericArrayListQueue<Integer>();
-        System.out.println("Running...");
-        assert queue.peek() == null;
-        assert queue.poll() == null;
-        assert queue.add(1) == true;
-        assert queue.peek() == 1;
-        assert queue.add(2) == true;
-        assert queue.peek() == 1;
-        assert queue.poll() == 1;
-        assert queue.peek() == 2;
-        assert queue.poll() == 2;
-        assert queue.peek() == null;
-        assert queue.poll() == null;
-        System.out.println("Finished.");
-    }
-}

DataStructures/Queues/PriorityQueues.java

@@ -1,123 +0,0 @@
-/**
- * This class implements a PriorityQueue.
- * 
- * A priority queue adds elements into positions based on their priority.
- * So the most important elements are placed at the front/on the top.
- * In this example I give numbers that are bigger, a higher priority.
- * Queues in theory have no fixed size but when using an array
- * implementation it does.
- * 
- * @author Unknown
- *
- */
-class PriorityQueue{
-	/** The max size of the queue */
-	private int maxSize;
-	/** The array for the queue */
-	private int[] queueArray;
-	/** How many items are in the queue */
-	private int nItems;
-
-	/**
-	 * Constructor
-	 * 
-	 * @param size Size of the queue
-	 */
-	public PriorityQueue(int size){
-		maxSize = size;
-		queueArray = new int[size];
-		nItems = 0;
-	}
-
-	/**
-	 * Inserts an element in it's appropriate place
-	 * 
-	 * @param value Value to be inserted
-	 */
-	public void insert(int value){
-		if(nItems == 0){
-			queueArray[0] = value;
-		}
-		else{
-			int j = nItems;
-			while(j > 0 && queueArray[j-1] > value){
-				queueArray[j] = queueArray[j-1]; //Shifts every element up to make room for insertion
-				j--;
-			}
-			queueArray[j] = value; //Once the correct position is found the value is inserted
-		}
-		nItems++;
-	}
-
-	/**
-	 * Remove the element from the front of the queue
-	 * 
-	 * @return The element removed
-	 */
-	public int remove(){
-		return queueArray[--nItems];
-	}
-
-	/**
-	 * Checks what's at the front of the queue
-	 * 
-	 * @return element at the front of the queue
-	 */
-	public int peek(){
-		return queueArray[nItems-1];
-	}
-
-	/**
-	 * Returns true if the queue is empty
-	 * 
-	 * @return true if the queue is empty
-	 */
-	public boolean isEmpty(){
-		return(nItems == 0);
-	}
-
-	/**
-	 * Returns true if the queue is full
-	 * 
-	 * @return true if the queue is full
-	 */
-	public boolean isFull(){
-		return(nItems == maxSize);
-	}
-
-	/**
-	 * Returns the number of elements in the queue
-	 * 
-	 * @return number of elements in the queue
-	 */
-	public int getSize(){
-		return nItems;
-	}
-}
-
-/**
- * This class implements the PriorityQueue class above.
- * 
- * @author Unknown
- *
- */
-public class PriorityQueues{
-	/**
-	 * Main method
-	 * 
-	 * @param args Command Line Arguments
-	 */
-	public static void main(String args[]){
-		PriorityQueue myQueue = new PriorityQueue(4);
-		myQueue.insert(10);
-		myQueue.insert(2);
-		myQueue.insert(5);
-		myQueue.insert(3);
-		//[2, 3, 5, 10] Here higher numbers have higher priority, so they are on the top
-
-		for(int i = 3; i>=0; i--)
-			System.out.print(myQueue.remove() + " "); //will print the queue in reverse order [10, 5, 3, 2]
-
-		//As you can see, a Priority Queue can be used as a sorting algotithm
-	}
-}

DataStructures/Queues/Queues.java

@@ -1,148 +0,0 @@
-/**
- * This implements Queues by using the class Queue.
- * 
- * A queue data structure functions the same as a real world queue.
- * The elements that are added first are the first to be removed.
- * New elements are added to the back/rear of the queue.
- * 
- * @author Unknown
- *
- */
-class Queue{
-	/** Max size of the queue */
-	private int maxSize;
-	/** The array representing the queue */
-	private int[] queueArray;
-	/** Front of the queue */
-	private int front;
-	/** Rear of the queue */
-	private int rear;
-	/** How many items are in the queue */
-	private int nItems;
-	
-	/**
-	 * Constructor
-	 * 
-	 * @param size Size of the new queue
-	 */
-	public Queue(int size){
-		maxSize = size;
-		queueArray = new int[size];
-		front = 0;
-		rear = -1;
-		nItems = 0;
-	}
-	
-	/**
-	 * Inserts an element at the rear of the queue
-	 * 
-	 * @param x element to be added
-	 * @return True if the element was added successfully
-	 */
-	public boolean insert(int x){
-		if(isFull())
-			return false;
-		if(rear == maxSize-1) //If the back of the queue is the end of the array wrap around to the front
-			rear = -1;
-		rear++;
-		queueArray[rear] = x;
-		nItems++;
-		return true;
-	}
-	
-	/**
-	 * Remove an element from the front of the queue
-	 * 
-	 * @return the new front of the queue
-	 */
-	public int remove(){ //Remove an element from the front of the queue
-		if(isEmpty()){
-			System.out.println("Queue is empty");
-			return -1;
-		}	
-		int temp = queueArray[front];
-		front++;
-		if(front == maxSize) //Dealing with wrap-around again
-			front = 0;
-		nItems--;
-		return temp;
-	}
-	
-	/**
-	 * Checks what's at the front of the queue
-	 * 
-	 * @return element at the front of the queue
-	 */
-	public int peekFront(){
-		return queueArray[front];
-	}
-	
-	/**
-	 * Checks what's at the rear of the queue
-	 * 
-	 * @return element at the rear of the queue
-	 */
-	public int peekRear(){
-		return queueArray[rear];
-	}
-	
-	/**
-	 * Returns true if the queue is empty
-	 * 
-	 * @return true if the queue is empty
-	 */
-	public boolean isEmpty(){
-		return(nItems == 0);
-	}
-	
-	/**
-	 * Returns true if the queue is full
-	 * 
-	 * @return true if the queue is full
-	 */
-	public boolean isFull(){
-		return(nItems == maxSize);
-	}
-	
-	/**
-	 * Returns the number of elements in the queue
-	 * 
-	 * @return number of elements in the queue
-	 */
-	public int getSize(){
-		return nItems;
-	}
-}
-
-/**
- * This class is the example for the Queue class
- * 
- * @author Unknown
- *
- */
-public class Queues{
-	/**
-	 * Main method
-	 * 
-	 * @param args Command line arguments
-	 */
-	public static void main(String args[]){
-		Queue myQueue = new Queue(4);
-		myQueue.insert(10);
-		myQueue.insert(2);
-		myQueue.insert(5);
-		myQueue.insert(3);
-		//[10(front), 2, 5, 3(rear)]
-		
-		System.out.println(myQueue.isFull()); //Will print true
-		
-		myQueue.remove(); //Will make 2 the new front, making 10 no longer part of the queue
-		//[10, 2(front), 5, 3(rear)]
-		
-		myQueue.insert(7); //Insert 7 at the rear which will be index 0 because of wrap around
-		// [7(rear), 2(front), 5, 3]
-		
-		System.out.println(myQueue.peekFront()); //Will print 2
-		System.out.println(myQueue.peekRear()); //Will print 7 	
-	}
-}

DataStructures/Stacks/BalancedBrackets.java

@@ -1,89 +0,0 @@
-package data_structures.Stacks;
-
-import java.util.Scanner;
-import java.util.Stack;
-
-/**
- *
- * The nested brackets problem is a problem that determines if a sequence of
- * brackets are properly nested. A sequence of brackets s is considered properly
- * nested if any of the following conditions are true: - s is empty - s has the
- * form (U) or [U] or {U} where U is a properly nested string - s has the form
- * VW where V and W are properly nested strings For example, the string
- * "()()[()]" is properly nested but "[(()]" is not. The function called
- * is_balanced takes as input a string S which is a sequence of brackets and
- * returns true if S is nested and false otherwise.
- *
- * @author akshay sharma
- * @date: 2017-10-17
- * @author <a href="https://github.com/khalil2535">khalil2535<a>
- *
- */
-class BalancedBrackets {
-
-    /**
-     *
-     * @param s
-     * @return
-     */
-    static boolean is_balanced(String s) {
-        Stack<Character> bracketsStack = new Stack<>();
-        char[] text = s.toCharArray();
-        for (char x : text) {
-            switch (x) {
-                case '{':
-                case '<':
-                case '(':
-                case '[':
-                    bracketsStack.push(x);
-                    break;
-                case '}':
-                    if (bracketsStack.peek() == '{') {
-                        bracketsStack.pop();
-                        break;
-                    } else {
-                        return false;
-                    }
-                case '>':
-                    if (bracketsStack.peek() == '<') {
-                        bracketsStack.pop();
-                        break;
-                    } else {
-                        return false;
-                    }
-                case ')':
-                    if (bracketsStack.peek() == '(') {
-                        bracketsStack.pop();
-                        break;
-                    } else {
-                        return false;
-                    }
-                case ']':
-                    if (bracketsStack.peek() == '[') {
-                        bracketsStack.pop();
-                        break;
-                    } else {
-                        return false;
-                    }
-            }
-        }
-        return bracketsStack.empty();
-    }
-
-    /**
-     *
-     * @param args
-     * @TODO remove main method and Test using JUnit or other methodology
-     */
-    public static void main(String args[]) {
-        try (Scanner in = new Scanner(System.in)) {
-            System.out.println("Enter sequence of brackets: ");
-            String s = in.nextLine();
-            if (is_balanced(s)) {
-                System.out.println(s + " is balanced");
-            } else {
-                System.out.println(s + " ain't balanced");
-            }
-        }
-    }
-}

DataStructures/Stacks/NodeStack.java

@@ -1,183 +0,0 @@
-/**
-* Implementation of a stack using nodes.
-* Unlimited size, no arraylist.
-*
-* @author Kyler Smith, 2017
-*/
-
-
-public class NodeStack<Item> {
-
-    /**
-    * Entry point for the program.
-    */
-    public static void main(String[] args) {
-        NodeStack<Integer> Stack = new NodeStack<Integer>();
-
-        Stack.push(3);
-        Stack.push(4);
-        Stack.push(5);
-        System.out.println("Testing :");
-        Stack.print();  			// prints : 5 4 3
-
-        Integer x = Stack.pop(); 	// x = 5
-        Stack.push(1);
-        Stack.push(8);
-        Integer y = Stack.peek();	// y = 8
-        System.out.println("Testing :");
-        Stack.print();				// prints : 8 1 4 3
-
-        System.out.println("Testing :");
-        System.out.println("x : " + x);
-        System.out.println("y : " + y);
-    }
-
-    /**
-    * Information each node should contain.
-    * @value data : information of the value in the node
-    * @value head : the head of the stack
-    * @value next : the next value from this node
-    * @value previous : the last value from this node
-    * @value size : size of the stack
-    */
-    private Item data;
-    private static NodeStack<?> head;
-    private NodeStack<?> next;
-    private NodeStack<?> previous;
-    private static int size = 0;
-
-
-    /**
-    * Constructors for the NodeStack.
-    */
-    public NodeStack() {
-	}
-
-    private NodeStack(Item item) {
-        this.data = item;
-    }
-
-    /**
-    * Put a value onto the stack.
-    *
-    * @param item : value to be put on the stack.
-    */
-    public void push(Item item) {
-
-    	NodeStack<Item> newNs = new NodeStack<Item>(item);
-
-        if(this.isEmpty()) {
-        	NodeStack.setHead(new NodeStack<>(item));
-        	newNs.setNext(null);
-        	newNs.setPrevious(null);
-        } else {
-        	newNs.setPrevious(NodeStack.head);
-        	NodeStack.head.setNext(newNs);
-        	NodeStack.head = newNs;
-        }
-
-        NodeStack.setSize(NodeStack.getSize() + 1);
-    }
-
-    /**
-    * Value to be taken off the stack.
-    *
-    * @return item : value that is returned.
-    */
-    public Item pop() {
-
-    	Item item = (Item) NodeStack.head.getData();
-
-    	NodeStack.head = NodeStack.head.getPrevious();
-    	NodeStack.head.setNext(null);
-
-    	NodeStack.setSize(NodeStack.getSize() - 1);
-
-        return item;
-    }
-
-    /**
-    * Value that is next to be taken off the stack.
-    *
-    * @return item : the next value that would be popped off the stack.
-    */
-    public Item peek() {
-        return (Item) NodeStack.head.getData();
-    }
-
-    /**
-    * If the stack is empty or there is a value in.
-    *
-    * @return boolean : whether or not the stack has anything in it.
-    */
-    public boolean isEmpty() {
-        return NodeStack.getSize() == 0;
-    }
-
-    /**
-    * Returns the size of the stack.
-    *
-    * @return int : number of values in the stack.
-    */
-    public int size() {
-        return NodeStack.getSize();
-    }
-
-    /**
-    * Print the contents of the stack in the following format.
-    *
-    * x <- head (next out)
-    * y
-    * z <- tail (first in)
-    * .
-    * .
-    * .
-    *
-    */
-    public void print() {
-    	for(NodeStack<?> n = NodeStack.head; n != null; n = n.previous) {
-    		System.out.println(n.getData().toString());
-    	}
-    }
-
-    /** Getters and setters (private) */
-    private NodeStack<?> getHead() {
-    	return NodeStack.head;
-    }
-
-    private static void setHead(NodeStack<?> ns) {
-    	NodeStack.head = ns;
-    }
-
-    private NodeStack<?> getNext() {
-		return next;
-	}
-
-    private void setNext(NodeStack<?> next) {
-		this.next = next;
-	}
-
-    private NodeStack<?> getPrevious() {
-		return previous;
-	}
-
-    private void setPrevious(NodeStack<?> previous) {
-		this.previous = previous;
-	}
-
-    private static int getSize() {
-		return size;
-	}
-
-    private static void setSize(int size) {
-		NodeStack.size = size;
-	}
-
-    private Item getData() {
-		return this.data;
-	}
-
-    private void setData(Item item) {
-		this.data = item;
-	}
-}

DataStructures/Stacks/StackOfLinkedList.java

@@ -1,109 +0,0 @@
-/**
- *
- * @author Varun Upadhyay (https://github.com/varunu28)
- *
- */
-
-// An implementation of a Stack using a Linked List
-
-class StackOfLinkedList {
-
-    public static void main(String[] args) {
-
-        LinkedListStack stack = new LinkedListStack();
-        stack.push(1);
-        stack.push(2);
-        stack.push(3);
-        stack.push(4);
-        stack.push(5);
-
-        stack.printStack();
-
-        System.out.println("Size of stack currently is: " + stack.getSize());
-
-        stack.pop();
-        stack.pop();
-
-        System.out.println("Top element of stack currently is: " + stack.peek());
-
-    }
-
-}
-
-// A node class
-
-class Node {
-    public int data;
-    public Node next;
-
-    public Node(int data) {
-        this.data = data;
-        this.next = null;
-    }
-}
-
-/**
- * A class which implements a stack using a linked list
- *
- * Contains all the stack methods : push, pop, printStack, isEmpty
- **/
-
-class LinkedListStack {
-
-    Node head = null;
-    int size = 0;
-
-    public void push(int x) {
-        Node n = new Node(x);
-        if (getSize() == 0) {
-            head = n;
-        }
-        else {
-            Node temp = head;
-            n.next = temp;
-            head = n;
-        }
-        size++;
-    }
-
-    public void pop() {
-        if (getSize() == 0) {
-            System.out.println("Empty stack. Nothing to pop");
-        }
-
-        Node temp = head;
-        head = head.next;
-        size--;
-
-        System.out.println("Popped element is: " + temp.data);
-    }
-
-    public int peek() {
-      if (getSize() == 0) {
-        return -1;
-      }
-
-      return head.data;
-    }
-
-    public void printStack() {
-
-        Node temp = head;
-        System.out.println("Stack is printed as below: ");
-        while (temp != null) {
-            System.out.println(temp.data + " ");
-            temp = temp.next;
-        }
-        System.out.println();
-
-    }
-
-    public boolean isEmpty() {
-        return getSize() == 0;
-    }
-
-    public int getSize() {
-        return size;
-    }
-
-}

DataStructures/Stacks/Stacks.java

@@ -1,240 +0,0 @@
-import java.util.ArrayList;
-
-/**
- * This class implements a Stack using two different implementations.
- * Stack is used with a regular array and Stack2 uses an ArrayList.
- *
- * A stack is exactly what it sounds like. An element gets added to the top of
- * the stack and only the element on the top may be removed. This is an example
- * of an array implementation of a Stack. So an element can only be added/removed
- * from the end of the array. In theory stack have no fixed size, but with an
- * array implementation it does.
- *
- * @author Unknown
- *
- */
-class Stack{
-	/** The max size of the Stack */
-	private int maxSize;
-	/** The array representation of the Stack */
-	private int[] stackArray;
-	/** The top of the stack */
-	private int top;
-
-	/**
-	 * Constructor
-	 *
-	 * @param size Size of the Stack
-	 */
-	public Stack(int size){
-		maxSize = size;
-		stackArray = new int[maxSize];
-		top = -1;
-	}
-
-	/**
-	 * Adds an element to the top of the stack
-	 *
-	 * @param value The element added
-	 */
-	public void push(int value){
-		if(!isFull()){ //Checks for a full stack
-			top++;
-			stackArray[top] = value;
-		}else{
-			resize(maxSize*2);
-                        push(value);// don't forget push after resizing
-		}
-	}
-
-	/**
-	 * Removes the top element of the stack and returns the value you've removed
-	 *
-	 * @return value popped off the Stack
-	 */
-	public int pop(){
-		if(!isEmpty()){ //Checks for an empty stack
-			return stackArray[top--];
-		}
-
-		if(top < maxSize/4){
-			resize(maxSize/2);
-			return pop();// don't forget pop after resizing
-		}
-		else{
-			System.out.println("The stack is already empty");
-			return -1;
-		}
-	}
-
-	/**
-	 * Returns the element at the top of the stack
-	 *
-	 * @return element at the top of the stack
-	 */
-	public int peek(){
-		if(!isEmpty()){ //Checks for an empty stack
-			return stackArray[top];
-		}else{
-			System.out.println("The stack is empty, cant peek");
-			return -1;
-		}
-	}
-
-	private void resize(int newSize){
-		//private int[] transferArray = new int[newSize]; we can't put modifires here !
-                int[] transferArray = new int[newSize];
-
-		//for(int i = 0; i < stackArray.length(); i++){ the length isn't a method .
-                for(int i = 0; i < stackArray.length; i++){
-			transferArray[i] = stackArray[i];
-			stackArray = transferArray;
-		}
-		maxSize = newSize;
-	}
-
-	/**
-	 * Returns true if the stack is empty
-	 *
-	 * @return true if the stack is empty
-	 */
-	public boolean isEmpty(){
-		return(top == -1);
-	}
-
-	/**
-	 * Returns true if the stack is full
-	 *
-	 * @return true if the stack is full
-	 */
-	public boolean isFull(){
-		return(top+1 == maxSize);
-	}
-
-	/**
-	 * Deletes everything in the Stack
-	 *
-	 * Doesn't delete elements in the array
-	 * but if you call push method after calling
-	 * makeEmpty it will overwrite previous
-	 * values
-	 */
-	public void makeEmpty(){ //Doesn't delete elements in the array but if you call
-		top = -1;			 //push method after calling makeEmpty it will overwrite previous values
-	}
-}
-
-/**
- * This is an ArrayList Implementation of stack, Where size is not
- * a problem we can extend the stack as much as we want.
- *
- * @author Unknown
- *
- */
-class Stack2{
-		/** ArrayList representation of the stack */
-		ArrayList<Integer> stackList;
-
-		/**
-		 * Constructor
-		 */
-		Stack2(){
-			stackList=new ArrayList<>();
-		}
-
-		/**
-		 * Adds value to the end of list which
-		 * is the top for stack
-		 *
-		 * @param value value to be added
-		 */
-		void push(int value){
-			stackList.add(value);
-		}
-
-		/**
-		 * Pops last element of list which is indeed
-		 * the top for Stack
-		 *
-		 * @return Element popped
-		 */
-		int pop(){
-
-			if(!isEmpty()){ // checks for an empty Stack
-
-				int popValue=stackList.get(stackList.size()-1);
-				stackList.remove(stackList.size()-1);  //removes the poped element from the list
-				return popValue;
-			}
-			else{
-				System.out.print("The stack is already empty  ");
-				return -1;
-			}
-
-		}
-
-		/**
-		 * Checks for empty Stack
-		 *
-		 * @return true if stack is empty
-		 */
-		boolean isEmpty(){
-			if(stackList.isEmpty())
-				return true;
-
-			else return false;
-
-		}
-
-		/**
-		 * Top element of stack
-		 *
-		 * @return top element of stack
-		 */
-		int peek(){
-			return stackList.get(stackList.size()-1);
-		}
-	}
-
-/**
- * This class implements the Stack and Stack2 created above
- *
- * @author Unknown
- *
- */
-public class Stacks{
-	/**
-	 * Main method
-	 *
-	 * @param args Command line arguments
-	 */
-	public static void main(String args[]){
-			Stack myStack = new Stack(4); //Declare a stack of maximum size 4
- 		//Populate the stack
- 		myStack.push(5);
- 		myStack.push(8);
-  		myStack.push(2);
-  		myStack.push(9);
-
-		System.out.println("*********************Stack Array Implementation*********************");
-  		System.out.println(myStack.isEmpty()); //will print false
-  		System.out.println(myStack.isFull()); //will print true
-  		System.out.println(myStack.peek()); //will print 9
-  		System.out.println(myStack.pop()); //will print 9
-  		System.out.println(myStack.peek()); // will print 2
-
-		Stack2 myStack2 = new Stack2(); //Declare a stack of maximum size 4
-  		//Populate the stack
- 		myStack2.push(5);
-		myStack2.push(8);
- 		myStack2.push(2);
- 		myStack2.push(9);
-
- 		System.out.println("*********************Stack List Implementation*********************");
- 		System.out.println(myStack2.isEmpty()); //will print false
- 		System.out.println(myStack2.peek()); //will print 9
- 		System.out.println(myStack2.pop()); //will print 9
- 		System.out.println(myStack2.peek()); // will print 2
- 		System.out.println(myStack2.pop()); //will print 2
-	}
-}

DataStructures/Trees/AVLTree.java

@@ -1,212 +0,0 @@
-public class AVLTree {
- 
-    private Node root;
- 
-    private class Node {
-        private int key;
-        private int balance;
-        private int height;
-        private Node left, right, parent;
- 
-        Node(int k, Node p) {
-            key = k;
-            parent = p;
-        }
-    }
- 
-    public boolean insert(int key) {
-        if (root == null)
-            root = new Node(key, null);
-        else {
-            Node n = root;
-            Node parent;
-            while (true) {
-                if (n.key == key)
-                    return false;
- 
-                parent = n;
- 
-                boolean goLeft = n.key > key;
-                n = goLeft ? n.left : n.right;
- 
-                if (n == null) {
-                    if (goLeft) {
-                        parent.left = new Node(key, parent);
-                    } else {
-                        parent.right = new Node(key, parent);
-                    }
-                    rebalance(parent);
-                    break;
-                }
-            }
-        }
-        return true;
-    }
- 
-    private void delete(Node node){
-        if(node.left == null && node.right == null){
-            if(node.parent == null) root = null;
-            else{
-                Node parent = node.parent;
-                if(parent.left == node){
-                    parent.left = null;
-                }else parent.right = null;
-                rebalance(parent);
-            }
-            return;
-        }
-        if(node.left!=null){
-            Node child = node.left;
-            while (child.right!=null) child = child.right;
-            node.key = child.key;
-            delete(child);
-        }else{
-            Node child = node.right;
-            while (child.left!=null) child = child.left;
-            node.key = child.key;
-            delete(child);
-        }
-    }
- 
-    public void delete(int delKey) {
-        if (root == null)
-            return;
-        Node node = root;
-        Node child = root;
- 
-        while (child != null) {
-            node = child;
-            child = delKey >= node.key ? node.right : node.left;
-            if (delKey == node.key) {
-                delete(node);
-                return;
-            }
-        }
-    }
- 
-    private void rebalance(Node n) {
-        setBalance(n);
- 
-        if (n.balance == -2) {
-            if (height(n.left.left) >= height(n.left.right))
-                n = rotateRight(n);
-            else
-                n = rotateLeftThenRight(n);
- 
-        } else if (n.balance == 2) {
-            if (height(n.right.right) >= height(n.right.left))
-                n = rotateLeft(n);
-            else
-                n = rotateRightThenLeft(n);
-        }
- 
-        if (n.parent != null) {
-            rebalance(n.parent);
-        } else {
-            root = n;
-        }
-    }
- 
-    private Node rotateLeft(Node a) {
- 
-        Node b = a.right;
-        b.parent = a.parent;
- 
-        a.right = b.left;
- 
-        if (a.right != null)
-            a.right.parent = a;
- 
-        b.left = a;
-        a.parent = b;
- 
-        if (b.parent != null) {
-            if (b.parent.right == a) {
-                b.parent.right = b;
-            } else {
-                b.parent.left = b;
-            }
-        }
- 
-        setBalance(a, b);
- 
-        return b;
-    }
- 
-    private Node rotateRight(Node a) {
- 
-        Node b = a.left;
-        b.parent = a.parent;
- 
-        a.left = b.right;
- 
-        if (a.left != null)
-            a.left.parent = a;
- 
-        b.right = a;
-        a.parent = b;
- 
-        if (b.parent != null) {
-            if (b.parent.right == a) {
-                b.parent.right = b;
-            } else {
-                b.parent.left = b;
-            }
-        }
- 
-        setBalance(a, b);
- 
-        return b;
-    }
- 
-    private Node rotateLeftThenRight(Node n) {
-        n.left = rotateLeft(n.left);
-        return rotateRight(n);
-    }
- 
-    private Node rotateRightThenLeft(Node n) {
-        n.right = rotateRight(n.right);
-        return rotateLeft(n);
-    }
- 
-    private int height(Node n) {
-        if (n == null)
-            return -1;
-        return n.height;
-    }
- 
-    private void setBalance(Node... nodes) {
-        for (Node n : nodes)
-            reheight(n);
-            n.balance = height(n.right) - height(n.left);
-    }
- 
-    public void printBalance() {
-        printBalance(root);
-    }
- 
-    private void printBalance(Node n) {
-        if (n != null) {
-            printBalance(n.left);
-            System.out.printf("%s ", n.balance);
-            printBalance(n.right);
-        }
-    }
- 
-    private void reheight(Node node){
-        if(node!=null){
-            node.height=1 + Math.max(height(node.left), height(node.right));
-        }
-    }
- 
-    public static void main(String[] args) {
-        AVLTree tree = new AVLTree();
- 
-        System.out.println("Inserting values 1 to 10");
-        for (int i = 1; i < 10; i++)
-            tree.insert(i);
- 
-        System.out.print("Printing balance: ");
-        tree.printBalance();
-    }
-}

DataStructures/Trees/BinaryTree.java

@@ -1,268 +0,0 @@
-/**
-* This entire class is used to build a Binary Tree data structure.
-* There is the Node Class and the Tree Class, both explained below.
-*
-* @author Unknown
-*
-*/
-
-
-/**
-* This class implements the nodes that will go on the Binary Tree.
-* They consist of the data in them, the node to the left, the node
-* to the right, and the parent from which they came from.
-*
-* @author Unknown
-*
-*/
-class Node{
-	/** Data for the node */
-	public int data;
-	/** The Node to the left of this one */
-	public Node left;
-	/** The Node to the right of this one */
-	public Node right;
-	/** The parent of this node */
-	public Node parent;
-
-	/**
-	* Constructor of Node
-	*
-	* @param value Value to put in the node
-	*/
-	public Node(int value){
-		data = value;
-		left = null;
-		right = null;
-		parent = null;
-	}
-}
-
-
-/**
-* A binary tree is a data structure in which an element
-* has two successors(children). The left child is usually
-* smaller than the parent, and the right child is usually
-* bigger.
-*
-* @author Unknown
-*
-*/
-class Tree{
-	/** The root of the Binary Tree */
-	private Node root;
-
-	/**
-	* Constructor
-	*/
-	public Tree(){
-		root = null;
-	}
-
-	/**
-	* Method to find a Node with a certain value
-	*
-	* @param key Value being looked for
-	* @return The node if it finds it, otherwise returns the parent
-	*/
-	public Node find(int key) {
-		Node current = root;
-		while (current != null) {
-			if(key < current.data) {
-				current = current.left;
-			} else if(key > current.data) {
-				current = current.right;
-			} else {	// If you find the value return it
-				return current;
-			}
-		}
-		return null;
-	}
-
-	/**
-	* Inserts certain value into the Binary Tree
-	*
-	* @param value Value to be inserted
-	*/
-	public void put(int value){
-		Node newNode = new Node(value);
-		if(root == null)
-		root = newNode;
-		else{
-			//This will return the soon to be parent of the value you're inserting
-			Node parent = find(value);
-
-			//This if/else assigns the new node to be either the left or right child of the parent
-			if(value < parent.data){
-				parent.left = newNode;
-				parent.left.parent = parent;
-				return;
-			}
-			else{
-				parent.right = newNode;
-				parent.right.parent = parent;
-				return;
-			}
-		}
-	}
-
-	/**
-	* Deletes a given value from the Binary Tree
-	*
-	* @param value Value to be deleted
-	* @return If the value was deleted
-	*/
-	public boolean remove(int value){
-		//temp is the node to be deleted
-		Node temp = find(value);
-
-		//If the value doesn't exist
-		if(temp.data != value)
-		return false;
-
-		//No children
-		if(temp.right == null && temp.left == null){
-			if(temp == root)
-			root = null;
-
-			//This if/else assigns the new node to be either the left or right child of the parent
-			else if(temp.parent.data < temp.data)
-			temp.parent.right = null;
-			else
-			temp.parent.left = null;
-			return true;
-		}
-
-		//Two children
-		else if(temp.left != null && temp.right != null){
-			Node successor = findSuccessor(temp);
-
-			//The left tree of temp is made the left tree of the successor
-			successor.left = temp.left;
-			successor.left.parent = successor;
-
-			//If the successor has a right child, the child's grandparent is it's new parent
-			if(successor.right != null && successor.parent != temp){
-				successor.right.parent = successor.parent;
-				successor.parent.left = successor.right;
-				successor.right = temp.right;
-				successor.right.parent = successor;
-			}
-			if(temp == root){
-				successor.parent = null;
-				root = successor;
-				return true;
-			}
-
-			//If you're not deleting the root
-			else{
-				successor.parent = temp.parent;
-
-				//This if/else assigns the new node to be either the left or right child of the parent
-				if(temp.parent.data < temp.data)
-				temp.parent.right = successor;
-				else
-				temp.parent.left = successor;
-				return true;
-			}
-		}
-		//One child
-		else{
-			//If it has a right child
-			if(temp.right != null){
-				if(temp == root){
-					root = temp.right; return true;}
-
-					temp.right.parent = temp.parent;
-
-					//Assigns temp to left or right child
-					if(temp.data < temp.parent.data)
-					temp.parent.left = temp.right;
-					else
-					temp.parent.right = temp.right;
-					return true;
-				}
-				//If it has a left child
-				else{
-					if(temp == root){
-						root = temp.left; return true;}
-
-						temp.left.parent = temp.parent;
-
-						//Assigns temp to left or right side
-						if(temp.data < temp.parent.data)
-						temp.parent.left = temp.left;
-						else
-						temp.parent.right = temp.left;
-						return true;
-					}
-				}
-			}
-
-			/**
-			* This method finds the Successor to the Node given.
-			* Move right once and go left down the tree as far as you can
-			*
-			* @param n Node that you want to find the Successor of
-			* @return The Successor of the node
-			*/
-			public Node findSuccessor(Node n){
-				if(n.right == null)
-				return n;
-				Node current = n.right;
-				Node parent = n.right;
-				while(current != null){
-					parent = current;
-					current = current.left;
-				}
-				return parent;
-			}
-
-			/**
-			* Returns the root of the Binary Tree
-			*
-			* @return the root of the Binary Tree
-			*/
-			public Node getRoot(){
-				return root;
-			}
-
-			/**
-			* Prints leftChild - root - rightChild
-			*
-			* @param localRoot The local root of the binary tree
-			*/
-			public void inOrder(Node localRoot){
-				if(localRoot != null){
-					inOrder(localRoot.left);
-					System.out.print(localRoot.data + " ");
-					inOrder(localRoot.right);
-				}
-			}
-
-			/**
-			* Prints root - leftChild - rightChild
-			*
-			* @param localRoot The local root of the binary tree
-			*/
-			public void preOrder(Node localRoot){
-				if(localRoot != null){
-					System.out.print(localRoot.data + " ");
-					preOrder(localRoot.left);
-					preOrder(localRoot.right);
-				}
-			}
-
-			/**
-			* Prints rightChild - leftChild - root
-			*
-			* @param localRoot The local root of the binary tree
-			*/
-			public void postOrder(Node localRoot){
-				if(localRoot != null){
-					postOrder(localRoot.left);
-					postOrder(localRoot.right);
-					System.out.print(localRoot.data + " ");
-				}
-			}
-		}

DataStructures/Trees/FindHeightOfTree.java

@@ -1,100 +0,0 @@
-/**
- *
- * @author Varun Upadhyay (https://github.com/varunu28)
- *
- */
-import java.util.LinkedList;
-
-public class FindHeightOfTree {
-
-    // Driver Program
-    public static void main(String[] args) {
-        Node tree = new Node(5);
-        tree.insert(3);
-        tree.insert(7);
-        tree.insert(1);
-        tree.insert(-1);
-        tree.insert(29);
-        tree.insert(93);
-        tree.insert(6);
-        tree.insert(0);
-        tree.insert(-5);
-        tree.insert(-6);
-        tree.insert(-8);
-        tree.insert(-1);
-
-        // A level order representation of the tree
-        tree.printLevelOrder();
-        System.out.println();
-
-        System.out.println("Height of the tree is: " + tree.findHeight());
-    }
-}
-
-/**
- * The Node class which initializes a Node of a tree
- * printLevelOrder: ROOT -> ROOT's CHILDREN -> ROOT's CHILDREN's CHILDREN -> etc
- * findHeight: Returns the height of the tree i.e. the number of links between root and farthest leaf
- */
-class Node {
-    Node left, right;
-    int data;
-
-    public Node(int data) {
-        this.data = data;
-    }
-
-    public void insert (int value) {
-        if (value < data) {
-            if (left == null) {
-                left = new Node(value);
-            }
-            else {
-                left.insert(value);
-            }
-        }
-        else {
-            if (right == null) {
-                right = new Node(value);
-            }
-            else {
-                right.insert(value);
-            }
-        }
-    }
-
-    public void printLevelOrder() {
-        LinkedList<Node> queue = new LinkedList<>();
-        queue.add(this);
-        while(!queue.isEmpty()) {
-            Node n = queue.poll();
-            System.out.print(n.data + " ");
-            if (n.left != null) {
-                queue.add(n.left);
-            }
-            if (n.right != null) {
-                queue.add(n.right);
-            }
-        }
-    }
-
-    public int findHeight() {
-        return findHeight(this);
-    }
-
-    private int findHeight(Node root) {
-        if (root.left == null && root.right == null) {
-            return 0;
-        }
-        else if (root.left != null && root.right != null) {
-            return 1 + Math.max(findHeight(root.left), findHeight(root.right));
-        }
-        else if (root.left == null && root.right != null) {
-            return 1 + findHeight(root.right);
-        }
-        else {
-            return 1 + findHeight(root.left);
-        }
-    }
-}
-

DataStructures/Trees/GenericTree.Java

@@ -1,226 +0,0 @@
-import java.util.ArrayList;
-import java.util.LinkedList;
-import java.util.Scanner;
-
-public class treeclass {
-	private class Node {
-		int data;
-		ArrayList<Node> child = new ArrayList<>();
-	}
-
-	private Node root;
-	private int size;
-
-	/*
-	A generic tree is a tree which can have as many children as it can be
-	It might be possible that every node present is directly connected to
-	root node.
-
-	In this code
-	Every function has two copies: one function is helper function which can be called from
-	main and from that function a private function is called which will do the actual work.
-	I have done this, while calling from main one have to give minimum parameters.
-
-	*/
-	public treeclass() {     //Constructor
-		Scanner scn = new Scanner(System.in);
-		root = create_treeG(null, 0, scn);
-	}
-
-	private Node create_treeG(Node node, int childindx, Scanner scn) {
-		// display
-		if (node == null) {
-			System.out.println("Enter root's data");
-		} else {
-			System.out.println("Enter data of parent of index " + node.data + " " + childindx);
-		}
-		// input
-		node = new Node();
-		node.data = scn.nextInt();
-		System.out.println("number of children");
-		int number = scn.nextInt();
-		for (int i = 0; i < number; i++) {
-			Node childd = create_treeG(node, i, scn);
-			size++;
-			node.child.add(childd);
-		}
-		return node;
-	}
-
-	/*
-	Function to display the generic tree
-	*/
-	public void display() {  //Helper function
-		display_1(root);
-		return;
-	}
-
-	private void display_1(Node parent) {
-		System.out.print(parent.data + "=>");
-		for (int i = 0; i < parent.child.size(); i++) {
-			System.out.print(parent.child.get(i).data + " ");
-		}
-		System.out.println(".");
-		for (int i = 0; i < parent.child.size(); i++) {
-			display_1(parent.child.get(i));
-		}
-		return;
-	}
-
-	/*
-	 One call store the size directly but if you are asked compute size this function to calcuate
-	 size goes as follows
-	 */
-
-	public int size2call() {
-		return size2(root);
-	}
-
-	public int size2(Node roott) {
-		int sz = 0;
-		for (int i = 0; i < roott.child.size(); i++) {
-			sz += size2(roott.child.get(i));
-		}
-		return sz + 1;
-	}
-
-	/*
-	Function to compute maximum value in the generic tree
-	*/
-	public int maxcall() {
-		int maxi = root.data;
-		return max(root, maxi);
-	}
-
-	private int max(Node roott, int maxi) {
-		if (maxi < roott.data)
-			maxi = roott.data;
-		for (int i = 0; i < roott.child.size(); i++) {
-			maxi = max(roott.child.get(i), maxi);
-		}
-
-		return maxi;
-	}
-
-	/*
-	Function to compute HEIGHT of the generic tree
-	*/
-
-	public int heightcall() {
-		return height(root) - 1;
-	}
-
-	private int height(Node node) {
-		int h = 0;
-		for (int i = 0; i < node.child.size(); i++) {
-			int k = height(node.child.get(i));
-			if (k > h)
-				h = k;
-		}
-		return h + 1;
-	}
-
-	/*
-	Function to find whether a number is present in the generic tree or not
-	*/
-
-	public boolean findcall(int info) {
-		return find(root, info);
-	}
-
-	private boolean find(Node node, int info) {
-		if (node.data == info)
-			return true;
-		for (int i = 0; i < node.child.size(); i++) {
-			if (find(node.child.get(i), info))
-				return true;
-		}
-		return false;
-	}
-
-	/*
-	Function to calculate depth of generic tree
-	*/
-	public void depthcaller(int dep) {
-		depth(root, dep);
-	}
-
-	public void depth(Node node, int dep) {
-		if (dep == 0) {
-			System.out.println(node.data);
-			return;
-		}
-		for (int i = 0; i < node.child.size(); i++)
-			depth(node.child.get(i), dep - 1);
-		return;
-	}
-
-	/*
-	Function to print generic tree in pre-order
-	*/
-	public void preordercall() {
-		preorder(root);
-		System.out.println(".");
-	}
-
-	private void preorder(Node node) {
-		System.out.print(node.data + " ");
-		for (int i = 0; i < node.child.size(); i++)
-			preorder(node.child.get(i));
-	}
-
-	/*
-	Function to print generic tree in post-order
-	*/
-	public void postordercall() {
-		postorder(root);
-		System.out.println(".");
-	}
-
-	private void postorder(Node node) {
-		for (int i = 0; i < node.child.size(); i++)
-			postorder(node.child.get(i));
-		System.out.print(node.data + " ");
-	}
-
-	/*
-	Function to print generic tree in level-order
-	*/
-
-	public void levelorder() {
-		LinkedList<Node> q = new LinkedList<>();
-		q.addLast(root);
-		while (!q.isEmpty()) {
-			int k = q.getFirst().data;
-			System.out.print(k + " ");
-
-			for (int i = 0; i < q.getFirst().child.size(); i++) {
-				q.addLast(q.getFirst().child.get(i));
-			}
-			q.removeFirst();
-		}
-		System.out.println(".");
-	}
-
-	/*
-	 Function to remove all leaves of generic tree
-	 */
-	public void removeleavescall() {
-		removeleaves(root);
-	}
-
-	private void removeleaves(Node node) {
-		ArrayList<Integer> arr = new ArrayList<>();
-		for (int i = 0; i < node.child.size(); i++) {
-			if (node.child.get(i).child.size() == 0) {
-				arr.add(i);
-				// node.child.remove(i);
-				// i--;
-			} else
-				removeleaves(node.child.get(i));
-		}
-		for (int i = arr.size() - 1; i >= 0; i--) {
-			node.child.remove(arr.get(i) + 0);
-		}
-	}
-

DataStructures/Trees/LevelOrderTraversal.java

@@ -1,78 +0,0 @@
-class Node
-{
-    int data;
-    Node left, right;
-    public Node(int item)
-    {
-        data = item;
-        left = right = null;
-    }
-}
- 
-public class LevelOrderTraversal
-{
-    // Root of the Binary Tree
-    Node root;
- 
-    public LevelOrderTraversal()
-    {
-        root = null;
-    }
- 
-    /* function to print level order traversal of tree*/
-    void printLevelOrder()
-    {
-        int h = height(root);
-        int i;
-        for (i=1; i<=h; i++)
-            printGivenLevel(root, i);
-    }
- 
-    /* Compute the "height" of a tree -- the number of
-    nodes along the longest path from the root node
-    down to the farthest leaf node.*/
-    int height(Node root)
-    {
-        if (root == null)
-           return 0;
-        else
-        {
-            /* compute  height of each subtree */
-            int lheight = height(root.left);
-            int rheight = height(root.right);
-             
-            /* use the larger one */
-            if (lheight > rheight)
-                return(lheight+1);
-            else return(rheight+1); 
-        }
-    }
- 
-    /* Print nodes at the given level */
-    void printGivenLevel (Node root ,int level)
-    {
-        if (root == null)
-            return;
-        if (level == 1)
-            System.out.print(root.data + " ");
-        else if (level > 1)
-        {
-            printGivenLevel(root.left, level-1);
-            printGivenLevel(root.right, level-1);
-        }
-    }
-     
-    /* Driver program to test above functions */
-    public static void main(String args[])
-    {
-       LevelOrderTraversal tree = new LevelOrderTraversal();
-       tree.root= new Node(1);
-       tree.root.left= new Node(2);
-       tree.root.right= new Node(3);
-       tree.root.left.left= new Node(4);
-       tree.root.left.right= new Node(5);
-        
-       System.out.println("Level order traversal of binary tree is ");
-       tree.printLevelOrder();
-    }
-}

DataStructures/Trees/LevelOrderTraversalQueue.java

@@ -1,62 +0,0 @@
-import java.util.Queue;
-import java.util.LinkedList;
- 
-/* Class to represent Tree node */
-class Node {
-    int data;
-    Node left, right;
- 
-    public Node(int item) {
-        data = item;
-        left = null;
-        right = null;
-    }
-}
- 
-/* Class to print Level Order Traversal */
-public class LevelOrderTraversalQueue {
- 
-    Node root;
- 
-    /* Given a binary tree. Print its nodes in level order
-     using array for implementing queue  */
-    void printLevelOrder() 
-    {
-        Queue<Node> queue = new LinkedList<Node>();
-        queue.add(root);
-        while (!queue.isEmpty()) 
-        {
- 
-            /* poll() removes the present head.
-            For more information on poll() visit 
-            http://www.tutorialspoint.com/java/util/linkedlist_poll.htm */
-            Node tempNode = queue.poll();
-            System.out.print(tempNode.data + " ");
- 
-            /*Enqueue left child */
-            if (tempNode.left != null) {
-                queue.add(tempNode.left);
-            }
- 
-            /*Enqueue right child */
-            if (tempNode.right != null) {
-                queue.add(tempNode.right);
-            }
-        }
-    }
- 
-    public static void main(String args[]) 
-    {
-        /* creating a binary tree and entering 
-         the nodes */
-    	LevelOrderTraversalQueue tree_level = new LevelOrderTraversalQueue();
-        tree_level.root = new Node(1);
-        tree_level.root.left = new Node(2);
-        tree_level.root.right = new Node(3);
-        tree_level.root.left.left = new Node(4);
-        tree_level.root.left.right = new Node(5);
- 
-        System.out.println("Level order traversal of binary tree is - ");
-        tree_level.printLevelOrder();
-    }
-}

DataStructures/Trees/PrintTopViewofTree.java

@@ -1,105 +0,0 @@
-// Java program to print top view of Binary tree
-import java.util.*;
- 
-// Class for a tree node
-class TreeNode
-{
-    // Members
-    int key;
-    TreeNode left, right;
- 
-    // Constructor
-    public TreeNode(int key)
-    {
-        this.key = key;
-        left = right = null;
-    }
-}
- 
-// A class to represent a queue item. The queue is used to do Level
-// order traversal. Every Queue item contains node and horizontal
-// distance of node from root
-class QItem
-{
-   TreeNode node;
-   int hd;
-   public QItem(TreeNode n, int h)
-   {
-        node = n;
-        hd = h;
-   }
-}
- 
-// Class for a Binary Tree
-class Tree
-{
-    TreeNode root;
- 
-    // Constructors
-    public Tree()  { root = null; }
-    public Tree(TreeNode n) { root = n; }
- 
-    // This method prints nodes in top view of binary tree
-    public void printTopView()
-    {
-        // base case
-        if (root == null) {  return;  }
- 
-        // Creates an empty hashset
-        HashSet<Integer> set = new HashSet<>();
- 
-        // Create a queue and add root to it
-        Queue<QItem> Q = new LinkedList<QItem>();
-        Q.add(new QItem(root, 0)); // Horizontal distance of root is 0
- 
-        // Standard BFS or level order traversal loop
-        while (!Q.isEmpty())
-        {
-            // Remove the front item and get its details
-            QItem qi = Q.remove();
-            int hd = qi.hd;
-            TreeNode n = qi.node;
- 
-            // If this is the first node at its horizontal distance,
-            // then this node is in top view
-            if (!set.contains(hd))
-            {
-                set.add(hd);
-                System.out.print(n.key + " ");
-            }
- 
-            // Enqueue left and right children of current node
-            if (n.left != null)
-                Q.add(new QItem(n.left, hd-1));
-            if (n.right != null)
-                Q.add(new QItem(n.right, hd+1));
-        }
-    }
-}
- 
-// Driver class to test above methods
-public class PrintTopViewofTree
-{
-    public static void main(String[] args)
-    {
-        /* Create following Binary Tree
-             1
-           /  \
-          2    3
-           \
-            4
-             \
-              5
-               \
-                6*/
-        TreeNode root = new TreeNode(1);
-        root.left = new TreeNode(2);
-        root.right = new TreeNode(3);
-        root.left.right = new TreeNode(4);
-        root.left.right.right = new TreeNode(5);
-        root.left.right.right.right = new TreeNode(6);
-        Tree t = new Tree(root);
-        System.out.println("Following are nodes in top view of Binary Tree");
-        t.printTopView();
-    }
-}

DataStructures/Trees/RedBlackBST.java

@@ -1,330 +0,0 @@
-/**
- *
- * @author jack870131
- */
-public class RedBlackBST {
-
-	private final int R = 0;
-	private final int B = 1;
-
-	private class Node {
-
-		int key = -1, color = B;
-		Node left = nil, right = nil, p = nil;
-
-		Node(int key) {
-			this.key = key;
-		}
-	}
-
-	private final Node nil = new Node(-1);
-	private Node root = nil;
-
-	public void printTree(Node node) {
-		if (node == nil) {
-			return;
-		}
-		printTree(node.left);
-		System.out.print(((node.color == R) ? " R " : " B ") + "Key: " + node.key + " Parent: " + node.p.key + "\n");
-		printTree(node.right);
-	}
-
-	public void printTreepre(Node node) {
-		if (node == nil) {
-			return;
-		}
-		System.out.print(((node.color == R) ? " R " : " B ") + "Key: " + node.key + " Parent: " + node.p.key + "\n");
-		printTree(node.left);
-		printTree(node.right);
-	}
-
-	private Node findNode(Node findNode, Node node) {
-		if (root == nil) {
-			return null;
-		}
-		if (findNode.key < node.key) {
-			if (node.left != nil) {
-				return findNode(findNode, node.left);
-			}
-		} else if (findNode.key > node.key) {
-			if (node.right != nil) {
-				return findNode(findNode, node.right);
-			}
-		} else if (findNode.key == node.key) {
-			return node;
-		}
-		return null;
-	}
-
-	private void insert(Node node) {
-		Node temp = root;
-		if (root == nil) {
-			root = node;
-			node.color = B;
-			node.p = nil;
-		} else {
-			node.color = R;
-			while (true) {
-				if (node.key < temp.key) {
-					if (temp.left == nil) {
-						temp.left = node;
-						node.p = temp;
-						break;
-					} else {
-						temp = temp.left;
-					}
-				} else if (node.key >= temp.key) {
-					if (temp.right == nil) {
-						temp.right = node;
-						node.p = temp;
-						break;
-					} else {
-						temp = temp.right;
-					}
-				}
-			}
-			fixTree(node);
-		}
-	}
-
-	private void fixTree(Node node) {
-		while (node.p.color == R) {
-			Node y = nil;
-			if (node.p == node.p.p.left) {
-				y = node.p.p.right;
-
-				if (y != nil && y.color == R) {
-					node.p.color = B;
-					y.color = B;
-					node.p.p.color = R;
-					node = node.p.p;
-					continue;
-				}
-				if (node == node.p.right) {
-					node = node.p;
-					rotateLeft(node);
-				}
-				node.p.color = B;
-				node.p.p.color = R;
-				rotateRight(node.p.p);
-			} else {
-				y = node.p.p.left;
-				if (y != nil && y.color == R) {
-					node.p.color = B;
-					y.color = B;
-					node.p.p.color = R;
-					node = node.p.p;
-					continue;
-				}
-				if (node == node.p.left) {
-					node = node.p;
-					rotateRight(node);
-				}
-				node.p.color = B;
-				node.p.p.color = R;
-				rotateLeft(node.p.p);
-			}
-		}
-		root.color = B;
-	}
-
-	void rotateLeft(Node node) {
-		if (node.p != nil) {
-			if (node == node.p.left) {
-				node.p.left = node.right;
-			} else {
-				node.p.right = node.right;
-			}
-			node.right.p = node.p;
-			node.p = node.right;
-			if (node.right.left != nil) {
-				node.right.left.p = node;
-			}
-			node.right = node.right.left;
-			node.p.left = node;
-		} else {
-			Node right = root.right;
-			root.right = right.left;
-			right.left.p = root;
-			root.p = right;
-			right.left = root;
-			right.p = nil;
-			root = right;
-		}
-	}
-
-	void rotateRight(Node node) {
-		if (node.p != nil) {
-			if (node == node.p.left) {
-				node.p.left = node.left;
-			} else {
-				node.p.right = node.left;
-			}
-
-			node.left.p = node.p;
-			node.p = node.left;
-			if (node.left.right != nil) {
-				node.left.right.p = node;
-			}
-			node.left = node.left.right;
-			node.p.right = node;
-		} else {
-			Node left = root.left;
-			root.left = root.left.right;
-			left.right.p = root;
-			root.p = left;
-			left.right = root;
-			left.p = nil;
-			root = left;
-		}
-	}
-
-	void transplant(Node target, Node with) {
-		if (target.p == nil) {
-			root = with;
-		} else if (target == target.p.left) {
-			target.p.left = with;
-		} else
-			target.p.right = with;
-		with.p = target.p;
-	}
-
-	Node treeMinimum(Node subTreeRoot) {
-		while (subTreeRoot.left != nil) {
-			subTreeRoot = subTreeRoot.left;
-		}
-		return subTreeRoot;
-	}
-
-	boolean delete(Node z) {
-		if ((z = findNode(z, root)) == null)
-			return false;
-		Node x;
-		Node y = z;
-		int yorigcolor = y.color;
-
-		if (z.left == nil) {
-			x = z.right;
-			transplant(z, z.right);
-		} else if (z.right == nil) {
-			x = z.left;
-			transplant(z, z.left);
-		} else {
-			y = treeMinimum(z.right);
-			yorigcolor = y.color;
-			x = y.right;
-			if (y.p == z)
-				x.p = y;
-			else {
-				transplant(y, y.right);
-				y.right = z.right;
-				y.right.p = y;
-			}
-			transplant(z, y);
-			y.left = z.left;
-			y.left.p = y;
-			y.color = z.color;
-		}
-		if (yorigcolor == B)
-			deleteFixup(x);
-		return true;
-	}
-
-	void deleteFixup(Node x) {
-		while (x != root && x.color == B) {
-			if (x == x.p.left) {
-				Node w = x.p.right;
-				if (w.color == R) {
-					w.color = B;
-					x.p.color = R;
-					rotateLeft(x.p);
-					w = x.p.right;
-				}
-				if (w.left.color == B && w.right.color == B) {
-					w.color = R;
-					x = x.p;
-					continue;
-				} else if (w.right.color == B) {
-					w.left.color = B;
-					w.color = R;
-					rotateRight(w);
-					w = x.p.right;
-				}
-				if (w.right.color == R) {
-					w.color = x.p.color;
-					x.p.color = B;
-					w.right.color = B;
-					rotateLeft(x.p);
-					x = root;
-				}
-			} else {
-				Node w = x.p.left;
-				if (w.color == R) {
-					w.color = B;
-					x.p.color = R;
-					rotateRight(x.p);
-					w = x.p.left;
-				}
-				if (w.right.color == B && w.left.color == B) {
-					w.color = R;
-					x = x.p;
-					continue;
-				} else if (w.left.color == B) {
-					w.right.color = B;
-					w.color = R;
-					rotateLeft(w);
-					w = x.p.left;
-				}
-				if (w.left.color == R) {
-					w.color = x.p.color;
-					x.p.color = B;
-					w.left.color = B;
-					rotateRight(x.p);
-					x = root;
-				}
-			}
-		}
-		x.color = B;
-	}
-
-	public void insertDemo() {
-		Scanner scan = new Scanner(System.in);
-		while (true) {
-			System.out.println("Add items");
-
-			int item;
-			Node node;
-
-			item = scan.nextInt();
-			while (item != -999) {
-				node = new Node(item);
-				insert(node);
-				item = scan.nextInt();
-			}
-			printTree(root);
-			System.out.println("Pre order");
-			printTreepre(root);
-			break;
-		}
-	}
-
-	public void deleteDemo() {
-		Scanner scan = new Scanner(System.in);
-		System.out.println("Delete items");
-		int item;
-		Node node;
-		item = scan.nextInt();
-		node = new Node(item);
-		System.out.print("Deleting item " + item);
-		if (delete(node)) {
-			System.out.print(": deleted!");
-		} else {
-			System.out.print(": does not exist!");
-		}
-
-		System.out.println();
-		printTree(root);
-		System.out.println("Pre order");
-		printTreepre(root);
-	}
-}

DataStructures/Trees/TreeTraversal.java

@@ -1,124 +0,0 @@
-import java.util.LinkedList;
-
-/**
-*
-* @author Varun Upadhyay (https://github.com/varunu28)
-*
-*/
-
-
-// Driver Program
-public class TreeTraversal {
-    public static void main(String[] args) {
-        Node tree = new Node(5);
-        tree.insert(3);
-        tree.insert(2);
-        tree.insert(7);
-        tree.insert(4);
-        tree.insert(6);
-        tree.insert(8);
-
-        // Prints 5 3 2 4 7 6 8
-        System.out.println("Pre order traversal:");
-        tree.printPreOrder();
-        System.out.println();
-        // Prints 2 3 4 5 6 7 8
-        System.out.println("In order traversal:");
-        tree.printInOrder();
-        System.out.println();
-        // Prints 2 4 3 6 8 7 5
-        System.out.println("Post order traversal:");
-        tree.printPostOrder();
-        System.out.println();
-        // Prints 5 3 7 2 4 6 8
-        System.out.println("Level order traversal:");
-        tree.printLevelOrder();
-        System.out.println();
-    }
-}
-
-/**
-* The Node class which initializes a Node of a tree
-* Consists of all 4 traversal methods: printInOrder, printPostOrder， printPreOrder & printLevelOrder
-* printInOrder: LEFT -> ROOT -> RIGHT
-* printPreOrder: ROOT -> LEFT -> RIGHT
-* printPostOrder: LEFT -> RIGHT -> ROOT
-* printLevelOrder: Prints by level (starting at root), from left to right.
-*/
-class Node {
-    Node left, right;
-    int data;
-
-    public Node(int data) {
-        this.data = data;
-    }
-
-    public void insert (int value) {
-        if (value < data) {
-            if (left == null) {
-                left = new Node(value);
-            }
-            else {
-                left.insert(value);
-            }
-        }
-        else {
-            if (right == null) {
-                right = new Node(value);
-            }
-            else {
-                right.insert(value);
-            }
-        }
-    }
-
-    public void printInOrder() {
-        if (left != null) {
-            left.printInOrder();
-        }
-        System.out.print(data + " ");
-        if (right != null) {
-            right.printInOrder();
-        }
-    }
-
-    public void printPreOrder() {
-        System.out.print(data + " ");
-        if (left != null) {
-            left.printPreOrder();
-        }
-        if (right != null) {
-            right.printPreOrder();
-        }
-    }
-
-    public void printPostOrder() {
-        if (left != null) {
-            left.printPostOrder();
-        }
-        if (right != null) {
-            right.printPostOrder();
-        }
-        System.out.print(data + " ");
-    }
-
-    /**
-    * O(n) time algorithm.
-    * Uses O(n) space to store nodes in a queue to aid in traversal.
-    */
-    public void printLevelOrder() {
-        LinkedList<Node> queue = new LinkedList<>();
-        queue.add(this);
-        while (queue.size() > 0) {
-            Node head = queue.remove();
-            System.out.print(head.data + " ");
-            // Add children of recently-printed node to queue, if they exist.
-            if (head.left != null) {
-                queue.add(head.left);
-            }
-            if (head.right != null) {
-                queue.add(head.right);
-            }
-        }
-    }
-}

DataStructures/Trees/TrieImp.java

@@ -1,135 +0,0 @@
-//Trie Data structure implementation without any libraries */
-
-/**
- *
- * @author Dheeraj Kumar Barnwal (https://github.com/dheeraj92)
- *
- */
-import java.util.Scanner;
-
-public class TrieImp {
-
-    public class TrieNode {
-        TrieNode[] child;
-        boolean end;
-
-        public TrieNode(){
-            child = new TrieNode[26];
-            end = false;
-        }
-    }
-    private final TrieNode root;
-    public TrieImp(){
-        root = new TrieNode();
-    }
-
-    public void insert(String word){
-        TrieNode currentNode = root;
-        for(int i=0; i < word.length();i++){
-            TrieNode node = currentNode.child[word.charAt(i)-'a'];
-            if(node == null){
-                node = new TrieNode();
-                currentNode.child[word.charAt(i)-'a']=node;
-            }
-            currentNode = node;
-        }
-        currentNode.end = true;
-    }
-    public boolean search(String word){
-        TrieNode currentNode = root;
-        for(int i=0;i<word.length();i++){
-            char ch = word.charAt(i);
-            TrieNode node = currentNode.child[ch-'a'];
-            if(node == null){
-                return false;
-            }
-            currentNode = node;
-        }
-        return currentNode.end;
-    }
-
-    public boolean delete(String word){
-        TrieNode currentNode = root;
-        for(int i=0;i<word.length();i++){
-            char ch = word.charAt(i);
-            TrieNode node = currentNode.child[ch-'a'];
-            if(node == null){
-                return false;
-            }
-            currentNode = node;
-        }
-        if(currentNode.end == true){
-            currentNode.end = false;
-            return true;
-        }
-        return false;
-    }
-
-    public static void sop(String print){
-        System.out.println(print);
-    }
-
-    //Regex to check if word contains only a-z character
-    public static boolean isValid(String word){
-        return word.matches("^[a-z]+$");
-    }
-
-    public static void main(String[] args) {
-        TrieImp obj = new TrieImp();
-        String word;
-        @SuppressWarnings("resource")
-        Scanner scan = new Scanner(System.in);
-        sop("string should contain only a-z character for all operation");
-        while(true){
-            sop("1. Insert\n2. Search\n3. Delete\n4. Quit");
-            try{
-                int t = scan.nextInt();
-                switch (t) {
-                    case 1:
-                        word = scan.next();
-                        if(isValid(word))
-                            obj.insert(word);
-                        else
-                            sop("Invalid string: allowed only a-z");
-                        break;
-                    case 2:
-                        word = scan.next();
-                        boolean resS=false;
-                        if(isValid(word))
-                            resS = obj.search(word);
-                        else
-                            sop("Invalid string: allowed only a-z");
-                        if(resS)
-                            sop("word found");
-                        else
-                            sop("word not found");
-                        break;
-                    case 3:
-                        word = scan.next();
-                        boolean resD=false;
-                        if(isValid(word))
-                            resD = obj.delete(word);
-                        else
-                            sop("Invalid string: allowed only a-z");
-                        if(resD){
-                            sop("word got deleted successfully");
-                        }else{
-                            sop("word not found");
-                        }
-                        break;
-                    case 4:
-                        sop("Quit successfully");
-                        System.exit(1);
-                        break;
-                    default:
-                        sop("Input int from 1-4");
-                        break;
-                }
-            }catch(Exception e){
-                String badInput = scan.next();
-                sop("This is bad input: " + badInput);
-            }
-        }
-    }
-
-}

DataStructures/Trees/ValidBSTOrNot.java

@@ -1,62 +0,0 @@
-class Node
-{
-    int data;
-    Node left, right;
- 
-    public Node(int item)
-    {
-        data = item;
-        left = right = null;
-    }
-}
- 
-public class ValidBSTOrNot
-{
-    //Root of the Binary Tree
-    Node root;
- 
-    /* can give min and max value according to your code or
-    can write a function to find min and max value of tree. */
- 
-    /* returns true if given search tree is binary
-     search tree (efficient version) */
-    boolean isBST()  {
-        return isBSTUtil(root, Integer.MIN_VALUE,
-                               Integer.MAX_VALUE);
-    }
- 
-    /* Returns true if the given tree is a BST and its
-      values are >= min and <= max. */
-    boolean isBSTUtil(Node node, int min, int max)
-    {
-        /* an empty tree is BST */
-        if (node == null)
-            return true;
- 
-        /* false if this node violates the min/max constraints */
-        if (node.data < min || node.data > max)
-            return false;
- 
-        /* otherwise check the subtrees recursively
-        tightening the min/max constraints */
-        // Allow only distinct values
-        return (isBSTUtil(node.left, min, node.data-1) &&
-                isBSTUtil(node.right, node.data+1, max));
-    }
- 
-    /* Driver program to test above functions */
-    public static void main(String args[])
-    {
-        ValidBSTOrNot tree = new ValidBSTOrNot();
-        tree.root = new Node(4);
-        tree.root.left = new Node(2);
-        tree.root.right = new Node(5);
-        tree.root.left.left = new Node(1);
-        tree.root.left.right = new Node(3);
- 
-        if (tree.isBST())
-            System.out.println("IS BST");
-        else
-            System.out.println("Not a BST");
-    }
-}

Dynamic Programming/CoinChange.java

@@ -1,50 +0,0 @@
-/**
- *
- * @author Varun Upadhyay (https://github.com/varunu28)
- *
- */
-
-public class CoinChange {
-
-    // Driver Program
-    public static void main(String[] args) {
-
-        int amount = 12;
-        int[] coins = {1, 2, 5};
-
-        System.out.println("Number of combinations of getting change for " + amount + " is: " + change(coins, amount));
-    }
-
-    /**
-     * This method finds the number of combinations of getting change for a given amount and change coins
-     *
-     * @param coins The list of coins
-     * @param amount The amount for which we need to find the change
-     * Finds the number of combinations of change
-     **/
-    public static int change(int[] coins, int amount) {
-
-        int[] combinations = new int[amount+1];
-        combinations[0] = 1;
-
-        for (int coin : coins) {
-            for (int i=coin; i<amount+1; i++) {
-                    combinations[i] += combinations[i-coin];
-            }
-            // Uncomment the below line to see the state of combinations for each coin
-            // printAmount(combinations);
-        }
-
-        return combinations[amount];
-    }
-
-    // A basic print method which prints all the contents of the array
-    public static void printAmount(int[] arr) {
-
-        for (int i=0; i<arr.length; i++) {
-            System.out.print(arr[i] + " ");
-        }
-        System.out.println();
-    }
-
-}

Dynamic Programming/Edit_Distance.java

@@ -1,89 +0,0 @@
-    /**
-    Author : SUBHAM SANGHAI
-    A Dynamic Programming based solution for Edit Distance problem In Java
-    **/
-
-    /**Description of Edit Distance with an Example:
-
-    Edit distance is a way of quantifying how dissimilar two strings (e.g., words) are to one another, 
-    by counting the minimum number of operations required to transform one string into the other. The
-    distance operations are the removal, insertion, or substitution of a character in the string.
-
-
-    The Distance between "kitten" and "sitting" is 3. A minimal edit script that transforms the former into the latter is:
-
-    kitten → sitten (substitution of "s" for "k")
-    sitten → sittin (substitution of "i" for "e")
-    sittin → sitting (insertion of "g" at the end).**/
-
-    import java.util.Scanner;
-    public class Edit_Distance
-    {
-
-      
-
-      public static int minDistance(String word1, String word2) 
-      {
-    	int len1 = word1.length();
-    	int len2 = word2.length();
-     	// len1+1, len2+1, because finally return dp[len1][len2]
-    	int[][] dp = new int[len1 + 1][len2 + 1];
-     	/* If second string is empty, the only option is to
-   	  insert all characters of first string into second*/
-    	for (int i = 0; i <= len1; i++) 
-    	{
-    		dp[i][0] = i;
-    	}
-     	/* If first string is empty, the only option is to
-   	  insert all characters of second string into first*/
-    	for (int j = 0; j <= len2; j++) 
-    	{
-    		dp[0][j] = j;
-    	}
-     	//iterate though, and check last char
-    	for (int i = 0; i < len1; i++) 
-    	{
-    		char c1 = word1.charAt(i);
-    		for (int j = 0; j < len2; j++) 
-    		{
-    			char c2 = word2.charAt(j);
-     			//if last two chars equal
-    			if (c1 == c2)
-    			{
-    				//update dp value for +1 length
-    				dp[i + 1][j + 1] = dp[i][j];
-    			} 
-    			else 
-    			{
-			/* if two characters are different ,
-			then take the minimum of the various operations(i.e insertion,removal,substitution)*/
-    				int replace = dp[i][j] + 1;
-    				int insert = dp[i][j + 1] + 1;
-    				int delete = dp[i + 1][j] + 1;
-     
-    				int min = replace > insert ? insert : replace;
-    				min = delete > min ? min : delete;
-    				dp[i + 1][j + 1] = min;
-    			}
-    		}
-    	}
-	/* return the final answer , after traversing through both the strings*/
-    	return dp[len1][len2];
-      }
-
-
-    	// Driver program to test above function
-    	public static void main(String args[])
-    	{
-    		Scanner input = new Scanner(System.in);
-    		String s1,s2;
-    		System.out.println("Enter the First String");
-    		s1 = input.nextLine();
-    		System.out.println("Enter the Second String");
-    		s2 = input.nextLine();
-    		//ans stores the final Edit Distance between the two strings
-    		int ans=0;
-    		ans=minDistance(s1,s2);
-    		System.out.println("The minimum Edit Distance between \"" + s1 + "\" and \"" + s2 +"\" is "+ans);
-    	}
-    }

Dynamic Programming/EggDropping.java

@@ -1,53 +0,0 @@
-//Dynamic Programming solution for the Egg Dropping Puzzle
-public class EggDropping
-{
-	
-	// min trials with n eggs and m floors 
-	
-	private static int minTrials(int n, int m)
-	{
-	    
-		int eggFloor[][] = new int[n+1][m+1];
-		int result, x;
-		
-		for (int i = 1; i <= n; i++)
-		{
-		    eggFloor[i][0] = 0;   // Zero trial for zero floor.
-		    eggFloor[i][1] = 1;   // One trial for one floor 
-		}
-		
-	        // j trials for only 1 egg
-		
-                for (int j = 1; j <= m; j++)
-			 eggFloor[1][j] = j;
-		
-		// Using bottom-up approach in DP
-		
-   		 for (int i = 2; i <= n; i++)
-		  {
-			for (int j = 2; j <= m; j++)
-			{
-				eggFloor[i][j] = Integer.MAX_VALUE;
-				for (x = 1; x <= j; x++)
-				{
-					result = 1 + Math.max(eggFloor[i-1][x-1], eggFloor[i][j-x]);
-          
-					//choose min of all values for particular x
-        				 if (result < eggFloor[i][j])
-					     eggFloor[i][j] = result;
-				}
-			}
-		}
-		  
-		return eggFloor[n][m];
-	}
-		
-	//testing program
-	public static void main(String args[])
-	{
-	      int n = 2, m = 4;
-              //result outputs min no. of trials in worst case for n eggs and m floors
-              int result = minTrials(n, m);
-	      System.out.println(result); 
-	}
-}

Dynamic Programming/Fibonacci.java

@@ -1,75 +0,0 @@
-import java.io.BufferedReader;
-import java.io.InputStreamReader;
-import java.util.HashMap;
-import java.util.Map;
-
-/**
- *
- * @author Varun Upadhyay (https://github.com/varunu28)
- *
- */
-
-public class Fibonacci {
-
-    private static Map<Integer,Integer> map = new HashMap<Integer,Integer>();
-
-    public static void main(String[] args) throws Exception {
-
-        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
-        int n = Integer.parseInt(br.readLine());
-
-        System.out.println(fibMemo(n)); // Returns 8 for n = 6
-        System.out.println(fibBotUp(n)); // Returns 8 for n = 6
-    }
-
-    /**
-     * This method finds the nth fibonacci number using memoization technique
-     *
-     * @param n The input n for which we have to determine the fibonacci number
-     * Outputs the nth fibonacci number
-     **/
-
-    private static int fibMemo(int n) {
-        if (map.containsKey(n)) {
-            return map.get(n);
-        }
-
-        int f;
-
-        if (n <= 2) {
-            f = 1;
-        }
-        else {
-            f = fibMemo(n-1) + fibMemo(n-2);
-            map.put(n,f);
-        }
-
-        return f;
-    }
-
-    /**
-     * This method finds the nth fibonacci number using bottom up
-     *
-     * @param n The input n for which we have to determine the fibonacci number
-     * Outputs the nth fibonacci number
-     **/
-
-    private static int fibBotUp(int n) {
-
-        Map<Integer,Integer> fib = new HashMap<Integer,Integer>();
-
-        for (int i=1;i<n+1;i++) {
-            int f = 1;
-            if (i<=2) {
-                f = 1;
-            }
-            else {
-                f = fib.get(i-1) + fib.get(i-2);
-            }
-            fib.put(i, f);
-        }
-
-        return fib.get(n);
-    }
-}
-

Dynamic Programming/KadaneAlgorithm.java

@@ -1,55 +0,0 @@
-import java.util.Scanner;
-
-/**
- * Program to implement Kadane’s Algorithm to 
- * calculate maximum contiguous subarray sum of an array
- * Time Complexity: O(n)
- * 
- * @author Nishita Aggarwal
- *
- */
-
-public class KadaneAlgorithm {
-	
-	/**
-	* This method implements Kadane's Algorithm
-	* 
-        * @param arr The input array
-	* @return The maximum contiguous subarray sum of the array
-        * 
-        */
-	static int largestContiguousSum(int arr[]){
-		int i,len=arr.length,cursum=0,maxsum=Integer.MIN_VALUE;
-		if(len==0)	//empty array
-			return 0;
-		for(i=0;i<len;i++){
-			cursum+=arr[i];
-			if(cursum>maxsum){
-				maxsum=cursum;
-			}
-			if(cursum<=0){
-				cursum=0;
-			}
-		}
-		return maxsum;
-	}
-
-	/**
-	 * Main method
-	 * 
-	 * @param args Command line arguments
-	 */
-	public static void main(String[] args) {
-		Scanner sc=new Scanner(System.in);
-		int n,arr[],i;
-		n=sc.nextInt();
-		arr=new int[n];
-		for(i=0;i<n;i++){
-			arr[i]=sc.nextInt();
-		}
-		int maxContSum=largestContiguousSum(arr);
-		System.out.println(maxContSum);
-		sc.close();
-	}
-
-}

Dynamic Programming/Knapsack.java

@@ -1,38 +0,0 @@
-// A Dynamic Programming based solution for 0-1 Knapsack problem
-
-public class Knapsack
-{
-    
-	private static int knapSack(int W, int wt[], int val[], int n)
-	{
-		int i, w;
-	int rv[][] = new int[n+1][W+1];    //rv means return value
-	
-	// Build table rv[][] in bottom up manner
-	for (i = 0; i <= n; i++)
-	{
-		for (w = 0; w <= W; w++)
-		{
-			if (i==0 || w==0)
-				rv[i][w] = 0;
-			else if (wt[i-1] <= w)
-				rv[i][w] = Math.max(val[i-1] + rv[i-1][w-wt[i-1]], rv[i-1][w]);
-			else
-				rv[i][w] = rv[i-1][w];
-		}
-	}
-	
-	return rv[n][W];
-	}
-
-
-	// Driver program to test above function
-	public static void main(String args[])
-	{
-		int val[] = new int[]{50, 100, 130};
-	int wt[] = new int[]{10, 20, 40};
-	int W = 50;
-	int n = val.length;
-	System.out.println(knapSack(W, wt, val, n));
-	}
-}

Dynamic Programming/LevenshteinDistance.java

@@ -1,55 +0,0 @@
-/**
- *
- * @author Kshitij VERMA (github.com/kv19971)
- * LEVENSHTEIN DISTANCE dyamic programming implementation to show the difference between two strings (https://en.wikipedia.org/wiki/Levenshtein_distance)
- *
- *
- */
-
-public class LevenshteinDistance{
-	private static int minimum(int a, int b, int c){
-		if(a < b && a < c){
-			return a;
-		}else if(b < a && b < c){
-			return b;
-		}else{
-			return c;
-		}
-	}
-	private static int calculate_distance(String a, String b){
-		int len_a = a.length() + 1;
-		int len_b = b.length() + 1;
-		int [][] distance_mat = new int[len_a][len_b];
-		for(int i = 0; i < len_a; i++){
-			distance_mat[i][0] = i;
-		}
-		for(int j = 0; j < len_b; j++){
-			distance_mat[0][j] = j;
-		}
-		for(int i = 0; i < len_a; i++){
-			for(int j = 0; i < len_b; j++){
-				int cost;
-				if (a.charAt(i) == b.charAt(j)){
-					cost = 0;
-				}else{
-					cost = 1;
-				}
-				distance_mat[i][j] = minimum(distance_mat[i-1][j], distance_mat[i-1][j-1], distance_mat[i][j-1]) + cost;
-
-								
-			}
-	
-		}
-		return distance_mat[len_a-1][len_b-1];
-		
-	}
-	public static void main(String [] args){
-		String a = ""; // enter your string here 
-		String b = ""; // enter your string here 
-		
-		System.out.print("Levenshtein distance between "+a + " and "+b+ " is: ");
-		System.out.println(calculate_distance(a,b));
-
-
-	}
-}

Dynamic Programming/LongestCommonSubsequence.java

@@ -1,66 +0,0 @@
-class LongestCommonSubsequence {
-
-	public static String getLCS(String str1, String str2) {
-
-		//At least one string is null
-		if(str1 == null || str2 == null)
-			return null;
-
-		//At least one string is empty
-		if(str1.length() == 0 || str2.length() == 0)
-			return "";
-
-		String[] arr1 = str1.split("");
-		String[] arr2 = str2.split("");
-
-		//lcsMatrix[i][j]  = LCS of first i elements of arr1 and first j characters of arr2
-		int[][] lcsMatrix = new int[arr1.length + 1][arr2.length + 1];
-
-		for(int i = 0; i < arr1.length + 1; i++)
-			lcsMatrix[i][0] = 0;
-		for(int j = 1; j < arr2.length + 1; j++)
-			lcsMatrix[0][j] = 0;
-		for(int i = 1; i < arr1.length + 1; i++) {
-			for(int j = 1; j < arr2.length + 1; j++) {
-				if(arr1[i-1].equals(arr2[j-1])) {
-					lcsMatrix[i][j] = lcsMatrix[i-1][j-1] + 1;
-				} else {
-					lcsMatrix[i][j] = lcsMatrix[i-1][j] > lcsMatrix[i][j-1] ? lcsMatrix[i-1][j] : lcsMatrix[i][j-1];
-				}
-			}
-		}
-		return lcsString(str1, str2, lcsMatrix);
-	}
-
-	public static String lcsString (String str1, String str2, int[][] lcsMatrix) {
-		StringBuilder lcs = new StringBuilder();
-		int i = str1.length(),
-			j = str2.length();
-		while(i > 0  && j > 0) {
-			if(str1.charAt(i-1) == str2.charAt(j-1)) {
-				lcs.append(str1.charAt(i-1));
-				i--;
-				j--;
-			} else if(lcsMatrix[i-1][j] > lcsMatrix[i][j-1]) {
-				i--;
-			} else {
-				j--;
-			}
-		}
-		return lcs.reverse().toString();
-	}
-
-	public static void main(String[] args) {
-		String str1 = "DSGSHSRGSRHTRD";
-		String str2 = "DATRGAGTSHS";
-		String lcs = getLCS(str1, str2);
-		
-		//Print LCS
-		if(lcs != null) {
-			System.out.println("String 1: " + str1);
-			System.out.println("String 2: " + str2);
-			System.out.println("LCS: " + lcs);
-			System.out.println("LCS length: " + lcs.length());
-		}
-	}
-}

Dynamic Programming/LongestIncreasingSubsequence.java

@@ -1,62 +0,0 @@
-import java.util.Scanner;
-
-/**
- *
- * @author Afrizal Fikri (https://github.com/icalF)
- *
- */
-public class LongestIncreasingSubsequence {
-    public static void main(String[] args) throws Exception {
-
-        Scanner sc = new Scanner(System.in);
-        int n = sc.nextInt();
-
-        int ar[] = new int[n];
-        for (int i = 0; i < n; i++) {
-            ar[i] = sc.nextInt();
-        }
-
-        System.out.println(LIS(ar));
-    }
-
-    private static int upperBound(int[] ar, int l, int r, int key) {
-        while (l < r-1) {
-            int m = (l + r) / 2;
-            if (ar[m] >= key)
-                r = m;
-            else
-                l = m;
-        }
-
-        return r;
-    }
-
-    private static int LIS(int[] array) {
-        int N = array.length;
-        if (N == 0)
-            return 0;
- 
-        int[] tail = new int[N];
-        int length = 1; // always points empty slot in tail
-     
-        tail[0] = array[0];
-        for (int i = 1; i < N; i++) {
-
-            // new smallest value
-            if (array[i] < tail[0])
-                tail[0] = array[i];
-
-            // array[i] extends largest subsequence
-            else if (array[i] > tail[length-1])
-                tail[length++] = array[i];
-
-            // array[i] will become end candidate of an existing subsequence or
-            // Throw away larger elements in all LIS, to make room for upcoming grater elements than array[i]
-            // (and also, array[i] would have already appeared in one of LIS, identify the location and replace it)
-            else
-                tail[upperBound(tail, -1, length-1, array[i])] = array[i];
-        }
-     
-        return length;
-    }
-}

Dynamic Programming/RodCutting.java

@@ -1,32 +0,0 @@
-/*  A Dynamic Programming solution for Rod cutting problem
-    Returns the best obtainable price for a rod of
-	length n and price[] as prices of different pieces */
-
-public class RodCutting {
-	
-	private static int cutRod(int price[],int n)
-	{
-		int val[] = new int[n+1];
-		val[0] = 0;
-
-		for (int i = 1; i<=n; i++)
-		{
-			int max_val = Integer.MIN_VALUE;
-			for (int j = 0; j < i; j++)
-				max_val = Math.max(max_val,price[j] + val[i-j-1]);
-		  
-       val[i] = max_val;
-		}
-
-		return val[n];
-	}
-
-	//main function to test
-	public static void main(String args[])
-	{
-		int arr[] = new int[] {2, 5, 13, 19, 20};
-		int size = arr.length;
-		System.out.println("Maximum Obtainable Value is " +
-							cutRod(arr, size));
-	}
-}

MinimizingLateness/MinimizingLateness.java

@@ -1,52 +0,0 @@
-import java.io.*;
-import java.util.*;
-
-public class MinimizingLateness {
-
-	private static class Schedule { // Schedule class
-		int t = 0; // Time required for the operation to be performed
-		int d = 0; // Time the job should be completed
-		int s = 0; // Start time of the task
-		int f = 0; // End time of the operation
-
-		public Schedule(int t, int d) {
-			this.t = t; 
-			this.d = d; 
-		}
-	}
-
-	public static void main(String[] args) throws IOException {
-		// TODO Auto-generated method stub
-		StringTokenizer token;
-
-		String ch;
-		BufferedReader in = new BufferedReader(new FileReader("input.txt"));
-		int indexCount; // size of array index
-		ch = in.readLine();
-		indexCount = Integer.parseInt(ch); // The first line specifies the size of the operation (= the size of the array)
-		System.out.println("Input Data : ");
-		System.out.println(indexCount); // number of operations
-		Schedule array[] = new Schedule[indexCount]; // Create an array to hold the operation
-		int i = 0;
-		while ((ch = in.readLine()) != null) {
-			token = new StringTokenizer(ch, " "); 
-			// Include the time required for the operation to be performed in the array and the time it should be completed.
-			array[i] = new Schedule(Integer.parseInt(token.nextToken()), Integer.parseInt(token.nextToken()));
-			i++; // 다음 인덱스
-			System.out.println(array[i - 1].t + " " + array[i - 1].d); 
-		}
-
-		int tryTime = 0; // Total time worked
-		int lateness = 0; // Lateness
-		for (int j = 0; j < indexCount - 1; j++) {
-			array[j].s = tryTime; // Start time of the task
-			array[j].f = tryTime + array[j].t; // Time finished
-			tryTime = tryTime + array[j].t; // Add total work time
-			// Lateness
-			lateness = lateness + Math.max(0, tryTime - array[j].d);
-		}
-		System.out.println();
-		System.out.println("Output Data : "); 
-		System.out.println(lateness);
-	}
-}

MinimizingLateness/data06_lateness.txt

@@ -1,7 +0,0 @@
-6
-3 6
-2 8
-1 9
-4 9
-3 14
-2 15

Misc/PalindromicPrime.java

@@ -1,41 +0,0 @@
-import java.util.Scanner;
-public class PalindromePrime {
-
-    public static void main(String[] args) { // Main funtion
-        Scanner in = new Scanner(System.in);
-        System.out.println("Enter the quantity of First Palindromic Primes you want");
-        int n = in.nextInt(); // Input of how mant first pallindromic prime we want
-        funtioning(n); // calling funtion - functioning  
-    }
-
-    public static boolean prime(int num) { // checking if number is prime or not
-        for (int divisor = 2; divisor <= num / 2; divisor++) {
-            if (num % divisor == 0) {
-                return false; //  false if not prime
-            }
-        }
-        return true; // True if prime
-    }
-
-    public static int reverse(int n){ //  Returns  the reverse of the number
-        int reverse = 0;
-        while(n!=0){
-            reverse = reverse * 10;
-            reverse = reverse + n%10;
-            n = n/10;
-        }
-        return reverse;
-    }
-
-    public static void funtioning(int y){
-            int count =0;
-            int num = 2;
-            while(count < y){
-                if(prime(num) && num == reverse(num)){ // number is prime and it's reverse is same
-                    count++; // counts check when to terminate while loop
-                    System.out.print(num + "\n"); // Print the Palindromic Prime
-                }
-                num++; // inrease iterator value by one
-            }
-    }
-};

Misc/heap_sort.java

@@ -1,73 +0,0 @@
-public class heap_sort
-{
-    public void sort(int arr[])
-    {
-        int n = arr.length;
- 
-        // Build heap (rearrange array)
-        for (int i = n / 2 - 1; i >= 0; i--)
-            heapify(arr, n, i);
- 
-        // One by one extract an element from heap
-        for (int i=n-1; i>=0; i--)
-        {
-            // Move current root to end
-            int temp = arr[0];
-            arr[0] = arr[i];
-            arr[i] = temp;
- 
-            // call max heapify on the reduced heap
-            heapify(arr, i, 0);
-        }
-    }
- 
-    // To heapify a subtree rooted with node i which is
-    // an index in arr[]. n is size of heap
-    void heapify(int arr[], int n, int i)
-    {
-        int largest = i;  // Initialize largest as root
-        int l = 2*i + 1;  // left = 2*i + 1
-        int r = 2*i + 2;  // right = 2*i + 2
- 
-        // If left child is larger than root
-        if (l < n && arr[l] > arr[largest])
-            largest = l;
- 
-        // If right child is larger than largest so far
-        if (r < n && arr[r] > arr[largest])
-            largest = r;
- 
-        // If largest is not root
-        if (largest != i)
-        {
-            int swap = arr[i];
-            arr[i] = arr[largest];
-            arr[largest] = swap;
- 
-            // Recursively heapify the affected sub-tree
-            heapify(arr, n, largest);
-        }
-    }
- 
-    /* A utility function to print array of size n */
-    static void printArray(int arr[])
-    {
-        int n = arr.length;
-        for (int i=0; i<n; ++i)
-            System.out.print(arr[i]+" ");
-        System.out.println();
-    }
- 
-    // Driver program
-    public static void main(String args[])
-    {
-        int arr[] = {12, 11, 13, 5, 6, 7};
-        int n = arr.length;
- 
-        heap_sort ob = new heap_sort();
-        ob.sort(arr);
- 
-        System.out.println("Sorted array is");
-        printArray(arr);
-    }
-}

Others/Abecedarian.java

@@ -1,17 +0,0 @@
-//Oskar Enmalm 29/9/17
-//An Abecadrian is a word where each letter is in alphabetical order
-    
-class Abecedarian{
-
-    public static boolean isAbecedarian(String s){
-        int index = s.length() - 1;
-
-        for(int i =0; i <index; i++){
-
-            if(s.charAt(i)<=s.charAt(i + 1)){} //Need to check if each letter for the whole word is less than the one before it
-
-            else{return false;}
-            }
-        return true;
-        }
-}

Others/Armstrong.java

@@ -1,47 +0,0 @@
-import java.util.Scanner;
-
-/**
- * A utility to check if a given number is armstrong or not. Armstrong number is
- * a number that is equal to the sum of cubes of its digits for example 0, 1,
- * 153, 370, 371, 407 etc. For example 153 = 1^3 + 5^3 +3^3
- * 
- * @author mani manasa mylavarapu
- * 
- */
-public class Armstrong {
-	public static void main(String[] args) {
-		Scanner scan = new Scanner(System.in);
-		System.out.println("please enter the number");
-		int n = scan.nextInt();
-		boolean isArmstrong = checkIfANumberIsAmstrongOrNot(n);
-		if (isArmstrong) {
-			System.out.println("the number is armstrong");
-		} else {
-			System.out.println("the number is not armstrong");
-		}
-	}
-
-	/**
-	 * Checks whether a given number is an armstrong number or not. Armstrong
-	 * number is a number that is equal to the sum of cubes of its digits for
-	 * example 0, 1, 153, 370, 371, 407 etc.
-	 * 
-	 * @param number
-	 * @return boolean
-	 */
-	public static boolean checkIfANumberIsAmstrongOrNot(int number) {
-		int remainder, sum = 0, temp = 0;
-		temp = number;
-		while (number > 0) {
-			remainder = number % 10;
-			sum = sum + (remainder * remainder * remainder);
-			number = number / 10;
-		}
-		if (sum == temp) {
-			return true;
-		} else {
-			return false;
-		}
-
-	}
-}

Others/BrianKernighanAlgorithm.java

@@ -1,55 +0,0 @@
-import java.util.Scanner;
-
-/**
- * 
- * @author Nishita Aggarwal
- *
- * Brian Kernighan’s Algorithm
- * 
- * algorithm to count the number of set bits in a given number
- * 
- * Subtraction of 1 from a number toggles all the bits (from right to left) till the rightmost set bit(including the
- * rightmost set bit). 
- * So if we subtract a number by 1 and do bitwise & with itself i.e. (n & (n-1)), we unset the rightmost set bit. 
- * 
- * If we do n & (n-1) in a loop and count the no of times loop executes we get the set bit count.
- * 
- * 
- * Time Complexity: O(logn)
- *
- */
-
-
-public class BrianKernighanAlgorithm {
-	
-	/**
-         * @param num: number in which we count the set bits
-         * 
-         * @return int: Number of set bits
-         * */
-	static int countSetBits(int num)
-	{
-		int cnt = 0;
-		while(num != 0)
-		{
-			num = num & (num-1);
-			cnt++;
-		}
-		return cnt;
-	}
-	
-	
-	/**
-	 *
-	 * @param args : command line arguments
-	 *
-	 */
-	public static void main(String args[])
-	{
-		Scanner sc = new Scanner(System.in);
-		int num = sc.nextInt();
-		int setBitCount = countSetBits(num);
-		System.out.println(setBitCount);
-		sc.close();
-	}
-}

Others/CountChar.java

@@ -1,43 +0,0 @@
-import java.util.Scanner;
-
-
-/**
- * @author Kyler Smith, 2017
- *
- * Implementation of a character count.
- * (Slow, could be improved upon, effectively O(n).
- * */
-
-public class CountChar {
-
-    public static void main(String[] args) {
-  	  	Scanner input = new Scanner(System.in);
-  	  	System.out.print("Enter your text: ");
-      	String str = input.nextLine();
-        input.close();
-        System.out.println("There are " + CountCharacters(str) + " characters.");
-    }
-	
-    /**
-     * @param str: String to count the characters
-     *
-     * @return int: Number of characters in the passed string
-     * */
-
-    private static int CountCharacters(String str) {
-
-    	int count = 0;
-
-    	if(str == "" || str == null) //Exceptions
-		{ 
-			return 0; 
-		}
-
-        for(int i = 0; i < str.length(); i++) {
-        	if(!Character.isWhitespace(str.charAt(i))) {
-        		count++;
-			}}
-
-        return count;
-     }
-}

Others/Dijkshtra.java

@@ -1,61 +0,0 @@
-/*
-@author  : Mayank K Jha
-
-*/
-
-
-import java.io.IOException;
-import java.util.Arrays;
-import java.util.Scanner;
-import java.util.Stack;
-
-public class Dijkshtra {
-
-public static void main(String[] args) throws IOException {
-	  Scanner in =new Scanner(System.in);
-	
-	int n=in.nextInt();             //n = Number of nodes or vertices
-        int m=in.nextInt();             //m = Number of Edges
-        long w[][]=new long [n+1][n+1]; //Adjacency Matrix  
-        
-	//Initializing Matrix with Certain Maximum Value for path b/w any two vertices 
-	for (long[] row: w)
-            Arrays.fill(row, 1000000l);
-	//From above,we Have assumed that,initially path b/w any two Pair of vertices is Infinite such that Infinite = 1000000l
-	//For simplicity , We can also take path Value = Long.MAX_VALUE , but i have taken Max Value = 1000000l .
-	
-	//Taking Input as Edge Location b/w a pair of vertices
-         for(int i=0;i<m;i++){
-             int x=in.nextInt(),y=in.nextInt();
-             long cmp=in.nextLong();
-             if(w[x][y]>cmp){                      //Comparing previous edge value with current value  -  Cycle Case
-            	w[x][y]=cmp; w[y][x]=cmp;        
-             }
-	}
-	
-	//Implementing Dijkshtra's Algorithm 
-	
-         Stack<Integer> t=new Stack<Integer>();
-          int src=in.nextInt();
-        for(int i=1;i<=n;i++){
-        	if(i!=src){t.push(i);}}
-        Stack <Integer> p=new Stack<Integer>();
-        p.push(src);
-        w[src][src]=0;
-         while(!t.isEmpty()){int min=989997979,loc=-1;
-        for(int i=0;i<t.size();i++){
-        	w[src][t.elementAt(i)]=Math.min(w[src][t.elementAt(i)],w[src][p.peek()]
-                +w[p.peek()][t.elementAt(i)]);
-            if(w[src][t.elementAt(i)]<=min){
-            	min=(int) w[src][t.elementAt(i)];loc=i;}
-        }
-        p.push(t.elementAt(loc));t.removeElementAt(loc);}
-	
-	//Printing shortest path from the given source src
-         for(int i=1;i<=n;i++){
-        	 if(i!=src && w[src][i]!=1000000l){System.out.print(w[src][i]+" ");}
-        	 else if(i!=src){System.out.print("-1"+" ");}    //Printing -1 if there is no path b/w given pair of edges
-         }
-         
-  }
-}

Others/Factorial.java

@@ -1,49 +0,0 @@
-import java.util.Scanner;
-
-/**
- * This program will print out the factorial of any non-negative
- * number that you input into it.
- * 
- * @author Marcus
- *
- */
-public class Factorial{
-
-	/**
-	 * The main method
-	 * 
-	 * @param args Command line arguments
-	 */
-	public static void main(String[] args){
-	  Scanner input = new Scanner(System.in);
-          System.out.print("Enter a non-negative integer: ");
-          
-       //If user does not enter an Integer, we want program to fail gracefully, letting the user know why it terminated   
-          try{
-            int number = input.nextInt();
-            
-       //We keep prompting the user until they enter a positive number 
-            while(number < 0){
-              System.out.println("Your input must be non-negative. Please enter a positive number: ");
-              number = input.nextInt();
-            }
-       //Display the result
- 	   System.out.println("The factorial of " + number + " will yield: " + factorial(number));  
-           
-          }catch(Exception e){
-            System.out.println("Error: You did not enter an integer. Program has terminated.");
-          }
-          input.close();
-        }
-        
-	/**
-	 * Recursive Factorial Method
-	 * 
-	 * @param n The number to factorial
-	 * @return The factorial of the number
-	 */
-	public static long factorial(int n){
-          if(n == 0 || n == 1) return 1;
-          return n * factorial(n - 1);
-	}
-}

Others/FibToN.java

@@ -1,24 +0,0 @@
-import java.util.Scanner;
-
-public class FibToN {
-
-	public static void main(String[] args) {
-		//take input
-		Scanner scn = new Scanner(System.in);
-		int N = scn.nextInt();
-		// print fibonacci sequence less than N
-		int first = 0, second = 1;
-		//first fibo and second fibonacci are 0 and 1 respectively
-		scn.close();
-		while(first <= N){
-			//print first fibo 0 then add second fibo into it while updating second as well
-			
-			System.out.println(first);
-			
-			int next = first+ second;
-			first = second;
-			second = next;
-		}
-	}
-
-}