Merge remote-tracking branch 'upstream/master'

Conversions/HexaDecimalToBinary.java

@@ -3,7 +3,7 @@ import java.util.*;
 import java.util.Scanner;
 import javax.swing.*;
 
-public class HexaToBin {
+public class HexaDecimalToBinary {
  
     private final int LONG_BITS = 8;
 
@@ -28,7 +28,7 @@ public class HexaToBin {
         //Testing Numbers:
         String[] hexNums = {"1", "A1", "ef", "BA", "AA", "BB",
             "19", "01", "02", "03", "04"};
-        Convert objConvert = new Convert();
+        HexaDecimalToBinary objConvert = new HexaDecimalToBinary();
 
         for (String num : hexNums) {
             objConvert.convert(num);

Conversions/OctalToDecimal.java

@@ -11,38 +11,37 @@ public class OctalToDecimal {
 	/**
 	 * Main method
 	 * 
-	 * @param args Command line arguments
+	 * @param args
+	 *            Command line arguments
 	 */
 	public static void main(String args[]) {
 		Scanner sc = new Scanner(System.in);
-		int o = sc.nextInt();
-		System.out.println("Decimal equivalent: " + convertOctalToDecimal(o));
+		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.
+	 * This method converts an octal number to a decimal number.
 	 * 
-	 * @param o The octal number
+	 * @param inputOctal
+	 *            The octal number
 	 * @return The decimal number
 	 */
-	public static int convertOctalToDecimal(int o) {
-		System.out.print("Octal Input: ");
-		// Read the input from the console which we are expecting as an octal number:
-		Scanner s = new Scanner(System.in);
-		String inputHex = s.nextLine();
-		try{
+	public static int convertOctalToDecimal(String inputOctal) {
+
+		try {
 			// Actual conversion of Octal to Decimal:
-			Integer outputDecimal = Integer.parseInt(inputHex, 8);
-			System.out.println("Decimal Equivalent : " + outputDecimal);
-		}
-		catch(NumberFormatException ne){
-			// Printing a warning message if the input is not a valid octal number:
+			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");
-		}
-		finally{
-			s.close();
+			return -1;
 		}
 	}
 }

Data Structures/Graphs/BFS.java

@@ -6,7 +6,7 @@ import java.util.*;
  * @author Unknown
  *
  */
-public class bfs{
+public class BFS{
 
 	/**
 	 * The BFS implemented in code to use.

Data Structures/Graphs/DFS.java

@@ -7,7 +7,7 @@ import java.util.*;
  *
  */
 
-public class dfs{
+public class DFS{
 	
 	/**
 	 * Implementation in code of a DFS

Data Structures/Graphs/MatrixGraphs.java

@@ -120,7 +120,7 @@ class AdjacencyMatrixGraph {
 	}
 
     /**
-     * this gives a list of verticies in the graph and their adjacencies
+     * this gives a list of vertices in the graph and their adjacencies
      * 
      * @return returns a string describing this graph
      */

Data Structures/Graphs/PrimMST.java

@@ -100,7 +100,7 @@ class PrimMST
         | /      \ |
         (3)-------(4)
              9          */
-        MST t = new MST();
+        PrimMST t = new PrimMST();
         int graph[][] = new int[][] {{0, 2, 0, 6, 0},
                                     {2, 0, 3, 8, 5},
                                     {0, 3, 0, 0, 7},

Data Structures/Trees/AVLTree.java

@@ -1,4 +1,4 @@
-public class AVLtree {
+public class AVLTree {
  
     private Node root;
  
@@ -200,7 +200,7 @@ public class AVLtree {
     }
  
     public static void main(String[] args) {
-        AVLtree tree = new AVLtree();
+        AVLTree tree = new AVLTree();
  
         System.out.println("Inserting values 1 to 10");
         for (int i = 1; i < 10; i++)

Data Structures/Trees/LevelOrderTraversal.java

@@ -9,12 +9,12 @@ class Node
     }
 }
  
-class BinaryTree
+public class LevelOrderTraversal
 {
     // Root of the Binary Tree
     Node root;
  
-    public BinaryTree()
+    public LevelOrderTraversal()
     {
         root = null;
     }
@@ -65,7 +65,7 @@ class BinaryTree
     /* Driver program to test above functions */
     public static void main(String args[])
     {
-       BinaryTree tree = new BinaryTree();
+       LevelOrderTraversal tree = new LevelOrderTraversal();
        tree.root= new Node(1);
        tree.root.left= new Node(2);
        tree.root.right= new Node(3);

Data Structures/Trees/LevelOrderTraversalQueue.java

@@ -14,7 +14,7 @@ class Node {
 }
  
 /* Class to print Level Order Traversal */
-class BinaryTree {
+public class LevelOrderTraversalQueue {
  
     Node root;
  
@@ -49,7 +49,7 @@ class BinaryTree {
     {
         /* creating a binary tree and entering 
          the nodes */
-        BinaryTree tree_level = new BinaryTree();
+    	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);

Data Structures/Trees/PrintTopViewofTree.java

@@ -78,7 +78,7 @@ class Tree
 }
  
 // Driver class to test above methods
-public class Main
+public class PrintTopViewofTree
 {
     public static void main(String[] args)
     {

Data Structures/Trees/ValidBSTOrNot.java

@@ -10,7 +10,7 @@ class Node
     }
 }
  
-public class BinaryTree
+public class ValidBSTOrNot
 {
     //Root of the Binary Tree
     Node root;
@@ -47,7 +47,7 @@ public class BinaryTree
     /* Driver program to test above functions */
     public static void main(String args[])
     {
-        BinaryTree tree = new BinaryTree();
+        ValidBSTOrNot tree = new ValidBSTOrNot();
         tree.root = new Node(4);
         tree.root.left = new Node(2);
         tree.root.right = new Node(5);

Dynamic Programming/LevenshteinDistance.java

@@ -6,7 +6,7 @@
  *
  */
 
-public class Levenshtein_distance{
+public class LevenshteinDistance{
 	private static int minimum(int a, int b, int c){
 		if(a < b && a < c){
 			return a;

Misc/heap_sort.java

@@ -1,4 +1,4 @@
-public class HeapSort
+public class heap_sort
 {
     public void sort(int arr[])
     {
@@ -64,7 +64,7 @@ public class HeapSort
         int arr[] = {12, 11, 13, 5, 6, 7};
         int n = arr.length;
  
-        HeapSort ob = new HeapSort();
+        heap_sort ob = new heap_sort();
         ob.sort(arr);
  
         System.out.println("Sorted array is");

Others/BrianKernighanAlgorithm.java

@@ -0,0 +1,55 @@
+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/Dijkshtra.java

@@ -9,7 +9,7 @@ import java.util.Arrays;
 import java.util.Scanner;
 import java.util.Stack;
 
-public class Solution {
+public class Dijkshtra {
 
 public static void main(String[] args) throws IOException {
 	  Scanner in =new Scanner(System.in);

Others/FibToN.java

@@ -9,7 +9,7 @@ public class FibToN {
 		// 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
 			

Others/FindingPrimes.java

@@ -1,45 +0,0 @@
-/**
- * The Sieve of Eratosthenes is an algorithm use to find prime numbers,
- * up to a given value.
- * Illustration: https://upload.wikimedia.org/wikipedia/commons/b/b9/Sieve_of_Eratosthenes_animation.gif
- * (This illustration is also in the github repository)
- * 
- * @author Unknown
- *
- */
-public class FindingPrimes{
-	/**
-	 * The Main method
-	 * 
-	 * @param args Command line arguments
-	 */
-	public static void main(String args[]){
-		SOE(20); //Example: Finds all the primes up to 20
-	}
-
-	/**
-	 * The method implementing the Sieve of Eratosthenes
-	 * 
-	 * @param n Number to perform SOE on
-	 */
-	public static void SOE(int n){
-		boolean sieve[] = new boolean[n];
-
-		int check = (int)Math.round(Math.sqrt(n)); //No need to check for multiples past the square root of n
-
-		sieve[0] = false;
-		sieve[1] = false;
-		for(int i = 2; i < n; i++)
-			sieve[i] = true; //Set every index to true except index 0 and 1
-
-		for(int i = 2; i< check; i++){
-			if(sieve[i]==true)					//If i is a prime
-				for(int j = i+i; j < n; j+=i)   //Step through the array in increments of i(the multiples of the prime)
-					sieve[j] = false;			//Set every multiple of i to false
-		}
-		for(int i = 0; i< n; i++){
-			if(sieve[i]==true)
-				System.out.print(i+" "); //In this example it will print 2 3 5 7 11 13 17 19
-		}
-	}
-}

Others/FloydTriangle.java

@@ -6,7 +6,7 @@ class FloydTriangle {
           Scanner sc = new Scanner(System.in);
           System.out.println("Enter the number of rows which you want in your Floyd Triangle: ");
           int r = sc.nextInt(), n = 0;
-
+          sc.close();
           for(int i=0; i < r; i++) {
               for(int j=0; j <= i; j++) {
                   System.out.print(++n + " ");

Others/InsertDeleteInArray.java

@@ -1,5 +1,5 @@
 import java.util.*;
-public class Array {
+public class InsertDeleteInArray {
 
 	public static void main(String[] args) {
 		Scanner s = new Scanner(System.in); // Input statement

Others/RootPrecision.java

@@ -4,7 +4,7 @@ import java.text.*;
 import java.math.*;
 import java.util.regex.*;
 
-public class Solution {
+public class RootPrecision {
 
     public static void main(String[] args) {
 	//take input    

Others/StackPostfixNotation.java

@@ -1,6 +1,6 @@
 import java.util.*;
 
-public class Postfix {
+public class StackPostfixNotation {
     public static void main(String[] args) {
          Scanner scanner = new Scanner(System.in);
         String post = scanner.nextLine();   // Takes input with spaces in between eg. "1 21 +"

Others/countwords.java

@@ -7,7 +7,7 @@ import java.util.Scanner;
  * @author Marcus
  *
  */
-  class CountTheWords{
+  public class countwords{
 
 	public static void main(String[] args){
 	  Scanner input = new Scanner(System.in);

Others/krishnamurthy.java

@@ -1,30 +1,28 @@
 import java.util.Scanner;
 
-class krishnamurthy
-{
- int fact(int n)
- {
-     int i,p=1;
-     for(i=n;i>=1;i--)
-     p=p*i;
+class krishnamurthy {
+	static int fact(int n) {
+		int i, p = 1;
+		for (i = n; i >= 1; i--)
+			p = p * i;
 		return p;
 	}
- public static void main(String args[])
-    {
-        Scanner sc=new Scanner(System.in);
-        int a,b,s=0;
+
+	public static void main(String args[]) {
+		Scanner sc = new Scanner(System.in);
+		int a, b, s = 0;
 		System.out.print("Enter the number : ");
-        a=sc.nextInt();
-        int n=a;
-        while(a>0)
-        {
-            b=a%10;
-            s=s+fact(b);
-            a=a/10;
+		a = sc.nextInt();
+		int n = a;
+		while (a > 0) {
+			b = a % 10;
+			s = s + fact(b);
+			a = a / 10;
 		}
-        if(s==n)
-        System.out.print(n+" is a krishnamurthy number");
+		if (s == n)
+			System.out.print(n + " is a krishnamurthy number");
 		else
-        System.out.print(n+" is not a krishnamurthy number");
+			System.out.print(n + " is not a krishnamurthy number");
+		sc.close();
 	}
 }