diff --git a/Compression/bin/HEncoder$Node$Nodecomparator.class b/Compression/bin/HEncoder$Node$Nodecomparator.class new file mode 100644 index 00000000..132ac19f Binary files /dev/null and b/Compression/bin/HEncoder$Node$Nodecomparator.class differ diff --git a/Compression/bin/HEncoder$Node.class b/Compression/bin/HEncoder$Node.class new file mode 100644 index 00000000..9fcce4c5 Binary files /dev/null and b/Compression/bin/HEncoder$Node.class differ diff --git a/Compression/bin/HEncoder.class b/Compression/bin/HEncoder.class new file mode 100644 index 00000000..3e740955 Binary files /dev/null and b/Compression/bin/HEncoder.class differ diff --git a/Compression/bin/compressclient.class b/Compression/bin/compressclient.class new file mode 100644 index 00000000..6465df8e Binary files /dev/null and b/Compression/bin/compressclient.class differ diff --git a/Compression/bin/genericheap.class b/Compression/bin/genericheap.class new file mode 100644 index 00000000..16c2d03a Binary files /dev/null and b/Compression/bin/genericheap.class differ diff --git a/Compression/src/HEncoder.java b/Compression/src/HEncoder.java new file mode 100644 index 00000000..37bd8fc0 --- /dev/null +++ b/Compression/src/HEncoder.java @@ -0,0 +1,108 @@ +import java.util.ArrayList; +import java.util.Comparator; +import java.util.HashMap; + +public class HEncoder { + + public HashMap encoder = new HashMap<>(); // in order to encode + public HashMap 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 { + + @Override + public int compare(Node o1, Node o2) { + return o2.freq - o1.freq; + } + + } + } + + public HEncoder(String feeder) { + // 1. freq map + HashMap 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 heap = new genericheap(Node.Ctor); + ArrayList 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; + } +} diff --git a/Compression/src/compressclient.java b/Compression/src/compressclient.java new file mode 100644 index 00000000..496c8a84 --- /dev/null +++ b/Compression/src/compressclient.java @@ -0,0 +1,11 @@ + +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")); + } + +} diff --git a/Compression/src/genericheap.java b/Compression/src/genericheap.java new file mode 100644 index 00000000..de00316f --- /dev/null +++ b/Compression/src/genericheap.java @@ -0,0 +1,93 @@ + + +import java.util.ArrayList; +import java.util.Comparator; + +public class genericheap { // create a generic heap class , where T can be of any type. + + private ArrayList data = new ArrayList<>(); + private Comparator ctor; + + public genericheap(Comparator 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 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); + } + } + +} diff --git a/Conversions/AnytoAny.java b/Conversions/AnytoAny.java new file mode 100644 index 00000000..a1acdb1a --- /dev/null +++ b/Conversions/AnytoAny.java @@ -0,0 +1,28 @@ +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); + } + +}