/*This is a Java Program to implement Count Min Sketch. The Count–min sketch (or CM sketch) is a probabilistic sub-linear space streaming algorithm which can be used to summarize a data stream in many different ways. Count–min sketches are somewhat similar to Bloom filters; the main distinction is that Bloom filters represent sets, while CM sketches represent multi-sets and frequency tables.*/ /** * Java Program to Implement CountMinSketch **/ import java.util.Scanner; class CountMinSketch { private int[] h1; private int[] h2; private int[] h3; private int size; private static int DEFAULT_SIZE = 11; /** Constructor **/ public CountMinSketch() { size = DEFAULT_SIZE; h1 = new int[ size ]; h2 = new int[ size ]; h3 = new int[ size ]; } /** Function to clear al counters **/ public void clear() { size = DEFAULT_SIZE; h1 = new int[ size ]; h2 = new int[ size ]; h3 = new int[ size ]; } /** Function to insert value **/ public void insert(int val) { int hash1 = hashFunc1(val); int hash2 = hashFunc2(val); int hash3 = hashFunc3(val); /** increment counters **/ h1[ hash1 ]++; h2[ hash2 ]++; h3[ hash3 ]++; } /** Function to get sketch count **/ public int sketchCount(int val) { int hash1 = hashFunc1(val); int hash2 = hashFunc2(val); int hash3 = hashFunc3(val); return min( h1[ hash1 ], h2[ hash2 ], h3[ hash3 ] ); } private int min(int a, int b, int c) { int min = a; if (b < min) min = b; if (c < min) min = c; return min; } /** Hash function 1 **/ private int hashFunc1(int val) { return val % size; } /** Hash function 2 **/ private int hashFunc2(int val) { return ((val * (val + 3)) % size); } /** Hash function 3 **/ private int hashFunc3(int val) { return (size - 1) - val % size; } /** Funtion to print all tables **/ public void print() { System.out.println("\nCounter Tables : \n"); System.out.print("h1 : "); for (int i = 0; i < size; i++) System.out.print(h1[i] +" "); System.out.print("\nh2 : "); for (int i = 0; i < size; i++) System.out.print(h2[i] +" "); System.out.print("\nh3 : "); for (int i = 0; i < size; i++) System.out.print(h3[i] +" "); System.out.println(); } } public class CountMinSketchTest { public static void main(String[] args) { Scanner scan = new Scanner(System.in); System.out.println("Count Min Sketch Test\n\n"); /** Make object of CountMinSketch **/ CountMinSketch cms = new CountMinSketch(); char ch; /** Perform CountMinSketch operations **/ do { System.out.println("\nCount Min Sketch Operations\n"); System.out.println("1. insert "); System.out.println("2. get sketch count"); System.out.println("3. clear"); int choice = scan.nextInt(); switch (choice) { case 1 : System.out.println("Enter int value"); cms.insert(scan.nextInt() ); break; case 2 : System.out.println("Enter int value"); int val = scan.nextInt(); System.out.println("\nSketch count for "+ val +" = "+ cms.sketchCount( val )); break; case 3 : cms.clear(); System.out.println("Counters Cleared\n"); break; default : System.out.println("Wrong Entry \n "); break; } /** Display counter table **/ cms.print(); System.out.println("\nDo you want to continue (Type y or n) \n"); ch = scan.next().charAt(0); } while (ch == 'Y'|| ch == 'y'); } } /* Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 1 Enter int value 45 Counter Tables : h1 : 0 1 0 0 0 0 0 0 0 0 0 h2 : 0 0 0 0 1 0 0 0 0 0 0 h3 : 0 0 0 0 0 0 0 0 0 1 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 1 Enter int value 67 Counter Tables : h1 : 0 2 0 0 0 0 0 0 0 0 0 h2 : 0 0 0 0 2 0 0 0 0 0 0 h3 : 0 0 0 0 0 0 0 0 0 2 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 1 Enter int value 23 Counter Tables : h1 : 0 3 0 0 0 0 0 0 0 0 0 h2 : 0 0 0 0 3 0 0 0 0 0 0 h3 : 0 0 0 0 0 0 0 0 0 3 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 1 Enter int value 47 Counter Tables : h1 : 0 3 0 1 0 0 0 0 0 0 0 h2 : 0 0 0 0 3 0 0 1 0 0 0 h3 : 0 0 0 0 0 0 0 1 0 3 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 1 Enter int value 23 Counter Tables : h1 : 0 4 0 1 0 0 0 0 0 0 0 h2 : 0 0 0 0 4 0 0 1 0 0 0 h3 : 0 0 0 0 0 0 0 1 0 4 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 1 Enter int value 31 Counter Tables : h1 : 0 4 0 1 0 0 0 0 0 1 0 h2 : 0 0 0 0 4 0 0 1 0 1 0 h3 : 0 1 0 0 0 0 0 1 0 4 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 1 Enter int value 59 Counter Tables : h1 : 0 4 0 1 1 0 0 0 0 1 0 h2 : 0 0 0 0 4 0 1 1 0 1 0 h3 : 0 1 0 0 0 0 1 1 0 4 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 1 Enter int value 13 Counter Tables : h1 : 0 4 1 1 1 0 0 0 0 1 0 h2 : 0 0 0 0 4 0 1 1 0 1 1 h3 : 0 1 0 0 0 0 1 1 1 4 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 1 Enter int value 17 Counter Tables : h1 : 0 4 1 1 1 0 1 0 0 1 0 h2 : 0 0 0 0 4 0 1 1 0 1 2 h3 : 0 1 0 0 1 0 1 1 1 4 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 2 Enter int value 17 Sketch count for 17 = 1 Counter Tables : h1 : 0 4 1 1 1 0 1 0 0 1 0 h2 : 0 0 0 0 4 0 1 1 0 1 2 h3 : 0 1 0 0 1 0 1 1 1 4 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 1 Enter int value 97 Counter Tables : h1 : 0 4 1 1 1 0 1 0 0 2 0 h2 : 0 0 0 0 4 0 1 1 0 2 2 h3 : 0 2 0 0 1 0 1 1 1 4 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 2 Enter int value 97 Sketch count for 97 = 2 Counter Tables : h1 : 0 4 1 1 1 0 1 0 0 2 0 h2 : 0 0 0 0 4 0 1 1 0 2 2 h3 : 0 2 0 0 1 0 1 1 1 4 0 Do you want to continue (Type y or n) y Count Min Sketch Operations 1. insert 2. get sketch count 3. clear 3 Counters Cleared Counter Tables : h1 : 0 0 0 0 0 0 0 0 0 0 0 h2 : 0 0 0 0 0 0 0 0 0 0 0 h3 : 0 0 0 0 0 0 0 0 0 0 0 Do you want to continue (Type y or n) n