Multiply same numbers in given array

Multiply the same numbers in a given array

• We can multiply same/similar numbers in the given array by using for -loops and hashmap.

Examples:

Input: { 2, 3, 4, 2, 3, 4, 4 }

o/p:    4 9 64

Here, 2 repeated 2 times, 3 repeated 2 times and 4 repeated 3 times. So multiply the same numbers in the given array (2*2, 3*3, 4*4*4)

Input: { 2, 3, 4, 2, 3, 4, 9 }

o/p:    4 9 16 9

Program:

import java.util.HashMap;
import java.util.Set;

public class multiplySameNumbers {
    public static void main(String[] args) {
        int[] a = { 2, 3, 4, 2, 3, 4, 9 };
        HashMap<Integer, Integer> hm = new HashMap<Integer, Integer>();
        for (int n : a) {
            if (hm.containsKey(n)) {
                hm.put(n, hm.get(n) + 1);
            } else {
                hm.put(n, 1);
            }
        }
        System.out.println("Given values in array");
        for (int n : a) {
            System.out.print(n + " ");
        }
        // printing count of each value in array
        System.out.println("\nHash Map key and values=" + hm);
        Set<Integer> s = hm.keySet();
        int value = 1;
        System.out.println("Multiply same numbers in given array");
        for (int sv : s) {
            for (int i = 0; i < hm.get(sv); i++) {
                value = value * sv; // based on count value,multiply number in array
            }
        System.out.print(value + " ");
        value = 1;
        }
    }
}

Output:

Multiply same numbers in given array
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