Array Subset of another array Java

PROGRAM TO FIND WHETHER AN ARRAY IS SUBSET OF ANOTHER ARRAY USING MAP




import java.util.*;

  

class MAIN

{

  

    // Function to check if an array is

    // subset of another array

    static int isSubset(int a[], int b[], int m, int n) 

    {

  

        // map to store the values of array a[]

        HashMap<Integer, Integer> mp1 = new

                HashMap<Integer, Integer>();

  

        for (int i = 0; i < m; i++)

            if (mp1.containsKey(a[i])) 

            {

                mp1.put(a[i], mp1.get(a[i]) + 1);

            } 

            else

            {

                mp1.put(a[i], 1);

            }

  

        // flag value

        int f = 0;

  

        for (int i = 0; i < n; i++) 

        {

            // if b[i] is not present in map

            // then array b[] can not be a

            // subset of array a[]

            if (!mp1.containsKey(b[i])) 

            {

                f = 1;

                break;

            }

  

            // if if b[i] is present in map

            // decrement by one

            else 

            {

                mp1.put(b[i], mp1.get(b[i]) - 1);

  

                if (mp1.get(b[i]) == 0)

                    mp1.remove(b[i]);

            }

        }

  

        return f;

    }

  

    // Driver code

    public static void main(String[] args)

    {

        int arr1[] = { 11, 1, 13, 21, 3, 7 };

        int arr2[] = { 11, 3, 7, 1 };

  

        int m = arr1.length;

        int n = arr2.length;

  

        if (isSubset(arr1, arr2, m, n)!=1)

            System.out.print("arr2[] is subset of arr1[] ");

        else

            System.out.print("arr2[] is not a subset of arr1[]");

    }

}







OUTPUT

arr2[] is subset of arr1[]

CREDITS: https://www.geeksforgeeks.org/find-whether-an-array-is-subset-of-another-array-using-map/