Find_subset_array.cpp

// Java code to find whether an array is subset of 
// another array 
import java.util.HashSet; 
class GFG 
{ 
    /* Return true if arr2[] is a subset of arr1[] */
    static boolean isSubset(int arr1[], int arr2[], int m, 
                                                 int n) 
    { 
        HashSet<Integer> hset= new HashSet<>(); 
          
        // hset stores all the values of arr1 
        for(int i = 0; i < m; i++) 
        { 
            if(!hset.contains(arr1[i])) 
                hset.add(arr1[i]); 
        } 
              
        // loop to check if all elements of arr2 also 
        // lies in arr1 
        for(int i = 0; i < n; i++) 
        { 
            if(!hset.contains(arr2[i])) 
                return false; 
        } 
        return true; 
    }  
  
    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)) 
        System.out.println("arr2 is a subset of arr1"); 
        else
        System.out.println("arr2 is not a subset of arr1"); 
    } 
}