26. Array subset of another array

26. Array subset of another array

Problem link :- click here

package programs;

import java.util.*;

public class Array__26
{

	static Boolean arraySubsetOfAnotherArray(int a[], int b[], int n1, int n2)
	{
		/*we have to check whether 'b' is a subset of 'a' 
		    a is a super set
		    b can be a subset of a
		    which means n1 must be greater than b*/
		if(n1<n2)
			return false;
		
		/*lets push all the elements of 'a' to a hash-set 
		    and we will iterate through 'b'  and 
		    if any element of 'b' is not present in 'a'
		                         then 'b' is not a subset of 'a'*/
		HashSet<Integer> hash_set = new HashSet<>();
		//we don't need to check whether any element is repeated
		//as they are giving us set (in set elements don't repeat)
		for(int i=0; i<n1; i++)
			hash_set.add(a[i]);
		
		//iterating through 'b'
		for(int i=0; i<n2; i++)
		{
			//checking if any element of 'b' is not present in 'a'
			if(  !hash_set.contains(b[i])  )
				return false;
		}
		
		return true;
	}
	
	public static void main(String[] args)
	{
		int i, m, n;
		
		Scanner s = new Scanner(System.in);
		
		System.out.print("Enter the size of the array 1 :");
		m = s.nextInt();
		int array1[] = new int[m];
		System.out.println("Enter the elements of the array 1 :");
		for(i=0; i<m; i++)
			array1[i] = s.nextInt();
		System.out.print("Enter the size of the array 2 :");
		n = s.nextInt();
		int array2[] = new int[n];
		System.out.println("Enter the elements of the array 2 :");
		for(i=0; i<n; i++)
			array2[i] = s.nextInt();
		
		System.out.println("Array 1 : ");
		print_array(array1);
		System.out.println("\nArray 2 : ");
		print_array(array2);
		
		Boolean ans = arraySubsetOfAnotherArray(array1, array2, m, n);
		if(ans)
			System.out.println("\n\nYes");
		else
			System.out.println("\n\nNo");
	}

	static void print_array(int arr[]) 
	{
		for(int i=0; i<arr.length; i++)
			System.out.print(arr[i] + " ");
	}
}

Time complexity :- O(n)
Space complexity :- O(n)