Question

Please use Java language to write an efficient function that compute the intersection of two arrays of integers (not necessary sorted).

Answer 1

CODE

import java.util.HashSet;

public class Main
{
   public static void findIntersectionForUnsortedArrays(int arr1[], int arr2[])
    {
        HashSet<Integer> hs = new HashSet<>();
        
        for (int i = 0; i < arr1.length; i++)
            hs.add(arr1[i]);
        
        for (int i = 0; i < arr2.length; i++)
            if (hs.contains(arr2[i]))
               System.out.print(arr2[i] + " ");
    }

   public static void main(String args[])
   {
       int arr1[] = {1, 9, 5, 4, 8, 6};
        int arr2[] = {7, 8, 9, 1, 17, 20, 4};
        findIntersectionForUnsortedArrays(arr1, arr2);
   }
}