Question: Find the Common Elements in Two Arrays

Question: Find the Common Elements in Two Arrays

Problem Description:
Given two arrays of integers, write a Java function to find and print the common elements present in both arrays.

Solution:

import java.util.HashSet;

public class CommonElementsInArrays {
    // Function to find common elements in two arrays
    static void findCommonElements(int[] arr1, int[] arr2) {
        HashSet<Integer> set = new HashSet<>();
        for (int num : arr1) {
            set.add(num);
        }

        System.out.print("Common elements: ");
        for (int num : arr2) {
            if (set.contains(num)) {
                System.out.print(num + " ");
            }
        }
    }

    public static void main(String[] args) {
        int[] arr1 = {1, 2, 4, 5, 6};
        int[] arr2 = {2, 3, 5, 7};

        System.out.println("Array 1: [1, 2, 4, 5, 6]");
        System.out.println("Array 2: [2, 3, 5, 7]");

        findCommonElements(arr1, arr2);
    }
}

Explanation:
This solution uses a HashSet to store unique elements from the first array (arr1). Then, it iterates through the second array (arr2) and checks if each element is present in the HashSet. If it is, the element is a common element, and it is printed.

This question assesses the candidate's knowledge of data structures (HashSet in this case) and their ability to efficiently solve problems involving arrays and sets.