Services
Technology Web App Development Mobile App Development Windows App Development Database Development UI/UX Development Cloud Development SEO Digital Marketing Guest Posting Content Writing Artificial Intelligence Data Science ERP Development CRM Development CMS Development LMS Development Business Listing Blockchain Technology Startup Promotion
Products
Data Converter Cleaner TUC - Unit Converter Import Export Survey Manager Tweet Controller
Developer
Article Blog Forum Interview Beginner News Startup Quiz
Users
Career
Apply Job Internship
Pricing
Login Sign Up Get a Quote

interview

home / developersection / interviews / java program to find all pairs of elements in an array whose sum is equal to a given number.
Ask Question

Java program to find all pairs of elements in an array whose sum is equal to a given number.

Ravi Vishwakarma 664 17 Jul 2024
java javajavac
Updated 17 Jul 2024
Ravi Vishwakarma
Ravi Vishwakarma

Software Developer

Hi, my self Ravi Vishwakarma. I have completed my studies at SPICBB Varanasi. now I completed MCA with 76% form Veer Bahadur Singh Purvanchal University Jaunpur. SWE @ MindStick | Software Engineer | Web Developer | .Net Developer | Web Developer | Backend Engineer | .NET Core Developer

Message

1 Answers

Ravi Vishwakarma
Ravi Vishwakarma 17 Jul 2024
Report Abuse

Here's a step-by-step implementation in Java:

  1. Initialize a HashSet to store the elements we encounter.
  2. Iterate through the array and for each element, calculate the complement that would sum to the target value.
  3. Check if the complement exists in the HashSet. If it does, print the pair.
  4. Add the current element to the HashSet.

Code Example:

import java.util.*;

public class Main {
    public static void findPairs(int[] array, int sum) {
        // Create a HashSet to store elements
        HashSet<Integer> seen = new HashSet<>();

        System.out.println("Pairs with sum " + sum + ":");
        // Iterate through each element in the array
        for (int num : array) {
            // Calculate the complement
            int complement = sum - num;

            // Check if the complement is in the HashSet
            if (seen.contains(complement)) {
                System.out.println("(" + complement + ", " + num + ")");
            }

            // Add the current element to the HashSet
            seen.add(num);
        }
    }

    public static void main(String[] args) {
        int[] array = {1, 4, 5, 7, 3, 9, 2, 10, 0};
        int sum = 10;

        findPairs(array, sum);
    }
}

Output,

Ravi Vishwakarma
MindStick Training