• Home
  • Subscribe
  • Contribute Us
    • Share Your Interview Experience
  • Contact Us
  • About
    • About CSEstack
    • Campus Ambassador
  • Forum & Discus
  • Tools for Geek
  • LeaderBoard
CSEstack

What do you want to Learn Today?

  • Programming
    • Tutorial- C/C++
    • Tutorial- Django
    • Tutorial- Git
    • Tutorial- HTML & CSS
    • Tutorial- Java
    • Tutorial- MySQL
    • Tutorial- Python
    • Competitive Coding Challenges
  • CSE Subject
    • (CD) Compiler Design
    • (CN) Computer Network
    • (COA) Computer Organization & Architecture
    • (DBMS) Database Management System
    • (DS) Data Structure
    • (OS) Operating System
    • (ToA) Theory of Automata
    • (WT) Web Technology
  • Interview Questions
    • Interview Questions- Company Wise
    • Interview Questions- Coding Round
    • Interview Questions- Python
    • Interview Questions- REST API
    • Interview Questions- Web Scraping
    • Interview Questions- HR Round
    • Aptitude Preparation Guide
  • GATE 2022
  • Linux
  • Trend
    • Full Stack Development
    • Artificial Intelligence (AI)
    • BigData
    • Cloud Computing
    • Machine Learning (ML)
  • Write for Us
    • Submit Article
    • Submit Source Code or Program
    • Share Your Interview Experience
  • Tools
    • IDE
    • CV Builder
    • Other Tools …
  • Jobs

[Solved] Program to Find Pairs that have Desired Sum in Java

Sachin Sharma/2628/1
CodeJAVA

Problem Statement: Consider an array of integers that may contain both positive and negative integers, called numbers. Write a program that finds all the pairs of integers whose sum is equal to a given value called the desired sum.

This question has been asked in interviews of many product-based companies like Amazon, Flipkart, Adobe, …

Java Program

Prerequisite:

  1. Understanding of generics in Java
  2. Understanding of ArrayLists in Java
  3. Knowledge of classes and objects in Java

Code:

Let’s write a program to find pairs that have desired sum in Java.

import java.util.*;
class Solution {
     public static void main(String[] args) {
          Scanner sc = new Scanner(System.in);
          // Enter the size of the array
          int n = sc.nextInt();
          int[] = arr = new int[n];
          for (int i = 0;i < arr.lenght;i++) {
               arr[i] = sc.nextInt();
          }
          // enter the desired sum
          int sum = sc.nextInt();
          System.out.println(findNumberOfPairs(arr, sum));
     }
      
     public static int fndNumberOfPairs(int[] arr, int sum) {
          Arrays.sort(arr);  // sort the array
          // using two pointer algorithm
          int left = 0, right = arr.lenght - 1, count = 0;
          currentSum = arr[left] + arr[right];
          while (left < right) {
               if (currentSum == sum) {
                   count ++;
                   left++;
                   right--;
               }
               else if (currentSum < sum)
                   left++;
               else
                   right--;
          }
          return count;
     }
}

Output:

Sample Input : n = 5, arr = [1, 2, 3, 4, 5], sum = 4
Sample Output : 1 as only (1, 3) pair has the sum equal to 4

You can use any programming language (C/C++, Python, etc.) of your choice to solve this competitive coding challenge to find pairs that have desired sum.

Codecoding challengeJava
Sachin Sharma
I am Sachin Sharma a complete JAVA geek and I also have good knowledge of Python, C, C++, and front-end development. I am a 5-star gold coder on Hckerrank in JAVA, Python, C++, and DSA. I am eager to share my coding knowledge to help people.

Your name can also be listed here. Got a tip? Submit it here to become an CSEstack author.

Comments

  • Reply
    parth
    March 28, 2022 at 1:37 pm

    currentSum = arr[left] + arr[right]; this line should be inside the while loop.

Leave a Reply Cancel reply

Why?

Why Competitive Programming Important?

Coding Challenges for Practice

  1. Count Common Factor
  2. Does it Divide
  3. Sum of Sub Arrays
  4. Pair of Desired Sum
  5. Remove Duplicate Char from String
  6. Sort String by Char Freq (Python)
  7. Sort String by Char Freq (Java)
  8. Split Array into Equal Sum Subarray
  9. Validate IP Address
  10. Validate PAN Card Number
  11. Validate Sudoku
  12. Sort Circular Rotated Array
  13. Min Arrow to Burst Bubbles
  14. Min Cost to Paint All Houses [Amazon]
  15. HourGlass with Largest Sum
  16. Max Profit by Buying/Selling Stocks
  17. Hailstone Sequence
  18. Reverse String without affecting Special Characters
  19. Secure Conversation by Encry/Decry
  20. Special Elements in Matrix
  21. Next Greater No with Same set of Digits
  22. Smallest Subarray with Sum Greater than Given Number
  23. Group Anagrams
  24. Find Duplicates in Array in O(n)
  25. Find Two Unique Numbers from Array in O(n)
  26. Number Patterns & Finding Smallest Number
  27. First Unique Element in a Stream
  28. Flip Equivalent Binary Trees [TeachMint]
  29. Minimum Cost of Merging Files [Amazon]
  30. Minimum Distance for Truck to Deliver Order [Amazon]
  31. Order Task for Given Dependencies
  32. Multilevel Parking System Design
  33. Minimum Coins Required
  34. Max Sum Subarray
  35. Max Avg Sum of Two Subsequences
  36. Merge Overlapping Intervals
  37. Longest Balanced Subarray
  38. Longest Path in a Weighted Tree
  39. Generate Balanced Parentheses
  40. PostOrder Traversal Without Recursion

© 2022 – CSEstack.org. All Rights Reserved.

  • Home
  • Subscribe
  • Contribute Us
    • Share Your Interview Experience
  • Contact Us
  • About
    • About CSEstack
    • Campus Ambassador
  • Forum & Discus
  • Tools for Geek
  • LeaderBoard