Java: Find all combination of four elements of a given array whose sum is equal to a given value

Java Array: Exercise-43 with Solution

Write a Java program to find all combinations of four elements of an array whose sum is equal to a given value.

Pictorial Presentation:

Sample Solution:

Java Code:

// Import necessary Java libraries.
import java.util.*;
import java.lang.*;

// Define a class named Main.
public class Main
{
    // The main method for executing the program.
    public static void main(String[] args) 
    {  
        // Define an array of integers.
        int nums[] = {10, 20, 30, 40, 1, 2};
        int n = nums.length;
        
        // Define the target sum value.
        int s = 53;
        System.out.println("Given value: " + s);
        System.out.print("Combination of four elements:");

        // Find combinations of four elements that sum up to the given value.
        // Fix the first element.
        for (int i = 0; i < n - 3; i++) 
        {
            // Fix the second element.
            for (int j = i + 1; j < n - 2; j++) 
            {
                // Fix the third element.
                for (int k = j + 1; k < n - 1; k++) 
                {
                    // Find the fourth element.
                    for (int l = k + 1; l < n; l++) 
                    {
                        // Check if the sum of these four elements matches the target value.
                        if (nums[i] + nums[j] + nums[k] + nums[l] == s) 
                            System.out.print("\n" + nums[i] + " " + nums[j] + " " + nums[k] + " " + nums[l]);
                    }
                }
            }
        }
    }
}

Sample Output:

                                                                              
Given value: 53
Combination of four elements:
10 40 1 2
20 30 1 2

Flowchart:

Java Code Editor:

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