Java Array Exercises: Find all the unique triplets such that sum of all the three elements equal to a specified number

Java Array: Exercise-36 with Solution

Write a Java program to find all the unique triplets such that sum of all the three elements [x, y, z (x ≤ y ≤ z)] equal to a specified number.
Sample array: [1, -2, 0, 5, -1, -4]
Target value: 2.

Pictorial Presentation:

Sample Solution:

Java Code:

import java.util.ArrayList;
import java.util.List;
public class Exercise36 {
    public static void main(String[] args) {
        int[] input = {1, -2, 0, 5, -1, -4};
		int target = 2;
		Exercise36 r = new Exercise36();
        System.out.println(r.threeSum(input,target));       
    }
    public List<List<Integer>> threeSum(int[] nums, int target) {
        List<List<Integer>> my_List = new ArrayList<List<Integer>>();
        
        for(int i = 0; i < nums.length; i++){
            for(int j = i; j < nums.length ;j++){
                for(int k = j; k<nums.length;k++){
                    if ( i != j && j != k && i != k && (nums[i] + nums[j] + nums[k] == target)){
                        List<Integer> inner_List = new ArrayList<Integer>(3);
                        inner_List.add(nums[i]);
                        inner_List.add(nums[j]);
                        inner_List.add(nums[k]);
                        my_List.add(inner_List);
                    }
                }
            }
        }
       return my_List;
    }
  }

Sample Output:

                                                                              
[[1, 5, -4], [-2, 5, -1]] 

Flowchart:

Java Code Editor:

Improve this sample solution and post your code through Disqus

Previous: Write a Java program to find the sum of the two elements of a given array which is equal to a given integer.
Next: Write a Java program to create an array of its anti-diagonals from a given square matrix.