Find All Triplets with Zero Sum

Given an array Arr consisting of N integers, find all distinct triplets in the array that sum up to zero.

Explanation:

An array is said to have a triplet {Arr[i], Arr[j], Arr[k]} with a 0 sum if there exist three indices i, j, and k such that i != j, j != k, i != k, and Arr[i] + Arr[j] + Arr[k] = 0.

Note:

• You can return the list of values in any order. For example, if a valid triplet is {1, 2, -3}, then {2, -3, 1}, {-3, 2, 1}, etc., is also a valid triplet. Also, the ordering of different triplets can be random; if there are more than one valid triplets, you can return them in any order.
• The elements in the array need not be distinct.
• If no such triplet is present in the array, return an empty list, and the output printed for such a test case will be "-1".

Input:

The first line of the input contains an integer T, denoting the number of test cases.
The first line of each test case contains the integer N, denoting the size of the array.
The second line of each test case contains N space-separated integers denoting the array elements.

Output:

For each test case, every line of output contains three spaced integers that correspond to the elements which add to zero. Refer to sample input 2 for more clarification.

Note:

You do not need to print anything; it has already been taken care of. Just implement the given function.

Constraints:

• 1 <= T <= 50
• 1 <= N <= 10^3
• -10^5 <= Arr[i] <= 10^5
• Time Limit: 1 sec