DIY: Three Sum

Problem statement

For this challenge, you are given a list called numbers, containing positive and negative integers. Your job is to find unique triplets $(a, b, c)$ in the list that add up to zero: $(a + b + c) = 0$.

Input

The function’s input will be a list containing positive and negative integers. The following is an example input:

[3, 0, 6, 2, 5, -8, -1]

Output

The output will be a list of lists representing the triplets that sum up to zero. The following is the output of the above input list:

[[-8, 5, 3], [-8, 6, 2]]