Sum of Three

Question

Write a function where given an list of integers, returns all unique triplets of integers that sum up to 0.

The order of the output and the order of the triplets should be sorted.

Input: [-1, 0, -2, 1, 3, 2]

Output: [[-2, -1, 3], [-2, 0, 2], [-1, 0, 1]]

Input: [-2, -1, 0, 0, 2, -1, 2, -2]

Output: [[-2, 0, 2], [-1, -1, 2]]

What are some questions you'd ask an interviewer?

If the given list is [-5, 2, 1, -4, 3], which of these would be a single valid triplet?

[-5, -4, 1]

[3, -4, 1]

[-4, 2, 2]

[]