3Sum

https://leetcode.com/problems/3sum/

Medium

Given an array nums of n integers, are there elements a, b, c in nums such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero.

Note: The solution set must not contain duplicate triplets.

Example:

Given array nums = [-1, 0, 1, 2, -1, -4]

[-4, -1, -1, 0, 1, 2]

A solution set is:

[
  [-1, 0, 1],
  [-1, -1, 2]
]