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.
Given array nums = [-1, 0, 1, 2, -1, -4],
A solution set is:
[ [-1, 0, 1], [-1, -1, 2] ]
See the full details of the problem 3Sum at LeetCode