0015. 3Sum

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

Description

Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, and nums[i] + nums[j] + nums[k] == 0.

Notice that the solution set must not contain duplicate triplets.

Example 1:

**Input:** nums = [-1,0,1,2,-1,-4]
**Output:** [[-1,-1,2],[-1,0,1]]

Example 2:

**Input:** nums = []
**Output:** []

Example 3:

**Input:** nums = [0]
**Output:** []

Constraints:

• 0 <= nums.length <= 3000

• -105 <= nums[i] <= 105

ac