Coder's Cat

## LeetCode: 3Sum

2019-10-15

Solution for LeetCode 3sum

## Question

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],

A solution set is:

## Explaination

For time optimization, we need to sort the given array. Then enumerate the elements from index 0(assume value v0), try to find the 2 elements which some sum of them is -v0.

Time complexity is: $$O(N^2)$$