q018_4sum

Overview ¶

[Medium] 4Sum https://leetcode.com/problems/4sum/

Given an array nums of n integers and an integer target, are there elements a, b, c, and d in nums such that a + b + c + d = target? Find all unique quadruplets in the array which gives the sum of target.

Note:

The solution set must not contain duplicate quadruplets.

Example:

Given array nums = [1, 0, -1, 0, -2, 2], and target = 0.

A solution set is: [

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

]