4Sum

Medium

Given an array nums of n integers and a target, return all unique quadruplets [nums[a], nums[b], nums[c], nums[d]] with distinct indices whose sum equals target.

The quadruplets may be returned in any order.

Example 1

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

Example 2

Input:  nums = [2,2,2,2,2], target = 8
Output: [[2,2,2,2]]

Constraints

• 1 <= nums.length <= 200
• -10^9 <= nums[i] <= 10^9
• -10^9 <= target <= 10^9