Solution.java

package Array.No_18_4Sum;


import java.util.List;

/**
 * FileName: Solution
 * Author:   EdisonLi的家用MacBook Pro
 * Date:     2019-06-20 23:15
 * Description: Maximum Binary Tree
 * Difficulty: Medium
 * 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]
 * ]
 */

public class Solution {
    public List<List<Integer>> fourSum(int[] nums, int target) {
        return null;
    }
}