class Solution {

public:

    vector<vector<int>> fourSum(vector<int>& nums, int target) {

        if(nums.size() < ) return {};

        set<vector<int>> res;

        sort(nums.begin(),nums.end());

        for(int i=;i < nums.size()-;i++){

            for(int j=i+;j < nums.size()-;j++){

                int cnt = target - nums[i] - nums[j];

                for(int m=j+,n=nums.size()-;m < n;){

                    int sum = nums[m]+nums[n];

                    if(sum < cnt){m++;}

                    else if(sum > cnt){n--;}

                    else{

                        res.insert({nums[i],nums[j],nums[m],nums[n]});

                        m++;n--;

                    }

                }

            }

        }

        return vector<vector<int>>(res.begin(),res.end());

    }

};