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class Solution {
public:
    typedef long long LL;

    vector<vector<int>> fourSum(vector<int>& nums, int target) {
        vector<vector<int>> res;
        sort(nums.begin(), nums.end());
        for (int i = 0; i < nums.size(); i ++ ) {
            if (i && nums[i] == nums[i - 1]) continue;
            for (int j = i + 1; j < nums.size(); j ++ ) {
                if (j > i + 1 && nums[j] == nums[j - 1]) continue;
                for (int k = j + 1, l = nums.size() - 1; k < l; k ++ ) {
                    if (k > j + 1 && nums[k] == nums[k - 1]) continue;
                    while (l - 1 > k && (LL)nums[i] + nums[j] + nums[k] + nums[l - 1] >= target) l -- ;
                    if ((LL)nums[i] + nums[j] + nums[k] + nums[l] == (LL)target) {
                        res.push_back({nums[i], nums[j], nums[k], nums[l]});
		            }
                }
            }
        }
        return res;
    }
};