leetcode

0 class Solution {

1 public:

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

3 vector<vector<int>> res;

4 int n = nums.size();

5

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

7 for (int i = 0; i < n; i++) {

8 for (int j = i + 1; j < n; j++) {

9 long long goal = (long long)target - nums[i] - nums[j];

10 int k = j + 1, l = n - 1;

11 while (k < l) {

12 long long crnt = nums[k] + nums[l];

13 if (crnt > goal)

14 l--;

15 else if (crnt < goal)

16 k++;

17 else {

18 res.push_back({nums[i], nums[j], nums[k], nums[l]});

19 k++, l--;

20 while (k < l && nums[l] == nums[l + 1])

21 l--;

22 }

23 }

24 while (j + 1 < n && nums[j] == nums[j + 1])

25 ++j;

26 }

27 while (i + 1 < n && nums[i] == nums[i + 1])

28 ++i;

29 }

30 return res;

31 }

32 };