leetcode

0 class Solution {

1 public:

2 vector<vector<int>> threeSum(vector<int> &num) {

3 sort(num.begin(), num.end());

4

5 vector<vector<int>> res;

6 for (int i = 0; i < num.size();) {

7 int target = -num[i], start = i + 1, end = num.size() - 1;

8

9 while (start < end) {

10 int sum = num[start] + num[end];

11 if (sum < target)

12 start++;

13 else if (sum > target)

14 end--;

15 else {

16 res.push_back({num[i], num[start], num[end]});

17 while (start < end && num[start] == res.back()[1])

18 start++;

19 while (start < end && num[end] == res.back()[2])

20 end--;

21 }

22 }

23 for (i++; i < num.size() && num[i] == num[i - 1]; i++)

24 ;

25 }

26

27 return res;

28 }

29 };