leetcode

0 class Solution {

1 public:

2 vector<vector<int>> pathSum(TreeNode *root, int targetSum) {

3 if (!root) return {};

4 stack<pair<TreeNode *, int>> st;

5 vector<vector<int>> res;

6 vector<int> path;

7 st.push({root, 0});

8 while (!st.empty()) {

9 auto [root, sum] = st.top();

10 if (sum == INT_MIN) {

11 st.pop();

12 path.pop_back();

13 continue;

14 }

15 sum += root->val;

16 st.top().second = INT_MIN;

17 path.push_back(root->val);

18

19 if (!root->left && !root->right && sum == targetSum) res.push_back(path);

20 if (root->left) st.push({root->left, sum});

21 if (root->right) st.push({root->right, sum});

22 }

23 return res;

24 }

25 };