leetcode

0 class Solution {

1 public:

2 int sumRootToLeaf(TreeNode *root) {

3 if (!root) return 0;

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

5 int sum = 0;

6

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

8 while (!st.empty()) {

9 TreeNode *root = st.top().first;

10 int val = (st.top().second << 1) | root->val;

11 st.pop();

12 if (!root->left && !root->right) {

13 sum += val;

14 continue;

15 }

16 if (root->left) st.push({root->left, val});

17 if (root->right) st.push({root->right, val});

18 }

19 return sum;

20 }

21 };