leetcode

0 class Solution {

1 public:

2 int widthOfBinaryTree(TreeNode *root) {

3 if (root == NULL) return 0;

4 queue<pair<TreeNode *, int>> q;

5

6 int res = 1;

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

8 while (!q.empty()) {

9 int start = q.front().second, end = q.back().second;

10

11 res = max(res, end - start + 1);

12 for (int k = q.size(); k > 0; k--) {

13 pair<TreeNode *, int> p = q.front();

14 q.pop();

15 int idx = p.second - start;

16

17 if (p.first->left) q.push({p.first->left, 2ll * idx + 1});

18 if (p.first->right) q.push({p.first->right, 2ll * idx + 2});

19 }

20 }

21

22 return res;

23 }

24 };