leetcode

0 class Solution {

1 public:

2 bool isValidSerialization(const string &preorder) const {

3 const int n = size(preorder);

4 int size = 1;

5

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

7 if (preorder[i] == ',') continue;

8 size--;

9 if (size < 0) return false;

10 if (preorder[i] != '#') {

11 while (i < n && preorder[i + 1] != ',')

12 i++;

13 size += 2;

14 }

15 }

16

17 return size == 0;

18 }

19 };