leetcode

0 class Solution {

1 public:

2 bool isValid(const string &s) const {

3 static char st[20001];

4 int n = 0;

5 for (const char c : s) {

6 if (c != 'c')

7 st[n++] = c;

8 else {

9 if (n < 2) return false;

10 if (st[n - 1] != 'b') return false;

11 if (st[n - 2] != 'a') return false;

12 n -= 2;

13 }

14 }

15 return n == 0;

16 }

17 };