leetcode

0 class Solution {

1 char is_open(char c) { return c == '(' || c == '[' || c == '{'; }

2 char get_open_pair(char c) {

3 switch (c) {

4 case ')': return '(';

5 case ']': return '[';

6 case '}': return '{';

7 default: return 0;

8 }

9 }

10

11 public:

12 bool isValid(string s) {

13 stack<char> st;

14

15 char t;

16 for (auto c : s)

17 if (is_open(c))

18 st.push(c);

19 else if ((t = get_open_pair(c)))

20 if (!st.empty() && st.top() == t)

21 st.pop();

22 else

23 return false;

24 else

25 return false;

26

27 return st.empty();

28 }

29 };