1 class Solution {
2 public:
3 bool isValid(string s) {
4 // IMPORTANT: Please reset any member data you declared, as
5 // the same Solution instance will be reused for each test case.
6 stack<char> sc;
7 int len = s.length();
8 for (int i=0; i<len; i++){
9 char c = s.at(i);
10 switch(c){
11 case '(':
12 case '{':
13 case '[':
14 sc.push(c);
15 break;
16 case '}':
17 if (sc.empty() ||sc.top()!='{')
18 return false;
19 else sc.pop();
20 break;
21 case ']':
22 if (sc.empty() ||sc.top()!='[')
23 return false;
24 else sc.pop();
25 break;
26 case ')':
27 if (sc.empty() ||sc.top()!='(')
28 return false;
29 else sc.pop();
30 break;
31 default:
32 return false;
33 }
34 }
35 if (!sc.empty())
36 return false;
37 return true;
38 }
39 };
