1 class Solution { 2 public: 3     bool isValid(string s) { 4         char stack[s.size()]; 5         int i = 0; 6         int j = 0; 7          8         //cout << s; 9         10         if(s[j] == ‘)‘ || s[j] == ‘]‘ || s[j] ==‘}‘)11             return false;12         else if(s[j] == ‘\0‘)13             return true;14         else15             stack[i++] = s[j++];16     17         while(1)18         {19             switch(s[j])20             {21                 case ‘\0‘:22                     if(i == 0)23                         return true;24                     else 25                         return false;26                 case ‘)‘:27                     if(stack[i-1] != ‘(‘)28                         return false;29                     else30                     {31                         i -= 1;32                         j += 1;33                     }34                     break;35                 case ‘]‘:36                     if(stack[i-1] != ‘[‘)37                         return false;38                     else39                     {40                         i -= 1;41                         j += 1;42                     }43                     break;44                 case ‘}‘:45                     if(stack[i-1] != ‘{‘)46                         return false;47                     else48                     {49                         i -= 1;50                         j += 1;51                     }52                     break;53                 default:54                     stack[i++] = s[j++];55                     break;56             }57         }58     }59 };