leetcode stackAquene 20 valid brackets

THE

problem

solution

Code

/*
思路: 涉及来回比较的问题选用栈来解决。将左符号存入栈，
然后遍历右符号，如果等于栈顶就继续，不然就

return false.

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- - 
- - 
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*/
class Solution {
    
    
public:
   bool isValid(string s) {
    
    


       int len = s.size();
       stack<char> in;
       for(int i =0;i<len;i++){
    
    

           if(s[i]=='(')in.push(')');
           else if(s[i]=='[')in.push(']');
           else if(s[i]=='{')in.push('}');

           if(s[i]==')'||s[i]=='}'||s[i]==']'){
    
    
               if(!in.empty()&&s[i] == in.top()){
    
    
                   in.pop();
               }
               else return false;
           }
       }
       return in.empty();


   }
};

Summary and reflection

1. Pay attention to consider the unparalleled judgment.