[LeetCode 20] effective brackets

Topic Link

【answer】

A sucker brackets match title

[Code]

class Solution {
public:
    bool isValid(string s) {
        vector<char> v;
        int len = s.size();
        for (int i = 0;i < len;i++){
            if (s[i]=='(' || s[i]=='[' || s[i]=='{'){
                v.push_back(s[i]);
            }else{
                if (v.empty()) return false;
                char x = v.back();
                if (x=='(' && s[i]!=')') return false;
                if (x=='[' && s[i]!=']') return false;
                if (x=='{' && s[i]!='}') return false;
                v.pop_back();
            }
        }
        if (!v.empty()) return false;
        return true;
    }
};