题解 | #有效括号序列#

class Solution {
public:
    /**
     * 
     * @param s string字符串 
     * @return bool布尔型
     */
    bool isValid(string s) {
        // write code here
        int num = s.length();
        if(num % 2 != 0)
            return false;
        stack<char> S;
        char tmp;
        for(int i = 0; i < num; i++){
            if(s[i] == '(' || s[i] == '{' || s[i] == '['){
                S.push(s[i]);
                continue;
            }
            if(S.empty()) return false;
            switch(s[i]){
                case ')':
                    tmp = S.top();
                    S.pop();
                    if(tmp != '(')
                        return false;
                    break;
                case '}':
                    tmp = S.top();
                    S.pop();
                    if(tmp != '{')
                        return false;
                    break;
                case ']':
                    tmp = S.top();
                    S.pop();
                    if(tmp != '[')
                        return false;
                    break;    
                default:
                    return false;
            }
        }
        if(!S.empty()) return false;
        return true;

    }
};