【leetcode】Valid Parentheses

Given a string containing just the characters ‘(‘, ‘)‘, ‘{‘, ‘}‘, ‘[‘ and ‘]‘, determine if the input string is valid.

The brackets must close in the correct order, "()" and "()[]{}" are all valid but "(]" and "([)]" are not.

【My Solution:】

#include "stdafx.h"
#include <iostream>
#include <vector>

using namespace std;

class Solution {
public:
    bool checkMatch(char first,char second){
        bool isMatch = false;
        if((first == ‘(‘ && second == ‘)‘)
            || (first == ‘[‘ && second == ‘]‘)
            || (first == ‘{‘ && second == ‘}‘))
        {
            isMatch = true;
        }
        return isMatch;
    }

    bool isValid(string s) {
        bool isValid = false;
        vector<char> vTemp;
        if(s.length() <= 0){
            return isValid;
        }
        //vTemp.push_back(s[0]);
        for(int i = 0; i < s.length(); i++){
            if(vTemp.size() == 0){
                vTemp.push_back(s[i]);
            }else{
                vector<char>::iterator id = vTemp.end()-1;
                if(checkMatch((*id),s[i])){
                    vTemp.erase(id);
                }else{
                    vTemp.push_back(s[i]);
                }
            }
        }
        if(vTemp.size() == 0){
            isValid = true;
        }
        return isValid;
    }
};

int main(){
    Solution solution;
    solution.isValid("()");
    solution.isValid("()[]{}");
    solution.isValid("([)]");
    return 0;
}

【other‘s】算法使用相同，都使用栈来实现，但his更简洁，1、直接用到了已有的数据结构stack；2、匹配用到了ASCII码，但这样不合适，万一输入为“sdsf”等字符，则结果不正确。

public class Solution {
public boolean isValid(String s) {
    char [] arr = s.toCharArray();
    Stack stack = new Stack();
    for(char ch : arr){
        if(stack.isEmpty()){
            stack.push(ch);
        }else{
            char top = (char)stack.lastElement();
            if(ch - top == 1 || ch - top == 2){
                stack.pop();
            }else{
                stack.push(ch);
            }
        }
    }
    if(stack.isEmpty()){
        return true;
    }
    return false;
}