LeetCiode--Valid Parentheses

標籤：leetcode   string   字串   

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.

Solutions:

class Solution {public:    bool isValid(string s)     {        stack<char> sta;        for(int i=0; i<s.length(); i++)        {            if(s[i]=='(' || s[i] =='[' || s[i] == '{')                sta.push(s[i]);            else            {                if(sta.empty())                    return false;                char temp = sta.top();                sta.pop();                if(s[i] == ')' && temp == '(')                    continue;                else if(s[i] == ']' && temp == '[')                    continue;                else if(s[i] == '}' && temp == '{')                    continue;                else                    return false;            }        }        if(sta.empty())            return true;        return false;    }};

LeetCiode--Valid Parentheses