0020 Valid Parentheses

• Simple
• C++

问题概述

解题思路

class Solution
{
public:
    bool isValid(std::string s)
    {
        std::stack<char> StackofS;
        char right = '\0';
        char left = '\0';

        for (std::string::iterator it = s.begin(); it != s.end(); it++)
        {
            switch (*it)
            {
            case '(':StackofS.push(*it); break;
            case '{':StackofS.push(*it); break;
            case '[':StackofS.push(*it); break;
            case ')':left = '('; right = *it; break;
            case '}':left = '{'; right = *it; break;
            case ']':left = '['; right = *it; break;
            default:
                break;
            }
            // std::cout << *it << std::endl;

            if (right == *it)
            {
                if (StackofS.empty()) { return false; }
                else
                {
                    char tmp = StackofS.top();
                    StackofS.pop();
                    if (tmp != left) { return false; }
                }
            }

        }
        if (StackofS.empty()) { return true; }
        else { return false; }
    }
};