【Leetcode-python】栈和队列题I

class Solution(object):
    """
    定义一个栈和一个字典
    如果进入左括号则append
    如果进入右括号则查看栈顶是否为空，非空与栈顶元素比较，两者匹配则继续，不匹配则返回错误
    """
    def isValid(self,s):
        stack = []
        map = {')':'(',']':'[','}':'{'}
        for x in s:
            if x not in map:
                stack.append(x)
            elif not stack or map[x]!=stack.pop():
                return False
        return not stack