题解 | #有效括号序列#

#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
# 
# @param s string字符串 
# @return bool布尔型
#
class Solution:
    def isValid(self , s: str) -> bool:
        # write code here
        """
        遇到左括号入栈
        遇到右括号，与栈顶是否匹配，匹配弹出栈顶
        """
        map = {"(": ")", "[": "]", "{": "}"}
        if not s:
            return True

        stack = []
        for i in range(len(s)):
            if s[i] in ["(", "[", "{"]:
                stack.append(s[i])
            elif stack and s[i] == map[stack[-1]]:
                stack.pop()
            else:
                return False

        if stack:
            return False
        else:
            return True