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
        stack = []
        cmap = {")":"(", "]":"[", "}":"{"}  # 键值对形式存储一对括号
        for c in s:
            if c in ["(", "[", "{"]:    # 左括号入栈
                stack.append(c)
            elif c in [")", "]", "}"]:  # 右括号不入栈
                if not stack or stack[-1] != cmap[c]: return False
                stack.pop() # 若栈顶为右括号对应的左括号时就弹出左括号
        return len(stack) == 0