表达式括号匹配

解题思路:

注意事项:

参考代码:

def func(s):

    stack = []

    mapping = {')': '('}

    for char in s:

        if char in mapping.values():

            stack.append(char)

        elif char in mapping.keys():

            if not stack or mapping[char] != stack.pop():

                return 'NO'

    return "YES" if len(stack) == 0 else "NO"

expression = input()

result = func(expression + '@')

print(result)