题解 | 括号配对问题

s = input()

def getresult(s):
    stack = []
    for c in s:
        if c=='(' or c=='[' or c=='{':#正括号入栈
            stack.append(c)
        elif c==')':#小括号配对
            if len(stack)>0 and stack[-1]=='(':
                stack.pop()
            else:
                return 'false'
        elif c==']':#中括号配对
            if len(stack)>0 and stack[-1]=='[':
                stack.pop()
            else:
                return 'false'
        elif c=='}':#大括号配对
            if len(stack)>0 and stack[-1]=='{':
                stack.pop()
            else:
                return 'false'
    return 'true' if len(stack)==0 else 'false'#查看所有括号是否配对完成

print(getresult(s))