백준 11723 파이썬 python : 집합 @@황소처럼 우직하게@@

import sys
input = sys.stdin.readline

S = []

def do(order, num):
    global S
    if order == 'add':
        if num not in S:
            S.append(num)
    elif order == 'remove':
        if num in S:
            S.remove(num)
    elif order == 'check':
        if num in S:
            print(1)
        else:
            print(0)
    elif order == 'toggle':
        if num in S:
            S.remove(num)
        else:
            S.append(num)
    elif order == 'all':
        S = [i for i in range(1, 21)]
    elif order == 'empty':
        S = []

n = int(input())
for i in range(n):
    s = input().strip()
    if s == 'all' or s == 'empty':
        do(s, 0)
        continue
    s = s.split()
    do(s[0], int(s[1]))