题解 | 禁止重复注册

import sys

c_users = ['Niuniu','Niumei','GURR','LOLO']
n_users = ['GurR','Niu Ke Le','LoLo','Tuo Rui Chi']

is_same = 0
for i in n_users:
    for j in c_users:
        if(i.upper() == j.upper()):
            print(f'The user name {i} has already been registered! Please change it and try again!')
            is_same = 1
            break
    if(is_same == 1):
        is_same = 0
    else:
        print(f'Congratulations, the user name {i} is available!')

#使用break 和标志is_same