字节跳动的一道python面试题

#!/usr/bin/python
#coding=utf-8
#好好学习，天天向上
lst = ['hongkong','xiantyk','chinat','guangdong','z']
lst2 = []
lst3 = []
lst4 = []
def get_num():
    for i in range(len(lst)):
        for j in range(i+1,len(lst)):
            lst2 = list(lst[i])
            lst3 = list(lst[j])
            if len(set(lst2+lst3)) == len(lst2+lst3):
                num = len(lst2)*len(lst3)
                lst4.append(num)
    if len(lst4) == 0:
       return 0
    else:
        return max(lst4)

if __name__ == '__main__':
    print(get_num())