题目
For two strings s and t, we say “t divides s” if and only if s = t + … + t (i.e., t is concatenated with itself one or more times).
Given two strings str1 and str2, return the largest string x such that x divides both str1 and str2.
解题思路
如果 s1 + s2 != s2 + s1 一定不存在答案，反之一定存在，对于存在的情况，结果为两个字符串长度的最大公约数
代码
import math
class Solution:
def gcdOfStrings(self, str1: str, str2: str) -> str:
if str1 + str2 != str2 + str1:
return ""
return str1[:math.gcd(len(str1), len(str2))]
