[LeetCode] # 1071 Greatest Common Divisor of Strings

Environment: Python 3.7

Key technique: Recursive Method

Example 1:

Input: str1 = "ABCABC", str2 = "ABC"
Output: "ABC"

Example 2:

Input: str1 = "ABABAB", str2 = "ABAB"
Output: "AB"

Example 3:

Input: str1 = "LEET", str2 = "CODE"
Output: ""

Solution:

class Solution:
    def gcdOfStrings(self, str1: str, str2: str) -> str:
                 l1, l2 =len(str1),len(str2)
                 if l1==0 :return str2
                 if l1<l2 :return self.gcdOfStrings(str2,str1)
                 if str1[0:l2] !=str2: return ""
                 return self.gcdOfStrings(str1[l2:],str2)

Submitted result:

Lesson learn:

Recursive Method can reduce code number and better than two for loop.

Reference:

https://kknews.cc/zh-tw/code/lm4op4z.html