gcd_of_strings.go

package main

func GCDOfStrings(str1 string, str2 string) string {
	if str1+str2 != str2+str1 {
		return ""
	}
	x := gcd(len(str1), len(str2))
	return str1[:x]
}

func gcd(a, b int) int {
	for b != 0 {
		a, b = b, a%b
	}
	return a
}

/*
1071. Greatest Common Divisor of Strings
Solved
Easy
Topics
Companies
Hint
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.



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: ""


Constraints:

1 <= str1.length, str2.length <= 1000
str1 and str2 consist of English uppercase letters.
*/