1071. Greatest Common Divisor of Strings

Easy53.4% acceptance925,569 / 1,732,080 submissions

Asked by 8 companies

Topics


For two strings s and t, we say "t divides s" if and only if s = t + t + t + ... + 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: ""

Example 4:

Input: str1 = "AAAAAB", str2 = "AAA"

Output: ""​​​​​​​

 

Constraints:

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

Hints

Hint 1
The greatest common divisor must be a prefix of each string, so we can try all prefixes.

Similar Questions