2023-02-01.md

题目

思路

1071. Greatest Common Divisor of Strings

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.

代码

// runtime 93.75% memory 95.83%
var gcdOfStrings = function(str1, str2) {
  function gcd(str1, str2) {
    if (str2.length == 0) {
      return str1
    }
    if (str1.indexOf(str2) == -1) {
      return ""
    }
    while (str1.startsWith(str2)) {
      str1 = str1.substr(str2.length)
    }
    return gcd(str2, str1)
  }
  return str1.length > str2.length ? gcd(str1, str2) : gcd(str2, str1)
}