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.
How do I solve it
Breakdown:
Shrink down each string using the length of the other (if they are following the same pattern).
To verify they follow the same pattern, verify str1 + str2 = str2 + str1.
What is this problem
How do I solve it
Breakdown:
str1 + str2
=str2 + str1
.