3137. Minimum Number of Operations to Make Word K-Periodic
You are given a string word
of size n
, and an integer k
such that k
divides n
.
In one operation, you can pick any two indices i
and j
, that are divisible by k
, then replace the substring of length k
starting at i
with the substring of length k
starting at j
. That is, replace the substring word[i..i + k - 1]
with the substring word[j..j + k - 1]
.
Return the minimum number of operations required to make word
k-periodic.
We say that word
is k-periodic if there is some string s
of length k
such that word
can be obtained by concatenating s
an arbitrary number of times. For example, if word == “ababab”
, then word
is 2-periodic for s = "ab"
.