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".
Example 1:
Input: word = "leetcodeleet", k = 4
Output: 1
Explanation:
We can obtain a 4-periodic string by picking i = 4 and j = 0. After this operation, word becomes equal to "leetleetleet".
Example 2:
Input: word = "leetcoleet", k = 2
Output: 3
Explanation:
We can obtain a 2-periodic string by applying the operations in the table below.
| i | j | word |
|---|---|---|
| 0 | 2 | etetcoleet |
| 4 | 0 | etetetleet |
| 6 | 0 | etetetetet |
Constraints:
1 <= n == word.length <= 1051 <= k <= word.lengthk divides word.length.word consists only of lowercase English letters.