1668. Maximum Repeating Substring

package LeetCode_1668

/**
 * 1668. Maximum Repeating Substring
 * https://leetcode.com/problems/maximum-repeating-substring/
 * For a string sequence, a string word is k-repeating if word concatenated k times is a substring of sequence.
 * The word's maximum k-repeating value is the highest value k where word is k-repeating in sequence.
 * If word is not a substring of sequence, word's maximum k-repeating value is 0.
Given strings sequence and word, return the maximum k-repeating value of word in sequence.

Example 1:
Input: sequence = "ababc", word = "ab"
Output: 2
Explanation: "abab" is a substring in "ababc".
 * */
class Solution {
    /*
    * Time:(n), Space:O(1)
    * */
    fun maxRepeating(sequence: String, word: String): Int {
        val l = sequence.length
        var max = 0
        var count = 0
        var start = 0
        while (start + word.length <= l) {
            val end = start + word.length
            if (sequence.substring(start, end) == word) {
                count++
                /*
                * jump into next right position, for example: "ababc" and "ab",
                * start is 0,then jump into 0+2
                * */
                start += word.length
                max = Math.max(max, count)
            } else {
                //if not match, reset the count and moving start
                count = 0
                start++
            }
        }
        return max
    }
}