# 1668. Maximum Repeating Substring

## Description

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".

Example 2:

Input: sequence = "ababc", word = "ba"
Output: 1
Explanation: "ba" is a substring in "ababc". "baba" is not a substring in "ababc".

Example 3:

Input: sequence = "ababc", word = "ac"
Output: 0
Explanation: "ac" is not a substring in "ababc".

Constraints:

• 1 <= sequence.length <= 100
• 1 <= word.length <= 100
• sequence and word contains only lowercase English letters.

## Solutions

• class Solution {
public int maxRepeating(String sequence, String word) {
for (int k = sequence.length() / word.length(); k > 0; --k) {
if (sequence.contains(word.repeat(k))) {
return k;
}
}
return 0;
}
}

• class Solution {
public:
int maxRepeating(string sequence, string word) {
int ans = 0;
string t = word;
int x = sequence.size() / word.size();
for (int k = 1; k <= x; ++k) {
// C++ 这里从小到大枚举重复值
if (sequence.find(t) != string::npos) {
ans = k;
}
t += word;
}
return ans;
}
};

• class Solution:
def maxRepeating(self, sequence: str, word: str) -> int:
for k in range(len(sequence) // len(word), -1, -1):
if word * k in sequence:
return k

• func maxRepeating(sequence string, word string) int {
for k := len(sequence) / len(word); k > 0; k-- {
if strings.Contains(sequence, strings.Repeat(word, k)) {
return k
}
}
return 0
}

• function maxRepeating(sequence: string, word: string): number {
let n = sequence.length;
let m = word.length;
for (let k = Math.floor(n / m); k > 0; k--) {
if (sequence.includes(word.repeat(k))) {
return k;
}
}
return 0;
}

• impl Solution {
pub fn max_repeating(sequence: String, word: String) -> i32 {
let n = sequence.len();
let m = word.len();
if n < m {
return 0;
}
let mut dp = vec![0; n - m + 1];
for i in 0..=n - m {
let s = &sequence[i..i + m];
if s == word {
dp[i] = (if (i as i32) - (m as i32) < 0 { 0 } else { dp[i - m] }) + 1;
}
}
*dp.iter().max().unwrap()
}
}