leetcode-1668-easy

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".
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.

思路一：遍历字符串，对每个位置开始的子串都统计一遍长度，选中最大长度

public int maxRepeating(String sequence, String word) {
    int count = 0;
    for (int i = 0; i < sequence.length(); i++) {
        count = Math.max(maxRepeating(sequence, word, i), count);
    }

    return count;
}

public int maxRepeating(String sequence, String word, int begin) {
    int N = word.length();

    int count = 0;
    for (int i = begin; i < sequence.length(); i++) {
        if (sequence.charAt(i) == word.charAt((i - begin) % N)) {
            count++;
        } else {
            break;
        }
    }

    return count / N;
}