| | | 1 | | // -------------------------------------------------------------------------------- |
| | | 2 | | // Copyright (C) 2025 Eugene Eremeev (also known as Yevhenii Yeriemeieiv). |
| | | 3 | | // All Rights Reserved. |
| | | 4 | | // -------------------------------------------------------------------------------- |
| | | 5 | | // This software is the confidential and proprietary information of Eugene Eremeev |
| | | 6 | | // (also known as Yevhenii Yeriemeieiv) ("Confidential Information"). You shall not |
| | | 7 | | // disclose such Confidential Information and shall use it only in accordance with |
| | | 8 | | // the terms of the license agreement you entered into with Eugene Eremeev (also |
| | | 9 | | // known as Yevhenii Yeriemeieiv). |
| | | 10 | | // -------------------------------------------------------------------------------- |
| | | 11 | | |
| | | 12 | | namespace LeetCode.Algorithms.RepeatedSubstringPattern; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class RepeatedSubstringPatternKMP : IRepeatedSubstringPattern |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n) |
| | | 19 | | /// Space complexity - O(n) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="s"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public bool RepeatedSubstringPattern(string s) |
| | 3 | 24 | | { |
| | 3 | 25 | | var n = s.Length; |
| | 3 | 26 | | var lps = new int[n]; |
| | | 27 | | |
| | 3 | 28 | | ComputeLPSArray(s, n, lps); |
| | | 29 | | |
| | 3 | 30 | | var len = lps[n - 1]; |
| | | 31 | | |
| | 3 | 32 | | return len > 0 && n % (n - len) == 0; |
| | 3 | 33 | | } |
| | | 34 | | |
| | | 35 | | private static void ComputeLPSArray(string s, int n, IList<int> lps) |
| | 3 | 36 | | { |
| | 3 | 37 | | var len = 0; |
| | 3 | 38 | | lps[0] = 0; |
| | | 39 | | |
| | 3 | 40 | | var i = 1; |
| | | 41 | | |
| | 19 | 42 | | while (i < n) |
| | 16 | 43 | | { |
| | 16 | 44 | | if (s[i] == s[len]) |
| | 12 | 45 | | { |
| | 12 | 46 | | len++; |
| | 12 | 47 | | lps[i] = len; |
| | 12 | 48 | | i++; |
| | 12 | 49 | | } |
| | | 50 | | else |
| | 4 | 51 | | { |
| | 4 | 52 | | if (len != 0) |
| | 0 | 53 | | { |
| | 0 | 54 | | len = lps[len - 1]; |
| | 0 | 55 | | } |
| | | 56 | | else |
| | 4 | 57 | | { |
| | 4 | 58 | | lps[i] = len; |
| | 4 | 59 | | i++; |
| | 4 | 60 | | } |
| | 4 | 61 | | } |
| | 16 | 62 | | } |
| | 3 | 63 | | } |
| | | 64 | | } |