| | | 1 | | // -------------------------------------------------------------------------------- |
| | | 2 | | // Copyright (C) 2026 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.DeleteColumnsToMakeSorted2; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public sealed class DeleteColumnsToMakeSorted2Greedy : IDeleteColumnsToMakeSorted2 |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(n * m) |
| | | 19 | | /// Space complexity - O(n) |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="strs"></param> |
| | | 22 | | /// <returns></returns> |
| | | 23 | | public int MinDeletionSize(string[] strs) |
| | 4 | 24 | | { |
| | 4 | 25 | | var result = 0; |
| | | 26 | | |
| | 4 | 27 | | var n = strs.Length; |
| | 4 | 28 | | var m = strs[0].Length; |
| | | 29 | | |
| | 4 | 30 | | Span<bool> skipped = stackalloc bool[n - 1]; |
| | | 31 | | |
| | 28 | 32 | | for (var i = 0; i < m; i++) |
| | 10 | 33 | | { |
| | 10 | 34 | | var needDelete = false; |
| | | 35 | | |
| | 40 | 36 | | for (var j = 0; j < n - 1; j++) |
| | 15 | 37 | | { |
| | 15 | 38 | | if (skipped[j] || strs[j][i] <= strs[j + 1][i]) |
| | 10 | 39 | | { |
| | 10 | 40 | | continue; |
| | | 41 | | } |
| | | 42 | | |
| | 5 | 43 | | needDelete = true; |
| | | 44 | | |
| | 5 | 45 | | break; |
| | | 46 | | } |
| | | 47 | | |
| | 10 | 48 | | if (needDelete) |
| | 5 | 49 | | { |
| | 5 | 50 | | result++; |
| | | 51 | | |
| | 5 | 52 | | continue; |
| | | 53 | | } |
| | | 54 | | |
| | 30 | 55 | | for (var j = 0; j < n - 1; j++) |
| | 10 | 56 | | { |
| | 10 | 57 | | if (skipped[j]) |
| | 3 | 58 | | { |
| | 3 | 59 | | continue; |
| | | 60 | | } |
| | | 61 | | |
| | 7 | 62 | | if (strs[j][i] < strs[j + 1][i]) |
| | 6 | 63 | | { |
| | 6 | 64 | | skipped[j] = true; |
| | 6 | 65 | | } |
| | 7 | 66 | | } |
| | 5 | 67 | | } |
| | | 68 | | |
| | 4 | 69 | | return result; |
| | 4 | 70 | | } |
| | | 71 | | } |