| | | 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.RegionsCutBySlashes; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class RegionsCutBySlashesDepthFirstSearch : IRegionsCutBySlashes |
| | | 16 | | { |
| | | 17 | | private const int Multiplier = 3; |
| | | 18 | | |
| | | 19 | | /// <summary> |
| | | 20 | | /// Time complexity - O(n^2) |
| | | 21 | | /// Space complexity - O(n) |
| | | 22 | | /// </summary> |
| | | 23 | | /// <param name="grid"></param> |
| | | 24 | | /// <returns></returns> |
| | | 25 | | public int RegionsBySlashes(string[] grid) |
| | 6 | 26 | | { |
| | 6 | 27 | | var matrix = new int[grid.Length * Multiplier][]; |
| | | 28 | | |
| | 68 | 29 | | for (var i = 0; i < grid.Length; i++) |
| | 28 | 30 | | { |
| | 28 | 31 | | var m = i * Multiplier; |
| | | 32 | | |
| | 224 | 33 | | for (var j = 0; j < Multiplier; j++) |
| | 84 | 34 | | { |
| | 84 | 35 | | matrix[m + j] = new int[grid[i].Length * Multiplier]; |
| | 84 | 36 | | } |
| | | 37 | | |
| | 628 | 38 | | for (var j = 0; j < grid[i].Length; j++) |
| | 286 | 39 | | { |
| | 286 | 40 | | var n = j * Multiplier; |
| | | 41 | | |
| | 286 | 42 | | switch (grid[i][j]) |
| | | 43 | | { |
| | | 44 | | case '/': |
| | | 45 | | |
| | 824 | 46 | | for (var k = 0; k < Multiplier; k++) |
| | 309 | 47 | | { |
| | 309 | 48 | | matrix[m + k][n + (Multiplier - 1) - k] = 1; |
| | 309 | 49 | | } |
| | | 50 | | |
| | 103 | 51 | | break; |
| | | 52 | | case '\\': |
| | 808 | 53 | | for (var k = 0; k < Multiplier; k++) |
| | 303 | 54 | | { |
| | 303 | 55 | | matrix[m + k][n + k] = 1; |
| | 303 | 56 | | } |
| | | 57 | | |
| | 101 | 58 | | break; |
| | | 59 | | } |
| | 286 | 60 | | } |
| | 28 | 61 | | } |
| | | 62 | | |
| | 6 | 63 | | var regionCount = 0; |
| | | 64 | | |
| | 180 | 65 | | for (var i = 0; i < matrix.Length; i++) |
| | 84 | 66 | | { |
| | 5316 | 67 | | for (var j = 0; j < matrix[i].Length; j++) |
| | 2574 | 68 | | { |
| | 2574 | 69 | | if (matrix[i][j] != 0) |
| | 2549 | 70 | | { |
| | 2549 | 71 | | continue; |
| | | 72 | | } |
| | | 73 | | |
| | 25 | 74 | | FindRegions(matrix, i, j); |
| | | 75 | | |
| | 25 | 76 | | regionCount++; |
| | 25 | 77 | | } |
| | 84 | 78 | | } |
| | | 79 | | |
| | 6 | 80 | | return regionCount; |
| | 6 | 81 | | } |
| | | 82 | | |
| | | 83 | | private static void FindRegions(IReadOnlyList<int[]> matrix, int i, int j) |
| | 1962 | 84 | | { |
| | 1962 | 85 | | matrix[i][j] = -1; |
| | | 86 | | |
| | 1962 | 87 | | if (i + 1 < matrix.Count && matrix[i + 1][j] == 0) |
| | 677 | 88 | | { |
| | 677 | 89 | | FindRegions(matrix, i + 1, j); |
| | 677 | 90 | | } |
| | | 91 | | |
| | 1962 | 92 | | if (i - 1 >= 0 && matrix[i - 1][j] == 0) |
| | 620 | 93 | | { |
| | 620 | 94 | | FindRegions(matrix, i - 1, j); |
| | 620 | 95 | | } |
| | | 96 | | |
| | 1962 | 97 | | if (j + 1 < matrix[i].Length && matrix[i][j + 1] == 0) |
| | 270 | 98 | | { |
| | 270 | 99 | | FindRegions(matrix, i, j + 1); |
| | 270 | 100 | | } |
| | | 101 | | |
| | 1962 | 102 | | if (j - 1 >= 0 && matrix[i][j - 1] == 0) |
| | 370 | 103 | | { |
| | 370 | 104 | | FindRegions(matrix, i, j - 1); |
| | 370 | 105 | | } |
| | 1962 | 106 | | } |
| | | 107 | | } |