| | | 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.FindIfPathExistsInGraph; |
| | | 13 | | |
| | | 14 | | /// <inheritdoc /> |
| | | 15 | | public class FindIfPathExistsInGraphDepthFirstSearch : IFindIfPathExistsInGraph |
| | | 16 | | { |
| | | 17 | | /// <summary> |
| | | 18 | | /// Time complexity - O(v + e), where v is the number of vertices and e is the number of edges |
| | | 19 | | /// Space complexity - O(v + e), where v is the number of vertices and e is the number of edges |
| | | 20 | | /// </summary> |
| | | 21 | | /// <param name="n"></param> |
| | | 22 | | /// <param name="edges"></param> |
| | | 23 | | /// <param name="source"></param> |
| | | 24 | | /// <param name="destination"></param> |
| | | 25 | | /// <returns></returns> |
| | | 26 | | public bool ValidPath(int n, int[][] edges, int source, int destination) |
| | 2 | 27 | | { |
| | 2 | 28 | | if (source == destination) |
| | 0 | 29 | | { |
| | 0 | 30 | | return true; |
| | | 31 | | } |
| | | 32 | | |
| | 2 | 33 | | var graph = new Dictionary<int, List<int>>(); |
| | | 34 | | |
| | 22 | 35 | | for (var i = 0; i < n; i++) |
| | 9 | 36 | | { |
| | 9 | 37 | | graph[i] = []; |
| | 9 | 38 | | } |
| | | 39 | | |
| | 22 | 40 | | foreach (var edge in edges) |
| | 8 | 41 | | { |
| | 8 | 42 | | graph[edge[0]].Add(edge[1]); |
| | 8 | 43 | | graph[edge[1]].Add(edge[0]); |
| | 8 | 44 | | } |
| | | 45 | | |
| | 2 | 46 | | return ValidPath(new HashSet<int>(), graph, source, destination); |
| | 2 | 47 | | } |
| | | 48 | | |
| | | 49 | | private static bool ValidPath(ISet<int> visited, IReadOnlyDictionary<int, List<int>> graph, int current, int target) |
| | 6 | 50 | | { |
| | 6 | 51 | | if (current == target) |
| | 1 | 52 | | { |
| | 1 | 53 | | return true; |
| | | 54 | | } |
| | | 55 | | |
| | 5 | 56 | | visited.Add(current); |
| | | 57 | | |
| | 5 | 58 | | return graph[current] |
| | 12 | 59 | | .Any(neighbor => !visited.Contains(neighbor) && ValidPath(visited, graph, neighbor, target)); |
| | 6 | 60 | | } |
| | | 61 | | } |