mirror of
https://github.com/krahets/hello-algo.git
synced 2026-06-28 08:34:28 +00:00
Yudong Jin
e720aa2d24
* Sync recent changes to the revised Word. * Revised the preface chapter * Revised the introduction chapter * Revised the computation complexity chapter * Revised the chapter data structure * Revised the chapter array and linked list * Revised the chapter stack and queue * Revised the chapter hashing * Revised the chapter tree * Revised the chapter heap * Revised the chapter graph * Revised the chapter searching * Reivised the sorting chapter * Revised the divide and conquer chapter * Revised the chapter backtacking * Revised the DP chapter * Revised the greedy chapter * Revised the appendix chapter * Revised the preface chapter doubly * Revised the figures
123 lines
3.5 KiB
C#
123 lines
3.5 KiB
C#
/**
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* File: graph_adjacency_list.cs
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* Created Time: 2023-02-06
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* Author: zjkung1123 (zjkung1123@gmail.com)
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*/
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namespace hello_algo.chapter_graph;
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/* 基于邻接表实现的无向图类 */
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public class GraphAdjList {
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// 邻接表，key：顶点，value：该顶点的所有邻接顶点
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public Dictionary<Vertex, List<Vertex>> adjList;
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/* 构造函数 */
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public GraphAdjList(Vertex[][] edges) {
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adjList = [];
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// 添加所有顶点和边
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foreach (Vertex[] edge in edges) {
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AddVertex(edge[0]);
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AddVertex(edge[1]);
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AddEdge(edge[0], edge[1]);
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}
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}
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/* 获取顶点数量 */
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int Size() {
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return adjList.Count;
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}
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/* 添加边 */
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public void AddEdge(Vertex vet1, Vertex vet2) {
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if (!adjList.ContainsKey(vet1) || !adjList.ContainsKey(vet2) || vet1 == vet2)
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throw new InvalidOperationException();
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// 添加边 vet1 - vet2
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adjList[vet1].Add(vet2);
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adjList[vet2].Add(vet1);
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}
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/* 删除边 */
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public void RemoveEdge(Vertex vet1, Vertex vet2) {
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if (!adjList.ContainsKey(vet1) || !adjList.ContainsKey(vet2) || vet1 == vet2)
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throw new InvalidOperationException();
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// 删除边 vet1 - vet2
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adjList[vet1].Remove(vet2);
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adjList[vet2].Remove(vet1);
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}
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/* 添加顶点 */
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public void AddVertex(Vertex vet) {
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if (adjList.ContainsKey(vet))
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return;
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// 在邻接表中添加一个新链表
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adjList.Add(vet, []);
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}
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/* 删除顶点 */
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public void RemoveVertex(Vertex vet) {
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if (!adjList.ContainsKey(vet))
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throw new InvalidOperationException();
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// 在邻接表中删除顶点 vet 对应的链表
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adjList.Remove(vet);
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// 遍历其他顶点的链表，删除所有包含 vet 的边
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foreach (List<Vertex> list in adjList.Values) {
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list.Remove(vet);
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}
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}
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/* 打印邻接表 */
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public void Print() {
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Console.WriteLine("邻接表 =");
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foreach (KeyValuePair<Vertex, List<Vertex>> pair in adjList) {
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List<int> tmp = [];
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foreach (Vertex vertex in pair.Value)
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tmp.Add(vertex.val);
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Console.WriteLine(pair.Key.val + ": [" + string.Join(", ", tmp) + "],");
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}
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}
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}
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public class graph_adjacency_list {
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[Test]
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public void Test() {
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/* 初始化无向图 */
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Vertex[] v = Vertex.ValsToVets([1, 3, 2, 5, 4]);
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Vertex[][] edges =
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[
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[v[0], v[1]],
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[v[0], v[3]],
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[v[1], v[2]],
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[v[2], v[3]],
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[v[2], v[4]],
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[v[3], v[4]]
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];
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GraphAdjList graph = new(edges);
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Console.WriteLine("\n初始化后，图为");
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graph.Print();
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/* 添加边 */
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// 顶点 1, 2 即 v[0], v[2]
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graph.AddEdge(v[0], v[2]);
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Console.WriteLine("\n添加边 1-2 后，图为");
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graph.Print();
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/* 删除边 */
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// 顶点 1, 3 即 v[0], v[1]
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graph.RemoveEdge(v[0], v[1]);
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Console.WriteLine("\n删除边 1-3 后，图为");
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graph.Print();
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/* 添加顶点 */
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Vertex v5 = new(6);
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graph.AddVertex(v5);
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Console.WriteLine("\n添加顶点 6 后，图为");
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graph.Print();
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/* 删除顶点 */
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// 顶点 3 即 v[1]
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graph.RemoveVertex(v[1]);
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Console.WriteLine("\n删除顶点 3 后，图为");
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graph.Print();
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}
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}
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