hello-algo/codes/csharp/chapter_graph/graph_adjacency_list.cs
Yudong Jin e720aa2d24
feat: Revised the book (#978)
* 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
2023-12-02 06:21:34 +08:00

122 lines
3.5 KiB
C#
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/**
* File: graph_adjacency_list.cs
* Created Time: 2023-02-06
* Author: zjkung1123 (zjkung1123@gmail.com)
*/
namespace hello_algo.chapter_graph;
/* 基于邻接表实现的无向图类 */
public class GraphAdjList {
// 邻接表key顶点value该顶点的所有邻接顶点
public Dictionary<Vertex, List<Vertex>> adjList;
/* 构造函数 */
public GraphAdjList(Vertex[][] edges) {
adjList = [];
// 添加所有顶点和边
foreach (Vertex[] edge in edges) {
AddVertex(edge[0]);
AddVertex(edge[1]);
AddEdge(edge[0], edge[1]);
}
}
/* 获取顶点数量 */
int Size() {
return adjList.Count;
}
/* 添加边 */
public void AddEdge(Vertex vet1, Vertex vet2) {
if (!adjList.ContainsKey(vet1) || !adjList.ContainsKey(vet2) || vet1 == vet2)
throw new InvalidOperationException();
// 添加边 vet1 - vet2
adjList[vet1].Add(vet2);
adjList[vet2].Add(vet1);
}
/* 删除边 */
public void RemoveEdge(Vertex vet1, Vertex vet2) {
if (!adjList.ContainsKey(vet1) || !adjList.ContainsKey(vet2) || vet1 == vet2)
throw new InvalidOperationException();
// 删除边 vet1 - vet2
adjList[vet1].Remove(vet2);
adjList[vet2].Remove(vet1);
}
/* 添加顶点 */
public void AddVertex(Vertex vet) {
if (adjList.ContainsKey(vet))
return;
// 在邻接表中添加一个新链表
adjList.Add(vet, []);
}
/* 删除顶点 */
public void RemoveVertex(Vertex vet) {
if (!adjList.ContainsKey(vet))
throw new InvalidOperationException();
// 在邻接表中删除顶点 vet 对应的链表
adjList.Remove(vet);
// 遍历其他顶点的链表,删除所有包含 vet 的边
foreach (List<Vertex> list in adjList.Values) {
list.Remove(vet);
}
}
/* 打印邻接表 */
public void Print() {
Console.WriteLine("邻接表 =");
foreach (KeyValuePair<Vertex, List<Vertex>> pair in adjList) {
List<int> tmp = [];
foreach (Vertex vertex in pair.Value)
tmp.Add(vertex.val);
Console.WriteLine(pair.Key.val + ": [" + string.Join(", ", tmp) + "],");
}
}
}
public class graph_adjacency_list {
[Test]
public void Test() {
/* 初始化无向图 */
Vertex[] v = Vertex.ValsToVets([1, 3, 2, 5, 4]);
Vertex[][] edges =
[
[v[0], v[1]],
[v[0], v[3]],
[v[1], v[2]],
[v[2], v[3]],
[v[2], v[4]],
[v[3], v[4]]
];
GraphAdjList graph = new(edges);
Console.WriteLine("\n初始化后图为");
graph.Print();
/* 添加边 */
// 顶点 1, 2 即 v[0], v[2]
graph.AddEdge(v[0], v[2]);
Console.WriteLine("\n添加边 1-2 后,图为");
graph.Print();
/* 删除边 */
// 顶点 1, 3 即 v[0], v[1]
graph.RemoveEdge(v[0], v[1]);
Console.WriteLine("\n删除边 1-3 后,图为");
graph.Print();
/* 添加顶点 */
Vertex v5 = new(6);
graph.AddVertex(v5);
Console.WriteLine("\n添加顶点 6 后,图为");
graph.Print();
/* 删除顶点 */
// 顶点 3 即 v[1]
graph.RemoveVertex(v[1]);
Console.WriteLine("\n删除顶点 3 后,图为");
graph.Print();
}
}