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149 lines
4.2 KiB
C#
149 lines
4.2 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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using hello_algo.include;
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using NUnit.Framework;
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namespace hello_algo.chapter_graph;
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/* 基于邻接矩阵实现的无向图类 */
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class GraphAdjMat
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{
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List<int> vertices; // 顶点列表,元素代表“顶点值”,索引代表“顶点索引”
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List<List<int>> adjMat; // 邻接矩阵,行列索引对应“顶点索引”
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/* 构造函数 */
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public GraphAdjMat(int[] vertices, int[][] edges)
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{
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this.vertices = new List<int>();
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this.adjMat = new List<List<int>>();
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// 添加顶点
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foreach (int val in vertices)
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{
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addVertex(val);
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}
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// 添加边
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// 请注意,edges 元素代表顶点索引,即对应 vertices 元素索引
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foreach (int[] e in edges)
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{
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addEdge(e[0], e[1]);
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}
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}
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/* 获取顶点数量 */
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public int size()
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{
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return vertices.Count;
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}
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/* 添加顶点 */
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public void addVertex(int val)
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{
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int n = size();
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// 向顶点列表中添加新顶点的值
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vertices.Add(val);
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// 在邻接矩阵中添加一行
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List<int> newRow = new List<int>(n);
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for (int j = 0; j < n; j++)
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{
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newRow.Add(0);
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}
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adjMat.Add(newRow);
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// 在邻接矩阵中添加一列
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foreach (List<int> row in adjMat)
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{
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row.Add(0);
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}
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}
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/* 删除顶点 */
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public void removeVertex(int index)
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{
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if (index >= size())
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throw new IndexOutOfRangeException();
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// 在顶点列表中移除索引 index 的顶点
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vertices.RemoveAt(index);
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// 在邻接矩阵中删除索引 index 的行
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adjMat.RemoveAt(index);
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// 在邻接矩阵中删除索引 index 的列
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foreach (List<int> row in adjMat)
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{
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row.RemoveAt(index);
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}
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}
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/* 添加边 */
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// 参数 i, j 对应 vertices 元素索引
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public void addEdge(int i, int j)
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{
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// 索引越界与相等处理
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if (i < 0 || j < 0 || i >= size() || j >= size() || i == j)
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throw new IndexOutOfRangeException();
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// 在无向图中,邻接矩阵沿主对角线对称,即满足 (i, j) == (j, i)
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adjMat[i][j] = 1;
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adjMat[j][i] = 1;
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}
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/* 删除边 */
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// 参数 i, j 对应 vertices 元素索引
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public void removeEdge(int i, int j)
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{
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// 索引越界与相等处理
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if (i < 0 || j < 0 || i >= size() || j >= size() || i == j)
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throw new IndexOutOfRangeException();
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adjMat[i][j] = 0;
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adjMat[j][i] = 0;
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}
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/* 打印邻接矩阵 */
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public void print()
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{
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Console.Write("顶点列表 = ");
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PrintUtil.PrintList(vertices);
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Console.WriteLine("邻接矩阵 =");
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PrintUtil.PrintMatrix(adjMat);
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}
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}
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public class graph_adjacency_matrix
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{
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[Test]
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public void Test()
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{
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/* 初始化无向图 */
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// 请注意,edges 元素代表顶点索引,即对应 vertices 元素索引
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int[] vertices = { 1, 3, 2, 5, 4 };
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int[][] edges = new int[][] { new int[] { 0, 1 }, new int[] { 0, 3 },
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new int[] { 1, 2 }, new int[] { 2, 3 },
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new int[] { 2, 4 }, new int[] { 3, 4 } };
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GraphAdjMat graph = new GraphAdjMat(vertices, 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 的索引分别为 0, 2
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graph.addEdge(0, 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 的索引分别为 0, 1
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graph.removeEdge(0, 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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graph.addVertex(6);
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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 的索引为 1
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graph.removeVertex(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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