c# - 在 C# 中创建图形类

Question

我的任务是在 C# 中创建 Graph 类，它具有以下属性:

private List<string> vertices;
private List<List<int>> adjacencyMatrix;
private int n;

n 是节点数，我相信其余部分不言自明。该类还应该有两个如下所示的方法:

添加(字符串顶点){}

AddConnection(string vertex1, string vertex2, int value){}

至此，我想通了Add方法(假设0代表顶点之间没有连接):

public void Add(string vertex)
{
     this.vertices.Add(vertex);
    List<int> temp = new List<int>();
    foreach(List<int> element in this.adjacencyMatrix)
    {
        element.Add(0);
    }
    foreach(string element in vertices)
    {
        temp.Add(0);
    }
    this.adjacencyMatrix.Add(temp);

    this.n++;
}

但是我还是不知道怎么添加连接。任何帮助将不胜感激

Answer 1

好吧，尽管有负面评论，我还是设法解决了它。我知道这种方法没有多大意义，但我没有选择它。如果有人感兴趣，请在 Add 和 AddConnection 方法下方，另外使用 SaveMatrix 方法将其很好地写入 txt 文件。

   public void Add(string vertex)
{
    this.vertices.Add(vertex);
    List<int> temp = new List<int>();

    foreach(List<int> element in this.adjacencyMatrix)
    {
        element.Add(0);
    }
    foreach(string element in vertices)
    {
        temp.Add(0);
    }
    this.adjacencyMatrix.Add(temp);

    this.n++;
}

  public void AddConnection(string vertex1, string vertex2, int value)
{
   if(this.vertices.Contains(vertex1) && this.vertices.Contains(vertex2))
    {
       int index1= this.vertices.IndexOf(vertex1);
        int index2 = this.vertices.IndexOf(vertex2);

        this.adjacencyMatrix[index1][index2] = value;
        this.adjacencyMatrix[index2][index1] = value;
    }
    else
    {
        Console.WriteLine("Graph doesn't contain passed vertex/vertices.");
    }
}

public void SaveMatrix(string filename)
{
    // save matrix with nice formatting
    // works if the names of the vertices are shorter than 16 chars and if edge weights are shorter than 100 (and positive)
    try
    {
        StreamWriter sw = new StreamWriter(filename);
        sw.Write("".PadRight(16)); // pad a string with white spaces to get exactly the specified length in chars
        foreach (string s in vertices) sw.Write(s.PadRight(16)); // write first row with names
        sw.WriteLine();
        int counter = 0;
        foreach (List<int> column in adjacencyMatrix) // other rows
        {
            sw.Write(vertices[counter].PadRight(16)); // start with vertex name
            counter++;
            foreach (int i in column)
            {
                if (i >= 10) sw.Write(i + "".PadRight(15)); // two digits
                else if (i > 0) sw.Write("0" + i + "".PadRight(15)); // one digit
                else sw.Write("--" + "".PadRight(15)); // no connection
            }
            sw.WriteLine();
        }
        sw.Close();
    }
    catch (IOException e)
    {
        Console.WriteLine("Error - the file could not be read");
        Console.WriteLine(e.Message);
    }
}