java - 返回有向图中每个顶点的边数 (jgrapht)

Question

我使用以下方法创建了一个有向图:

    public static DirectedGraph<Point, DefaultEdge> directedGraph = new DefaultDirectedGraph<Point, DefaultEdge>(DefaultEdge.class);

 void setup() { 

  Point myPoint = new Point(x, y);
  Point myNextPoint = new Point(xToFillNext, yToFillNext);
  directedGraph.addVertex(myPoint);
  directedGraph.addVertex(myNextPoint);
  directedGraph.addEdge(myPoint, myNextPoint);

  Point mySecondPoint = new Point(x, y);
  Point mySecondNextPoint = new Point(xToFillNext, yToFillNext);
  directedGraph.addVertex(mySecondPoint);
  directedGraph.addVertex(mySecondNextPoint);
  directedGraph.addEdge(mySecondPoint, mySecondNextPoint);

System.out.println("#vertices: "+ directedGraph.vertexSet());

}

 public static class Point {

  public int x;
  public int y;

  public  Point(int x, int y) 
  {

    this.x = x;
    this.y = y;
  }
  @Override
    public String toString() {
    return ("[x="+x+" y="+y+"]");
  }

  @Override
public int hashCode() {
    int hash = 7;
    hash = 71 * hash + this.x;
    hash = 71 * hash + this.y;
    return hash;
}



@Override
public boolean equals(Object other) 
{
    if (this == other)
       return true;

    if (!(other instanceof Point))
       return false;

    Point otherPoint = (Point) other;
    return otherPoint.x == x && otherPoint.y == y;
}
}

我想使用以下方法获取每个顶点的向外边数:

directedGraph.outDegreeOf()

但我不想逐个顶点地执行此操作(这是一个简单的代码，可以更轻松地完成它，在我的整个程序中，我有更多的顶点)并且我想遍历顶点自动设置并返回集合中每个顶点的向外边的数量，无论有多少个顶点。

我应该如何继续执行此操作？

(我使用的是基于java的处理)

Answer 1

查看 JGrapht API 。

DirectedGraph界面包含 vertexSet()功能。您可以使用它来迭代您添加的顶点，并且可以获得每个顶点的 outDegreeValue():

for(Point p : directedGraph.vertexSet()){
   int degree = directedGraph.outDegreeOf(p);
   System.out.println("Degree of " p.toString() + ": " + degree);
}