将方法参数更改为对象时出错（jgrapht 库）

Question

我正在尝试修改 Jgrapht 的函数以将一个点的坐标对 (int, int) 作为参数。我创建了一个 class 和一个由 (x,y) 定义的 Point 对象，并将其作为 directedGraph 的参数

    public 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+"]");
      }
    }
  // --------------------------------------------------------------

    public class DirectedGraphDemo {
      public  void graph(String args[]) {

        //Create the directed graph
        public DirectedGraph<Point, DefaultEdge> directedGraph = new DefaultDirectedGraph<Point, DefaultEdge>(DefaultEdge.class);

        // constructs a directed graph with the specified vertices and edges

        directedGraph.addVertex(1,2);
        directedGraph.addVertex(1,3);
        directedGraph.addVertex(1,4);

        directedGraph.addEdge((1,2),(1,3));
        directedGraph.addEdge((1,3),(1,4));
        directedGraph.addEdge((1,4),(1,2));

        // computes all the strongly connected components of the directed graph
        StrongConnectivityInspector sci =
          new StrongConnectivityInspector(directedGraph);
        List stronglyConnectedSubgraphs = sci.stronglyConnectedSubgraphs();

        // prints the strongly connected components
        System.out.println("Strongly connected components:");
        for (int i = 0; i < stronglyConnectedSubgraphs.size (); i++) {
          System.out.println(stronglyConnectedSubgraphs.get(i));
        }
        System.out.println();

        // Prints the shortest path from vertex i to vertex c. This certainly
        // exists for our particular directed graph.
        System.out.println("Shortest path from (1,2) to (1,3):");
        List path =
          DijkstraShortestPath.findPathBetween(directedGraph, (1,2),(1,3);
        System.out.println(path + "\n");

        // Prints the shortest path from vertex c to vertex i. This path does
        // NOT exist for our particular directed graph. Hence the path is
        // empty and the variable "path"; must be null.
        System.out.println("Shortest path from (1,2) to (1,3):");
        path = DijkstraShortestPath.findPathBetween(directedGraph, (1,2), (1,3));
        System.out.println(path);
      }
    }

我想做的是能够使用：

directedGraph.addVertex(x1,y1);
directedGraph.addVertex(x2,y2);
directedGraph.addEdge((x1,y1), (x2,y2));
path = DijkstraShortestPath.findPathBetween(directedGraph,(x1,y1),(x2,y2));

当我运行代码时，即使参数为 Point，我也会收到错误 "the method addVertex is not applicable for the argument (int,int)"，这是由 (int,int) 定义的。我应该如何进行这项工作？

我使用基于Java

的Processing

Answer 1

此类问题最好通过查看 the API 来回答。

addVertex() 函数接受一个 Point 参数，正如您在通用参数中指定的那样。您不能只替换两个 int 值并期望它起作用。相反，您必须提供 Point 值：

directedGraph.addVertex(new Point(1,2));

同样，您也必须将 Point 值传递给 DijkstraShortestPath.findPathBetween() 函数：

path = DijkstraShortestPath.findPathBetween(directedGraph, new Point(x1,y1),new Point(x2,y2));

将方法参数更改为对象时出错（jgrapht 库）

Error when changing method parameter to an object (jgrapht library)

java

processing

jgrapht

digraphs