Graph(int V, double d)
      {
	Fence f1,f2;
        f1 = new Fence(new Point(0.5,0.2),
                       new Point(0.5,0.8));
        f2 = new Fence(new Point(0.2,0.5),
                       new Point(0.8,0.5));

        this.V = V; this.E = 0;
        adj = new Node[V]; 
        p = new Point[V]; 
        for (int i = 0; i < V; i++)
          p[i] = new Point(Math.random(), Math.random());
        for (int i = 0; i < V; i++)
          adj[i] = new Node(i, null);
        for (int i = 0; i < V; i++)
          for (int j = i+1; j < V; j++)
            if ((Point.distance(p[i], p[j]) < d) &&
	         !Fence.cross(f1,p[i],p[j]) &&
                 !Fence.cross(f2,p[i],p[j]))
              { E++;
                adj[j].next = new Node(i, adj[j].next);
                adj[i].next = new Node(j, adj[i].next);
              }
        System.out.println(V + " vertices, " + E + " edges.");
      }