private static void DiGraph()
        {
            IDiGraph  G       = new DiGraph.DiGraph(new Scanner(new StreamReader(File.OpenRead("tinyDG.txt"))));
            Bag <int> sources = new Bag <int>();

            StdOut.Println("搜索几个结点:");
            int i = StdIn.ReadInt();

            while (i-- > 0)
            {
                sources.Add(StdIn.ReadInt());
            }
            DirectedDFS reachable = new DirectedDFS(G, sources);

            for (int v = 0; v < G.V; v++)
            {
                if (reachable.Marked(v))
                {
                    StdOut.Print(v + " ");
                }
            }

            //string filename = "jobs.txt"; //文件有问题
            //string seperator = "/";
            //SymbolDiGraph sg = new SymbolDiGraph(filename, seperator);
            //Topological topological = new Topological(sg.G);
            //foreach (int v in topological.Order)
            //    StdOut.Println(sg.Name(v));

            StdOut.Println();
            StdOut.Println("强连通分量的数量");
            ISCC scc = new KosarajuSCC(G);

            StdOut.Println(scc.Count);
        }
        public IDiGraph Reverse()
        {
            IDiGraph R = new DiGraph(V);

            for (int v = 0; v < V; v++)
            {
                foreach (int w in Adj(v))
                {
                    R.AddEdge(w, v);
                }
            }
            return(R);
        }
        public Topological(IEdgeWeightedDIgraph G)
        {
            IDiGraph g = new DiGraph(G.V);

            for (int i = 0; i < G.V; i++)
            {
                foreach (var e in G.Adj(i))
                {
                    g.AddEdge(e.From, e.To);
                }
            }
            Order = Init(g);
        }