Path-based strongly connected components algorithm

        /// <summary>
        /// Path-based strongly connected components algorithm
        /// </summary>
        public void Path_based_SCC()
        {
            Func<Queue<Nodo>, Queue<Nodo>> SCC_DFS = null;
            SCC_DFS = (H) =>
            {
                var tempo = 0;
                Sbianca();

                Action<Nodo, Queue<Nodo>> SCCC_Visita = null;
                SCCC_Visita = (u, Z) =>
                {
                    tempo++;
                    u.d = tempo;
                    u.colore = Nodo.Colori.Grigio;

                    foreach (var v in Adj[u])
                        if (v.colore == Nodo.Colori.Bianco)
                        {
                            v.Pred = u;

                            if (Z == null)
                                Console.Write(v.N + " ");

                            SCCC_Visita(v, Z);
                        }

                    tempo++;
                    u.f = tempo;
                    u.colore = Nodo.Colori.Nero;

                    if (Z != null)
                        Z.Enqueue(u);
                };

                if (H == null)
                {
                    var L = new Queue<Nodo>();

                    foreach (var v in V)
                        if (v.colore == Nodo.Colori.Bianco)
                            SCCC_Visita(v, L);

                    return L;
                }
                else
                {
                    while (H.Count > 0)
                    {
                        var u = H.Dequeue();
                        if (u.colore == Nodo.Colori.Bianco)
                        {
                            Console.Write("SCC: ");
                            SCCC_Visita(u, null);
                            Console.WriteLine(u.N + " ");
                        }
                    }

                    return null;
                }
            };

            SCC_DFS(SCC_DFS(null));
        }