private static void menu() {
        Scanner sc = new Scanner(System.in);
        int choice = 0;

        while(true) {
            System.out.println("** Menu **");
            System.out.println("1- Programation Dynamique");
            System.out.println("2- Floyd-Warshall");
            System.out.println("3- Méthode des potentiels");
            System.out.println("4- Johnson");
            System.out.println("5- Ford-Fulkerson");
            System.out.println("6- Branch and Bound");
            System.out.println("7- Simplexe");
            System.out.println("\n0- Sortie");
            System.out.print("\nChoix : ");
            choice = Integer.parseInt(sc.nextLine());
            System.out.println("\n");
            
            switch (choice) {
		case 1 :
		    ProgrammationDynamique.main(new String[0]);
		    break;
                case 2 :
                    FloydWarshall.main(new String[0]);
                    break;
                case 3 : 
                    MPM.main(new String[0]);
                    break;
                case 4:
                    Johnson.main(new String[0]);
                    break;
                case 5:
                    fordfulkerson();
                    break;
                case 6:
                    branchBound();
                    break;
                case 7:
                    try {
                        simplexe();
                    } catch (MatrixException ex) {
                        Logger.getLogger(Start.class.getName()).log(Level.SEVERE, null, ex);
                    }
                    break;
                default:
                    System.exit(0);
            }
            
            System.out.println("Tapez sur une touche pour continuer ...");
            sc.nextLine();
        }

    }