static void filePrompt() {
        Graph g = null;
        while (g == null) {
            System.out.println("Which file to read graph from?");
            System.out.println("Or alternatively, type 'random size' for randomly "
                    + "generated graph, eg. 'random 4' for a graph with 4 vertices, "
                    + "or 'quick size' for a quicker graph generation algorithm with "
                    + "'size' vertices.");
            String graph = s.nextLine();
            if (!graph.startsWith("random") && !graph.startsWith("quick")) {
                try {
                    g = GraphParser.initialize(FileLoader.loadFile(graph));
                } catch (FileNotFoundException ex) {
                    System.out.println("File not found, try again.");

                }
            } else if (graph.startsWith("random")) {
                g = GraphParser.initialize(RandomGraph.generateRandom(Integer.parseInt(graph.substring(7))));
            } else if (graph.startsWith("quick")) {
                g = RandomGraph.quick(Integer.parseInt(graph.substring(6)));
            }
            if (g != null) {
                AssignCoordinates.initialize(g);
                GraphInterface.setGraph(g);
                String algorithmChoice = "";
                algorithmPrompt(g);
            }
        }
    }