DegreesOfSeparationDFS.java

Below is the syntax highlighted version of DegreesOfSeparationDFS.java from §4.1 Undirected Graphs.

/******************************************************************************
 *  Compilation:  javac DegreesOfSeparationDFS.java
 *  Execution:    java DegreesOfSeparationDFS filename delimiter source
 *  Dependencies: SymbolGraph.java Graph.java DepthFirstPaths.java StdOut.java
 *  Data files:   https://algs4.cs.princeton.edu/41graph/routes.txt
 *                https://algs4.cs.princeton.edu/41graph/movies.txt
 *
 *
 *  % java DegreesOfSeparationDFS movies.txt "/" "Bacon, Kevin"
 *  Kidman, Nicole
 *     Bacon, Kevin
 *     Woodsman, The (2004)
 *     Sedgwick, Kyra
 *     Something to Talk About (1995)
 *     Gillan, Lisa Roberts
 *     Runaway Bride (1999)
 *     Schertler, Jean
 *     ... [1782 movies ] (!)
 *     Eskelson, Dana
 *     Interpreter, The (2005)
 *     Silver, Tracey (II)
 *     Copycat (1995)
 *     Chua, Jeni
 *     Metro (1997)
 *     Ejogo, Carmen
 *     Avengers, The (1998)
 *     Atkins, Eileen
 *     Hours, The (2002)
 *     Kidman, Nicole
 *
 ******************************************************************************/

public class DegreesOfSeparationDFS {
    public static void main(String[] args) {
        String filename  = args[0];
        String delimiter = args[1];
        String source    = args[2];

        // StdOut.println("Source: " + source);

        SymbolGraph sg = new SymbolGraph(filename, delimiter);
        Graph G = sg.graph();
        if (!sg.contains(source)) {
            StdOut.println(source + " not in database.");
            return;
        }

        int s = sg.indexOf(source);
        DepthFirstPaths bfs = new DepthFirstPaths(G, s);

        while (!StdIn.isEmpty()) {
            String sink = StdIn.readLine();
            if (sg.contains(sink)) {
                int t = sg.indexOf(sink);
                if (bfs.hasPathTo(t)) {
                    for (int v : bfs.pathTo(t)) {
                        StdOut.println("   " + sg.nameOf(v));
                    }
                }
                else {
                    StdOut.println("Not connected");
                }
            }
            else {
                StdOut.println("   Not in database.");
            }
        }
    }
}