edu.princeton.cs.algs4.DegreesOfSeparation Maven / Gradle / Ivy
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/******************************************************************************
* Compilation: javac DegreesOfSeparation.java
* Execution: java DegreesOfSeparation filename delimiter source
* Dependencies: SymbolGraph.java Graph.java BreadthFirstPaths.java StdOut.java
* Data files: https://algs4.cs.princeton.edu/41graph/routes.txt
* https://algs4.cs.princeton.edu/41graph/movies.txt
*
*
* % java DegreesOfSeparation routes.txt " " "JFK"
* LAS
* JFK
* ORD
* DEN
* LAS
* DFW
* JFK
* ORD
* DFW
* EWR
* Not in database.
*
* % java DegreesOfSeparation movies.txt "/" "Bacon, Kevin"
* Kidman, Nicole
* Bacon, Kevin
* Woodsman, The (2004)
* Grier, David Alan
* Bewitched (2005)
* Kidman, Nicole
* Grant, Cary
* Bacon, Kevin
* Planes, Trains & Automobiles (1987)
* Martin, Steve (I)
* Dead Men Don't Wear Plaid (1982)
* Grant, Cary
*
* % java DegreesOfSeparation movies.txt "/" "Animal House (1978)"
* Titanic (1997)
* Animal House (1978)
* Allen, Karen (I)
* Raiders of the Lost Ark (1981)
* Taylor, Rocky (I)
* Titanic (1997)
* To Catch a Thief (1955)
* Animal House (1978)
* Vernon, John (I)
* Topaz (1969)
* Hitchcock, Alfred (I)
* To Catch a Thief (1955)
*
******************************************************************************/
package edu.princeton.cs.algs4;
/**
* The {@code DegreesOfSeparation} class provides a client for finding
* the degree of separation between one distinguished individual and
* every other individual in a social network.
* As an example, if the social network consists of actors in which
* two actors are connected by a link if they appeared in the same movie,
* and Kevin Bacon is the distinguished individual, then the client
* computes the Kevin Bacon number of every actor in the network.
*
* The running time is proportional to the number of individuals and
* connections in the network. If the connections are given implicitly,
* as in the movie network example (where every two actors are connected
* if they appear in the same movie), the efficiency of the algorithm
* is improved by allowing both movie and actor vertices and connecting
* each movie to all of the actors that appear in that movie.
*
* For additional documentation,
* see Section 4.1 of
* Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne.
*
* @author Robert Sedgewick
* @author Kevin Wayne
*/
public class DegreesOfSeparation {
// this class cannot be instantiated
private DegreesOfSeparation() { }
/**
* Reads in a social network from a file, and then repeatedly reads in
* individuals from standard input and prints out their degrees of
* separation.
* Takes three command-line arguments: the name of a file,
* a delimiter, and the name of the distinguished individual.
* Each line in the file contains the name of a vertex, followed by a
* list of the names of the vertices adjacent to that vertex,
* separated by the delimiter.
*
* @param args the command-line arguments
*/
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);
BreadthFirstPaths bfs = new BreadthFirstPaths(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.");
}
}
}
}
/******************************************************************************
* Copyright 2002-2018, Robert Sedgewick and Kevin Wayne.
*
* This file is part of algs4.jar, which accompanies the textbook
*
* Algorithms, 4th edition by Robert Sedgewick and Kevin Wayne,
* Addison-Wesley Professional, 2011, ISBN 0-321-57351-X.
* http://algs4.cs.princeton.edu
*
*
* algs4.jar is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* algs4.jar is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with algs4.jar. If not, see http://www.gnu.org/licenses.
******************************************************************************/