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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* $Id$ */
package org.apache.fop.util.dijkstra;
import java.util.Iterator;
import java.util.LinkedList;
import junit.framework.TestCase;
/**
* Tests the Dijkstra algorithm implementation. We're comparing best solutions with focus on
* time or distance getting from St. Gallen to Lucerne on Switzerland's railroads.
*/
public class DijkstraTestCase extends TestCase {
private static final boolean DEBUG = false;
private static final City ROMANSHORN = new City("Romanshorn");
private static final City ST_GALLEN = new City("St. Gallen");
private static final City WINTERTHUR = new City("Winterthur");
private static final City ZURICH = new City("Zurich");
private static final City ZUG = new City("Zug");
private static final City RAPPERSWIL = new City("Rapperswil");
private static final City ARTH_GOLDAU = new City("Arth-Goldau");
private static final City LUCERNE = new City("Lucerne");
private static final City NOWHERE = new City("nowhere");
private DijkstraAlgorithm algo;
private DefaultEdgeDirectory edges;
private Mode mode;
/** {@inheritDoc} */
protected void setUp() throws Exception {
super.setUp();
edges = new DefaultEdgeDirectory();
algo = new DijkstraAlgorithm(edges);
mode = new Mode();
//St.Gallen - Winterthur - Zurich - Zug - Lucerne: 161 km, 2h 01min
edges.addEdge(new TrainRoute(mode, ST_GALLEN, WINTERTHUR, 61, 39));
edges.addEdge(new TrainRoute(mode, WINTERTHUR, ZURICH, 31, 31));
edges.addEdge(new TrainRoute(mode, ZURICH, ZUG, 39, 31));
edges.addEdge(new TrainRoute(mode, ZUG, LUCERNE, 30, 20));
//St.Gallen - Rapperswil - Arth-Goldau - Lucerne: 158km, 2h 18min
edges.addEdge(new TrainRoute(mode, ST_GALLEN, RAPPERSWIL, 72, 57));
edges.addEdge(new TrainRoute(mode, RAPPERSWIL, ARTH_GOLDAU, 55, 48));
edges.addEdge(new TrainRoute(mode, ARTH_GOLDAU, LUCERNE, 31, 33));
//A detour to make it interesting (St.Gallen - Romanshorn - Winterthur): 89km, 1h 23min
edges.addEdge(new TrainRoute(mode, ST_GALLEN, ROMANSHORN, 30, 32));
edges.addEdge(new TrainRoute(mode, ROMANSHORN, WINTERTHUR, 59, 51));
}
public void testAlgorithmWithDistance() throws Exception {
mode.useDistance();
City origin = ST_GALLEN;
City destination = LUCERNE;
String route = executeAlgorithm(origin, destination);
int distance = algo.getLowestPenalty(destination);
if (DEBUG) {
System.out.println(route + " " + distance + " km");
}
assertEquals(158, distance);
assertEquals("St. Gallen - Rapperswil - Arth-Goldau - Lucerne", route);
}
public void testAlgorithmWithDuration() throws Exception {
mode.useDuration();
City origin = ST_GALLEN;
City destination = LUCERNE;
String route = executeAlgorithm(origin, destination);
int duration = algo.getLowestPenalty(destination);
if (DEBUG) {
System.out.println(route + " " + duration + " minutes");
}
assertEquals(121, duration);
assertEquals("St. Gallen - Winterthur - Zurich - Zug - Lucerne", route);
}
public void testAlgorithmWithNonExistentRoute() throws Exception {
City origin = ST_GALLEN;
City destination = NOWHERE;
algo.execute(origin, destination);
Vertex pred = algo.getPredecessor(destination);
assertNull(pred);
}
private String executeAlgorithm(City origin, City destination) {
algo.execute(origin, destination);
Vertex prev = destination;
Vertex pred = algo.getPredecessor(destination);
if (pred == null) {
fail("No route found!");
}
LinkedList stops = new LinkedList();
stops.addLast(destination);
while ((pred = algo.getPredecessor(prev)) != null) {
stops.addFirst(pred);
prev = pred;
}
StringBuffer sb = new StringBuffer();
Iterator iter = stops.iterator();
while (iter.hasNext()) {
if (sb.length() > 0) {
sb.append(" - ");
}
sb.append(iter.next());
}
String route = sb.toString();
return route;
}
}
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