/*
* Created on Jul 10, 2005
*
* Copyright (c) 2005, the JUNG Project and the Regents of the University
* of California
* All rights reserved.
*
* This software is open-source under the BSD license; see either
* "license.txt" or
* http://jung.sourceforge.net/license.txt for a description.
*/
package edu.uci.ics.jung.algorithms.shortestpath;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import edu.uci.ics.jung.graph.Graph;
import edu.uci.ics.jung.graph.util.Pair;
/**
* Utilities relating to the shortest paths in a graph.
*/
public class ShortestPathUtils
{
/**
* Returns a List
of the edges on the shortest path from
* source
to target
, in order of their
* occurrence on this path.
*/
public static List getPath(Graph graph, ShortestPath sp, V source, V target)
{
LinkedList path = new LinkedList();
Map incomingEdges = sp.getIncomingEdgeMap(source);
if (incomingEdges.isEmpty() || incomingEdges.get(target) == null)
return path;
V current = target;
while (!current.equals(source))
{
E incoming = incomingEdges.get(current);
path.addFirst(incoming);
Pair endpoints = graph.getEndpoints(incoming);
if(endpoints.getFirst().equals(current)) {
current = endpoints.getSecond();
} else {
current = endpoints.getFirst();
}
//incoming.getOpposite(current);
}
return path;
}
}