org.jgrapht.alg

Class BellmanFordShortestPath<V,E>

java.lang.Object

org.jgrapht.alg.BellmanFordShortestPath<V,E>

public class BellmanFordShortestPath<V,E>
extends Object

Bellman-Ford algorithm: weights could be negative, paths could be constrained by a maximum number of edges.

Field Summary

Fields

Modifier and Type	Field and Description
protected Graph<V,E>	graph Graph on which shortest paths are searched.
protected V	startVertex Start vertex.

Constructor Summary

Constructors

Constructor and Description
BellmanFordShortestPath(Graph<V,E> graph, V startVertex) Creates an object to calculate shortest paths between the start vertex and others vertices using the Bellman-Ford algorithm.
BellmanFordShortestPath(Graph<V,E> graph, V startVertex, int nMaxHops) Creates an object to calculate shortest paths between the start vertex and others vertices using the Bellman-Ford algorithm.
BellmanFordShortestPath(Graph<V,E> graph, V startVertex, int nMaxHops, double epsilon) Creates an object to calculate shortest paths between the start vertex and others vertices using the Bellman-Ford algorithm.

Method Summary

Methods

Modifier and Type	Method and Description
static <V,E> List<E>	findPathBetween(Graph<V,E> graph, V startVertex, V endVertex) Convenience method to find the shortest path via a single static method call.
double	getCost(V endVertex)
List<E>	getPathEdgeList(V endVertex)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

graph

protected Graph<V,E> graph

Graph on which shortest paths are searched.

startVertex

protected V startVertex

Start vertex.

Constructor Detail

BellmanFordShortestPath

public BellmanFordShortestPath(Graph<V,E> graph,
                       V startVertex)

Creates an object to calculate shortest paths between the start vertex and others vertices using the Bellman-Ford algorithm.

Parameters:

graph -

startVertex -

BellmanFordShortestPath

public BellmanFordShortestPath(Graph<V,E> graph,
                       V startVertex,
                       int nMaxHops)

Creates an object to calculate shortest paths between the start vertex and others vertices using the Bellman-Ford algorithm.

Parameters:

graph -

startVertex -

nMaxHops - maximum number of edges of the calculated paths.

BellmanFordShortestPath

public BellmanFordShortestPath(Graph<V,E> graph,
                       V startVertex,
                       int nMaxHops,
                       double epsilon)

Creates an object to calculate shortest paths between the start vertex and others vertices using the Bellman-Ford algorithm.

Parameters:

graph -

startVertex -

nMaxHops - maximum number of edges of the calculated paths.

epsilon - tolerance factor.

Method Detail

getCost

public double getCost(V endVertex)

Parameters:

endVertex - end vertex.

Returns:

the cost of the shortest path between the start vertex and the end vertex.

getPathEdgeList

public List<E> getPathEdgeList(V endVertex)

Parameters:

endVertex - end vertex.

Returns:

list of Edge, or null if no path exists between the start vertex and the end vertex.

findPathBetween

public static <V,E> List<E> findPathBetween(Graph<V,E> graph,
                            V startVertex,
                            V endVertex)

Convenience method to find the shortest path via a single static method call. If you need a more advanced search (e.g. limited by hops, or computation of the path length), use the constructor instead.

Parameters:

graph - the graph to be searched

startVertex - the vertex at which the path should start

endVertex - the vertex at which the path should end

Returns:

List of Edges, or null if no path exists