Module org.jgrapht.core
Package org.jgrapht.alg.shortestpath

Class EppsteinKShortestPath<V,​E>

java.lang.Object
org.jgrapht.alg.shortestpath.EppsteinKShortestPath<V,​E>
Type Parameters:
V - the graph vertex type
E - the graph edge type
All Implemented Interfaces:
KShortestPathAlgorithm<V,​E>
public class EppsteinKShortestPath<V,​E>
extends java.lang.Object
implements KShortestPathAlgorithm<V,​E>
Implementation of the Eppstein`s algorithm for finding $k$ shortest path between two vertices in a graph.

The algorithm is originally described in: David Eppstein. 1999. Finding the k Shortest Paths. SIAM J. Comput. 28, 2 (February 1999), 652-673. DOI=http://dx.doi.org/10.1137/S0097539795290477.

The main advantage ot this algorithm is that it achieves the complexity of $O(m + n\log n + k\log k)$ while guaranteeing that the paths are produced in sorted order by weight, where $m$ is the number of edges in the graph, $n$ is the number of vertices in the graph and $k$ is the number of paths needed.

This implementation can only be used for directed simple graphs.

Author:
Semen Chudakov
See Also:
EppsteinShortestPathIterator

  • Constructor Summary

    Constructors 
    Constructor Description
    EppsteinKShortestPath​(Graph<V,​E> graph)
    Constructs the algorithm instance for the given graph.

  • Method Summary

    Modifier and Type Method Description
    java.util.List<GraphPath<V,​E>> getPaths​(V source, V sink, int k)
    Computes k shortest paths between source and sink.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • EppsteinKShortestPath

      public EppsteinKShortestPath​(Graph<V,​E> graph)
      Constructs the algorithm instance for the given graph.
      Parameters:
      graph - graph

  • Method Details

    • getPaths

      public java.util.List<GraphPath<V,​E>> getPaths​(V source, V sink, int k)
      Computes k shortest paths between source and sink. If the number of paths is denoted by $n$, the method returns $m = min\{k, n\}$ such paths. The paths are produced in sorted order by weights.
      Specified by:
      getPaths in interface KShortestPathAlgorithm<V,​E>
      Parameters:
      source - the source vertex
      sink - the target vertex
      k - the number of shortest paths to return
      Returns:
      a list of k shortest paths