Class BidirectionalDijkstraShortestPath<V,​E>

  • Type Parameters:
    V - the graph vertex type
    E - the graph edge type
    All Implemented Interfaces:
    ShortestPathAlgorithm<V,​E>

    public final class BidirectionalDijkstraShortestPath<V,​E>
    extends BaseBidirectionalShortestPathAlgorithm<V,​E>
    A bidirectional version of Dijkstra's algorithm.

    See the Wikipedia article for details and references about bidirectional search. This technique does not change the worst-case behavior of the algorithm but reduces, in some cases, the number of visited vertices in practice. This implementation alternatively constructs forward and reverse paths from the source and target vertices respectively.

    This iterator can use a custom heap implementation, which can specified during the construction time. Pairing heap is used by default

    See Also:
    DijkstraShortestPath
    • Field Detail

      • radius

        private double radius
      • heapSupplier

        private final java.util.function.Supplier<org.jheaps.AddressableHeap<java.lang.Double,​Pair<V,​E>>> heapSupplier
    • Constructor Detail

      • BidirectionalDijkstraShortestPath

        public BidirectionalDijkstraShortestPath​(Graph<V,​E> graph)
        Constructs a new instance for a specified graph.
        Parameters:
        graph - the input graph
      • BidirectionalDijkstraShortestPath

        public BidirectionalDijkstraShortestPath​(Graph<V,​E> graph,
                                                 java.util.function.Supplier<org.jheaps.AddressableHeap<java.lang.Double,​Pair<V,​E>>> heapSupplier)
        Constructs a new instance for a specified graph. The constructed algorithm will use the heap supplied by the heapSupplier.
        Parameters:
        graph - the input graph
        heapSupplier - supplier of the preferable heap implementation
      • BidirectionalDijkstraShortestPath

        public BidirectionalDijkstraShortestPath​(Graph<V,​E> graph,
                                                 double radius)
        Constructs a new instance for a specified graph.
        Parameters:
        graph - the input graph
        radius - limit on path length, or Double.POSITIVE_INFINITY for unbounded search
      • BidirectionalDijkstraShortestPath

        public BidirectionalDijkstraShortestPath​(Graph<V,​E> graph,
                                                 double radius,
                                                 java.util.function.Supplier<org.jheaps.AddressableHeap<java.lang.Double,​Pair<V,​E>>> heapSupplier)
        Constructs a new instance for a specified graph. The constructed algorithm will use the heap supplied by the heapSupplier.
        Parameters:
        graph - the input graph
        radius - limit on path length, or Double.POSITIVE_INFINITY for unbounded search
        heapSupplier - supplier of the preferable heap implementation
    • Method Detail

      • findPathBetween

        public static <V,​E> GraphPath<V,​E> findPathBetween​(Graph<V,​E> graph,
                                                                       V source,
                                                                       V sink)
        Find a path between two vertices. For a more advanced search (e.g. limited by radius), use the constructor instead.
        Type Parameters:
        V - the graph vertex type
        E - the graph edge type
        Parameters:
        graph - the graph to be searched
        source - the vertex at which the path should start
        sink - the vertex at which the path should end
        Returns:
        a shortest path, or null if no path exists
      • getPath

        public GraphPath<V,​E> getPath​(V source,
                                            V sink)
        Description copied from interface: ShortestPathAlgorithm
        Get a shortest path from a source vertex to a sink vertex.
        Parameters:
        source - the source vertex
        sink - the target vertex
        Returns:
        a shortest path or null if no path exists