lemon/dijkstra.h
author Alpar Juttner <alpar@cs.elte.hu>
Sun, 21 Sep 2008 18:26:25 +0100
changeset 271 cea3cb3bbcd7
parent 257 8d76a7bf9961
parent 251 a1ffc9099c25
child 278 931190050520
child 280 e7f8647ce760
permissions -rw-r--r--
Merge
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/* -*- mode: C++; indent-tabs-mode: nil; -*-
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 *
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 * This file is a part of LEMON, a generic C++ optimization library.
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 *
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 * Copyright (C) 2003-2008
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 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
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 * (Egervary Research Group on Combinatorial Optimization, EGRES).
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 *
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 * Permission to use, modify and distribute this software is granted
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 * provided that this copyright notice appears in all copies. For
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 * precise terms see the accompanying LICENSE file.
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 *
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 * This software is provided "AS IS" with no warranty of any kind,
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 * express or implied, and with no claim as to its suitability for any
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 * purpose.
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 *
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 */
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#ifndef LEMON_DIJKSTRA_H
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#define LEMON_DIJKSTRA_H
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///\ingroup shortest_path
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///\file
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///\brief Dijkstra algorithm.
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#include <limits>
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#include <lemon/list_graph.h>
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#include <lemon/bin_heap.h>
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#include <lemon/bits/path_dump.h>
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#include <lemon/core.h>
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#include <lemon/error.h>
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#include <lemon/maps.h>
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namespace lemon {
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  /// \brief Default operation traits for the Dijkstra algorithm class.
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  ///
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  /// This operation traits class defines all computational operations and
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  /// constants which are used in the Dijkstra algorithm.
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  template <typename Value>
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  struct DijkstraDefaultOperationTraits {
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    /// \brief Gives back the zero value of the type.
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    static Value zero() {
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      return static_cast<Value>(0);
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    }
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    /// \brief Gives back the sum of the given two elements.
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    static Value plus(const Value& left, const Value& right) {
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      return left + right;
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    }
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    /// \brief Gives back true only if the first value is less than the second.
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    static bool less(const Value& left, const Value& right) {
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      return left < right;
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    }
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  };
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  /// \brief Widest path operation traits for the Dijkstra algorithm class.
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  ///
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  /// This operation traits class defines all computational operations and
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  /// constants which are used in the Dijkstra algorithm for widest path
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  /// computation.
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  ///
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  /// \see DijkstraDefaultOperationTraits
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  template <typename Value>
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  struct DijkstraWidestPathOperationTraits {
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    /// \brief Gives back the maximum value of the type.
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    static Value zero() {
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      return std::numeric_limits<Value>::max();
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    }
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    /// \brief Gives back the minimum of the given two elements.
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    static Value plus(const Value& left, const Value& right) {
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      return std::min(left, right);
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    }
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    /// \brief Gives back true only if the first value is less than the second.
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    static bool less(const Value& left, const Value& right) {
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      return left < right;
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    }
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  };
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  ///Default traits class of Dijkstra class.
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  ///Default traits class of Dijkstra class.
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  ///\tparam GR The type of the digraph.
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  ///\tparam LM The type of the length map.
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  template<class GR, class LM>
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  struct DijkstraDefaultTraits
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  {
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    ///The type of the digraph the algorithm runs on.
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    typedef GR Digraph;
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    ///The type of the map that stores the arc lengths.
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    ///The type of the map that stores the arc lengths.
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    ///It must meet the \ref concepts::ReadMap "ReadMap" concept.
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    typedef LM LengthMap;
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    ///The type of the length of the arcs.
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    typedef typename LM::Value Value;
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    /// Operation traits for Dijkstra algorithm.
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    /// This class defines the operations that are used in the algorithm.
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    /// \see DijkstraDefaultOperationTraits
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    typedef DijkstraDefaultOperationTraits<Value> OperationTraits;
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    /// The cross reference type used by the heap.
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    /// The cross reference type used by the heap.
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    /// Usually it is \c Digraph::NodeMap<int>.
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    typedef typename Digraph::template NodeMap<int> HeapCrossRef;
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    ///Instantiates a \ref HeapCrossRef.
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    ///This function instantiates a \ref HeapCrossRef.
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    /// \param g is the digraph, to which we would like to define the
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    /// \ref HeapCrossRef.
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    static HeapCrossRef *createHeapCrossRef(const Digraph &g)
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    {
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      return new HeapCrossRef(g);
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    }
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    ///The heap type used by the Dijkstra algorithm.
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    ///The heap type used by the Dijkstra algorithm.
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    ///
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    ///\sa BinHeap
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    ///\sa Dijkstra
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    typedef BinHeap<typename LM::Value, HeapCrossRef, std::less<Value> > Heap;
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    ///Instantiates a \ref Heap.
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    ///This function instantiates a \ref Heap.
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    static Heap *createHeap(HeapCrossRef& r)
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    {
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      return new Heap(r);
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    }
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    ///\brief The type of the map that stores the predecessor
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    ///arcs of the shortest paths.
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    ///
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    ///The type of the map that stores the predecessor
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    ///arcs of the shortest paths.
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    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
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    typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
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    ///Instantiates a \ref PredMap.
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    ///This function instantiates a \ref PredMap.
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    ///\param g is the digraph, to which we would like to define the
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    ///\ref PredMap.
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    ///\todo The digraph alone may be insufficient for the initialization
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    static PredMap *createPredMap(const Digraph &g)
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    {
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      return new PredMap(g);
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    }
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    ///The type of the map that indicates which nodes are processed.
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    ///The type of the map that indicates which nodes are processed.
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    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
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    ///By default it is a NullMap.
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    ///\todo If it is set to a real map,
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    ///Dijkstra::processed() should read this.
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    typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
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    ///Instantiates a \ref ProcessedMap.
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    ///This function instantiates a \ref ProcessedMap.
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    ///\param g is the digraph, to which
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    ///we would like to define the \ref ProcessedMap
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#ifdef DOXYGEN
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    static ProcessedMap *createProcessedMap(const Digraph &g)
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#else
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    static ProcessedMap *createProcessedMap(const Digraph &)
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#endif
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    {
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      return new ProcessedMap();
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    }
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    ///The type of the map that stores the distances of the nodes.
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    ///The type of the map that stores the distances of the nodes.
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    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
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    typedef typename Digraph::template NodeMap<typename LM::Value> DistMap;
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    ///Instantiates a \ref DistMap.
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    ///This function instantiates a \ref DistMap.
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    ///\param g is the digraph, to which we would like to define
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    ///the \ref DistMap
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    static DistMap *createDistMap(const Digraph &g)
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    {
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      return new DistMap(g);
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    }
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  };
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  ///%Dijkstra algorithm class.
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  /// \ingroup shortest_path
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  ///This class provides an efficient implementation of the %Dijkstra algorithm.
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  ///
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  ///The arc lengths are passed to the algorithm using a
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  ///\ref concepts::ReadMap "ReadMap",
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  ///so it is easy to change it to any kind of length.
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  ///The type of the length is determined by the
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  ///\ref concepts::ReadMap::Value "Value" of the length map.
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  ///It is also possible to change the underlying priority heap.
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  ///
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  ///There is also a \ref dijkstra() "function type interface" for the
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  ///%Dijkstra algorithm, which is convenient in the simplier cases and
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  ///it can be used easier.
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  ///
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  ///\tparam GR The type of the digraph the algorithm runs on.
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  ///The default value is \ref ListDigraph.
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  ///The value of GR is not used directly by \ref Dijkstra, it is only
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  ///passed to \ref DijkstraDefaultTraits.
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  ///\tparam LM A readable arc map that determines the lengths of the
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  ///arcs. It is read once for each arc, so the map may involve in
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  ///relatively time consuming process to compute the arc lengths if
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  ///it is necessary. The default map type is \ref
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  ///concepts::Digraph::ArcMap "Digraph::ArcMap<int>".
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  ///The value of LM is not used directly by \ref Dijkstra, it is only
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  ///passed to \ref DijkstraDefaultTraits.
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  ///\tparam TR Traits class to set various data types used by the algorithm.
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  ///The default traits class is \ref DijkstraDefaultTraits
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  ///"DijkstraDefaultTraits<GR,LM>". See \ref DijkstraDefaultTraits
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  ///for the documentation of a Dijkstra traits class.
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#ifdef DOXYGEN
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  template <typename GR, typename LM, typename TR>
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#else
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  template <typename GR=ListDigraph,
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            typename LM=typename GR::template ArcMap<int>,
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            typename TR=DijkstraDefaultTraits<GR,LM> >
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#endif
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  class Dijkstra {
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  public:
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    ///\ref Exception for uninitialized parameters.
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    ///This error represents problems in the initialization of the
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    ///parameters of the algorithm.
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    class UninitializedParameter : public lemon::UninitializedParameter {
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    public:
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      virtual const char* what() const throw() {
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        return "lemon::Dijkstra::UninitializedParameter";
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      }
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    };
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    ///The type of the digraph the algorithm runs on.
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    typedef typename TR::Digraph Digraph;
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    ///The type of the length of the arcs.
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    typedef typename TR::LengthMap::Value Value;
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    ///The type of the map that stores the arc lengths.
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    typedef typename TR::LengthMap LengthMap;
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    ///\brief The type of the map that stores the predecessor arcs of the
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    ///shortest paths.
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    typedef typename TR::PredMap PredMap;
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    ///The type of the map that stores the distances of the nodes.
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    typedef typename TR::DistMap DistMap;
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    ///The type of the map that indicates which nodes are processed.
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    typedef typename TR::ProcessedMap ProcessedMap;
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    ///The type of the paths.
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    typedef PredMapPath<Digraph, PredMap> Path;
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    ///The cross reference type used for the current heap.
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    typedef typename TR::HeapCrossRef HeapCrossRef;
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    ///The heap type used by the algorithm.
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    typedef typename TR::Heap Heap;
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    ///The operation traits class.
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    typedef typename TR::OperationTraits OperationTraits;
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    ///The traits class.
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    typedef TR Traits;
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  private:
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    typedef typename Digraph::Node Node;
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    typedef typename Digraph::NodeIt NodeIt;
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    typedef typename Digraph::Arc Arc;
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    typedef typename Digraph::OutArcIt OutArcIt;
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    //Pointer to the underlying digraph.
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    const Digraph *G;
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    //Pointer to the length map.
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    const LengthMap *length;
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    //Pointer to the map of predecessors arcs.
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    PredMap *_pred;
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    //Indicates if _pred is locally allocated (true) or not.
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    bool local_pred;
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    //Pointer to the map of distances.
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    DistMap *_dist;
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    //Indicates if _dist is locally allocated (true) or not.
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    bool local_dist;
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    //Pointer to the map of processed status of the nodes.
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    ProcessedMap *_processed;
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    //Indicates if _processed is locally allocated (true) or not.
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    bool local_processed;
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    //Pointer to the heap cross references.
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    HeapCrossRef *_heap_cross_ref;
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    //Indicates if _heap_cross_ref is locally allocated (true) or not.
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    bool local_heap_cross_ref;
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    //Pointer to the heap.
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    Heap *_heap;
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    //Indicates if _heap is locally allocated (true) or not.
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    bool local_heap;
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    ///Creates the maps if necessary.
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    ///\todo Better memory allocation (instead of new).
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    void create_maps()
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    {
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      if(!_pred) {
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        local_pred = true;
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        _pred = Traits::createPredMap(*G);
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      }
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      if(!_dist) {
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        local_dist = true;
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        _dist = Traits::createDistMap(*G);
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      }
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      if(!_processed) {
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        local_processed = true;
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        _processed = Traits::createProcessedMap(*G);
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      }
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      if (!_heap_cross_ref) {
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        local_heap_cross_ref = true;
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        _heap_cross_ref = Traits::createHeapCrossRef(*G);
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      }
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      if (!_heap) {
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        local_heap = true;
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        _heap = Traits::createHeap(*_heap_cross_ref);
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      }
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    }
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  public:
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    typedef Dijkstra Create;
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    ///\name Named template parameters
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    ///@{
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    template <class T>
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    struct SetPredMapTraits : public Traits {
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      typedef T PredMap;
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      static PredMap *createPredMap(const Digraph &)
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      {
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        throw UninitializedParameter();
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      }
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    };
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    ///\brief \ref named-templ-param "Named parameter" for setting
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    ///\ref PredMap type.
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    ///
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    ///\ref named-templ-param "Named parameter" for setting
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    ///\ref PredMap type.
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    template <class T>
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    struct SetPredMap
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      : public Dijkstra< Digraph, LengthMap, SetPredMapTraits<T> > {
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      typedef Dijkstra< Digraph, LengthMap, SetPredMapTraits<T> > Create;
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    };
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    template <class T>
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    struct SetDistMapTraits : public Traits {
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      typedef T DistMap;
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      static DistMap *createDistMap(const Digraph &)
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      {
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        throw UninitializedParameter();
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      }
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    };
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    ///\brief \ref named-templ-param "Named parameter" for setting
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    ///\ref DistMap type.
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    ///
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    ///\ref named-templ-param "Named parameter" for setting
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    ///\ref DistMap type.
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    template <class T>
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    struct SetDistMap
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      : public Dijkstra< Digraph, LengthMap, SetDistMapTraits<T> > {
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      typedef Dijkstra< Digraph, LengthMap, SetDistMapTraits<T> > Create;
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    };
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    template <class T>
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    struct SetProcessedMapTraits : public Traits {
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      typedef T ProcessedMap;
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      static ProcessedMap *createProcessedMap(const Digraph &)
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      {
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        throw UninitializedParameter();
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      }
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    };
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    ///\brief \ref named-templ-param "Named parameter" for setting
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    ///\ref ProcessedMap type.
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    ///
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    ///\ref named-templ-param "Named parameter" for setting
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    ///\ref ProcessedMap type.
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    template <class T>
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    struct SetProcessedMap
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      : public Dijkstra< Digraph, LengthMap, SetProcessedMapTraits<T> > {
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      typedef Dijkstra< Digraph, LengthMap, SetProcessedMapTraits<T> > Create;
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    };
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    struct SetStandardProcessedMapTraits : public Traits {
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      typedef typename Digraph::template NodeMap<bool> ProcessedMap;
kpeter@244
   392
      static ProcessedMap *createProcessedMap(const Digraph &g)
alpar@100
   393
      {
kpeter@244
   394
        return new ProcessedMap(g);
alpar@100
   395
      }
alpar@100
   396
    };
kpeter@244
   397
    ///\brief \ref named-templ-param "Named parameter" for setting
kpeter@244
   398
    ///\ref ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
alpar@100
   399
    ///
kpeter@244
   400
    ///\ref named-templ-param "Named parameter" for setting
kpeter@244
   401
    ///\ref ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
kpeter@244
   402
    ///If you don't set it explicitly, it will be automatically allocated.
kpeter@257
   403
    struct SetStandardProcessedMap
kpeter@257
   404
      : public Dijkstra< Digraph, LengthMap, SetStandardProcessedMapTraits > {
kpeter@257
   405
      typedef Dijkstra< Digraph, LengthMap, SetStandardProcessedMapTraits >
alpar@210
   406
      Create;
alpar@100
   407
    };
alpar@100
   408
alpar@100
   409
    template <class H, class CR>
kpeter@257
   410
    struct SetHeapTraits : public Traits {
alpar@100
   411
      typedef CR HeapCrossRef;
alpar@100
   412
      typedef H Heap;
alpar@100
   413
      static HeapCrossRef *createHeapCrossRef(const Digraph &) {
alpar@209
   414
        throw UninitializedParameter();
alpar@100
   415
      }
alpar@209
   416
      static Heap *createHeap(HeapCrossRef &)
alpar@100
   417
      {
alpar@209
   418
        throw UninitializedParameter();
alpar@100
   419
      }
alpar@100
   420
    };
alpar@100
   421
    ///\brief \ref named-templ-param "Named parameter" for setting
alpar@100
   422
    ///heap and cross reference type
alpar@100
   423
    ///
alpar@209
   424
    ///\ref named-templ-param "Named parameter" for setting heap and cross
kpeter@244
   425
    ///reference type.
alpar@100
   426
    template <class H, class CR = typename Digraph::template NodeMap<int> >
kpeter@257
   427
    struct SetHeap
kpeter@257
   428
      : public Dijkstra< Digraph, LengthMap, SetHeapTraits<H, CR> > {
kpeter@257
   429
      typedef Dijkstra< Digraph, LengthMap, SetHeapTraits<H, CR> > Create;
alpar@100
   430
    };
alpar@100
   431
alpar@100
   432
    template <class H, class CR>
kpeter@257
   433
    struct SetStandardHeapTraits : public Traits {
alpar@100
   434
      typedef CR HeapCrossRef;
alpar@100
   435
      typedef H Heap;
alpar@100
   436
      static HeapCrossRef *createHeapCrossRef(const Digraph &G) {
alpar@209
   437
        return new HeapCrossRef(G);
alpar@100
   438
      }
alpar@209
   439
      static Heap *createHeap(HeapCrossRef &R)
alpar@100
   440
      {
alpar@209
   441
        return new Heap(R);
alpar@100
   442
      }
alpar@100
   443
    };
alpar@100
   444
    ///\brief \ref named-templ-param "Named parameter" for setting
alpar@100
   445
    ///heap and cross reference type with automatic allocation
alpar@100
   446
    ///
alpar@209
   447
    ///\ref named-templ-param "Named parameter" for setting heap and cross
alpar@209
   448
    ///reference type. It can allocate the heap and the cross reference
alpar@209
   449
    ///object if the cross reference's constructor waits for the digraph as
alpar@100
   450
    ///parameter and the heap's constructor waits for the cross reference.
alpar@100
   451
    template <class H, class CR = typename Digraph::template NodeMap<int> >
kpeter@257
   452
    struct SetStandardHeap
kpeter@257
   453
      : public Dijkstra< Digraph, LengthMap, SetStandardHeapTraits<H, CR> > {
kpeter@257
   454
      typedef Dijkstra< Digraph, LengthMap, SetStandardHeapTraits<H, CR> >
alpar@100
   455
      Create;
alpar@100
   456
    };
alpar@100
   457
alpar@100
   458
    template <class T>
kpeter@257
   459
    struct SetOperationTraitsTraits : public Traits {
alpar@100
   460
      typedef T OperationTraits;
alpar@100
   461
    };
alpar@209
   462
alpar@209
   463
    /// \brief \ref named-templ-param "Named parameter" for setting
kpeter@244
   464
    ///\ref OperationTraits type
alpar@100
   465
    ///
kpeter@244
   466
    ///\ref named-templ-param "Named parameter" for setting
kpeter@244
   467
    ///\ref OperationTraits type.
alpar@100
   468
    template <class T>
kpeter@257
   469
    struct SetOperationTraits
kpeter@257
   470
      : public Dijkstra<Digraph, LengthMap, SetOperationTraitsTraits<T> > {
kpeter@257
   471
      typedef Dijkstra<Digraph, LengthMap, SetOperationTraitsTraits<T> >
alpar@100
   472
      Create;
alpar@100
   473
    };
alpar@209
   474
alpar@100
   475
    ///@}
alpar@100
   476
alpar@100
   477
  protected:
alpar@100
   478
alpar@100
   479
    Dijkstra() {}
alpar@100
   480
alpar@209
   481
  public:
alpar@209
   482
alpar@100
   483
    ///Constructor.
alpar@209
   484
kpeter@244
   485
    ///Constructor.
kpeter@244
   486
    ///\param _g The digraph the algorithm runs on.
kpeter@244
   487
    ///\param _length The length map used by the algorithm.
kpeter@244
   488
    Dijkstra(const Digraph& _g, const LengthMap& _length) :
kpeter@244
   489
      G(&_g), length(&_length),
alpar@100
   490
      _pred(NULL), local_pred(false),
alpar@100
   491
      _dist(NULL), local_dist(false),
alpar@100
   492
      _processed(NULL), local_processed(false),
alpar@100
   493
      _heap_cross_ref(NULL), local_heap_cross_ref(false),
alpar@100
   494
      _heap(NULL), local_heap(false)
alpar@100
   495
    { }
alpar@209
   496
alpar@100
   497
    ///Destructor.
alpar@209
   498
    ~Dijkstra()
alpar@100
   499
    {
alpar@100
   500
      if(local_pred) delete _pred;
alpar@100
   501
      if(local_dist) delete _dist;
alpar@100
   502
      if(local_processed) delete _processed;
alpar@100
   503
      if(local_heap_cross_ref) delete _heap_cross_ref;
alpar@100
   504
      if(local_heap) delete _heap;
alpar@100
   505
    }
alpar@100
   506
alpar@100
   507
    ///Sets the length map.
alpar@100
   508
alpar@100
   509
    ///Sets the length map.
alpar@100
   510
    ///\return <tt> (*this) </tt>
alpar@209
   511
    Dijkstra &lengthMap(const LengthMap &m)
alpar@100
   512
    {
alpar@100
   513
      length = &m;
alpar@100
   514
      return *this;
alpar@100
   515
    }
alpar@100
   516
kpeter@244
   517
    ///Sets the map that stores the predecessor arcs.
alpar@100
   518
kpeter@244
   519
    ///Sets the map that stores the predecessor arcs.
alpar@100
   520
    ///If you don't use this function before calling \ref run(),
kpeter@244
   521
    ///it will allocate one. The destructor deallocates this
alpar@100
   522
    ///automatically allocated map, of course.
alpar@100
   523
    ///\return <tt> (*this) </tt>
alpar@209
   524
    Dijkstra &predMap(PredMap &m)
alpar@100
   525
    {
alpar@100
   526
      if(local_pred) {
alpar@209
   527
        delete _pred;
alpar@209
   528
        local_pred=false;
alpar@100
   529
      }
alpar@100
   530
      _pred = &m;
alpar@100
   531
      return *this;
alpar@100
   532
    }
alpar@100
   533
kpeter@244
   534
    ///Sets the map that indicates which nodes are processed.
alpar@100
   535
kpeter@244
   536
    ///Sets the map that indicates which nodes are processed.
alpar@100
   537
    ///If you don't use this function before calling \ref run(),
kpeter@244
   538
    ///it will allocate one. The destructor deallocates this
kpeter@244
   539
    ///automatically allocated map, of course.
kpeter@244
   540
    ///\return <tt> (*this) </tt>
kpeter@244
   541
    Dijkstra &processedMap(ProcessedMap &m)
kpeter@244
   542
    {
kpeter@244
   543
      if(local_processed) {
kpeter@244
   544
        delete _processed;
kpeter@244
   545
        local_processed=false;
kpeter@244
   546
      }
kpeter@244
   547
      _processed = &m;
kpeter@244
   548
      return *this;
kpeter@244
   549
    }
kpeter@244
   550
kpeter@244
   551
    ///Sets the map that stores the distances of the nodes.
kpeter@244
   552
kpeter@244
   553
    ///Sets the map that stores the distances of the nodes calculated by the
kpeter@244
   554
    ///algorithm.
kpeter@244
   555
    ///If you don't use this function before calling \ref run(),
kpeter@244
   556
    ///it will allocate one. The destructor deallocates this
alpar@100
   557
    ///automatically allocated map, of course.
alpar@100
   558
    ///\return <tt> (*this) </tt>
alpar@209
   559
    Dijkstra &distMap(DistMap &m)
alpar@100
   560
    {
alpar@100
   561
      if(local_dist) {
alpar@209
   562
        delete _dist;
alpar@209
   563
        local_dist=false;
alpar@100
   564
      }
alpar@100
   565
      _dist = &m;
alpar@100
   566
      return *this;
alpar@100
   567
    }
alpar@100
   568
alpar@100
   569
    ///Sets the heap and the cross reference used by algorithm.
alpar@100
   570
alpar@100
   571
    ///Sets the heap and the cross reference used by algorithm.
alpar@100
   572
    ///If you don't use this function before calling \ref run(),
kpeter@244
   573
    ///it will allocate one. The destructor deallocates this
alpar@100
   574
    ///automatically allocated heap and cross reference, of course.
alpar@100
   575
    ///\return <tt> (*this) </tt>
alpar@100
   576
    Dijkstra &heap(Heap& hp, HeapCrossRef &cr)
alpar@100
   577
    {
alpar@100
   578
      if(local_heap_cross_ref) {
alpar@209
   579
        delete _heap_cross_ref;
alpar@209
   580
        local_heap_cross_ref=false;
alpar@100
   581
      }
alpar@100
   582
      _heap_cross_ref = &cr;
alpar@100
   583
      if(local_heap) {
alpar@209
   584
        delete _heap;
alpar@209
   585
        local_heap=false;
alpar@100
   586
      }
alpar@100
   587
      _heap = &hp;
alpar@100
   588
      return *this;
alpar@100
   589
    }
alpar@100
   590
alpar@100
   591
  private:
kpeter@244
   592
alpar@100
   593
    void finalizeNodeData(Node v,Value dst)
alpar@100
   594
    {
alpar@100
   595
      _processed->set(v,true);
alpar@100
   596
      _dist->set(v, dst);
alpar@100
   597
    }
alpar@100
   598
alpar@100
   599
  public:
alpar@100
   600
alpar@100
   601
    ///\name Execution control
kpeter@244
   602
    ///The simplest way to execute the algorithm is to use one of the
kpeter@244
   603
    ///member functions called \ref lemon::Dijkstra::run() "run()".
alpar@100
   604
    ///\n
kpeter@244
   605
    ///If you need more control on the execution, first you must call
kpeter@244
   606
    ///\ref lemon::Dijkstra::init() "init()", then you can add several
kpeter@244
   607
    ///source nodes with \ref lemon::Dijkstra::addSource() "addSource()".
kpeter@244
   608
    ///Finally \ref lemon::Dijkstra::start() "start()" will perform the
kpeter@244
   609
    ///actual path computation.
alpar@100
   610
alpar@100
   611
    ///@{
alpar@100
   612
alpar@100
   613
    ///Initializes the internal data structures.
alpar@100
   614
alpar@100
   615
    ///Initializes the internal data structures.
alpar@100
   616
    ///
alpar@100
   617
    void init()
alpar@100
   618
    {
alpar@100
   619
      create_maps();
alpar@100
   620
      _heap->clear();
alpar@100
   621
      for ( NodeIt u(*G) ; u!=INVALID ; ++u ) {
alpar@209
   622
        _pred->set(u,INVALID);
alpar@209
   623
        _processed->set(u,false);
alpar@209
   624
        _heap_cross_ref->set(u,Heap::PRE_HEAP);
alpar@100
   625
      }
alpar@100
   626
    }
alpar@209
   627
alpar@100
   628
    ///Adds a new source node.
alpar@100
   629
alpar@100
   630
    ///Adds a new source node to the priority heap.
alpar@100
   631
    ///The optional second parameter is the initial distance of the node.
alpar@100
   632
    ///
kpeter@244
   633
    ///The function checks if the node has already been added to the heap and
alpar@100
   634
    ///it is pushed to the heap only if either it was not in the heap
alpar@100
   635
    ///or the shortest path found till then is shorter than \c dst.
alpar@100
   636
    void addSource(Node s,Value dst=OperationTraits::zero())
alpar@100
   637
    {
alpar@100
   638
      if(_heap->state(s) != Heap::IN_HEAP) {
alpar@209
   639
        _heap->push(s,dst);
alpar@100
   640
      } else if(OperationTraits::less((*_heap)[s], dst)) {
alpar@209
   641
        _heap->set(s,dst);
alpar@209
   642
        _pred->set(s,INVALID);
alpar@100
   643
      }
alpar@100
   644
    }
alpar@209
   645
alpar@100
   646
    ///Processes the next node in the priority heap
alpar@100
   647
alpar@100
   648
    ///Processes the next node in the priority heap.
alpar@100
   649
    ///
alpar@100
   650
    ///\return The processed node.
alpar@100
   651
    ///
kpeter@244
   652
    ///\warning The priority heap must not be empty.
alpar@100
   653
    Node processNextNode()
alpar@100
   654
    {
alpar@209
   655
      Node v=_heap->top();
alpar@100
   656
      Value oldvalue=_heap->prio();
alpar@100
   657
      _heap->pop();
alpar@100
   658
      finalizeNodeData(v,oldvalue);
alpar@209
   659
alpar@100
   660
      for(OutArcIt e(*G,v); e!=INVALID; ++e) {
alpar@209
   661
        Node w=G->target(e);
alpar@209
   662
        switch(_heap->state(w)) {
alpar@209
   663
        case Heap::PRE_HEAP:
alpar@209
   664
          _heap->push(w,OperationTraits::plus(oldvalue, (*length)[e]));
alpar@209
   665
          _pred->set(w,e);
alpar@209
   666
          break;
alpar@209
   667
        case Heap::IN_HEAP:
alpar@209
   668
          {
alpar@209
   669
            Value newvalue = OperationTraits::plus(oldvalue, (*length)[e]);
alpar@209
   670
            if ( OperationTraits::less(newvalue, (*_heap)[w]) ) {
alpar@209
   671
              _heap->decrease(w, newvalue);
alpar@209
   672
              _pred->set(w,e);
alpar@209
   673
            }
alpar@209
   674
          }
alpar@209
   675
          break;
alpar@209
   676
        case Heap::POST_HEAP:
alpar@209
   677
          break;
alpar@209
   678
        }
alpar@100
   679
      }
alpar@100
   680
      return v;
alpar@100
   681
    }
alpar@100
   682
kpeter@244
   683
    ///The next node to be processed.
alpar@209
   684
kpeter@244
   685
    ///Returns the next node to be processed or \c INVALID if the
kpeter@244
   686
    ///priority heap is empty.
kpeter@244
   687
    Node nextNode() const
alpar@209
   688
    {
alpar@100
   689
      return !_heap->empty()?_heap->top():INVALID;
alpar@100
   690
    }
alpar@209
   691
alpar@100
   692
    ///\brief Returns \c false if there are nodes
kpeter@244
   693
    ///to be processed.
alpar@100
   694
    ///
alpar@100
   695
    ///Returns \c false if there are nodes
kpeter@244
   696
    ///to be processed in the priority heap.
kpeter@244
   697
    bool emptyQueue() const { return _heap->empty(); }
kpeter@244
   698
alpar@100
   699
    ///Returns the number of the nodes to be processed in the priority heap
alpar@100
   700
kpeter@244
   701
    ///Returns the number of the nodes to be processed in the priority heap.
alpar@100
   702
    ///
kpeter@244
   703
    int queueSize() const { return _heap->size(); }
alpar@209
   704
alpar@100
   705
    ///Executes the algorithm.
alpar@100
   706
alpar@100
   707
    ///Executes the algorithm.
alpar@100
   708
    ///
kpeter@244
   709
    ///This method runs the %Dijkstra algorithm from the root node(s)
kpeter@244
   710
    ///in order to compute the shortest path to each node.
kpeter@244
   711
    ///
kpeter@244
   712
    ///The algorithm computes
kpeter@244
   713
    ///- the shortest path tree (forest),
kpeter@244
   714
    ///- the distance of each node from the root(s).
kpeter@244
   715
    ///
kpeter@244
   716
    ///\pre init() must be called and at least one root node should be
kpeter@244
   717
    ///added with addSource() before using this function.
kpeter@244
   718
    ///
kpeter@244
   719
    ///\note <tt>d.start()</tt> is just a shortcut of the following code.
kpeter@244
   720
    ///\code
kpeter@244
   721
    ///  while ( !d.emptyQueue() ) {
kpeter@244
   722
    ///    d.processNextNode();
kpeter@244
   723
    ///  }
kpeter@244
   724
    ///\endcode
kpeter@244
   725
    void start()
kpeter@244
   726
    {
kpeter@244
   727
      while ( !emptyQueue() ) processNextNode();
kpeter@244
   728
    }
kpeter@244
   729
kpeter@244
   730
    ///Executes the algorithm until the given target node is reached.
kpeter@244
   731
kpeter@244
   732
    ///Executes the algorithm until the given target node is reached.
alpar@100
   733
    ///
alpar@100
   734
    ///This method runs the %Dijkstra algorithm from the root node(s)
kpeter@244
   735
    ///in order to compute the shortest path to \c dest.
alpar@100
   736
    ///
kpeter@244
   737
    ///The algorithm computes
kpeter@244
   738
    ///- the shortest path to \c dest,
kpeter@244
   739
    ///- the distance of \c dest from the root(s).
alpar@100
   740
    ///
kpeter@244
   741
    ///\pre init() must be called and at least one root node should be
kpeter@244
   742
    ///added with addSource() before using this function.
alpar@100
   743
    void start(Node dest)
alpar@100
   744
    {
alpar@100
   745
      while ( !_heap->empty() && _heap->top()!=dest ) processNextNode();
alpar@100
   746
      if ( !_heap->empty() ) finalizeNodeData(_heap->top(),_heap->prio());
alpar@100
   747
    }
alpar@209
   748
alpar@100
   749
    ///Executes the algorithm until a condition is met.
alpar@100
   750
alpar@100
   751
    ///Executes the algorithm until a condition is met.
alpar@100
   752
    ///
kpeter@244
   753
    ///This method runs the %Dijkstra algorithm from the root node(s) in
kpeter@244
   754
    ///order to compute the shortest path to a node \c v with
kpeter@244
   755
    /// <tt>nm[v]</tt> true, if such a node can be found.
alpar@100
   756
    ///
kpeter@244
   757
    ///\param nm A \c bool (or convertible) node map. The algorithm
alpar@100
   758
    ///will stop when it reaches a node \c v with <tt>nm[v]</tt> true.
alpar@100
   759
    ///
alpar@100
   760
    ///\return The reached node \c v with <tt>nm[v]</tt> true or
alpar@100
   761
    ///\c INVALID if no such node was found.
kpeter@244
   762
    ///
kpeter@244
   763
    ///\pre init() must be called and at least one root node should be
kpeter@244
   764
    ///added with addSource() before using this function.
alpar@100
   765
    template<class NodeBoolMap>
alpar@100
   766
    Node start(const NodeBoolMap &nm)
alpar@100
   767
    {
alpar@100
   768
      while ( !_heap->empty() && !nm[_heap->top()] ) processNextNode();
alpar@100
   769
      if ( _heap->empty() ) return INVALID;
alpar@100
   770
      finalizeNodeData(_heap->top(),_heap->prio());
alpar@100
   771
      return _heap->top();
alpar@100
   772
    }
alpar@209
   773
kpeter@244
   774
    ///Runs the algorithm from the given node.
alpar@209
   775
kpeter@244
   776
    ///This method runs the %Dijkstra algorithm from node \c s
kpeter@244
   777
    ///in order to compute the shortest path to each node.
alpar@100
   778
    ///
kpeter@244
   779
    ///The algorithm computes
kpeter@244
   780
    ///- the shortest path tree,
kpeter@244
   781
    ///- the distance of each node from the root.
kpeter@244
   782
    ///
kpeter@244
   783
    ///\note <tt>d.run(s)</tt> is just a shortcut of the following code.
alpar@100
   784
    ///\code
alpar@100
   785
    ///  d.init();
alpar@100
   786
    ///  d.addSource(s);
alpar@100
   787
    ///  d.start();
alpar@100
   788
    ///\endcode
alpar@100
   789
    void run(Node s) {
alpar@100
   790
      init();
alpar@100
   791
      addSource(s);
alpar@100
   792
      start();
alpar@100
   793
    }
alpar@209
   794
alpar@100
   795
    ///Finds the shortest path between \c s and \c t.
alpar@209
   796
kpeter@244
   797
    ///This method runs the %Dijkstra algorithm from node \c s
kpeter@244
   798
    ///in order to compute the shortest path to \c t.
alpar@100
   799
    ///
kpeter@244
   800
    ///\return The length of the shortest <tt>s</tt>--<tt>t</tt> path,
kpeter@244
   801
    ///if \c t is reachable form \c s, \c 0 otherwise.
kpeter@244
   802
    ///
kpeter@244
   803
    ///\note Apart from the return value, <tt>d.run(s,t)</tt> is just a
kpeter@244
   804
    ///shortcut of the following code.
alpar@100
   805
    ///\code
alpar@100
   806
    ///  d.init();
alpar@100
   807
    ///  d.addSource(s);
alpar@100
   808
    ///  d.start(t);
alpar@100
   809
    ///\endcode
alpar@100
   810
    Value run(Node s,Node t) {
alpar@100
   811
      init();
alpar@100
   812
      addSource(s);
alpar@100
   813
      start(t);
alpar@100
   814
      return (*_pred)[t]==INVALID?OperationTraits::zero():(*_dist)[t];
alpar@100
   815
    }
alpar@209
   816
alpar@100
   817
    ///@}
alpar@100
   818
alpar@100
   819
    ///\name Query Functions
alpar@100
   820
    ///The result of the %Dijkstra algorithm can be obtained using these
alpar@100
   821
    ///functions.\n
kpeter@244
   822
    ///Either \ref lemon::Dijkstra::run() "run()" or
kpeter@244
   823
    ///\ref lemon::Dijkstra::start() "start()" must be called before
kpeter@244
   824
    ///using them.
alpar@209
   825
alpar@100
   826
    ///@{
alpar@100
   827
kpeter@244
   828
    ///The shortest path to a node.
alpar@209
   829
kpeter@244
   830
    ///Returns the shortest path to a node.
kpeter@244
   831
    ///
kpeter@244
   832
    ///\warning \c t should be reachable from the root(s).
kpeter@244
   833
    ///
kpeter@244
   834
    ///\pre Either \ref run() or \ref start() must be called before
kpeter@244
   835
    ///using this function.
kpeter@244
   836
    Path path(Node t) const { return Path(*G, *_pred, t); }
alpar@100
   837
kpeter@244
   838
    ///The distance of a node from the root(s).
alpar@100
   839
kpeter@244
   840
    ///Returns the distance of a node from the root(s).
kpeter@244
   841
    ///
kpeter@244
   842
    ///\warning If node \c v is not reachable from the root(s), then
kpeter@244
   843
    ///the return value of this function is undefined.
kpeter@244
   844
    ///
kpeter@244
   845
    ///\pre Either \ref run() or \ref start() must be called before
kpeter@244
   846
    ///using this function.
alpar@100
   847
    Value dist(Node v) const { return (*_dist)[v]; }
alpar@100
   848
kpeter@244
   849
    ///Returns the 'previous arc' of the shortest path tree for a node.
alpar@100
   850
kpeter@244
   851
    ///This function returns the 'previous arc' of the shortest path
kpeter@244
   852
    ///tree for the node \c v, i.e. it returns the last arc of a
kpeter@244
   853
    ///shortest path from the root(s) to \c v. It is \c INVALID if \c v
kpeter@244
   854
    ///is not reachable from the root(s) or if \c v is a root.
kpeter@244
   855
    ///
kpeter@244
   856
    ///The shortest path tree used here is equal to the shortest path
kpeter@244
   857
    ///tree used in \ref predNode().
kpeter@244
   858
    ///
kpeter@244
   859
    ///\pre Either \ref run() or \ref start() must be called before
kpeter@244
   860
    ///using this function.
alpar@100
   861
    Arc predArc(Node v) const { return (*_pred)[v]; }
alpar@100
   862
kpeter@244
   863
    ///Returns the 'previous node' of the shortest path tree for a node.
alpar@100
   864
kpeter@244
   865
    ///This function returns the 'previous node' of the shortest path
kpeter@244
   866
    ///tree for the node \c v, i.e. it returns the last but one node
kpeter@244
   867
    ///from a shortest path from the root(s) to \c v. It is \c INVALID
kpeter@244
   868
    ///if \c v is not reachable from the root(s) or if \c v is a root.
kpeter@244
   869
    ///
kpeter@244
   870
    ///The shortest path tree used here is equal to the shortest path
kpeter@244
   871
    ///tree used in \ref predArc().
kpeter@244
   872
    ///
kpeter@244
   873
    ///\pre Either \ref run() or \ref start() must be called before
alpar@100
   874
    ///using this function.
alpar@100
   875
    Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
alpar@209
   876
                                  G->source((*_pred)[v]); }
alpar@209
   877
kpeter@244
   878
    ///\brief Returns a const reference to the node map that stores the
kpeter@244
   879
    ///distances of the nodes.
kpeter@244
   880
    ///
kpeter@244
   881
    ///Returns a const reference to the node map that stores the distances
kpeter@244
   882
    ///of the nodes calculated by the algorithm.
kpeter@244
   883
    ///
kpeter@244
   884
    ///\pre Either \ref run() or \ref init()
kpeter@244
   885
    ///must be called before using this function.
alpar@100
   886
    const DistMap &distMap() const { return *_dist;}
alpar@209
   887
kpeter@244
   888
    ///\brief Returns a const reference to the node map that stores the
kpeter@244
   889
    ///predecessor arcs.
kpeter@244
   890
    ///
kpeter@244
   891
    ///Returns a const reference to the node map that stores the predecessor
kpeter@244
   892
    ///arcs, which form the shortest path tree.
kpeter@244
   893
    ///
kpeter@244
   894
    ///\pre Either \ref run() or \ref init()
kpeter@244
   895
    ///must be called before using this function.
alpar@100
   896
    const PredMap &predMap() const { return *_pred;}
alpar@209
   897
kpeter@244
   898
    ///Checks if a node is reachable from the root(s).
alpar@100
   899
kpeter@244
   900
    ///Returns \c true if \c v is reachable from the root(s).
kpeter@244
   901
    ///\pre Either \ref run() or \ref start()
kpeter@244
   902
    ///must be called before using this function.
kpeter@244
   903
    bool reached(Node v) const { return (*_heap_cross_ref)[v] !=
kpeter@244
   904
                                        Heap::PRE_HEAP; }
alpar@100
   905
alpar@100
   906
    ///Checks if a node is processed.
alpar@100
   907
alpar@100
   908
    ///Returns \c true if \c v is processed, i.e. the shortest
alpar@100
   909
    ///path to \c v has already found.
kpeter@244
   910
    ///\pre Either \ref run() or \ref start()
kpeter@244
   911
    ///must be called before using this function.
kpeter@244
   912
    bool processed(Node v) const { return (*_heap_cross_ref)[v] ==
kpeter@244
   913
                                          Heap::POST_HEAP; }
kpeter@244
   914
kpeter@244
   915
    ///The current distance of a node from the root(s).
kpeter@244
   916
kpeter@244
   917
    ///Returns the current distance of a node from the root(s).
kpeter@244
   918
    ///It may be decreased in the following processes.
kpeter@244
   919
    ///\pre \c v should be reached but not processed.
kpeter@244
   920
    Value currentDist(Node v) const { return (*_heap)[v]; }
alpar@209
   921
alpar@100
   922
    ///@}
alpar@100
   923
  };
alpar@100
   924
alpar@100
   925
kpeter@244
   926
  ///Default traits class of dijkstra() function.
alpar@100
   927
kpeter@244
   928
  ///Default traits class of dijkstra() function.
kpeter@244
   929
  ///\tparam GR The type of the digraph.
kpeter@244
   930
  ///\tparam LM The type of the length map.
alpar@100
   931
  template<class GR, class LM>
alpar@100
   932
  struct DijkstraWizardDefaultTraits
alpar@100
   933
  {
kpeter@244
   934
    ///The type of the digraph the algorithm runs on.
alpar@100
   935
    typedef GR Digraph;
alpar@100
   936
    ///The type of the map that stores the arc lengths.
alpar@100
   937
alpar@100
   938
    ///The type of the map that stores the arc lengths.
alpar@100
   939
    ///It must meet the \ref concepts::ReadMap "ReadMap" concept.
alpar@100
   940
    typedef LM LengthMap;
kpeter@244
   941
    ///The type of the length of the arcs.
alpar@100
   942
    typedef typename LM::Value Value;
kpeter@244
   943
alpar@100
   944
    /// Operation traits for Dijkstra algorithm.
alpar@100
   945
kpeter@244
   946
    /// This class defines the operations that are used in the algorithm.
alpar@100
   947
    /// \see DijkstraDefaultOperationTraits
alpar@100
   948
    typedef DijkstraDefaultOperationTraits<Value> OperationTraits;
alpar@100
   949
kpeter@244
   950
    /// The cross reference type used by the heap.
alpar@100
   951
kpeter@244
   952
    /// The cross reference type used by the heap.
alpar@100
   953
    /// Usually it is \c Digraph::NodeMap<int>.
alpar@100
   954
    typedef typename Digraph::template NodeMap<int> HeapCrossRef;
kpeter@244
   955
    ///Instantiates a \ref HeapCrossRef.
alpar@100
   956
alpar@209
   957
    ///This function instantiates a \ref HeapCrossRef.
kpeter@244
   958
    /// \param g is the digraph, to which we would like to define the
alpar@100
   959
    /// HeapCrossRef.
alpar@100
   960
    /// \todo The digraph alone may be insufficient for the initialization
kpeter@244
   961
    static HeapCrossRef *createHeapCrossRef(const Digraph &g)
alpar@100
   962
    {
kpeter@244
   963
      return new HeapCrossRef(g);
alpar@100
   964
    }
alpar@209
   965
kpeter@244
   966
    ///The heap type used by the Dijkstra algorithm.
alpar@100
   967
kpeter@244
   968
    ///The heap type used by the Dijkstra algorithm.
alpar@100
   969
    ///
alpar@100
   970
    ///\sa BinHeap
alpar@100
   971
    ///\sa Dijkstra
kpeter@244
   972
    typedef BinHeap<Value, typename Digraph::template NodeMap<int>,
alpar@209
   973
                    std::less<Value> > Heap;
alpar@100
   974
kpeter@244
   975
    ///Instantiates a \ref Heap.
kpeter@244
   976
kpeter@244
   977
    ///This function instantiates a \ref Heap.
kpeter@244
   978
    /// \param r is the HeapCrossRef which is used.
kpeter@244
   979
    static Heap *createHeap(HeapCrossRef& r)
alpar@100
   980
    {
kpeter@244
   981
      return new Heap(r);
alpar@100
   982
    }
alpar@100
   983
kpeter@244
   984
    ///\brief The type of the map that stores the predecessor
alpar@100
   985
    ///arcs of the shortest paths.
alpar@209
   986
    ///
kpeter@244
   987
    ///The type of the map that stores the predecessor
alpar@100
   988
    ///arcs of the shortest paths.
alpar@100
   989
    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
kpeter@244
   990
    typedef NullMap <typename Digraph::Node,typename Digraph::Arc> PredMap;
kpeter@244
   991
    ///Instantiates a \ref PredMap.
alpar@209
   992
alpar@209
   993
    ///This function instantiates a \ref PredMap.
kpeter@244
   994
    ///\param g is the digraph, to which we would like to define the
kpeter@244
   995
    ///\ref PredMap.
kpeter@244
   996
    ///\todo The digraph alone may be insufficient to initialize
alpar@100
   997
#ifdef DOXYGEN
kpeter@244
   998
    static PredMap *createPredMap(const Digraph &g)
alpar@100
   999
#else
kpeter@244
  1000
    static PredMap *createPredMap(const Digraph &)
alpar@100
  1001
#endif
alpar@100
  1002
    {
alpar@100
  1003
      return new PredMap();
alpar@100
  1004
    }
alpar@209
  1005
kpeter@244
  1006
    ///The type of the map that indicates which nodes are processed.
kpeter@244
  1007
kpeter@244
  1008
    ///The type of the map that indicates which nodes are processed.
alpar@100
  1009
    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
alpar@100
  1010
    ///By default it is a NullMap.
alpar@100
  1011
    ///\todo If it is set to a real map,
alpar@100
  1012
    ///Dijkstra::processed() should read this.
alpar@100
  1013
    ///\todo named parameter to set this type, function to read and write.
alpar@100
  1014
    typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
kpeter@244
  1015
    ///Instantiates a \ref ProcessedMap.
alpar@209
  1016
alpar@209
  1017
    ///This function instantiates a \ref ProcessedMap.
alpar@100
  1018
    ///\param g is the digraph, to which
kpeter@244
  1019
    ///we would like to define the \ref ProcessedMap.
alpar@100
  1020
#ifdef DOXYGEN
kpeter@244
  1021
    static ProcessedMap *createProcessedMap(const Digraph &g)
alpar@100
  1022
#else
kpeter@244
  1023
    static ProcessedMap *createProcessedMap(const Digraph &)
alpar@100
  1024
#endif
alpar@100
  1025
    {
alpar@100
  1026
      return new ProcessedMap();
alpar@100
  1027
    }
alpar@209
  1028
kpeter@244
  1029
    ///The type of the map that stores the distances of the nodes.
kpeter@244
  1030
kpeter@244
  1031
    ///The type of the map that stores the distances of the nodes.
alpar@100
  1032
    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
kpeter@244
  1033
    typedef NullMap<typename Digraph::Node,Value> DistMap;
kpeter@244
  1034
    ///Instantiates a \ref DistMap.
alpar@209
  1035
alpar@209
  1036
    ///This function instantiates a \ref DistMap.
alpar@210
  1037
    ///\param g is the digraph, to which we would like to define
alpar@210
  1038
    ///the \ref DistMap
alpar@100
  1039
#ifdef DOXYGEN
kpeter@244
  1040
    static DistMap *createDistMap(const Digraph &g)
alpar@100
  1041
#else
kpeter@244
  1042
    static DistMap *createDistMap(const Digraph &)
alpar@100
  1043
#endif
alpar@100
  1044
    {
alpar@100
  1045
      return new DistMap();
alpar@100
  1046
    }
alpar@100
  1047
  };
alpar@209
  1048
kpeter@244
  1049
  /// Default traits class used by \ref DijkstraWizard
alpar@100
  1050
alpar@100
  1051
  /// To make it easier to use Dijkstra algorithm
kpeter@244
  1052
  /// we have created a wizard class.
alpar@100
  1053
  /// This \ref DijkstraWizard class needs default traits,
kpeter@244
  1054
  /// as well as the \ref Dijkstra class.
alpar@100
  1055
  /// The \ref DijkstraWizardBase is a class to be the default traits of the
alpar@100
  1056
  /// \ref DijkstraWizard class.
alpar@100
  1057
  /// \todo More named parameters are required...
alpar@100
  1058
  template<class GR,class LM>
alpar@100
  1059
  class DijkstraWizardBase : public DijkstraWizardDefaultTraits<GR,LM>
alpar@100
  1060
  {
alpar@100
  1061
    typedef DijkstraWizardDefaultTraits<GR,LM> Base;
alpar@100
  1062
  protected:
kpeter@244
  1063
    //The type of the nodes in the digraph.
alpar@100
  1064
    typedef typename Base::Digraph::Node Node;
alpar@100
  1065
kpeter@244
  1066
    //Pointer to the digraph the algorithm runs on.
alpar@100
  1067
    void *_g;
kpeter@244
  1068
    //Pointer to the length map
alpar@100
  1069
    void *_length;
kpeter@251
  1070
    //Pointer to the map of processed nodes.
kpeter@251
  1071
    void *_processed;
kpeter@244
  1072
    //Pointer to the map of predecessors arcs.
alpar@100
  1073
    void *_pred;
kpeter@244
  1074
    //Pointer to the map of distances.
alpar@100
  1075
    void *_dist;
kpeter@244
  1076
    //Pointer to the source node.
alpar@100
  1077
    Node _source;
alpar@100
  1078
kpeter@244
  1079
  public:
alpar@100
  1080
    /// Constructor.
alpar@209
  1081
alpar@100
  1082
    /// This constructor does not require parameters, therefore it initiates
alpar@100
  1083
    /// all of the attributes to default values (0, INVALID).
kpeter@251
  1084
    DijkstraWizardBase() : _g(0), _length(0), _processed(0), _pred(0),
alpar@209
  1085
                           _dist(0), _source(INVALID) {}
alpar@100
  1086
alpar@100
  1087
    /// Constructor.
alpar@209
  1088
alpar@100
  1089
    /// This constructor requires some parameters,
alpar@100
  1090
    /// listed in the parameters list.
alpar@100
  1091
    /// Others are initiated to 0.
kpeter@244
  1092
    /// \param g The digraph the algorithm runs on.
kpeter@244
  1093
    /// \param l The length map.
kpeter@244
  1094
    /// \param s The source node.
alpar@100
  1095
    DijkstraWizardBase(const GR &g,const LM &l, Node s=INVALID) :
alpar@209
  1096
      _g(reinterpret_cast<void*>(const_cast<GR*>(&g))),
alpar@209
  1097
      _length(reinterpret_cast<void*>(const_cast<LM*>(&l))),
kpeter@251
  1098
      _processed(0), _pred(0), _dist(0), _source(s) {}
alpar@100
  1099
alpar@100
  1100
  };
alpar@209
  1101
kpeter@244
  1102
  /// Auxiliary class for the function type interface of Dijkstra algorithm.
alpar@100
  1103
kpeter@244
  1104
  /// This auxiliary class is created to implement the function type
kpeter@244
  1105
  /// interface of \ref Dijkstra algorithm. It uses the functions and features
kpeter@244
  1106
  /// of the plain \ref Dijkstra, but it is much simpler to use it.
kpeter@244
  1107
  /// It should only be used through the \ref dijkstra() function, which makes
kpeter@244
  1108
  /// it easier to use the algorithm.
alpar@100
  1109
  ///
alpar@100
  1110
  /// Simplicity means that the way to change the types defined
alpar@100
  1111
  /// in the traits class is based on functions that returns the new class
alpar@100
  1112
  /// and not on templatable built-in classes.
alpar@100
  1113
  /// When using the plain \ref Dijkstra
alpar@100
  1114
  /// the new class with the modified type comes from
alpar@100
  1115
  /// the original class by using the ::
alpar@100
  1116
  /// operator. In the case of \ref DijkstraWizard only
kpeter@244
  1117
  /// a function have to be called, and it will
alpar@100
  1118
  /// return the needed class.
alpar@100
  1119
  ///
kpeter@244
  1120
  /// It does not have own \ref run() method. When its \ref run() method
kpeter@244
  1121
  /// is called, it initiates a plain \ref Dijkstra object, and calls the
kpeter@244
  1122
  /// \ref Dijkstra::run() method of it.
alpar@100
  1123
  template<class TR>
alpar@100
  1124
  class DijkstraWizard : public TR
alpar@100
  1125
  {
alpar@100
  1126
    typedef TR Base;
alpar@100
  1127
kpeter@244
  1128
    ///The type of the digraph the algorithm runs on.
alpar@100
  1129
    typedef typename TR::Digraph Digraph;
kpeter@244
  1130
alpar@100
  1131
    typedef typename Digraph::Node Node;
alpar@100
  1132
    typedef typename Digraph::NodeIt NodeIt;
alpar@100
  1133
    typedef typename Digraph::Arc Arc;
alpar@100
  1134
    typedef typename Digraph::OutArcIt OutArcIt;
alpar@209
  1135
alpar@100
  1136
    ///The type of the map that stores the arc lengths.
alpar@100
  1137
    typedef typename TR::LengthMap LengthMap;
alpar@100
  1138
    ///The type of the length of the arcs.
alpar@100
  1139
    typedef typename LengthMap::Value Value;
kpeter@244
  1140
    ///\brief The type of the map that stores the predecessor
alpar@100
  1141
    ///arcs of the shortest paths.
alpar@100
  1142
    typedef typename TR::PredMap PredMap;
kpeter@244
  1143
    ///The type of the map that stores the distances of the nodes.
alpar@100
  1144
    typedef typename TR::DistMap DistMap;
kpeter@244
  1145
    ///The type of the map that indicates which nodes are processed.
kpeter@244
  1146
    typedef typename TR::ProcessedMap ProcessedMap;
alpar@100
  1147
    ///The heap type used by the dijkstra algorithm.
alpar@100
  1148
    typedef typename TR::Heap Heap;
kpeter@244
  1149
alpar@100
  1150
  public:
kpeter@244
  1151
alpar@100
  1152
    /// Constructor.
alpar@100
  1153
    DijkstraWizard() : TR() {}
alpar@100
  1154
alpar@100
  1155
    /// Constructor that requires parameters.
alpar@100
  1156
alpar@100
  1157
    /// Constructor that requires parameters.
alpar@100
  1158
    /// These parameters will be the default values for the traits class.
alpar@100
  1159
    DijkstraWizard(const Digraph &g,const LengthMap &l, Node s=INVALID) :
alpar@100
  1160
      TR(g,l,s) {}
alpar@100
  1161
alpar@100
  1162
    ///Copy constructor
alpar@100
  1163
    DijkstraWizard(const TR &b) : TR(b) {}
alpar@100
  1164
alpar@100
  1165
    ~DijkstraWizard() {}
alpar@100
  1166
kpeter@244
  1167
    ///Runs Dijkstra algorithm from a source node.
alpar@209
  1168
kpeter@244
  1169
    ///Runs Dijkstra algorithm from a source node.
kpeter@244
  1170
    ///The node can be given with the \ref source() function.
alpar@100
  1171
    void run()
alpar@100
  1172
    {
alpar@100
  1173
      if(Base::_source==INVALID) throw UninitializedParameter();
alpar@209
  1174
      Dijkstra<Digraph,LengthMap,TR>
alpar@209
  1175
        dij(*reinterpret_cast<const Digraph*>(Base::_g),
alpar@100
  1176
            *reinterpret_cast<const LengthMap*>(Base::_length));
kpeter@251
  1177
      if(Base::_processed)
kpeter@251
  1178
        dij.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
kpeter@251
  1179
      if(Base::_pred)
kpeter@251
  1180
        dij.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
kpeter@251
  1181
      if(Base::_dist)
kpeter@251
  1182
        dij.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
alpar@100
  1183
      dij.run(Base::_source);
alpar@100
  1184
    }
alpar@100
  1185
alpar@100
  1186
    ///Runs Dijkstra algorithm from the given node.
alpar@100
  1187
alpar@100
  1188
    ///Runs Dijkstra algorithm from the given node.
alpar@100
  1189
    ///\param s is the given source.
alpar@100
  1190
    void run(Node s)
alpar@100
  1191
    {
alpar@100
  1192
      Base::_source=s;
alpar@100
  1193
      run();
alpar@100
  1194
    }
alpar@100
  1195
kpeter@244
  1196
    /// Sets the source node, from which the Dijkstra algorithm runs.
kpeter@244
  1197
kpeter@244
  1198
    /// Sets the source node, from which the Dijkstra algorithm runs.
kpeter@244
  1199
    /// \param s is the source node.
kpeter@244
  1200
    DijkstraWizard<TR> &source(Node s)
kpeter@244
  1201
    {
kpeter@244
  1202
      Base::_source=s;
kpeter@244
  1203
      return *this;
kpeter@244
  1204
    }
kpeter@244
  1205
alpar@100
  1206
    template<class T>
kpeter@257
  1207
    struct SetPredMapBase : public Base {
alpar@100
  1208
      typedef T PredMap;
alpar@100
  1209
      static PredMap *createPredMap(const Digraph &) { return 0; };
kpeter@257
  1210
      SetPredMapBase(const TR &b) : TR(b) {}
alpar@100
  1211
    };
alpar@100
  1212
    ///\brief \ref named-templ-param "Named parameter"
kpeter@244
  1213
    ///for setting \ref PredMap object.
alpar@100
  1214
    ///
kpeter@244
  1215
    ///\ref named-templ-param "Named parameter"
kpeter@244
  1216
    ///for setting \ref PredMap object.
alpar@100
  1217
    template<class T>
kpeter@257
  1218
    DijkstraWizard<SetPredMapBase<T> > predMap(const T &t)
alpar@100
  1219
    {
alpar@100
  1220
      Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
kpeter@257
  1221
      return DijkstraWizard<SetPredMapBase<T> >(*this);
alpar@100
  1222
    }
alpar@209
  1223
alpar@100
  1224
    template<class T>
kpeter@257
  1225
    struct SetProcessedMapBase : public Base {
kpeter@244
  1226
      typedef T ProcessedMap;
kpeter@244
  1227
      static ProcessedMap *createProcessedMap(const Digraph &) { return 0; };
kpeter@257
  1228
      SetProcessedMapBase(const TR &b) : TR(b) {}
kpeter@244
  1229
    };
kpeter@244
  1230
    ///\brief \ref named-templ-param "Named parameter"
kpeter@244
  1231
    ///for setting \ref ProcessedMap object.
kpeter@244
  1232
    ///
kpeter@244
  1233
    /// \ref named-templ-param "Named parameter"
kpeter@244
  1234
    ///for setting \ref ProcessedMap object.
kpeter@244
  1235
    template<class T>
kpeter@257
  1236
    DijkstraWizard<SetProcessedMapBase<T> > processedMap(const T &t)
kpeter@244
  1237
    {
kpeter@244
  1238
      Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t));
kpeter@257
  1239
      return DijkstraWizard<SetProcessedMapBase<T> >(*this);
kpeter@244
  1240
    }
kpeter@244
  1241
kpeter@244
  1242
    template<class T>
kpeter@257
  1243
    struct SetDistMapBase : public Base {
alpar@100
  1244
      typedef T DistMap;
alpar@100
  1245
      static DistMap *createDistMap(const Digraph &) { return 0; };
kpeter@257
  1246
      SetDistMapBase(const TR &b) : TR(b) {}
alpar@100
  1247
    };
alpar@100
  1248
    ///\brief \ref named-templ-param "Named parameter"
kpeter@244
  1249
    ///for setting \ref DistMap object.
alpar@100
  1250
    ///
kpeter@244
  1251
    ///\ref named-templ-param "Named parameter"
kpeter@244
  1252
    ///for setting \ref DistMap object.
alpar@100
  1253
    template<class T>
kpeter@257
  1254
    DijkstraWizard<SetDistMapBase<T> > distMap(const T &t)
alpar@100
  1255
    {
alpar@100
  1256
      Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t));
kpeter@257
  1257
      return DijkstraWizard<SetDistMapBase<T> >(*this);
alpar@100
  1258
    }
alpar@209
  1259
alpar@100
  1260
  };
alpar@209
  1261
alpar@100
  1262
  ///Function type interface for Dijkstra algorithm.
alpar@100
  1263
alpar@100
  1264
  /// \ingroup shortest_path
alpar@100
  1265
  ///Function type interface for Dijkstra algorithm.
alpar@100
  1266
  ///
alpar@100
  1267
  ///This function also has several
alpar@100
  1268
  ///\ref named-templ-func-param "named parameters",
alpar@100
  1269
  ///they are declared as the members of class \ref DijkstraWizard.
alpar@100
  1270
  ///The following
alpar@100
  1271
  ///example shows how to use these parameters.
alpar@100
  1272
  ///\code
alpar@100
  1273
  ///  dijkstra(g,length,source).predMap(preds).run();
alpar@100
  1274
  ///\endcode
alpar@100
  1275
  ///\warning Don't forget to put the \ref DijkstraWizard::run() "run()"
alpar@100
  1276
  ///to the end of the parameter list.
alpar@100
  1277
  ///\sa DijkstraWizard
alpar@100
  1278
  ///\sa Dijkstra
alpar@100
  1279
  template<class GR, class LM>
alpar@100
  1280
  DijkstraWizard<DijkstraWizardBase<GR,LM> >
alpar@100
  1281
  dijkstra(const GR &g,const LM &l,typename GR::Node s=INVALID)
alpar@100
  1282
  {
alpar@100
  1283
    return DijkstraWizard<DijkstraWizardBase<GR,LM> >(g,l,s);
alpar@100
  1284
  }
alpar@100
  1285
alpar@100
  1286
} //END OF NAMESPACE LEMON
alpar@100
  1287
alpar@100
  1288
#endif