alpar@209: /* -*- mode: C++; indent-tabs-mode: nil; -*-
alpar@100:  *
alpar@209:  * This file is a part of LEMON, a generic C++ optimization library.
alpar@100:  *
alpar@100:  * Copyright (C) 2003-2008
alpar@100:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
alpar@100:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
alpar@100:  *
alpar@100:  * Permission to use, modify and distribute this software is granted
alpar@100:  * provided that this copyright notice appears in all copies. For
alpar@100:  * precise terms see the accompanying LICENSE file.
alpar@100:  *
alpar@100:  * This software is provided "AS IS" with no warranty of any kind,
alpar@100:  * express or implied, and with no claim as to its suitability for any
alpar@100:  * purpose.
alpar@100:  *
alpar@100:  */
alpar@100: 
alpar@100: #ifndef LEMON_DIJKSTRA_H
alpar@100: #define LEMON_DIJKSTRA_H
alpar@100: 
alpar@100: ///\ingroup shortest_path
alpar@100: ///\file
alpar@100: ///\brief Dijkstra algorithm.
alpar@100: 
alpar@184: #include <limits>
kpeter@169: #include <lemon/list_graph.h>
alpar@100: #include <lemon/bin_heap.h>
alpar@100: #include <lemon/bits/path_dump.h>
deba@220: #include <lemon/core.h>
alpar@100: #include <lemon/error.h>
alpar@100: #include <lemon/maps.h>
kpeter@278: #include <lemon/path.h>
alpar@100: 
alpar@100: namespace lemon {
alpar@100: 
kpeter@244:   /// \brief Default operation traits for the Dijkstra algorithm class.
alpar@209:   ///
kpeter@244:   /// This operation traits class defines all computational operations and
kpeter@244:   /// constants which are used in the Dijkstra algorithm.
alpar@100:   template <typename Value>
alpar@100:   struct DijkstraDefaultOperationTraits {
alpar@100:     /// \brief Gives back the zero value of the type.
alpar@100:     static Value zero() {
alpar@100:       return static_cast<Value>(0);
alpar@100:     }
alpar@100:     /// \brief Gives back the sum of the given two elements.
alpar@100:     static Value plus(const Value& left, const Value& right) {
alpar@100:       return left + right;
alpar@100:     }
kpeter@244:     /// \brief Gives back true only if the first value is less than the second.
alpar@100:     static bool less(const Value& left, const Value& right) {
alpar@100:       return left < right;
alpar@100:     }
alpar@100:   };
alpar@100: 
kpeter@244:   /// \brief Widest path operation traits for the Dijkstra algorithm class.
alpar@209:   ///
kpeter@244:   /// This operation traits class defines all computational operations and
kpeter@244:   /// constants which are used in the Dijkstra algorithm for widest path
kpeter@244:   /// computation.
kpeter@244:   ///
kpeter@244:   /// \see DijkstraDefaultOperationTraits
alpar@100:   template <typename Value>
alpar@100:   struct DijkstraWidestPathOperationTraits {
alpar@100:     /// \brief Gives back the maximum value of the type.
alpar@100:     static Value zero() {
alpar@100:       return std::numeric_limits<Value>::max();
alpar@100:     }
alpar@100:     /// \brief Gives back the minimum of the given two elements.
alpar@100:     static Value plus(const Value& left, const Value& right) {
alpar@100:       return std::min(left, right);
alpar@100:     }
kpeter@244:     /// \brief Gives back true only if the first value is less than the second.
alpar@100:     static bool less(const Value& left, const Value& right) {
alpar@100:       return left < right;
alpar@100:     }
alpar@100:   };
alpar@209: 
alpar@100:   ///Default traits class of Dijkstra class.
alpar@100: 
alpar@100:   ///Default traits class of Dijkstra class.
kpeter@244:   ///\tparam GR The type of the digraph.
kpeter@244:   ///\tparam LM The type of the length map.
alpar@100:   template<class GR, class LM>
alpar@100:   struct DijkstraDefaultTraits
alpar@100:   {
kpeter@244:     ///The type of the digraph the algorithm runs on.
alpar@100:     typedef GR Digraph;
kpeter@244: 
alpar@100:     ///The type of the map that stores the arc lengths.
alpar@100: 
alpar@100:     ///The type of the map that stores the arc lengths.
alpar@100:     ///It must meet the \ref concepts::ReadMap "ReadMap" concept.
alpar@100:     typedef LM LengthMap;
kpeter@244:     ///The type of the length of the arcs.
alpar@100:     typedef typename LM::Value Value;
kpeter@244: 
alpar@100:     /// Operation traits for Dijkstra algorithm.
alpar@100: 
kpeter@244:     /// This class defines the operations that are used in the algorithm.
alpar@100:     /// \see DijkstraDefaultOperationTraits
alpar@100:     typedef DijkstraDefaultOperationTraits<Value> OperationTraits;
alpar@100: 
kpeter@244:     /// The cross reference type used by the heap.
alpar@100: 
kpeter@244:     /// The cross reference type used by the heap.
alpar@100:     /// Usually it is \c Digraph::NodeMap<int>.
alpar@100:     typedef typename Digraph::template NodeMap<int> HeapCrossRef;
kpeter@244:     ///Instantiates a \ref HeapCrossRef.
alpar@100: 
kpeter@244:     ///This function instantiates a \ref HeapCrossRef.
kpeter@244:     /// \param g is the digraph, to which we would like to define the
kpeter@244:     /// \ref HeapCrossRef.
kpeter@244:     static HeapCrossRef *createHeapCrossRef(const Digraph &g)
alpar@100:     {
kpeter@244:       return new HeapCrossRef(g);
alpar@100:     }
alpar@209: 
kpeter@244:     ///The heap type used by the Dijkstra algorithm.
alpar@100: 
kpeter@244:     ///The heap type used by the Dijkstra algorithm.
alpar@100:     ///
alpar@100:     ///\sa BinHeap
alpar@100:     ///\sa Dijkstra
alpar@100:     typedef BinHeap<typename LM::Value, HeapCrossRef, std::less<Value> > Heap;
kpeter@244:     ///Instantiates a \ref Heap.
alpar@100: 
kpeter@244:     ///This function instantiates a \ref Heap.
kpeter@244:     static Heap *createHeap(HeapCrossRef& r)
alpar@100:     {
kpeter@244:       return new Heap(r);
alpar@100:     }
alpar@100: 
kpeter@244:     ///\brief The type of the map that stores the predecessor
alpar@100:     ///arcs of the shortest paths.
alpar@209:     ///
kpeter@244:     ///The type of the map that stores the predecessor
alpar@100:     ///arcs of the shortest paths.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
kpeter@244:     typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
kpeter@305:     ///Instantiates a PredMap.
alpar@209: 
kpeter@305:     ///This function instantiates a PredMap.
kpeter@244:     ///\param g is the digraph, to which we would like to define the
kpeter@305:     ///PredMap.
kpeter@244:     static PredMap *createPredMap(const Digraph &g)
alpar@100:     {
kpeter@244:       return new PredMap(g);
alpar@100:     }
alpar@100: 
kpeter@244:     ///The type of the map that indicates which nodes are processed.
alpar@209: 
kpeter@244:     ///The type of the map that indicates which nodes are processed.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
alpar@100:     ///By default it is a NullMap.
alpar@100:     typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
kpeter@305:     ///Instantiates a ProcessedMap.
alpar@209: 
kpeter@305:     ///This function instantiates a ProcessedMap.
alpar@100:     ///\param g is the digraph, to which
kpeter@305:     ///we would like to define the ProcessedMap
alpar@100: #ifdef DOXYGEN
kpeter@244:     static ProcessedMap *createProcessedMap(const Digraph &g)
alpar@100: #else
kpeter@244:     static ProcessedMap *createProcessedMap(const Digraph &)
alpar@100: #endif
alpar@100:     {
alpar@100:       return new ProcessedMap();
alpar@100:     }
alpar@209: 
kpeter@244:     ///The type of the map that stores the distances of the nodes.
kpeter@244: 
kpeter@244:     ///The type of the map that stores the distances of the nodes.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
alpar@100:     typedef typename Digraph::template NodeMap<typename LM::Value> DistMap;
kpeter@305:     ///Instantiates a DistMap.
alpar@209: 
kpeter@305:     ///This function instantiates a DistMap.
kpeter@244:     ///\param g is the digraph, to which we would like to define
kpeter@305:     ///the DistMap
kpeter@244:     static DistMap *createDistMap(const Digraph &g)
alpar@100:     {
kpeter@244:       return new DistMap(g);
alpar@100:     }
alpar@100:   };
alpar@209: 
alpar@100:   ///%Dijkstra algorithm class.
alpar@209: 
alpar@100:   /// \ingroup shortest_path
kpeter@244:   ///This class provides an efficient implementation of the %Dijkstra algorithm.
kpeter@244:   ///
alpar@100:   ///The arc lengths are passed to the algorithm using a
alpar@100:   ///\ref concepts::ReadMap "ReadMap",
alpar@100:   ///so it is easy to change it to any kind of length.
alpar@100:   ///The type of the length is determined by the
alpar@100:   ///\ref concepts::ReadMap::Value "Value" of the length map.
alpar@100:   ///It is also possible to change the underlying priority heap.
alpar@100:   ///
kpeter@278:   ///There is also a \ref dijkstra() "function-type interface" for the
kpeter@244:   ///%Dijkstra algorithm, which is convenient in the simplier cases and
kpeter@244:   ///it can be used easier.
kpeter@244:   ///
kpeter@244:   ///\tparam GR The type of the digraph the algorithm runs on.
kpeter@244:   ///The default value is \ref ListDigraph.
kpeter@244:   ///The value of GR is not used directly by \ref Dijkstra, it is only
kpeter@244:   ///passed to \ref DijkstraDefaultTraits.
kpeter@244:   ///\tparam LM A readable arc map that determines the lengths of the
alpar@100:   ///arcs. It is read once for each arc, so the map may involve in
kpeter@244:   ///relatively time consuming process to compute the arc lengths if
alpar@100:   ///it is necessary. The default map type is \ref
kpeter@244:   ///concepts::Digraph::ArcMap "Digraph::ArcMap<int>".
kpeter@244:   ///The value of LM is not used directly by \ref Dijkstra, it is only
kpeter@244:   ///passed to \ref DijkstraDefaultTraits.
kpeter@244:   ///\tparam TR Traits class to set various data types used by the algorithm.
kpeter@244:   ///The default traits class is \ref DijkstraDefaultTraits
kpeter@244:   ///"DijkstraDefaultTraits<GR,LM>". See \ref DijkstraDefaultTraits
kpeter@244:   ///for the documentation of a Dijkstra traits class.
alpar@100: #ifdef DOXYGEN
alpar@100:   template <typename GR, typename LM, typename TR>
alpar@100: #else
alpar@100:   template <typename GR=ListDigraph,
alpar@209:             typename LM=typename GR::template ArcMap<int>,
alpar@209:             typename TR=DijkstraDefaultTraits<GR,LM> >
alpar@100: #endif
alpar@100:   class Dijkstra {
alpar@100:   public:
alpar@100: 
kpeter@244:     ///The type of the digraph the algorithm runs on.
alpar@100:     typedef typename TR::Digraph Digraph;
alpar@209: 
alpar@100:     ///The type of the length of the arcs.
alpar@100:     typedef typename TR::LengthMap::Value Value;
alpar@100:     ///The type of the map that stores the arc lengths.
alpar@100:     typedef typename TR::LengthMap LengthMap;
kpeter@244:     ///\brief The type of the map that stores the predecessor arcs of the
kpeter@244:     ///shortest paths.
alpar@100:     typedef typename TR::PredMap PredMap;
kpeter@244:     ///The type of the map that stores the distances of the nodes.
kpeter@244:     typedef typename TR::DistMap DistMap;
kpeter@244:     ///The type of the map that indicates which nodes are processed.
alpar@100:     typedef typename TR::ProcessedMap ProcessedMap;
kpeter@244:     ///The type of the paths.
kpeter@244:     typedef PredMapPath<Digraph, PredMap> Path;
alpar@100:     ///The cross reference type used for the current heap.
alpar@100:     typedef typename TR::HeapCrossRef HeapCrossRef;
kpeter@244:     ///The heap type used by the algorithm.
alpar@100:     typedef typename TR::Heap Heap;
kpeter@244:     ///The operation traits class.
alpar@100:     typedef typename TR::OperationTraits OperationTraits;
kpeter@244: 
kpeter@244:     ///The traits class.
kpeter@244:     typedef TR Traits;
kpeter@244: 
alpar@100:   private:
kpeter@244: 
kpeter@244:     typedef typename Digraph::Node Node;
kpeter@244:     typedef typename Digraph::NodeIt NodeIt;
kpeter@244:     typedef typename Digraph::Arc Arc;
kpeter@244:     typedef typename Digraph::OutArcIt OutArcIt;
kpeter@244: 
kpeter@244:     //Pointer to the underlying digraph.
alpar@100:     const Digraph *G;
kpeter@244:     //Pointer to the length map.
alpar@100:     const LengthMap *length;
kpeter@244:     //Pointer to the map of predecessors arcs.
alpar@100:     PredMap *_pred;
kpeter@244:     //Indicates if _pred is locally allocated (true) or not.
alpar@100:     bool local_pred;
kpeter@244:     //Pointer to the map of distances.
alpar@100:     DistMap *_dist;
kpeter@244:     //Indicates if _dist is locally allocated (true) or not.
alpar@100:     bool local_dist;
kpeter@244:     //Pointer to the map of processed status of the nodes.
alpar@100:     ProcessedMap *_processed;
kpeter@244:     //Indicates if _processed is locally allocated (true) or not.
alpar@100:     bool local_processed;
kpeter@244:     //Pointer to the heap cross references.
alpar@100:     HeapCrossRef *_heap_cross_ref;
kpeter@244:     //Indicates if _heap_cross_ref is locally allocated (true) or not.
alpar@100:     bool local_heap_cross_ref;
kpeter@244:     //Pointer to the heap.
alpar@100:     Heap *_heap;
kpeter@244:     //Indicates if _heap is locally allocated (true) or not.
alpar@100:     bool local_heap;
alpar@100: 
alpar@280:     //Creates the maps if necessary.
alpar@209:     void create_maps()
alpar@100:     {
alpar@100:       if(!_pred) {
alpar@209:         local_pred = true;
alpar@209:         _pred = Traits::createPredMap(*G);
alpar@100:       }
alpar@100:       if(!_dist) {
alpar@209:         local_dist = true;
alpar@209:         _dist = Traits::createDistMap(*G);
alpar@100:       }
alpar@100:       if(!_processed) {
alpar@209:         local_processed = true;
alpar@209:         _processed = Traits::createProcessedMap(*G);
alpar@100:       }
alpar@100:       if (!_heap_cross_ref) {
alpar@209:         local_heap_cross_ref = true;
alpar@209:         _heap_cross_ref = Traits::createHeapCrossRef(*G);
alpar@100:       }
alpar@100:       if (!_heap) {
alpar@209:         local_heap = true;
alpar@209:         _heap = Traits::createHeap(*_heap_cross_ref);
alpar@100:       }
alpar@100:     }
alpar@209: 
kpeter@244:   public:
alpar@100: 
alpar@100:     typedef Dijkstra Create;
alpar@209: 
alpar@100:     ///\name Named template parameters
alpar@100: 
alpar@100:     ///@{
alpar@100: 
alpar@100:     template <class T>
kpeter@257:     struct SetPredMapTraits : public Traits {
alpar@100:       typedef T PredMap;
alpar@100:       static PredMap *createPredMap(const Digraph &)
alpar@100:       {
deba@290:         LEMON_ASSERT(false, "PredMap is not initialized");
deba@290:         return 0; // ignore warnings
alpar@100:       }
alpar@100:     };
kpeter@244:     ///\brief \ref named-templ-param "Named parameter" for setting
kpeter@305:     ///PredMap type.
alpar@100:     ///
kpeter@244:     ///\ref named-templ-param "Named parameter" for setting
kpeter@305:     ///PredMap type.
alpar@100:     template <class T>
kpeter@257:     struct SetPredMap
kpeter@257:       : public Dijkstra< Digraph, LengthMap, SetPredMapTraits<T> > {
kpeter@257:       typedef Dijkstra< Digraph, LengthMap, SetPredMapTraits<T> > Create;
alpar@100:     };
alpar@209: 
alpar@100:     template <class T>
kpeter@257:     struct SetDistMapTraits : public Traits {
alpar@100:       typedef T DistMap;
alpar@100:       static DistMap *createDistMap(const Digraph &)
alpar@100:       {
deba@290:         LEMON_ASSERT(false, "DistMap is not initialized");
deba@290:         return 0; // ignore warnings
alpar@100:       }
alpar@100:     };
kpeter@244:     ///\brief \ref named-templ-param "Named parameter" for setting
kpeter@305:     ///DistMap type.
alpar@100:     ///
kpeter@244:     ///\ref named-templ-param "Named parameter" for setting
kpeter@305:     ///DistMap type.
alpar@100:     template <class T>
kpeter@257:     struct SetDistMap
kpeter@257:       : public Dijkstra< Digraph, LengthMap, SetDistMapTraits<T> > {
kpeter@257:       typedef Dijkstra< Digraph, LengthMap, SetDistMapTraits<T> > Create;
alpar@100:     };
alpar@209: 
alpar@100:     template <class T>
kpeter@257:     struct SetProcessedMapTraits : public Traits {
alpar@100:       typedef T ProcessedMap;
kpeter@244:       static ProcessedMap *createProcessedMap(const Digraph &)
alpar@100:       {
deba@290:         LEMON_ASSERT(false, "ProcessedMap is not initialized");
deba@290:         return 0; // ignore warnings
alpar@100:       }
alpar@100:     };
kpeter@244:     ///\brief \ref named-templ-param "Named parameter" for setting
kpeter@305:     ///ProcessedMap type.
alpar@100:     ///
kpeter@244:     ///\ref named-templ-param "Named parameter" for setting
kpeter@305:     ///ProcessedMap type.
alpar@100:     template <class T>
kpeter@257:     struct SetProcessedMap
kpeter@257:       : public Dijkstra< Digraph, LengthMap, SetProcessedMapTraits<T> > {
kpeter@257:       typedef Dijkstra< Digraph, LengthMap, SetProcessedMapTraits<T> > Create;
alpar@100:     };
alpar@209: 
kpeter@257:     struct SetStandardProcessedMapTraits : public Traits {
alpar@100:       typedef typename Digraph::template NodeMap<bool> ProcessedMap;
kpeter@244:       static ProcessedMap *createProcessedMap(const Digraph &g)
alpar@100:       {
kpeter@244:         return new ProcessedMap(g);
alpar@100:       }
alpar@100:     };
kpeter@244:     ///\brief \ref named-templ-param "Named parameter" for setting
kpeter@305:     ///ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
alpar@100:     ///
kpeter@244:     ///\ref named-templ-param "Named parameter" for setting
kpeter@305:     ///ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
kpeter@244:     ///If you don't set it explicitly, it will be automatically allocated.
kpeter@257:     struct SetStandardProcessedMap
kpeter@257:       : public Dijkstra< Digraph, LengthMap, SetStandardProcessedMapTraits > {
kpeter@257:       typedef Dijkstra< Digraph, LengthMap, SetStandardProcessedMapTraits >
alpar@210:       Create;
alpar@100:     };
alpar@100: 
alpar@100:     template <class H, class CR>
kpeter@257:     struct SetHeapTraits : public Traits {
alpar@100:       typedef CR HeapCrossRef;
alpar@100:       typedef H Heap;
alpar@100:       static HeapCrossRef *createHeapCrossRef(const Digraph &) {
deba@290:         LEMON_ASSERT(false, "HeapCrossRef is not initialized");
deba@290:         return 0; // ignore warnings
alpar@100:       }
alpar@209:       static Heap *createHeap(HeapCrossRef &)
alpar@100:       {
deba@290:         LEMON_ASSERT(false, "Heap is not initialized");
deba@290:         return 0; // ignore warnings
alpar@100:       }
alpar@100:     };
alpar@100:     ///\brief \ref named-templ-param "Named parameter" for setting
alpar@100:     ///heap and cross reference type
alpar@100:     ///
alpar@209:     ///\ref named-templ-param "Named parameter" for setting heap and cross
kpeter@244:     ///reference type.
alpar@100:     template <class H, class CR = typename Digraph::template NodeMap<int> >
kpeter@257:     struct SetHeap
kpeter@257:       : public Dijkstra< Digraph, LengthMap, SetHeapTraits<H, CR> > {
kpeter@257:       typedef Dijkstra< Digraph, LengthMap, SetHeapTraits<H, CR> > Create;
alpar@100:     };
alpar@100: 
alpar@100:     template <class H, class CR>
kpeter@257:     struct SetStandardHeapTraits : public Traits {
alpar@100:       typedef CR HeapCrossRef;
alpar@100:       typedef H Heap;
alpar@100:       static HeapCrossRef *createHeapCrossRef(const Digraph &G) {
alpar@209:         return new HeapCrossRef(G);
alpar@100:       }
alpar@209:       static Heap *createHeap(HeapCrossRef &R)
alpar@100:       {
alpar@209:         return new Heap(R);
alpar@100:       }
alpar@100:     };
alpar@100:     ///\brief \ref named-templ-param "Named parameter" for setting
alpar@100:     ///heap and cross reference type with automatic allocation
alpar@100:     ///
alpar@209:     ///\ref named-templ-param "Named parameter" for setting heap and cross
alpar@209:     ///reference type. It can allocate the heap and the cross reference
alpar@209:     ///object if the cross reference's constructor waits for the digraph as
alpar@100:     ///parameter and the heap's constructor waits for the cross reference.
alpar@100:     template <class H, class CR = typename Digraph::template NodeMap<int> >
kpeter@257:     struct SetStandardHeap
kpeter@257:       : public Dijkstra< Digraph, LengthMap, SetStandardHeapTraits<H, CR> > {
kpeter@257:       typedef Dijkstra< Digraph, LengthMap, SetStandardHeapTraits<H, CR> >
alpar@100:       Create;
alpar@100:     };
alpar@100: 
alpar@100:     template <class T>
kpeter@257:     struct SetOperationTraitsTraits : public Traits {
alpar@100:       typedef T OperationTraits;
alpar@100:     };
alpar@209: 
alpar@209:     /// \brief \ref named-templ-param "Named parameter" for setting
kpeter@317:     ///\c OperationTraits type
alpar@100:     ///
kpeter@244:     ///\ref named-templ-param "Named parameter" for setting
kpeter@244:     ///\ref OperationTraits type.
alpar@100:     template <class T>
kpeter@257:     struct SetOperationTraits
kpeter@257:       : public Dijkstra<Digraph, LengthMap, SetOperationTraitsTraits<T> > {
kpeter@257:       typedef Dijkstra<Digraph, LengthMap, SetOperationTraitsTraits<T> >
alpar@100:       Create;
alpar@100:     };
alpar@209: 
alpar@100:     ///@}
alpar@100: 
alpar@100:   protected:
alpar@100: 
alpar@100:     Dijkstra() {}
alpar@100: 
alpar@209:   public:
alpar@209: 
alpar@100:     ///Constructor.
alpar@209: 
kpeter@244:     ///Constructor.
kpeter@244:     ///\param _g The digraph the algorithm runs on.
kpeter@244:     ///\param _length The length map used by the algorithm.
kpeter@244:     Dijkstra(const Digraph& _g, const LengthMap& _length) :
kpeter@244:       G(&_g), length(&_length),
alpar@100:       _pred(NULL), local_pred(false),
alpar@100:       _dist(NULL), local_dist(false),
alpar@100:       _processed(NULL), local_processed(false),
alpar@100:       _heap_cross_ref(NULL), local_heap_cross_ref(false),
alpar@100:       _heap(NULL), local_heap(false)
alpar@100:     { }
alpar@209: 
alpar@100:     ///Destructor.
alpar@209:     ~Dijkstra()
alpar@100:     {
alpar@100:       if(local_pred) delete _pred;
alpar@100:       if(local_dist) delete _dist;
alpar@100:       if(local_processed) delete _processed;
alpar@100:       if(local_heap_cross_ref) delete _heap_cross_ref;
alpar@100:       if(local_heap) delete _heap;
alpar@100:     }
alpar@100: 
alpar@100:     ///Sets the length map.
alpar@100: 
alpar@100:     ///Sets the length map.
alpar@100:     ///\return <tt> (*this) </tt>
alpar@209:     Dijkstra &lengthMap(const LengthMap &m)
alpar@100:     {
alpar@100:       length = &m;
alpar@100:       return *this;
alpar@100:     }
alpar@100: 
kpeter@244:     ///Sets the map that stores the predecessor arcs.
alpar@100: 
kpeter@244:     ///Sets the map that stores the predecessor arcs.
alpar@100:     ///If you don't use this function before calling \ref run(),
kpeter@244:     ///it will allocate one. The destructor deallocates this
alpar@100:     ///automatically allocated map, of course.
alpar@100:     ///\return <tt> (*this) </tt>
alpar@209:     Dijkstra &predMap(PredMap &m)
alpar@100:     {
alpar@100:       if(local_pred) {
alpar@209:         delete _pred;
alpar@209:         local_pred=false;
alpar@100:       }
alpar@100:       _pred = &m;
alpar@100:       return *this;
alpar@100:     }
alpar@100: 
kpeter@244:     ///Sets the map that indicates which nodes are processed.
alpar@100: 
kpeter@244:     ///Sets the map that indicates which nodes are processed.
alpar@100:     ///If you don't use this function before calling \ref run(),
kpeter@244:     ///it will allocate one. The destructor deallocates this
kpeter@244:     ///automatically allocated map, of course.
kpeter@244:     ///\return <tt> (*this) </tt>
kpeter@244:     Dijkstra &processedMap(ProcessedMap &m)
kpeter@244:     {
kpeter@244:       if(local_processed) {
kpeter@244:         delete _processed;
kpeter@244:         local_processed=false;
kpeter@244:       }
kpeter@244:       _processed = &m;
kpeter@244:       return *this;
kpeter@244:     }
kpeter@244: 
kpeter@244:     ///Sets the map that stores the distances of the nodes.
kpeter@244: 
kpeter@244:     ///Sets the map that stores the distances of the nodes calculated by the
kpeter@244:     ///algorithm.
kpeter@244:     ///If you don't use this function before calling \ref run(),
kpeter@244:     ///it will allocate one. The destructor deallocates this
alpar@100:     ///automatically allocated map, of course.
alpar@100:     ///\return <tt> (*this) </tt>
alpar@209:     Dijkstra &distMap(DistMap &m)
alpar@100:     {
alpar@100:       if(local_dist) {
alpar@209:         delete _dist;
alpar@209:         local_dist=false;
alpar@100:       }
alpar@100:       _dist = &m;
alpar@100:       return *this;
alpar@100:     }
alpar@100: 
alpar@100:     ///Sets the heap and the cross reference used by algorithm.
alpar@100: 
alpar@100:     ///Sets the heap and the cross reference used by algorithm.
alpar@100:     ///If you don't use this function before calling \ref run(),
kpeter@244:     ///it will allocate one. The destructor deallocates this
alpar@100:     ///automatically allocated heap and cross reference, of course.
alpar@100:     ///\return <tt> (*this) </tt>
alpar@100:     Dijkstra &heap(Heap& hp, HeapCrossRef &cr)
alpar@100:     {
alpar@100:       if(local_heap_cross_ref) {
alpar@209:         delete _heap_cross_ref;
alpar@209:         local_heap_cross_ref=false;
alpar@100:       }
alpar@100:       _heap_cross_ref = &cr;
alpar@100:       if(local_heap) {
alpar@209:         delete _heap;
alpar@209:         local_heap=false;
alpar@100:       }
alpar@100:       _heap = &hp;
alpar@100:       return *this;
alpar@100:     }
alpar@100: 
alpar@100:   private:
kpeter@244: 
alpar@100:     void finalizeNodeData(Node v,Value dst)
alpar@100:     {
alpar@100:       _processed->set(v,true);
alpar@100:       _dist->set(v, dst);
alpar@100:     }
alpar@100: 
alpar@100:   public:
alpar@100: 
alpar@100:     ///\name Execution control
kpeter@244:     ///The simplest way to execute the algorithm is to use one of the
kpeter@244:     ///member functions called \ref lemon::Dijkstra::run() "run()".
alpar@100:     ///\n
kpeter@244:     ///If you need more control on the execution, first you must call
kpeter@244:     ///\ref lemon::Dijkstra::init() "init()", then you can add several
kpeter@244:     ///source nodes with \ref lemon::Dijkstra::addSource() "addSource()".
kpeter@244:     ///Finally \ref lemon::Dijkstra::start() "start()" will perform the
kpeter@244:     ///actual path computation.
alpar@100: 
alpar@100:     ///@{
alpar@100: 
alpar@100:     ///Initializes the internal data structures.
alpar@100: 
alpar@100:     ///Initializes the internal data structures.
alpar@100:     ///
alpar@100:     void init()
alpar@100:     {
alpar@100:       create_maps();
alpar@100:       _heap->clear();
alpar@100:       for ( NodeIt u(*G) ; u!=INVALID ; ++u ) {
alpar@209:         _pred->set(u,INVALID);
alpar@209:         _processed->set(u,false);
alpar@209:         _heap_cross_ref->set(u,Heap::PRE_HEAP);
alpar@100:       }
alpar@100:     }
alpar@209: 
alpar@100:     ///Adds a new source node.
alpar@100: 
alpar@100:     ///Adds a new source node to the priority heap.
alpar@100:     ///The optional second parameter is the initial distance of the node.
alpar@100:     ///
kpeter@244:     ///The function checks if the node has already been added to the heap and
alpar@100:     ///it is pushed to the heap only if either it was not in the heap
alpar@100:     ///or the shortest path found till then is shorter than \c dst.
alpar@100:     void addSource(Node s,Value dst=OperationTraits::zero())
alpar@100:     {
alpar@100:       if(_heap->state(s) != Heap::IN_HEAP) {
alpar@209:         _heap->push(s,dst);
alpar@100:       } else if(OperationTraits::less((*_heap)[s], dst)) {
alpar@209:         _heap->set(s,dst);
alpar@209:         _pred->set(s,INVALID);
alpar@100:       }
alpar@100:     }
alpar@209: 
alpar@100:     ///Processes the next node in the priority heap
alpar@100: 
alpar@100:     ///Processes the next node in the priority heap.
alpar@100:     ///
alpar@100:     ///\return The processed node.
alpar@100:     ///
kpeter@244:     ///\warning The priority heap must not be empty.
alpar@100:     Node processNextNode()
alpar@100:     {
alpar@209:       Node v=_heap->top();
alpar@100:       Value oldvalue=_heap->prio();
alpar@100:       _heap->pop();
alpar@100:       finalizeNodeData(v,oldvalue);
alpar@209: 
alpar@100:       for(OutArcIt e(*G,v); e!=INVALID; ++e) {
alpar@209:         Node w=G->target(e);
alpar@209:         switch(_heap->state(w)) {
alpar@209:         case Heap::PRE_HEAP:
alpar@209:           _heap->push(w,OperationTraits::plus(oldvalue, (*length)[e]));
alpar@209:           _pred->set(w,e);
alpar@209:           break;
alpar@209:         case Heap::IN_HEAP:
alpar@209:           {
alpar@209:             Value newvalue = OperationTraits::plus(oldvalue, (*length)[e]);
alpar@209:             if ( OperationTraits::less(newvalue, (*_heap)[w]) ) {
alpar@209:               _heap->decrease(w, newvalue);
alpar@209:               _pred->set(w,e);
alpar@209:             }
alpar@209:           }
alpar@209:           break;
alpar@209:         case Heap::POST_HEAP:
alpar@209:           break;
alpar@209:         }
alpar@100:       }
alpar@100:       return v;
alpar@100:     }
alpar@100: 
kpeter@244:     ///The next node to be processed.
alpar@209: 
kpeter@244:     ///Returns the next node to be processed or \c INVALID if the
kpeter@244:     ///priority heap is empty.
kpeter@244:     Node nextNode() const
alpar@209:     {
alpar@100:       return !_heap->empty()?_heap->top():INVALID;
alpar@100:     }
alpar@209: 
alpar@100:     ///\brief Returns \c false if there are nodes
kpeter@244:     ///to be processed.
alpar@100:     ///
alpar@100:     ///Returns \c false if there are nodes
kpeter@244:     ///to be processed in the priority heap.
kpeter@244:     bool emptyQueue() const { return _heap->empty(); }
kpeter@244: 
alpar@100:     ///Returns the number of the nodes to be processed in the priority heap
alpar@100: 
kpeter@244:     ///Returns the number of the nodes to be processed in the priority heap.
alpar@100:     ///
kpeter@244:     int queueSize() const { return _heap->size(); }
alpar@209: 
alpar@100:     ///Executes the algorithm.
alpar@100: 
alpar@100:     ///Executes the algorithm.
alpar@100:     ///
kpeter@244:     ///This method runs the %Dijkstra algorithm from the root node(s)
kpeter@244:     ///in order to compute the shortest path to each node.
kpeter@244:     ///
kpeter@244:     ///The algorithm computes
kpeter@244:     ///- the shortest path tree (forest),
kpeter@244:     ///- the distance of each node from the root(s).
kpeter@244:     ///
kpeter@244:     ///\pre init() must be called and at least one root node should be
kpeter@244:     ///added with addSource() before using this function.
kpeter@244:     ///
kpeter@244:     ///\note <tt>d.start()</tt> is just a shortcut of the following code.
kpeter@244:     ///\code
kpeter@244:     ///  while ( !d.emptyQueue() ) {
kpeter@244:     ///    d.processNextNode();
kpeter@244:     ///  }
kpeter@244:     ///\endcode
kpeter@244:     void start()
kpeter@244:     {
kpeter@244:       while ( !emptyQueue() ) processNextNode();
kpeter@244:     }
kpeter@244: 
kpeter@286:     ///Executes the algorithm until the given target node is processed.
kpeter@244: 
kpeter@286:     ///Executes the algorithm until the given target node is processed.
alpar@100:     ///
alpar@100:     ///This method runs the %Dijkstra algorithm from the root node(s)
kpeter@286:     ///in order to compute the shortest path to \c t.
alpar@100:     ///
kpeter@244:     ///The algorithm computes
kpeter@286:     ///- the shortest path to \c t,
kpeter@286:     ///- the distance of \c t from the root(s).
alpar@100:     ///
kpeter@244:     ///\pre init() must be called and at least one root node should be
kpeter@244:     ///added with addSource() before using this function.
kpeter@286:     void start(Node t)
alpar@100:     {
kpeter@286:       while ( !_heap->empty() && _heap->top()!=t ) processNextNode();
kpeter@286:       if ( !_heap->empty() ) {
kpeter@286:         finalizeNodeData(_heap->top(),_heap->prio());
kpeter@286:         _heap->pop();
kpeter@286:       }
alpar@100:     }
alpar@209: 
alpar@100:     ///Executes the algorithm until a condition is met.
alpar@100: 
alpar@100:     ///Executes the algorithm until a condition is met.
alpar@100:     ///
kpeter@244:     ///This method runs the %Dijkstra algorithm from the root node(s) in
kpeter@244:     ///order to compute the shortest path to a node \c v with
kpeter@244:     /// <tt>nm[v]</tt> true, if such a node can be found.
alpar@100:     ///
kpeter@244:     ///\param nm A \c bool (or convertible) node map. The algorithm
alpar@100:     ///will stop when it reaches a node \c v with <tt>nm[v]</tt> true.
alpar@100:     ///
alpar@100:     ///\return The reached node \c v with <tt>nm[v]</tt> true or
alpar@100:     ///\c INVALID if no such node was found.
kpeter@244:     ///
kpeter@244:     ///\pre init() must be called and at least one root node should be
kpeter@244:     ///added with addSource() before using this function.
alpar@100:     template<class NodeBoolMap>
alpar@100:     Node start(const NodeBoolMap &nm)
alpar@100:     {
alpar@100:       while ( !_heap->empty() && !nm[_heap->top()] ) processNextNode();
alpar@100:       if ( _heap->empty() ) return INVALID;
alpar@100:       finalizeNodeData(_heap->top(),_heap->prio());
alpar@100:       return _heap->top();
alpar@100:     }
alpar@209: 
kpeter@286:     ///Runs the algorithm from the given source node.
alpar@209: 
kpeter@244:     ///This method runs the %Dijkstra algorithm from node \c s
kpeter@244:     ///in order to compute the shortest path to each node.
alpar@100:     ///
kpeter@244:     ///The algorithm computes
kpeter@244:     ///- the shortest path tree,
kpeter@244:     ///- the distance of each node from the root.
kpeter@244:     ///
kpeter@244:     ///\note <tt>d.run(s)</tt> is just a shortcut of the following code.
alpar@100:     ///\code
alpar@100:     ///  d.init();
alpar@100:     ///  d.addSource(s);
alpar@100:     ///  d.start();
alpar@100:     ///\endcode
alpar@100:     void run(Node s) {
alpar@100:       init();
alpar@100:       addSource(s);
alpar@100:       start();
alpar@100:     }
alpar@209: 
alpar@100:     ///Finds the shortest path between \c s and \c t.
alpar@209: 
kpeter@244:     ///This method runs the %Dijkstra algorithm from node \c s
kpeter@286:     ///in order to compute the shortest path to node \c t
kpeter@286:     ///(it stops searching when \c t is processed).
alpar@100:     ///
kpeter@286:     ///\return \c true if \c t is reachable form \c s.
kpeter@244:     ///
kpeter@244:     ///\note Apart from the return value, <tt>d.run(s,t)</tt> is just a
kpeter@244:     ///shortcut of the following code.
alpar@100:     ///\code
alpar@100:     ///  d.init();
alpar@100:     ///  d.addSource(s);
alpar@100:     ///  d.start(t);
alpar@100:     ///\endcode
kpeter@286:     bool run(Node s,Node t) {
alpar@100:       init();
alpar@100:       addSource(s);
alpar@100:       start(t);
kpeter@286:       return (*_heap_cross_ref)[t] == Heap::POST_HEAP;
alpar@100:     }
alpar@209: 
alpar@100:     ///@}
alpar@100: 
alpar@100:     ///\name Query Functions
alpar@100:     ///The result of the %Dijkstra algorithm can be obtained using these
alpar@100:     ///functions.\n
kpeter@244:     ///Either \ref lemon::Dijkstra::run() "run()" or
kpeter@244:     ///\ref lemon::Dijkstra::start() "start()" must be called before
kpeter@244:     ///using them.
alpar@209: 
alpar@100:     ///@{
alpar@100: 
kpeter@244:     ///The shortest path to a node.
alpar@209: 
kpeter@244:     ///Returns the shortest path to a node.
kpeter@244:     ///
kpeter@244:     ///\warning \c t should be reachable from the root(s).
kpeter@244:     ///
kpeter@244:     ///\pre Either \ref run() or \ref start() must be called before
kpeter@244:     ///using this function.
kpeter@244:     Path path(Node t) const { return Path(*G, *_pred, t); }
alpar@100: 
kpeter@244:     ///The distance of a node from the root(s).
alpar@100: 
kpeter@244:     ///Returns the distance of a node from the root(s).
kpeter@244:     ///
kpeter@244:     ///\warning If node \c v is not reachable from the root(s), then
kpeter@244:     ///the return value of this function is undefined.
kpeter@244:     ///
kpeter@244:     ///\pre Either \ref run() or \ref start() must be called before
kpeter@244:     ///using this function.
alpar@100:     Value dist(Node v) const { return (*_dist)[v]; }
alpar@100: 
kpeter@244:     ///Returns the 'previous arc' of the shortest path tree for a node.
alpar@100: 
kpeter@244:     ///This function returns the 'previous arc' of the shortest path
kpeter@244:     ///tree for the node \c v, i.e. it returns the last arc of a
kpeter@244:     ///shortest path from the root(s) to \c v. It is \c INVALID if \c v
kpeter@244:     ///is not reachable from the root(s) or if \c v is a root.
kpeter@244:     ///
kpeter@244:     ///The shortest path tree used here is equal to the shortest path
kpeter@244:     ///tree used in \ref predNode().
kpeter@244:     ///
kpeter@244:     ///\pre Either \ref run() or \ref start() must be called before
kpeter@244:     ///using this function.
alpar@100:     Arc predArc(Node v) const { return (*_pred)[v]; }
alpar@100: 
kpeter@244:     ///Returns the 'previous node' of the shortest path tree for a node.
alpar@100: 
kpeter@244:     ///This function returns the 'previous node' of the shortest path
kpeter@244:     ///tree for the node \c v, i.e. it returns the last but one node
kpeter@244:     ///from a shortest path from the root(s) to \c v. It is \c INVALID
kpeter@244:     ///if \c v is not reachable from the root(s) or if \c v is a root.
kpeter@244:     ///
kpeter@244:     ///The shortest path tree used here is equal to the shortest path
kpeter@244:     ///tree used in \ref predArc().
kpeter@244:     ///
kpeter@244:     ///\pre Either \ref run() or \ref start() must be called before
alpar@100:     ///using this function.
alpar@100:     Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
alpar@209:                                   G->source((*_pred)[v]); }
alpar@209: 
kpeter@244:     ///\brief Returns a const reference to the node map that stores the
kpeter@244:     ///distances of the nodes.
kpeter@244:     ///
kpeter@244:     ///Returns a const reference to the node map that stores the distances
kpeter@244:     ///of the nodes calculated by the algorithm.
kpeter@244:     ///
kpeter@244:     ///\pre Either \ref run() or \ref init()
kpeter@244:     ///must be called before using this function.
alpar@100:     const DistMap &distMap() const { return *_dist;}
alpar@209: 
kpeter@244:     ///\brief Returns a const reference to the node map that stores the
kpeter@244:     ///predecessor arcs.
kpeter@244:     ///
kpeter@244:     ///Returns a const reference to the node map that stores the predecessor
kpeter@244:     ///arcs, which form the shortest path tree.
kpeter@244:     ///
kpeter@244:     ///\pre Either \ref run() or \ref init()
kpeter@244:     ///must be called before using this function.
alpar@100:     const PredMap &predMap() const { return *_pred;}
alpar@209: 
kpeter@244:     ///Checks if a node is reachable from the root(s).
alpar@100: 
kpeter@244:     ///Returns \c true if \c v is reachable from the root(s).
kpeter@244:     ///\pre Either \ref run() or \ref start()
kpeter@244:     ///must be called before using this function.
kpeter@244:     bool reached(Node v) const { return (*_heap_cross_ref)[v] !=
kpeter@244:                                         Heap::PRE_HEAP; }
alpar@100: 
alpar@100:     ///Checks if a node is processed.
alpar@100: 
alpar@100:     ///Returns \c true if \c v is processed, i.e. the shortest
alpar@100:     ///path to \c v has already found.
kpeter@286:     ///\pre Either \ref run() or \ref init()
kpeter@244:     ///must be called before using this function.
kpeter@244:     bool processed(Node v) const { return (*_heap_cross_ref)[v] ==
kpeter@244:                                           Heap::POST_HEAP; }
kpeter@244: 
kpeter@244:     ///The current distance of a node from the root(s).
kpeter@244: 
kpeter@244:     ///Returns the current distance of a node from the root(s).
kpeter@244:     ///It may be decreased in the following processes.
kpeter@286:     ///\pre Either \ref run() or \ref init()
kpeter@286:     ///must be called before using this function and
kpeter@286:     ///node \c v must be reached but not necessarily processed.
kpeter@286:     Value currentDist(Node v) const {
kpeter@286:       return processed(v) ? (*_dist)[v] : (*_heap)[v];
kpeter@286:     }
alpar@209: 
alpar@100:     ///@}
alpar@100:   };
alpar@100: 
alpar@100: 
kpeter@244:   ///Default traits class of dijkstra() function.
alpar@100: 
kpeter@244:   ///Default traits class of dijkstra() function.
kpeter@244:   ///\tparam GR The type of the digraph.
kpeter@244:   ///\tparam LM The type of the length map.
alpar@100:   template<class GR, class LM>
alpar@100:   struct DijkstraWizardDefaultTraits
alpar@100:   {
kpeter@244:     ///The type of the digraph the algorithm runs on.
alpar@100:     typedef GR Digraph;
alpar@100:     ///The type of the map that stores the arc lengths.
alpar@100: 
alpar@100:     ///The type of the map that stores the arc lengths.
alpar@100:     ///It must meet the \ref concepts::ReadMap "ReadMap" concept.
alpar@100:     typedef LM LengthMap;
kpeter@244:     ///The type of the length of the arcs.
alpar@100:     typedef typename LM::Value Value;
kpeter@244: 
alpar@100:     /// Operation traits for Dijkstra algorithm.
alpar@100: 
kpeter@244:     /// This class defines the operations that are used in the algorithm.
alpar@100:     /// \see DijkstraDefaultOperationTraits
alpar@100:     typedef DijkstraDefaultOperationTraits<Value> OperationTraits;
alpar@100: 
kpeter@244:     /// The cross reference type used by the heap.
alpar@100: 
kpeter@244:     /// The cross reference type used by the heap.
alpar@100:     /// Usually it is \c Digraph::NodeMap<int>.
alpar@100:     typedef typename Digraph::template NodeMap<int> HeapCrossRef;
kpeter@244:     ///Instantiates a \ref HeapCrossRef.
alpar@100: 
alpar@209:     ///This function instantiates a \ref HeapCrossRef.
kpeter@244:     /// \param g is the digraph, to which we would like to define the
alpar@100:     /// HeapCrossRef.
kpeter@244:     static HeapCrossRef *createHeapCrossRef(const Digraph &g)
alpar@100:     {
kpeter@244:       return new HeapCrossRef(g);
alpar@100:     }
alpar@209: 
kpeter@244:     ///The heap type used by the Dijkstra algorithm.
alpar@100: 
kpeter@244:     ///The heap type used by the Dijkstra algorithm.
alpar@100:     ///
alpar@100:     ///\sa BinHeap
alpar@100:     ///\sa Dijkstra
kpeter@244:     typedef BinHeap<Value, typename Digraph::template NodeMap<int>,
alpar@209:                     std::less<Value> > Heap;
alpar@100: 
kpeter@244:     ///Instantiates a \ref Heap.
kpeter@244: 
kpeter@244:     ///This function instantiates a \ref Heap.
kpeter@244:     /// \param r is the HeapCrossRef which is used.
kpeter@244:     static Heap *createHeap(HeapCrossRef& r)
alpar@100:     {
kpeter@244:       return new Heap(r);
alpar@100:     }
alpar@100: 
kpeter@244:     ///\brief The type of the map that stores the predecessor
alpar@100:     ///arcs of the shortest paths.
alpar@209:     ///
kpeter@244:     ///The type of the map that stores the predecessor
alpar@100:     ///arcs of the shortest paths.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
kpeter@278:     typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
kpeter@305:     ///Instantiates a PredMap.
alpar@209: 
kpeter@305:     ///This function instantiates a PredMap.
kpeter@244:     ///\param g is the digraph, to which we would like to define the
kpeter@305:     ///PredMap.
kpeter@244:     static PredMap *createPredMap(const Digraph &g)
alpar@100:     {
kpeter@278:       return new PredMap(g);
alpar@100:     }
alpar@209: 
kpeter@244:     ///The type of the map that indicates which nodes are processed.
kpeter@244: 
kpeter@244:     ///The type of the map that indicates which nodes are processed.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
alpar@100:     ///By default it is a NullMap.
alpar@100:     typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
kpeter@305:     ///Instantiates a ProcessedMap.
alpar@209: 
kpeter@305:     ///This function instantiates a ProcessedMap.
alpar@100:     ///\param g is the digraph, to which
kpeter@305:     ///we would like to define the ProcessedMap.
alpar@100: #ifdef DOXYGEN
kpeter@244:     static ProcessedMap *createProcessedMap(const Digraph &g)
alpar@100: #else
kpeter@244:     static ProcessedMap *createProcessedMap(const Digraph &)
alpar@100: #endif
alpar@100:     {
alpar@100:       return new ProcessedMap();
alpar@100:     }
alpar@209: 
kpeter@244:     ///The type of the map that stores the distances of the nodes.
kpeter@244: 
kpeter@244:     ///The type of the map that stores the distances of the nodes.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
kpeter@278:     typedef typename Digraph::template NodeMap<typename LM::Value> DistMap;
kpeter@305:     ///Instantiates a DistMap.
alpar@209: 
kpeter@305:     ///This function instantiates a DistMap.
alpar@210:     ///\param g is the digraph, to which we would like to define
kpeter@305:     ///the DistMap
kpeter@244:     static DistMap *createDistMap(const Digraph &g)
alpar@100:     {
kpeter@278:       return new DistMap(g);
alpar@100:     }
kpeter@278: 
kpeter@278:     ///The type of the shortest paths.
kpeter@278: 
kpeter@278:     ///The type of the shortest paths.
kpeter@278:     ///It must meet the \ref concepts::Path "Path" concept.
kpeter@278:     typedef lemon::Path<Digraph> Path;
alpar@100:   };
alpar@209: 
kpeter@317:   /// Default traits class used by DijkstraWizard
alpar@100: 
alpar@100:   /// To make it easier to use Dijkstra algorithm
kpeter@244:   /// we have created a wizard class.
alpar@100:   /// This \ref DijkstraWizard class needs default traits,
kpeter@244:   /// as well as the \ref Dijkstra class.
alpar@100:   /// The \ref DijkstraWizardBase is a class to be the default traits of the
alpar@100:   /// \ref DijkstraWizard class.
alpar@100:   template<class GR,class LM>
alpar@100:   class DijkstraWizardBase : public DijkstraWizardDefaultTraits<GR,LM>
alpar@100:   {
alpar@100:     typedef DijkstraWizardDefaultTraits<GR,LM> Base;
alpar@100:   protected:
kpeter@244:     //The type of the nodes in the digraph.
alpar@100:     typedef typename Base::Digraph::Node Node;
alpar@100: 
kpeter@244:     //Pointer to the digraph the algorithm runs on.
alpar@100:     void *_g;
kpeter@278:     //Pointer to the length map.
alpar@100:     void *_length;
kpeter@251:     //Pointer to the map of processed nodes.
kpeter@251:     void *_processed;
kpeter@244:     //Pointer to the map of predecessors arcs.
alpar@100:     void *_pred;
kpeter@244:     //Pointer to the map of distances.
alpar@100:     void *_dist;
kpeter@278:     //Pointer to the shortest path to the target node.
kpeter@278:     void *_path;
kpeter@278:     //Pointer to the distance of the target node.
kpeter@278:     void *_di;
alpar@100: 
kpeter@244:   public:
alpar@100:     /// Constructor.
alpar@209: 
alpar@100:     /// This constructor does not require parameters, therefore it initiates
kpeter@278:     /// all of the attributes to \c 0.
kpeter@251:     DijkstraWizardBase() : _g(0), _length(0), _processed(0), _pred(0),
kpeter@278:                            _dist(0), _path(0), _di(0) {}
alpar@100: 
alpar@100:     /// Constructor.
alpar@209: 
kpeter@278:     /// This constructor requires two parameters,
kpeter@278:     /// others are initiated to \c 0.
kpeter@244:     /// \param g The digraph the algorithm runs on.
kpeter@244:     /// \param l The length map.
kpeter@278:     DijkstraWizardBase(const GR &g,const LM &l) :
alpar@209:       _g(reinterpret_cast<void*>(const_cast<GR*>(&g))),
alpar@209:       _length(reinterpret_cast<void*>(const_cast<LM*>(&l))),
kpeter@278:       _processed(0), _pred(0), _dist(0), _path(0), _di(0) {}
alpar@100: 
alpar@100:   };
alpar@209: 
kpeter@278:   /// Auxiliary class for the function-type interface of Dijkstra algorithm.
alpar@100: 
kpeter@278:   /// This auxiliary class is created to implement the
kpeter@278:   /// \ref dijkstra() "function-type interface" of \ref Dijkstra algorithm.
kpeter@278:   /// It does not have own \ref run() method, it uses the functions
kpeter@278:   /// and features of the plain \ref Dijkstra.
alpar@100:   ///
kpeter@278:   /// This class should only be used through the \ref dijkstra() function,
kpeter@278:   /// which makes it easier to use the algorithm.
alpar@100:   template<class TR>
alpar@100:   class DijkstraWizard : public TR
alpar@100:   {
alpar@100:     typedef TR Base;
alpar@100: 
kpeter@244:     ///The type of the digraph the algorithm runs on.
alpar@100:     typedef typename TR::Digraph Digraph;
kpeter@244: 
alpar@100:     typedef typename Digraph::Node Node;
alpar@100:     typedef typename Digraph::NodeIt NodeIt;
alpar@100:     typedef typename Digraph::Arc Arc;
alpar@100:     typedef typename Digraph::OutArcIt OutArcIt;
alpar@209: 
alpar@100:     ///The type of the map that stores the arc lengths.
alpar@100:     typedef typename TR::LengthMap LengthMap;
alpar@100:     ///The type of the length of the arcs.
alpar@100:     typedef typename LengthMap::Value Value;
kpeter@244:     ///\brief The type of the map that stores the predecessor
alpar@100:     ///arcs of the shortest paths.
alpar@100:     typedef typename TR::PredMap PredMap;
kpeter@244:     ///The type of the map that stores the distances of the nodes.
alpar@100:     typedef typename TR::DistMap DistMap;
kpeter@244:     ///The type of the map that indicates which nodes are processed.
kpeter@244:     typedef typename TR::ProcessedMap ProcessedMap;
kpeter@278:     ///The type of the shortest paths
kpeter@278:     typedef typename TR::Path Path;
alpar@100:     ///The heap type used by the dijkstra algorithm.
alpar@100:     typedef typename TR::Heap Heap;
kpeter@244: 
alpar@100:   public:
kpeter@244: 
alpar@100:     /// Constructor.
alpar@100:     DijkstraWizard() : TR() {}
alpar@100: 
alpar@100:     /// Constructor that requires parameters.
alpar@100: 
alpar@100:     /// Constructor that requires parameters.
alpar@100:     /// These parameters will be the default values for the traits class.
kpeter@278:     /// \param g The digraph the algorithm runs on.
kpeter@278:     /// \param l The length map.
kpeter@278:     DijkstraWizard(const Digraph &g, const LengthMap &l) :
kpeter@278:       TR(g,l) {}
alpar@100: 
alpar@100:     ///Copy constructor
alpar@100:     DijkstraWizard(const TR &b) : TR(b) {}
alpar@100: 
alpar@100:     ~DijkstraWizard() {}
alpar@100: 
kpeter@278:     ///Runs Dijkstra algorithm from the given source node.
alpar@209: 
kpeter@278:     ///This method runs %Dijkstra algorithm from the given source node
kpeter@278:     ///in order to compute the shortest path to each node.
kpeter@278:     void run(Node s)
alpar@100:     {
alpar@209:       Dijkstra<Digraph,LengthMap,TR>
kpeter@278:         dijk(*reinterpret_cast<const Digraph*>(Base::_g),
kpeter@278:              *reinterpret_cast<const LengthMap*>(Base::_length));
kpeter@278:       if (Base::_pred)
kpeter@278:         dijk.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
kpeter@278:       if (Base::_dist)
kpeter@278:         dijk.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
kpeter@278:       if (Base::_processed)
kpeter@278:         dijk.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
kpeter@278:       dijk.run(s);
alpar@100:     }
alpar@100: 
kpeter@278:     ///Finds the shortest path between \c s and \c t.
alpar@100: 
kpeter@278:     ///This method runs the %Dijkstra algorithm from node \c s
kpeter@278:     ///in order to compute the shortest path to node \c t
kpeter@278:     ///(it stops searching when \c t is processed).
kpeter@278:     ///
kpeter@278:     ///\return \c true if \c t is reachable form \c s.
kpeter@278:     bool run(Node s, Node t)
alpar@100:     {
kpeter@278:       Dijkstra<Digraph,LengthMap,TR>
kpeter@278:         dijk(*reinterpret_cast<const Digraph*>(Base::_g),
kpeter@278:              *reinterpret_cast<const LengthMap*>(Base::_length));
kpeter@278:       if (Base::_pred)
kpeter@278:         dijk.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
kpeter@278:       if (Base::_dist)
kpeter@278:         dijk.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
kpeter@278:       if (Base::_processed)
kpeter@278:         dijk.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
kpeter@278:       dijk.run(s,t);
kpeter@278:       if (Base::_path)
kpeter@278:         *reinterpret_cast<Path*>(Base::_path) = dijk.path(t);
kpeter@278:       if (Base::_di)
kpeter@278:         *reinterpret_cast<Value*>(Base::_di) = dijk.dist(t);
kpeter@278:       return dijk.reached(t);
kpeter@244:     }
kpeter@244: 
alpar@100:     template<class T>
kpeter@257:     struct SetPredMapBase : public Base {
alpar@100:       typedef T PredMap;
alpar@100:       static PredMap *createPredMap(const Digraph &) { return 0; };
kpeter@257:       SetPredMapBase(const TR &b) : TR(b) {}
alpar@100:     };
kpeter@278:     ///\brief \ref named-func-param "Named parameter"
kpeter@305:     ///for setting PredMap object.
alpar@100:     ///
kpeter@278:     ///\ref named-func-param "Named parameter"
kpeter@305:     ///for setting PredMap object.
alpar@100:     template<class T>
kpeter@257:     DijkstraWizard<SetPredMapBase<T> > predMap(const T &t)
alpar@100:     {
alpar@100:       Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
kpeter@257:       return DijkstraWizard<SetPredMapBase<T> >(*this);
alpar@100:     }
alpar@209: 
alpar@100:     template<class T>
kpeter@278:     struct SetDistMapBase : public Base {
kpeter@278:       typedef T DistMap;
kpeter@278:       static DistMap *createDistMap(const Digraph &) { return 0; };
kpeter@278:       SetDistMapBase(const TR &b) : TR(b) {}
kpeter@278:     };
kpeter@278:     ///\brief \ref named-func-param "Named parameter"
kpeter@305:     ///for setting DistMap object.
kpeter@278:     ///
kpeter@278:     ///\ref named-func-param "Named parameter"
kpeter@305:     ///for setting DistMap object.
kpeter@278:     template<class T>
kpeter@278:     DijkstraWizard<SetDistMapBase<T> > distMap(const T &t)
kpeter@278:     {
kpeter@278:       Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t));
kpeter@278:       return DijkstraWizard<SetDistMapBase<T> >(*this);
kpeter@278:     }
kpeter@278: 
kpeter@278:     template<class T>
kpeter@257:     struct SetProcessedMapBase : public Base {
kpeter@244:       typedef T ProcessedMap;
kpeter@244:       static ProcessedMap *createProcessedMap(const Digraph &) { return 0; };
kpeter@257:       SetProcessedMapBase(const TR &b) : TR(b) {}
kpeter@244:     };
kpeter@278:     ///\brief \ref named-func-param "Named parameter"
kpeter@305:     ///for setting ProcessedMap object.
kpeter@244:     ///
kpeter@278:     /// \ref named-func-param "Named parameter"
kpeter@305:     ///for setting ProcessedMap object.
kpeter@244:     template<class T>
kpeter@257:     DijkstraWizard<SetProcessedMapBase<T> > processedMap(const T &t)
kpeter@244:     {
kpeter@244:       Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t));
kpeter@257:       return DijkstraWizard<SetProcessedMapBase<T> >(*this);
kpeter@244:     }
kpeter@244: 
kpeter@244:     template<class T>
kpeter@278:     struct SetPathBase : public Base {
kpeter@278:       typedef T Path;
kpeter@278:       SetPathBase(const TR &b) : TR(b) {}
alpar@100:     };
kpeter@278:     ///\brief \ref named-func-param "Named parameter"
kpeter@278:     ///for getting the shortest path to the target node.
alpar@100:     ///
kpeter@278:     ///\ref named-func-param "Named parameter"
kpeter@278:     ///for getting the shortest path to the target node.
alpar@100:     template<class T>
kpeter@278:     DijkstraWizard<SetPathBase<T> > path(const T &t)
alpar@100:     {
kpeter@278:       Base::_path=reinterpret_cast<void*>(const_cast<T*>(&t));
kpeter@278:       return DijkstraWizard<SetPathBase<T> >(*this);
kpeter@278:     }
kpeter@278: 
kpeter@278:     ///\brief \ref named-func-param "Named parameter"
kpeter@278:     ///for getting the distance of the target node.
kpeter@278:     ///
kpeter@278:     ///\ref named-func-param "Named parameter"
kpeter@278:     ///for getting the distance of the target node.
kpeter@278:     DijkstraWizard dist(const Value &d)
kpeter@278:     {
kpeter@278:       Base::_di=reinterpret_cast<void*>(const_cast<Value*>(&d));
kpeter@278:       return *this;
alpar@100:     }
alpar@209: 
alpar@100:   };
alpar@209: 
kpeter@278:   ///Function-type interface for Dijkstra algorithm.
alpar@100: 
alpar@100:   /// \ingroup shortest_path
kpeter@278:   ///Function-type interface for Dijkstra algorithm.
alpar@100:   ///
kpeter@278:   ///This function also has several \ref named-func-param "named parameters",
alpar@100:   ///they are declared as the members of class \ref DijkstraWizard.
kpeter@278:   ///The following examples show how to use these parameters.
alpar@100:   ///\code
kpeter@278:   ///  // Compute shortest path from node s to each node
kpeter@278:   ///  dijkstra(g,length).predMap(preds).distMap(dists).run(s);
kpeter@278:   ///
kpeter@278:   ///  // Compute shortest path from s to t
kpeter@278:   ///  bool reached = dijkstra(g,length).path(p).dist(d).run(s,t);
alpar@100:   ///\endcode
alpar@100:   ///\warning Don't forget to put the \ref DijkstraWizard::run() "run()"
alpar@100:   ///to the end of the parameter list.
alpar@100:   ///\sa DijkstraWizard
alpar@100:   ///\sa Dijkstra
alpar@100:   template<class GR, class LM>
alpar@100:   DijkstraWizard<DijkstraWizardBase<GR,LM> >
kpeter@278:   dijkstra(const GR &digraph, const LM &length)
alpar@100:   {
kpeter@278:     return DijkstraWizard<DijkstraWizardBase<GR,LM> >(digraph,length);
alpar@100:   }
alpar@100: 
alpar@100: } //END OF NAMESPACE LEMON
alpar@100: 
alpar@100: #endif