alpar@100: /* -*- C++ -*-
alpar@100:  *
alpar@100:  * 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@100: 
alpar@100: #include <lemon/list_digraph.h>
alpar@100: #include <lemon/bin_heap.h>
alpar@100: #include <lemon/bits/path_dump.h>
alpar@100: #include <lemon/bits/invalid.h>
alpar@100: #include <lemon/error.h>
alpar@100: #include <lemon/maps.h>
alpar@100: 
alpar@100: 
alpar@100: namespace lemon {
alpar@100: 
alpar@100:   /// \brief Default OperationTraits for the Dijkstra algorithm class.
alpar@100:   ///  
alpar@100:   /// It defines all computational operations and constants which are
alpar@100:   /// 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:     }
alpar@100:     /// \brief Gives back true only if the first value 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: 
alpar@100:   /// \brief Widest path OperationTraits for the Dijkstra algorithm class.
alpar@100:   ///  
alpar@100:   /// It defines all computational operations and constants which are
alpar@100:   /// used in the Dijkstra algorithm for widest path computation.
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:     }
alpar@100:     /// \brief Gives back true only if the first value 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:   
alpar@100:   ///Default traits class of Dijkstra class.
alpar@100: 
alpar@100:   ///Default traits class of Dijkstra class.
alpar@100:   ///\param GR Digraph type.
alpar@100:   ///\param LM Type of length map.
alpar@100:   template<class GR, class LM>
alpar@100:   struct DijkstraDefaultTraits
alpar@100:   {
alpar@100:     ///The digraph type 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;
alpar@100:     //The type of the length of the arcs.
alpar@100:     typedef typename LM::Value Value;
alpar@100:     /// Operation traits for Dijkstra algorithm.
alpar@100: 
alpar@100:     /// It defines the used operation by the algorithm.
alpar@100:     /// \see DijkstraDefaultOperationTraits
alpar@100:     typedef DijkstraDefaultOperationTraits<Value> OperationTraits;
alpar@100:     /// The cross reference type used by heap.
alpar@100: 
alpar@100: 
alpar@100:     /// The cross reference type used by heap.
alpar@100:     /// Usually it is \c Digraph::NodeMap<int>.
alpar@100:     typedef typename Digraph::template NodeMap<int> HeapCrossRef;
alpar@100:     ///Instantiates a HeapCrossRef.
alpar@100: 
alpar@100:     ///This function instantiates a \c HeapCrossRef. 
alpar@100:     /// \param G is the digraph, to which we would like to define the 
alpar@100:     /// HeapCrossRef.
alpar@100:     static HeapCrossRef *createHeapCrossRef(const GR &G) 
alpar@100:     {
alpar@100:       return new HeapCrossRef(G);
alpar@100:     }
alpar@100:     
alpar@100:     ///The heap type used by Dijkstra algorithm.
alpar@100: 
alpar@100:     ///The heap type used by Dijkstra algorithm.
alpar@100:     ///
alpar@100:     ///\sa BinHeap
alpar@100:     ///\sa Dijkstra
alpar@100:     typedef BinHeap<typename LM::Value, HeapCrossRef, std::less<Value> > Heap;
alpar@100: 
alpar@100:     static Heap *createHeap(HeapCrossRef& R) 
alpar@100:     {
alpar@100:       return new Heap(R);
alpar@100:     }
alpar@100: 
alpar@100:     ///\brief The type of the map that stores the last
alpar@100:     ///arcs of the shortest paths.
alpar@100:     /// 
alpar@100:     ///The type of the map that stores the last
alpar@100:     ///arcs of the shortest paths.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
alpar@100:     ///
alpar@100:     typedef typename Digraph::template NodeMap<typename GR::Arc> PredMap;
alpar@100:     ///Instantiates a PredMap.
alpar@100:  
alpar@100:     ///This function instantiates a \c PredMap. 
alpar@100:     ///\param G is the digraph, to which we would like to define the PredMap.
alpar@100:     ///\todo The digraph alone may be insufficient for the initialization
alpar@100:     static PredMap *createPredMap(const GR &G) 
alpar@100:     {
alpar@100:       return new PredMap(G);
alpar@100:     }
alpar@100: 
alpar@100:     ///The type of the map that stores whether a nodes is processed.
alpar@100:  
alpar@100:     ///The type of the map that stores whether a nodes is processed.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
alpar@100:     ///By default it is a NullMap.
alpar@100:     ///\todo If it is set to a real map,
alpar@100:     ///Dijkstra::processed() should read this.
alpar@100:     ///\todo named parameter to set this type, function to read and write.
alpar@100:     typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
alpar@100:     ///Instantiates a ProcessedMap.
alpar@100:  
alpar@100:     ///This function instantiates a \c ProcessedMap. 
alpar@100:     ///\param g is the digraph, to which
alpar@100:     ///we would like to define the \c ProcessedMap
alpar@100: #ifdef DOXYGEN
alpar@100:     static ProcessedMap *createProcessedMap(const GR &g)
alpar@100: #else
alpar@100:     static ProcessedMap *createProcessedMap(const GR &)
alpar@100: #endif
alpar@100:     {
alpar@100:       return new ProcessedMap();
alpar@100:     }
alpar@100:     ///The type of the map that stores the dists of the nodes.
alpar@100:  
alpar@100:     ///The type of the map that stores the dists of the nodes.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
alpar@100:     ///
alpar@100:     typedef typename Digraph::template NodeMap<typename LM::Value> DistMap;
alpar@100:     ///Instantiates a DistMap.
alpar@100:  
alpar@100:     ///This function instantiates a \ref DistMap. 
alpar@100:     ///\param G is the digraph, to which we would like to define the \ref DistMap
alpar@100:     static DistMap *createDistMap(const GR &G)
alpar@100:     {
alpar@100:       return new DistMap(G);
alpar@100:     }
alpar@100:   };
alpar@100:   
alpar@100:   ///%Dijkstra algorithm class.
alpar@100:   
alpar@100:   /// \ingroup shortest_path
alpar@100:   ///This class provides an efficient implementation of %Dijkstra algorithm.
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:   ///
alpar@100:   ///The type of the length is determined by the
alpar@100:   ///\ref concepts::ReadMap::Value "Value" of the length map.
alpar@100:   ///
alpar@100:   ///It is also possible to change the underlying priority heap.
alpar@100:   ///
alpar@100:   ///\param GR The digraph type the algorithm runs on. The default value
alpar@100:   ///is \ref ListDigraph. The value of GR is not used directly by
alpar@100:   ///Dijkstra, it is only passed to \ref DijkstraDefaultTraits.
alpar@100:   ///\param LM This read-only ArcMap determines the lengths of the
alpar@100:   ///arcs. It is read once for each arc, so the map may involve in
alpar@100:   ///relatively time consuming process to compute the arc length if
alpar@100:   ///it is necessary. The default map type is \ref
alpar@100:   ///concepts::Digraph::ArcMap "Digraph::ArcMap<int>".  The value
alpar@100:   ///of LM is not used directly by Dijkstra, it is only passed to \ref
alpar@100:   ///DijkstraDefaultTraits.  \param TR Traits class to set
alpar@100:   ///various data types used by the algorithm.  The default traits
alpar@100:   ///class is \ref DijkstraDefaultTraits
alpar@100:   ///"DijkstraDefaultTraits<GR,LM>".  See \ref
alpar@100:   ///DijkstraDefaultTraits for the documentation of a Dijkstra traits
alpar@100:   ///class.
alpar@100:   ///
alpar@100:   ///\author Jacint Szabo and Alpar Juttner
alpar@100: 
alpar@100: #ifdef DOXYGEN
alpar@100:   template <typename GR, typename LM, typename TR>
alpar@100: #else
alpar@100:   template <typename GR=ListDigraph,
alpar@100: 	    typename LM=typename GR::template ArcMap<int>,
alpar@100: 	    typename TR=DijkstraDefaultTraits<GR,LM> >
alpar@100: #endif
alpar@100:   class Dijkstra {
alpar@100:   public:
alpar@100:     /**
alpar@100:      * \brief \ref Exception for uninitialized parameters.
alpar@100:      *
alpar@100:      * This error represents problems in the initialization
alpar@100:      * of the parameters of the algorithms.
alpar@100:      */
alpar@100:     class UninitializedParameter : public lemon::UninitializedParameter {
alpar@100:     public:
alpar@100:       virtual const char* what() const throw() {
alpar@100: 	return "lemon::Dijkstra::UninitializedParameter";
alpar@100:       }
alpar@100:     };
alpar@100: 
alpar@100:     typedef TR Traits;
alpar@100:     ///The type of the underlying digraph.
alpar@100:     typedef typename TR::Digraph Digraph;
alpar@100:     ///\e
alpar@100:     typedef typename Digraph::Node Node;
alpar@100:     ///\e
alpar@100:     typedef typename Digraph::NodeIt NodeIt;
alpar@100:     ///\e
alpar@100:     typedef typename Digraph::Arc Arc;
alpar@100:     ///\e
alpar@100:     typedef typename Digraph::OutArcIt OutArcIt;
alpar@100:     
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;
alpar@100:     ///\brief The type of the map that stores the last
alpar@100:     ///arcs of the shortest paths.
alpar@100:     typedef typename TR::PredMap PredMap;
alpar@100:     ///The type of the map indicating if a node is processed.
alpar@100:     typedef typename TR::ProcessedMap ProcessedMap;
alpar@100:     ///The type of the map that stores the dists of the nodes.
alpar@100:     typedef typename TR::DistMap DistMap;
alpar@100:     ///The cross reference type used for the current heap.
alpar@100:     typedef typename TR::HeapCrossRef HeapCrossRef;
alpar@100:     ///The heap type used by the dijkstra algorithm.
alpar@100:     typedef typename TR::Heap Heap;
alpar@100:     ///The operation traits.
alpar@100:     typedef typename TR::OperationTraits OperationTraits;
alpar@100:   private:
alpar@100:     /// Pointer to the underlying digraph.
alpar@100:     const Digraph *G;
alpar@100:     /// Pointer to the length map
alpar@100:     const LengthMap *length;
alpar@100:     ///Pointer to the map of predecessors arcs.
alpar@100:     PredMap *_pred;
alpar@100:     ///Indicates if \ref _pred is locally allocated (\c true) or not.
alpar@100:     bool local_pred;
alpar@100:     ///Pointer to the map of distances.
alpar@100:     DistMap *_dist;
alpar@100:     ///Indicates if \ref _dist is locally allocated (\c true) or not.
alpar@100:     bool local_dist;
alpar@100:     ///Pointer to the map of processed status of the nodes.
alpar@100:     ProcessedMap *_processed;
alpar@100:     ///Indicates if \ref _processed is locally allocated (\c true) or not.
alpar@100:     bool local_processed;
alpar@100:     ///Pointer to the heap cross references.
alpar@100:     HeapCrossRef *_heap_cross_ref;
alpar@100:     ///Indicates if \ref _heap_cross_ref is locally allocated (\c true) or not.
alpar@100:     bool local_heap_cross_ref;
alpar@100:     ///Pointer to the heap.
alpar@100:     Heap *_heap;
alpar@100:     ///Indicates if \ref _heap is locally allocated (\c true) or not.
alpar@100:     bool local_heap;
alpar@100: 
alpar@100:     ///Creates the maps if necessary.
alpar@100:     
alpar@100:     ///\todo Better memory allocation (instead of new).
alpar@100:     void create_maps() 
alpar@100:     {
alpar@100:       if(!_pred) {
alpar@100: 	local_pred = true;
alpar@100: 	_pred = Traits::createPredMap(*G);
alpar@100:       }
alpar@100:       if(!_dist) {
alpar@100: 	local_dist = true;
alpar@100: 	_dist = Traits::createDistMap(*G);
alpar@100:       }
alpar@100:       if(!_processed) {
alpar@100: 	local_processed = true;
alpar@100: 	_processed = Traits::createProcessedMap(*G);
alpar@100:       }
alpar@100:       if (!_heap_cross_ref) {
alpar@100: 	local_heap_cross_ref = true;
alpar@100: 	_heap_cross_ref = Traits::createHeapCrossRef(*G);
alpar@100:       }
alpar@100:       if (!_heap) {
alpar@100: 	local_heap = true;
alpar@100: 	_heap = Traits::createHeap(*_heap_cross_ref);
alpar@100:       }
alpar@100:     }
alpar@100:     
alpar@100:   public :
alpar@100: 
alpar@100:     typedef Dijkstra Create;
alpar@100:  
alpar@100:     ///\name Named template parameters
alpar@100: 
alpar@100:     ///@{
alpar@100: 
alpar@100:     template <class T>
alpar@100:     struct DefPredMapTraits : public Traits {
alpar@100:       typedef T PredMap;
alpar@100:       static PredMap *createPredMap(const Digraph &)
alpar@100:       {
alpar@100: 	throw UninitializedParameter();
alpar@100:       }
alpar@100:     };
alpar@100:     ///\ref named-templ-param "Named parameter" for setting PredMap type
alpar@100: 
alpar@100:     ///\ref named-templ-param "Named parameter" for setting PredMap type
alpar@100:     ///
alpar@100:     template <class T>
alpar@100:     struct DefPredMap 
alpar@100:       : public Dijkstra< Digraph,	LengthMap, DefPredMapTraits<T> > {
alpar@100:       typedef Dijkstra< Digraph,	LengthMap, DefPredMapTraits<T> > Create;
alpar@100:     };
alpar@100:     
alpar@100:     template <class T>
alpar@100:     struct DefDistMapTraits : public Traits {
alpar@100:       typedef T DistMap;
alpar@100:       static DistMap *createDistMap(const Digraph &)
alpar@100:       {
alpar@100: 	throw UninitializedParameter();
alpar@100:       }
alpar@100:     };
alpar@100:     ///\ref named-templ-param "Named parameter" for setting DistMap type
alpar@100: 
alpar@100:     ///\ref named-templ-param "Named parameter" for setting DistMap type
alpar@100:     ///
alpar@100:     template <class T>
alpar@100:     struct DefDistMap 
alpar@100:       : public Dijkstra< Digraph, LengthMap, DefDistMapTraits<T> > { 
alpar@100:       typedef Dijkstra< Digraph, LengthMap, DefDistMapTraits<T> > Create;
alpar@100:     };
alpar@100:     
alpar@100:     template <class T>
alpar@100:     struct DefProcessedMapTraits : public Traits {
alpar@100:       typedef T ProcessedMap;
alpar@100:       static ProcessedMap *createProcessedMap(const Digraph &G) 
alpar@100:       {
alpar@100: 	throw UninitializedParameter();
alpar@100:       }
alpar@100:     };
alpar@100:     ///\ref named-templ-param "Named parameter" for setting ProcessedMap type
alpar@100: 
alpar@100:     ///\ref named-templ-param "Named parameter" for setting ProcessedMap type
alpar@100:     ///
alpar@100:     template <class T>
alpar@100:     struct DefProcessedMap 
alpar@100:       : public Dijkstra< Digraph,	LengthMap, DefProcessedMapTraits<T> > { 
alpar@100:       typedef Dijkstra< Digraph,	LengthMap, DefProcessedMapTraits<T> > Create;
alpar@100:     };
alpar@100:     
alpar@100:     struct DefDigraphProcessedMapTraits : public Traits {
alpar@100:       typedef typename Digraph::template NodeMap<bool> ProcessedMap;
alpar@100:       static ProcessedMap *createProcessedMap(const Digraph &G) 
alpar@100:       {
alpar@100: 	return new ProcessedMap(G);
alpar@100:       }
alpar@100:     };
alpar@100:     ///\brief \ref named-templ-param "Named parameter"
alpar@100:     ///for setting the ProcessedMap type to be Digraph::NodeMap<bool>.
alpar@100:     ///
alpar@100:     ///\ref named-templ-param "Named parameter"
alpar@100:     ///for setting the ProcessedMap type to be Digraph::NodeMap<bool>.
alpar@100:     ///If you don't set it explicitely, it will be automatically allocated.
alpar@100:     template <class T>
alpar@100:     struct DefProcessedMapToBeDefaultMap 
alpar@100:       : public Dijkstra< Digraph, LengthMap, DefDigraphProcessedMapTraits> {
alpar@100:       typedef Dijkstra< Digraph, LengthMap, DefDigraphProcessedMapTraits> Create;
alpar@100:     };
alpar@100: 
alpar@100:     template <class H, class CR>
alpar@100:     struct DefHeapTraits : public Traits {
alpar@100:       typedef CR HeapCrossRef;
alpar@100:       typedef H Heap;
alpar@100:       static HeapCrossRef *createHeapCrossRef(const Digraph &) {
alpar@100: 	throw UninitializedParameter();
alpar@100:       }
alpar@100:       static Heap *createHeap(HeapCrossRef &) 
alpar@100:       {
alpar@100: 	throw UninitializedParameter();
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@100:     ///\ref named-templ-param "Named parameter" for setting heap and cross 
alpar@100:     ///reference type
alpar@100:     ///
alpar@100:     template <class H, class CR = typename Digraph::template NodeMap<int> >
alpar@100:     struct DefHeap
alpar@100:       : public Dijkstra< Digraph,	LengthMap, DefHeapTraits<H, CR> > { 
alpar@100:       typedef Dijkstra< Digraph,	LengthMap, DefHeapTraits<H, CR> > Create;
alpar@100:     };
alpar@100: 
alpar@100:     template <class H, class CR>
alpar@100:     struct DefStandardHeapTraits : public Traits {
alpar@100:       typedef CR HeapCrossRef;
alpar@100:       typedef H Heap;
alpar@100:       static HeapCrossRef *createHeapCrossRef(const Digraph &G) {
alpar@100: 	return new HeapCrossRef(G);
alpar@100:       }
alpar@100:       static Heap *createHeap(HeapCrossRef &R) 
alpar@100:       {
alpar@100: 	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@100:     ///\ref named-templ-param "Named parameter" for setting heap and cross 
alpar@100:     ///reference type. It can allocate the heap and the cross reference 
alpar@100:     ///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> >
alpar@100:     struct DefStandardHeap
alpar@100:       : public Dijkstra< Digraph,	LengthMap, DefStandardHeapTraits<H, CR> > { 
alpar@100:       typedef Dijkstra< Digraph,	LengthMap, DefStandardHeapTraits<H, CR> > 
alpar@100:       Create;
alpar@100:     };
alpar@100: 
alpar@100:     template <class T>
alpar@100:     struct DefOperationTraitsTraits : public Traits {
alpar@100:       typedef T OperationTraits;
alpar@100:     };
alpar@100:     
alpar@100:     /// \brief \ref named-templ-param "Named parameter" for setting 
alpar@100:     /// OperationTraits type
alpar@100:     ///
alpar@100:     /// \ref named-templ-param "Named parameter" for setting OperationTraits
alpar@100:     /// type
alpar@100:     template <class T>
alpar@100:     struct DefOperationTraits
alpar@100:       : public Dijkstra<Digraph, LengthMap, DefOperationTraitsTraits<T> > {
alpar@100:       typedef Dijkstra<Digraph, LengthMap, DefOperationTraitsTraits<T> >
alpar@100:       Create;
alpar@100:     };
alpar@100:     
alpar@100:     ///@}
alpar@100: 
alpar@100: 
alpar@100:   protected:
alpar@100: 
alpar@100:     Dijkstra() {}
alpar@100: 
alpar@100:   public:      
alpar@100:     
alpar@100:     ///Constructor.
alpar@100:     
alpar@100:     ///\param _G the digraph the algorithm will run on.
alpar@100:     ///\param _length the length map used by the algorithm.
alpar@100:     Dijkstra(const Digraph& _G, const LengthMap& _length) :
alpar@100:       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@100:     
alpar@100:     ///Destructor.
alpar@100:     ~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@100:     Dijkstra &lengthMap(const LengthMap &m) 
alpar@100:     {
alpar@100:       length = &m;
alpar@100:       return *this;
alpar@100:     }
alpar@100: 
alpar@100:     ///Sets the map storing the predecessor arcs.
alpar@100: 
alpar@100:     ///Sets the map storing the predecessor arcs.
alpar@100:     ///If you don't use this function before calling \ref run(),
alpar@100:     ///it will allocate one. The destuctor deallocates this
alpar@100:     ///automatically allocated map, of course.
alpar@100:     ///\return <tt> (*this) </tt>
alpar@100:     Dijkstra &predMap(PredMap &m) 
alpar@100:     {
alpar@100:       if(local_pred) {
alpar@100: 	delete _pred;
alpar@100: 	local_pred=false;
alpar@100:       }
alpar@100:       _pred = &m;
alpar@100:       return *this;
alpar@100:     }
alpar@100: 
alpar@100:     ///Sets the map storing the distances calculated by the algorithm.
alpar@100: 
alpar@100:     ///Sets the map storing the distances calculated by the algorithm.
alpar@100:     ///If you don't use this function before calling \ref run(),
alpar@100:     ///it will allocate one. The destuctor deallocates this
alpar@100:     ///automatically allocated map, of course.
alpar@100:     ///\return <tt> (*this) </tt>
alpar@100:     Dijkstra &distMap(DistMap &m) 
alpar@100:     {
alpar@100:       if(local_dist) {
alpar@100: 	delete _dist;
alpar@100: 	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(),
alpar@100:     ///it will allocate one. The destuctor 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@100: 	delete _heap_cross_ref;
alpar@100: 	local_heap_cross_ref=false;
alpar@100:       }
alpar@100:       _heap_cross_ref = &cr;
alpar@100:       if(local_heap) {
alpar@100: 	delete _heap;
alpar@100: 	local_heap=false;
alpar@100:       }
alpar@100:       _heap = &hp;
alpar@100:       return *this;
alpar@100:     }
alpar@100: 
alpar@100:   private:
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:     typedef PredMapPath<Digraph, PredMap> Path;
alpar@100: 
alpar@100:     ///\name Execution control
alpar@100:     ///The simplest way to execute the algorithm is to use
alpar@100:     ///one of the member functions called \c run(...).
alpar@100:     ///\n
alpar@100:     ///If you need more control on the execution,
alpar@100:     ///first you must call \ref init(), then you can add several source nodes
alpar@100:     ///with \ref addSource().
alpar@100:     ///Finally \ref start() will perform the actual path
alpar@100:     ///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@100: 	_pred->set(u,INVALID);
alpar@100: 	_processed->set(u,false);
alpar@100: 	_heap_cross_ref->set(u,Heap::PRE_HEAP);
alpar@100:       }
alpar@100:     }
alpar@100:     
alpar@100:     ///Adds a new source node.
alpar@100: 
alpar@100:     ///Adds a new source node to the priority heap.
alpar@100:     ///
alpar@100:     ///The optional second parameter is the initial distance of the node.
alpar@100:     ///
alpar@100:     ///It 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@100: 	_heap->push(s,dst);
alpar@100:       } else if(OperationTraits::less((*_heap)[s], dst)) {
alpar@100: 	_heap->set(s,dst);
alpar@100: 	_pred->set(s,INVALID);
alpar@100:       }
alpar@100:     }
alpar@100:     
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:     ///
alpar@100:     ///\warning The priority heap must not be empty!
alpar@100:     Node processNextNode()
alpar@100:     {
alpar@100:       Node v=_heap->top(); 
alpar@100:       Value oldvalue=_heap->prio();
alpar@100:       _heap->pop();
alpar@100:       finalizeNodeData(v,oldvalue);
alpar@100:       
alpar@100:       for(OutArcIt e(*G,v); e!=INVALID; ++e) {
alpar@100: 	Node w=G->target(e); 
alpar@100: 	switch(_heap->state(w)) {
alpar@100: 	case Heap::PRE_HEAP:
alpar@100: 	  _heap->push(w,OperationTraits::plus(oldvalue, (*length)[e])); 
alpar@100: 	  _pred->set(w,e);
alpar@100: 	  break;
alpar@100: 	case Heap::IN_HEAP:
alpar@100: 	  {
alpar@100: 	    Value newvalue = OperationTraits::plus(oldvalue, (*length)[e]);
alpar@100: 	    if ( OperationTraits::less(newvalue, (*_heap)[w]) ) {
alpar@100: 	      _heap->decrease(w, newvalue); 
alpar@100: 	      _pred->set(w,e);
alpar@100: 	    }
alpar@100: 	  }
alpar@100: 	  break;
alpar@100: 	case Heap::POST_HEAP:
alpar@100: 	  break;
alpar@100: 	}
alpar@100:       }
alpar@100:       return v;
alpar@100:     }
alpar@100: 
alpar@100:     ///Next node to be processed.
alpar@100:     
alpar@100:     ///Next node to be processed.
alpar@100:     ///
alpar@100:     ///\return The next node to be processed or INVALID if the priority heap
alpar@100:     /// is empty.
alpar@100:     Node nextNode()
alpar@100:     { 
alpar@100:       return !_heap->empty()?_heap->top():INVALID;
alpar@100:     }
alpar@100:  
alpar@100:     ///\brief Returns \c false if there are nodes
alpar@100:     ///to be processed in the priority heap
alpar@100:     ///
alpar@100:     ///Returns \c false if there are nodes
alpar@100:     ///to be processed in the priority heap
alpar@100:     bool emptyQueue() { return _heap->empty(); }
alpar@100:     ///Returns the number of the nodes to be processed in the priority heap
alpar@100: 
alpar@100:     ///Returns the number of the nodes to be processed in the priority heap
alpar@100:     ///
alpar@100:     int queueSize() { return _heap->size(); }
alpar@100:     
alpar@100:     ///Executes the algorithm.
alpar@100: 
alpar@100:     ///Executes the algorithm.
alpar@100:     ///
alpar@100:     ///\pre init() must be called and at least one node should be added
alpar@100:     ///with addSource() before using this function.
alpar@100:     ///
alpar@100:     ///This method runs the %Dijkstra algorithm from the root node(s)
alpar@100:     ///in order to
alpar@100:     ///compute the
alpar@100:     ///shortest path to each node. The algorithm computes
alpar@100:     ///- The shortest path tree.
alpar@100:     ///- The distance of each node from the root(s).
alpar@100:     ///
alpar@100:     void start()
alpar@100:     {
alpar@100:       while ( !_heap->empty() ) processNextNode();
alpar@100:     }
alpar@100:     
alpar@100:     ///Executes the algorithm until \c dest is reached.
alpar@100: 
alpar@100:     ///Executes the algorithm until \c dest is reached.
alpar@100:     ///
alpar@100:     ///\pre init() must be called and at least one node should be added
alpar@100:     ///with addSource() before using this function.
alpar@100:     ///
alpar@100:     ///This method runs the %Dijkstra algorithm from the root node(s)
alpar@100:     ///in order to
alpar@100:     ///compute the
alpar@100:     ///shortest path to \c dest. The algorithm computes
alpar@100:     ///- The shortest path to \c  dest.
alpar@100:     ///- The distance of \c dest from the root(s).
alpar@100:     ///
alpar@100:     void start(Node dest)
alpar@100:     {
alpar@100:       while ( !_heap->empty() && _heap->top()!=dest ) processNextNode();
alpar@100:       if ( !_heap->empty() ) finalizeNodeData(_heap->top(),_heap->prio());
alpar@100:     }
alpar@100:     
alpar@100:     ///Executes the algorithm until a condition is met.
alpar@100: 
alpar@100:     ///Executes the algorithm until a condition is met.
alpar@100:     ///
alpar@100:     ///\pre init() must be called and at least one node should be added
alpar@100:     ///with addSource() before using this function.
alpar@100:     ///
alpar@100:     ///\param nm must be a 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.
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@100:     
alpar@100:     ///Runs %Dijkstra algorithm from node \c s.
alpar@100:     
alpar@100:     ///This method runs the %Dijkstra algorithm from a root node \c s
alpar@100:     ///in order to
alpar@100:     ///compute the
alpar@100:     ///shortest path to each node. The algorithm computes
alpar@100:     ///- The shortest path tree.
alpar@100:     ///- The distance of each node from the root.
alpar@100:     ///
alpar@100:     ///\note d.run(s) 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@100:     
alpar@100:     ///Finds the shortest path between \c s and \c t.
alpar@100:     
alpar@100:     ///Finds the shortest path between \c s and \c t.
alpar@100:     ///
alpar@100:     ///\return The length of the shortest s---t path if there exists one,
alpar@100:     ///0 otherwise.
alpar@100:     ///\note Apart from the return value, d.run(s) is
alpar@100:     ///just a 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
alpar@100:     Value run(Node s,Node t) {
alpar@100:       init();
alpar@100:       addSource(s);
alpar@100:       start(t);
alpar@100:       return (*_pred)[t]==INVALID?OperationTraits::zero():(*_dist)[t];
alpar@100:     }
alpar@100:     
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
alpar@100:     ///Before the use of these functions,
alpar@100:     ///either run() or start() must be called.
alpar@100:     
alpar@100:     ///@{
alpar@100: 
alpar@100:     ///Gives back the shortest path.
alpar@100:     
alpar@100:     ///Gives back the shortest path.
alpar@100:     ///\pre The \c t should be reachable from the source.
alpar@100:     Path path(Node t) 
alpar@100:     {
alpar@100:       return Path(*G, *_pred, t);
alpar@100:     }
alpar@100: 
alpar@100:     ///The distance of a node from the root.
alpar@100: 
alpar@100:     ///Returns the distance of a node from the root.
alpar@100:     ///\pre \ref run() must be called before using this function.
alpar@100:     ///\warning If node \c v in unreachable from the root the return value
alpar@100:     ///of this funcion is undefined.
alpar@100:     Value dist(Node v) const { return (*_dist)[v]; }
alpar@100: 
alpar@100:     ///The current distance of a node from the root.
alpar@100: 
alpar@100:     ///Returns the current distance of a node from the root.
alpar@100:     ///It may be decreased in the following processes.
alpar@100:     ///\pre \c node should be reached but not processed
alpar@100:     Value currentDist(Node v) const { return (*_heap)[v]; }
alpar@100: 
alpar@100:     ///Returns the 'previous arc' of the shortest path tree.
alpar@100: 
alpar@100:     ///For a node \c v it returns the 'previous arc' of the shortest path tree,
alpar@100:     ///i.e. it returns the last arc of a shortest path from the root to \c
alpar@100:     ///v. It is \ref INVALID
alpar@100:     ///if \c v is unreachable from the root or if \c v=s. The
alpar@100:     ///shortest path tree used here is equal to the shortest path tree used in
alpar@100:     ///\ref predNode().  \pre \ref run() must be called before using
alpar@100:     ///this function.
alpar@100:     Arc predArc(Node v) const { return (*_pred)[v]; }
alpar@100: 
alpar@100:     ///Returns the 'previous node' of the shortest path tree.
alpar@100: 
alpar@100:     ///For a node \c v it returns the 'previous node' of the shortest path tree,
alpar@100:     ///i.e. it returns the last but one node from a shortest path from the
alpar@100:     ///root to \c /v. It is INVALID if \c v is unreachable from the root or if
alpar@100:     ///\c v=s. The shortest path tree used here is equal to the shortest path
alpar@100:     ///tree used in \ref predArc().  \pre \ref run() must be called before
alpar@100:     ///using this function.
alpar@100:     Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
alpar@100: 				  G->source((*_pred)[v]); }
alpar@100:     
alpar@100:     ///Returns a reference to the NodeMap of distances.
alpar@100: 
alpar@100:     ///Returns a reference to the NodeMap of distances. \pre \ref run() must
alpar@100:     ///be called before using this function.
alpar@100:     const DistMap &distMap() const { return *_dist;}
alpar@100:  
alpar@100:     ///Returns a reference to the shortest path tree map.
alpar@100: 
alpar@100:     ///Returns a reference to the NodeMap of the arcs of the
alpar@100:     ///shortest path tree.
alpar@100:     ///\pre \ref run() must be called before using this function.
alpar@100:     const PredMap &predMap() const { return *_pred;}
alpar@100:  
alpar@100:     ///Checks if a node is reachable from the root.
alpar@100: 
alpar@100:     ///Returns \c true if \c v is reachable from the root.
alpar@100:     ///\warning The source nodes are inditated as unreached.
alpar@100:     ///\pre \ref run() must be called before using this function.
alpar@100:     ///
alpar@100:     bool reached(Node v) { return (*_heap_cross_ref)[v] != 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.
alpar@100:     ///\pre \ref run() must be called before using this function.
alpar@100:     ///
alpar@100:     bool processed(Node v) { return (*_heap_cross_ref)[v] == Heap::POST_HEAP; }
alpar@100:     
alpar@100:     ///@}
alpar@100:   };
alpar@100: 
alpar@100: 
alpar@100: 
alpar@100: 
alpar@100:  
alpar@100:   ///Default traits class of Dijkstra function.
alpar@100: 
alpar@100:   ///Default traits class of Dijkstra function.
alpar@100:   ///\param GR Digraph type.
alpar@100:   ///\param LM Type of length map.
alpar@100:   template<class GR, class LM>
alpar@100:   struct DijkstraWizardDefaultTraits
alpar@100:   {
alpar@100:     ///The digraph type 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;
alpar@100:     //The type of the length of the arcs.
alpar@100:     typedef typename LM::Value Value;
alpar@100:     /// Operation traits for Dijkstra algorithm.
alpar@100: 
alpar@100:     /// It defines the used operation by the algorithm.
alpar@100:     /// \see DijkstraDefaultOperationTraits
alpar@100:     typedef DijkstraDefaultOperationTraits<Value> OperationTraits;
alpar@100:     ///The heap type used by Dijkstra algorithm.
alpar@100: 
alpar@100:     /// The cross reference type used by heap.
alpar@100: 
alpar@100:     /// The cross reference type used by heap.
alpar@100:     /// Usually it is \c Digraph::NodeMap<int>.
alpar@100:     typedef typename Digraph::template NodeMap<int> HeapCrossRef;
alpar@100:     ///Instantiates a HeapCrossRef.
alpar@100: 
alpar@100:     ///This function instantiates a \ref HeapCrossRef. 
alpar@100:     /// \param G is the digraph, to which we would like to define the 
alpar@100:     /// HeapCrossRef.
alpar@100:     /// \todo The digraph alone may be insufficient for the initialization
alpar@100:     static HeapCrossRef *createHeapCrossRef(const GR &G) 
alpar@100:     {
alpar@100:       return new HeapCrossRef(G);
alpar@100:     }
alpar@100:     
alpar@100:     ///The heap type used by Dijkstra algorithm.
alpar@100: 
alpar@100:     ///The heap type used by Dijkstra algorithm.
alpar@100:     ///
alpar@100:     ///\sa BinHeap
alpar@100:     ///\sa Dijkstra
alpar@100:     typedef BinHeap<typename LM::Value, typename GR::template NodeMap<int>,
alpar@100: 		    std::less<Value> > Heap;
alpar@100: 
alpar@100:     static Heap *createHeap(HeapCrossRef& R) 
alpar@100:     {
alpar@100:       return new Heap(R);
alpar@100:     }
alpar@100: 
alpar@100:     ///\brief The type of the map that stores the last
alpar@100:     ///arcs of the shortest paths.
alpar@100:     /// 
alpar@100:     ///The type of the map that stores the last
alpar@100:     ///arcs of the shortest paths.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
alpar@100:     ///
alpar@100:     typedef NullMap <typename GR::Node,typename GR::Arc> PredMap;
alpar@100:     ///Instantiates a PredMap.
alpar@100:  
alpar@100:     ///This function instantiates a \ref PredMap. 
alpar@100:     ///\param g is the digraph, to which we would like to define the PredMap.
alpar@100:     ///\todo The digraph alone may be insufficient for the initialization
alpar@100: #ifdef DOXYGEN
alpar@100:     static PredMap *createPredMap(const GR &g) 
alpar@100: #else
alpar@100:     static PredMap *createPredMap(const GR &) 
alpar@100: #endif
alpar@100:     {
alpar@100:       return new PredMap();
alpar@100:     }
alpar@100:     ///The type of the map that stores whether a nodes is processed.
alpar@100:  
alpar@100:     ///The type of the map that stores whether a nodes is processed.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
alpar@100:     ///By default it is a NullMap.
alpar@100:     ///\todo If it is set to a real map,
alpar@100:     ///Dijkstra::processed() should read this.
alpar@100:     ///\todo named parameter to set this type, function to read and write.
alpar@100:     typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
alpar@100:     ///Instantiates a ProcessedMap.
alpar@100:  
alpar@100:     ///This function instantiates a \ref ProcessedMap. 
alpar@100:     ///\param g is the digraph, to which
alpar@100:     ///we would like to define the \ref ProcessedMap
alpar@100: #ifdef DOXYGEN
alpar@100:     static ProcessedMap *createProcessedMap(const GR &g)
alpar@100: #else
alpar@100:     static ProcessedMap *createProcessedMap(const GR &)
alpar@100: #endif
alpar@100:     {
alpar@100:       return new ProcessedMap();
alpar@100:     }
alpar@100:     ///The type of the map that stores the dists of the nodes.
alpar@100:  
alpar@100:     ///The type of the map that stores the dists of the nodes.
alpar@100:     ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
alpar@100:     ///
alpar@100:     typedef NullMap<typename Digraph::Node,typename LM::Value> DistMap;
alpar@100:     ///Instantiates a DistMap.
alpar@100:  
alpar@100:     ///This function instantiates a \ref DistMap. 
alpar@100:     ///\param g is the digraph, to which we would like to define the \ref DistMap
alpar@100: #ifdef DOXYGEN
alpar@100:     static DistMap *createDistMap(const GR &g)
alpar@100: #else
alpar@100:     static DistMap *createDistMap(const GR &)
alpar@100: #endif
alpar@100:     {
alpar@100:       return new DistMap();
alpar@100:     }
alpar@100:   };
alpar@100:   
alpar@100:   /// Default traits used by \ref DijkstraWizard
alpar@100: 
alpar@100:   /// To make it easier to use Dijkstra algorithm
alpar@100:   ///we have created a wizard class.
alpar@100:   /// This \ref DijkstraWizard class needs default traits,
alpar@100:   ///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:   /// \todo More named parameters are required...
alpar@100:   template<class GR,class LM>
alpar@100:   class DijkstraWizardBase : public DijkstraWizardDefaultTraits<GR,LM>
alpar@100:   {
alpar@100: 
alpar@100:     typedef DijkstraWizardDefaultTraits<GR,LM> Base;
alpar@100:   protected:
alpar@100:     /// Type of the nodes in the digraph.
alpar@100:     typedef typename Base::Digraph::Node Node;
alpar@100: 
alpar@100:     /// Pointer to the underlying digraph.
alpar@100:     void *_g;
alpar@100:     /// Pointer to the length map
alpar@100:     void *_length;
alpar@100:     ///Pointer to the map of predecessors arcs.
alpar@100:     void *_pred;
alpar@100:     ///Pointer to the map of distances.
alpar@100:     void *_dist;
alpar@100:     ///Pointer to the source node.
alpar@100:     Node _source;
alpar@100: 
alpar@100:     public:
alpar@100:     /// Constructor.
alpar@100:     
alpar@100:     /// This constructor does not require parameters, therefore it initiates
alpar@100:     /// all of the attributes to default values (0, INVALID).
alpar@100:     DijkstraWizardBase() : _g(0), _length(0), _pred(0),
alpar@100: 			   _dist(0), _source(INVALID) {}
alpar@100: 
alpar@100:     /// Constructor.
alpar@100:     
alpar@100:     /// This constructor requires some parameters,
alpar@100:     /// listed in the parameters list.
alpar@100:     /// Others are initiated to 0.
alpar@100:     /// \param g is the initial value of  \ref _g
alpar@100:     /// \param l is the initial value of  \ref _length
alpar@100:     /// \param s is the initial value of  \ref _source
alpar@100:     DijkstraWizardBase(const GR &g,const LM &l, Node s=INVALID) :
alpar@100:       _g(reinterpret_cast<void*>(const_cast<GR*>(&g))), 
alpar@100:       _length(reinterpret_cast<void*>(const_cast<LM*>(&l))), 
alpar@100:       _pred(0), _dist(0), _source(s) {}
alpar@100: 
alpar@100:   };
alpar@100:   
alpar@100:   /// A class to make the usage of Dijkstra algorithm easier
alpar@100: 
alpar@100:   /// This class is created to make it easier to use Dijkstra algorithm.
alpar@100:   /// It uses the functions and features of the plain \ref Dijkstra,
alpar@100:   /// but it is much simpler to use it.
alpar@100:   ///
alpar@100:   /// Simplicity means that the way to change the types defined
alpar@100:   /// in the traits class is based on functions that returns the new class
alpar@100:   /// and not on templatable built-in classes.
alpar@100:   /// When using the plain \ref Dijkstra
alpar@100:   /// the new class with the modified type comes from
alpar@100:   /// the original class by using the ::
alpar@100:   /// operator. In the case of \ref DijkstraWizard only
alpar@100:   /// a function have to be called and it will
alpar@100:   /// return the needed class.
alpar@100:   ///
alpar@100:   /// It does not have own \ref run method. When its \ref run method is called
alpar@100:   /// it initiates a plain \ref Dijkstra class, and calls the \ref 
alpar@100:   /// Dijkstra::run method of it.
alpar@100:   template<class TR>
alpar@100:   class DijkstraWizard : public TR
alpar@100:   {
alpar@100:     typedef TR Base;
alpar@100: 
alpar@100:     ///The type of the underlying digraph.
alpar@100:     typedef typename TR::Digraph Digraph;
alpar@100:     //\e
alpar@100:     typedef typename Digraph::Node Node;
alpar@100:     //\e
alpar@100:     typedef typename Digraph::NodeIt NodeIt;
alpar@100:     //\e
alpar@100:     typedef typename Digraph::Arc Arc;
alpar@100:     //\e
alpar@100:     typedef typename Digraph::OutArcIt OutArcIt;
alpar@100:     
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;
alpar@100:     ///\brief The type of the map that stores the last
alpar@100:     ///arcs of the shortest paths.
alpar@100:     typedef typename TR::PredMap PredMap;
alpar@100:     ///The type of the map that stores the dists of the nodes.
alpar@100:     typedef typename TR::DistMap DistMap;
alpar@100:     ///The heap type used by the dijkstra algorithm.
alpar@100:     typedef typename TR::Heap Heap;
alpar@100:   public:
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.
alpar@100:     DijkstraWizard(const Digraph &g,const LengthMap &l, Node s=INVALID) :
alpar@100:       TR(g,l,s) {}
alpar@100: 
alpar@100:     ///Copy constructor
alpar@100:     DijkstraWizard(const TR &b) : TR(b) {}
alpar@100: 
alpar@100:     ~DijkstraWizard() {}
alpar@100: 
alpar@100:     ///Runs Dijkstra algorithm from a given node.
alpar@100:     
alpar@100:     ///Runs Dijkstra algorithm from a given node.
alpar@100:     ///The node can be given by the \ref source function.
alpar@100:     void run()
alpar@100:     {
alpar@100:       if(Base::_source==INVALID) throw UninitializedParameter();
alpar@100:       Dijkstra<Digraph,LengthMap,TR> 
alpar@100: 	dij(*reinterpret_cast<const Digraph*>(Base::_g),
alpar@100:             *reinterpret_cast<const LengthMap*>(Base::_length));
alpar@100:       if(Base::_pred) dij.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
alpar@100:       if(Base::_dist) dij.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
alpar@100:       dij.run(Base::_source);
alpar@100:     }
alpar@100: 
alpar@100:     ///Runs Dijkstra algorithm from the given node.
alpar@100: 
alpar@100:     ///Runs Dijkstra algorithm from the given node.
alpar@100:     ///\param s is the given source.
alpar@100:     void run(Node s)
alpar@100:     {
alpar@100:       Base::_source=s;
alpar@100:       run();
alpar@100:     }
alpar@100: 
alpar@100:     template<class T>
alpar@100:     struct DefPredMapBase : public Base {
alpar@100:       typedef T PredMap;
alpar@100:       static PredMap *createPredMap(const Digraph &) { return 0; };
alpar@100:       DefPredMapBase(const TR &b) : TR(b) {}
alpar@100:     };
alpar@100:     
alpar@100:     ///\brief \ref named-templ-param "Named parameter"
alpar@100:     ///function for setting PredMap type
alpar@100:     ///
alpar@100:     /// \ref named-templ-param "Named parameter"
alpar@100:     ///function for setting PredMap type
alpar@100:     ///
alpar@100:     template<class T>
alpar@100:     DijkstraWizard<DefPredMapBase<T> > predMap(const T &t) 
alpar@100:     {
alpar@100:       Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
alpar@100:       return DijkstraWizard<DefPredMapBase<T> >(*this);
alpar@100:     }
alpar@100:     
alpar@100:     template<class T>
alpar@100:     struct DefDistMapBase : public Base {
alpar@100:       typedef T DistMap;
alpar@100:       static DistMap *createDistMap(const Digraph &) { return 0; };
alpar@100:       DefDistMapBase(const TR &b) : TR(b) {}
alpar@100:     };
alpar@100:     
alpar@100:     ///\brief \ref named-templ-param "Named parameter"
alpar@100:     ///function for setting DistMap type
alpar@100:     ///
alpar@100:     /// \ref named-templ-param "Named parameter"
alpar@100:     ///function for setting DistMap type
alpar@100:     ///
alpar@100:     template<class T>
alpar@100:     DijkstraWizard<DefDistMapBase<T> > distMap(const T &t) 
alpar@100:     {
alpar@100:       Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t));
alpar@100:       return DijkstraWizard<DefDistMapBase<T> >(*this);
alpar@100:     }
alpar@100:     
alpar@100:     /// Sets the source node, from which the Dijkstra algorithm runs.
alpar@100: 
alpar@100:     /// Sets the source node, from which the Dijkstra algorithm runs.
alpar@100:     /// \param s is the source node.
alpar@100:     DijkstraWizard<TR> &source(Node s) 
alpar@100:     {
alpar@100:       Base::_source=s;
alpar@100:       return *this;
alpar@100:     }
alpar@100:     
alpar@100:   };
alpar@100:   
alpar@100:   ///Function type interface for Dijkstra algorithm.
alpar@100: 
alpar@100:   /// \ingroup shortest_path
alpar@100:   ///Function type interface for Dijkstra algorithm.
alpar@100:   ///
alpar@100:   ///This function also has several
alpar@100:   ///\ref named-templ-func-param "named parameters",
alpar@100:   ///they are declared as the members of class \ref DijkstraWizard.
alpar@100:   ///The following
alpar@100:   ///example shows how to use these parameters.
alpar@100:   ///\code
alpar@100:   ///  dijkstra(g,length,source).predMap(preds).run();
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> >
alpar@100:   dijkstra(const GR &g,const LM &l,typename GR::Node s=INVALID)
alpar@100:   {
alpar@100:     return DijkstraWizard<DijkstraWizardBase<GR,LM> >(g,l,s);
alpar@100:   }
alpar@100: 
alpar@100: } //END OF NAMESPACE LEMON
alpar@100: 
alpar@100: #endif