alpar@906: /* -*- C++ -*-
alpar@921:  * src/lemon/dijkstra.h - Part of LEMON, a generic C++ optimization library
alpar@906:  *
alpar@1164:  * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
alpar@906:  * (Egervary Combinatorial Optimization Research Group, EGRES).
alpar@906:  *
alpar@906:  * Permission to use, modify and distribute this software is granted
alpar@906:  * provided that this copyright notice appears in all copies. For
alpar@906:  * precise terms see the accompanying LICENSE file.
alpar@906:  *
alpar@906:  * This software is provided "AS IS" with no warranty of any kind,
alpar@906:  * express or implied, and with no claim as to its suitability for any
alpar@906:  * purpose.
alpar@906:  *
alpar@906:  */
alpar@906: 
alpar@921: #ifndef LEMON_DIJKSTRA_H
alpar@921: #define LEMON_DIJKSTRA_H
alpar@255: 
alpar@758: ///\ingroup flowalgs
alpar@255: ///\file
alpar@255: ///\brief Dijkstra algorithm.
alpar@255: 
alpar@953: #include <lemon/list_graph.h>
alpar@921: #include <lemon/bin_heap.h>
alpar@921: #include <lemon/invalid.h>
alpar@1119: #include <lemon/error.h>
alpar@1119: #include <lemon/maps.h>
alpar@255: 
alpar@921: namespace lemon {
jacint@385: 
alpar@1119: 
alpar@1151:   
alpar@954:   ///Default traits class of Dijkstra class.
alpar@954: 
alpar@954:   ///Default traits class of Dijkstra class.
alpar@954:   ///\param GR Graph type.
alpar@954:   ///\param LM Type of length map.
alpar@953:   template<class GR, class LM>
alpar@953:   struct DijkstraDefaultTraits
alpar@953:   {
alpar@954:     ///The graph type the algorithm runs on. 
alpar@953:     typedef GR Graph;
alpar@953:     ///The type of the map that stores the edge lengths.
alpar@953: 
hegyi@1124:     ///The type of the map that stores the edge lengths.
alpar@967:     ///It must meet the \ref concept::ReadMap "ReadMap" concept.
alpar@953:     typedef LM LengthMap;
alpar@954:     //The type of the length of the edges.
alpar@987:     typedef typename LM::Value Value;
alpar@954:     ///The heap type used by Dijkstra algorithm.
alpar@967: 
alpar@967:     ///The heap type used by Dijkstra algorithm.
alpar@967:     ///
alpar@967:     ///\sa BinHeap
alpar@967:     ///\sa Dijkstra
alpar@953:     typedef BinHeap<typename Graph::Node,
alpar@987: 		    typename LM::Value,
alpar@953: 		    typename GR::template NodeMap<int>,
alpar@987: 		    std::less<Value> > Heap;
alpar@953: 
alpar@953:     ///\brief The type of the map that stores the last
alpar@953:     ///edges of the shortest paths.
alpar@953:     /// 
hegyi@1124:     ///The type of the map that stores the last
hegyi@1124:     ///edges of the shortest paths.
alpar@967:     ///It must meet the \ref concept::WriteMap "WriteMap" concept.
alpar@953:     ///
alpar@954:     typedef typename Graph::template NodeMap<typename GR::Edge> PredMap;
alpar@954:     ///Instantiates a PredMap.
alpar@953:  
hegyi@1123:     ///This function instantiates a \ref PredMap. 
hegyi@1123:     ///\param G is the graph, to which we would like to define the PredMap.
alpar@1119:     ///\todo The graph alone may be insufficient for the initialization
alpar@954:     static PredMap *createPredMap(const GR &G) 
alpar@953:     {
alpar@953:       return new PredMap(G);
alpar@953:     }
alpar@953:     ///\brief The type of the map that stores the last but one
alpar@953:     ///nodes of the shortest paths.
alpar@953:     ///
hegyi@1124:     ///The type of the map that stores the last but one
hegyi@1124:     ///nodes of the shortest paths.
alpar@967:     ///It must meet the \ref concept::WriteMap "WriteMap" concept.
alpar@953:     ///
alpar@1130:     typedef NullMap<typename Graph::Node,typename Graph::Node> PredNodeMap;
alpar@954:     ///Instantiates a PredNodeMap.
alpar@1125:     
hegyi@1123:     ///This function instantiates a \ref PredNodeMap. 
alpar@1156:     ///\param G is the graph, to which
alpar@1156:     ///we would like to define the \ref PredNodeMap
alpar@954:     static PredNodeMap *createPredNodeMap(const GR &G)
alpar@953:     {
alpar@1130:       return new PredNodeMap();
alpar@953:     }
alpar@1119: 
alpar@1119:     ///The type of the map that stores whether a nodes is reached.
alpar@1119:  
hegyi@1124:     ///The type of the map that stores whether a nodes is reached.
alpar@1119:     ///It must meet the \ref concept::WriteMap "WriteMap" concept.
alpar@1119:     ///By default it is a NullMap.
alpar@1119:     ///\todo If it is set to a real map, Dijkstra::reached() should read this.
alpar@1119:     ///\todo named parameter to set this type, function to read and write.
alpar@1119:     typedef NullMap<typename Graph::Node,bool> ReachedMap;
alpar@1119:     ///Instantiates a ReachedMap.
alpar@1119:  
hegyi@1123:     ///This function instantiates a \ref ReachedMap. 
alpar@1156:     ///\param G is the graph, to which
alpar@1156:     ///we would like to define the \ref ReachedMap
alpar@1119:     static ReachedMap *createReachedMap(const GR &G)
alpar@1119:     {
alpar@1119:       return new ReachedMap();
alpar@1119:     }
alpar@953:     ///The type of the map that stores the dists of the nodes.
alpar@953:  
hegyi@1124:     ///The type of the map that stores the dists of the nodes.
alpar@967:     ///It must meet the \ref concept::WriteMap "WriteMap" concept.
alpar@953:     ///
alpar@987:     typedef typename Graph::template NodeMap<typename LM::Value> DistMap;
alpar@954:     ///Instantiates a DistMap.
alpar@953:  
hegyi@1123:     ///This function instantiates a \ref DistMap. 
hegyi@1123:     ///\param G is the graph, to which we would like to define the \ref DistMap
alpar@954:     static DistMap *createDistMap(const GR &G)
alpar@953:     {
alpar@953:       return new DistMap(G);
alpar@953:     }
alpar@953:   };
alpar@953:   
alpar@255:   ///%Dijkstra algorithm class.
alpar@1125:   
alpar@1151:   /// \ingroup flowalgs
alpar@255:   ///This class provides an efficient implementation of %Dijkstra algorithm.
alpar@255:   ///The edge lengths are passed to the algorithm using a
klao@959:   ///\ref concept::ReadMap "ReadMap",
alpar@255:   ///so it is easy to change it to any kind of length.
alpar@255:   ///
alpar@880:   ///The type of the length is determined by the
alpar@987:   ///\ref concept::ReadMap::Value "Value" of the length map.
alpar@255:   ///
alpar@255:   ///It is also possible to change the underlying priority heap.
alpar@255:   ///
alpar@953:   ///\param GR The graph type the algorithm runs on. The default value is
alpar@955:   ///\ref ListGraph. The value of GR is not used directly by Dijkstra, it
alpar@954:   ///is only passed to \ref DijkstraDefaultTraits.
alpar@584:   ///\param LM This read-only
jacint@385:   ///EdgeMap
jacint@385:   ///determines the
jacint@385:   ///lengths of the edges. It is read once for each edge, so the map
jacint@385:   ///may involve in relatively time consuming process to compute the edge
jacint@385:   ///length if it is necessary. The default map type is
klao@959:   ///\ref concept::StaticGraph::EdgeMap "Graph::EdgeMap<int>".
alpar@955:   ///The value of LM is not used directly by Dijkstra, it
alpar@954:   ///is only passed to \ref DijkstraDefaultTraits.
alpar@954:   ///\param TR Traits class to set various data types used by the algorithm.
alpar@954:   ///The default traits class is
alpar@955:   ///\ref DijkstraDefaultTraits "DijkstraDefaultTraits<GR,LM>".
alpar@954:   ///See \ref DijkstraDefaultTraits for the documentation of
alpar@954:   ///a Dijkstra traits class.
alpar@456:   ///
alpar@689:   ///\author Jacint Szabo and Alpar Juttner
alpar@1128:   ///\todo A compare object would be nice.
alpar@584: 
alpar@255: #ifdef DOXYGEN
alpar@584:   template <typename GR,
alpar@584: 	    typename LM,
alpar@953: 	    typename TR>
alpar@255: #else
alpar@953:   template <typename GR=ListGraph,
alpar@584: 	    typename LM=typename GR::template EdgeMap<int>,
alpar@953: 	    typename TR=DijkstraDefaultTraits<GR,LM> >
alpar@255: #endif
alpar@1116:   class Dijkstra {
alpar@255:   public:
alpar@1125:     /**
alpar@1125:      * \brief \ref Exception for uninitialized parameters.
alpar@1125:      *
alpar@1125:      * This error represents problems in the initialization
alpar@1125:      * of the parameters of the algorithms.
alpar@1125:      */
alpar@1125:     class UninitializedParameter : public lemon::UninitializedParameter {
alpar@1125:     public:
alpar@1125:       virtual const char* exceptionName() const {
alpar@1125: 	return "lemon::Dijsktra::UninitializedParameter";
alpar@1125:       }
alpar@1125:     };
alpar@1119: 
alpar@953:     typedef TR Traits;
alpar@584:     ///The type of the underlying graph.
alpar@954:     typedef typename TR::Graph Graph;
alpar@911:     ///\e
alpar@255:     typedef typename Graph::Node Node;
alpar@911:     ///\e
alpar@255:     typedef typename Graph::NodeIt NodeIt;
alpar@911:     ///\e
alpar@255:     typedef typename Graph::Edge Edge;
alpar@911:     ///\e
alpar@255:     typedef typename Graph::OutEdgeIt OutEdgeIt;
alpar@255:     
alpar@584:     ///The type of the length of the edges.
alpar@987:     typedef typename TR::LengthMap::Value Value;
alpar@693:     ///The type of the map that stores the edge lengths.
alpar@954:     typedef typename TR::LengthMap LengthMap;
alpar@693:     ///\brief The type of the map that stores the last
alpar@584:     ///edges of the shortest paths.
alpar@953:     typedef typename TR::PredMap PredMap;
alpar@693:     ///\brief The type of the map that stores the last but one
alpar@584:     ///nodes of the shortest paths.
alpar@953:     typedef typename TR::PredNodeMap PredNodeMap;
alpar@1119:     ///The type of the map indicating if a node is reached.
alpar@1119:     typedef typename TR::ReachedMap ReachedMap;
alpar@693:     ///The type of the map that stores the dists of the nodes.
alpar@953:     typedef typename TR::DistMap DistMap;
alpar@953:     ///The heap type used by the dijkstra algorithm.
alpar@953:     typedef typename TR::Heap Heap;
alpar@255:   private:
alpar@802:     /// Pointer to the underlying graph.
alpar@688:     const Graph *G;
alpar@802:     /// Pointer to the length map
alpar@954:     const LengthMap *length;
alpar@802:     ///Pointer to the map of predecessors edges.
alpar@1119:     PredMap *_pred;
alpar@1119:     ///Indicates if \ref _pred is locally allocated (\c true) or not.
alpar@1119:     bool local_pred;
alpar@802:     ///Pointer to the map of predecessors nodes.
alpar@1130:     PredNodeMap *_predNode;
alpar@1130:     ///Indicates if \ref _predNode is locally allocated (\c true) or not.
alpar@1130:     bool local_predNode;
alpar@802:     ///Pointer to the map of distances.
alpar@1130:     DistMap *_dist;
alpar@1130:     ///Indicates if \ref _dist is locally allocated (\c true) or not.
alpar@1130:     bool local_dist;
alpar@1119:     ///Pointer to the map of reached status of the nodes.
alpar@1119:     ReachedMap *_reached;
alpar@1119:     ///Indicates if \ref _reached is locally allocated (\c true) or not.
alpar@1119:     bool local_reached;
alpar@688: 
alpar@802:     ///The source node of the last execution.
alpar@774:     Node source;
alpar@774: 
alpar@1128:     ///Creates the maps if necessary.
alpar@688:     
alpar@694:     ///\todo Error if \c G or are \c NULL. What about \c length?
alpar@688:     ///\todo Better memory allocation (instead of new).
alpar@1128:     void create_maps() 
alpar@688:     {
alpar@1119:       if(!_pred) {
alpar@1119: 	local_pred = true;
alpar@1119: 	_pred = Traits::createPredMap(*G);
alpar@688:       }
alpar@1130:       if(!_predNode) {
alpar@1130: 	local_predNode = true;
alpar@1130: 	_predNode = Traits::createPredNodeMap(*G);
alpar@688:       }
alpar@1130:       if(!_dist) {
alpar@1130: 	local_dist = true;
alpar@1130: 	_dist = Traits::createDistMap(*G);
alpar@688:       }
alpar@1119:       if(!_reached) {
alpar@1119: 	local_reached = true;
alpar@1119: 	_reached = Traits::createReachedMap(*G);
alpar@1119:       }
alpar@688:     }
alpar@255:     
alpar@255:   public :
alpar@1116:  
alpar@1128:     ///\name Named template parameters
alpar@1128: 
alpar@1128:     ///@{
alpar@1128: 
alpar@953:     template <class T>
alpar@1116:     struct DefPredMapTraits : public Traits {
alpar@953:       typedef T PredMap;
alpar@953:       static PredMap *createPredMap(const Graph &G) 
alpar@953:       {
alpar@1126: 	throw UninitializedParameter();
alpar@953:       }
alpar@953:     };
alpar@954:     ///\ref named-templ-param "Named parameter" for setting PredMap type
alpar@954: 
alpar@954:     ///\ref named-templ-param "Named parameter" for setting PredMap type
alpar@1043:     ///
alpar@953:     template <class T>
alpar@1116:     class DefPredMap : public Dijkstra< Graph,
alpar@953: 					LengthMap,
alpar@1116: 					DefPredMapTraits<T> > { };
alpar@953:     
alpar@953:     template <class T>
alpar@1116:     struct DefPredNodeMapTraits : public Traits {
alpar@953:       typedef T PredNodeMap;
alpar@953:       static PredNodeMap *createPredNodeMap(const Graph &G) 
alpar@953:       {
alpar@1126: 	throw UninitializedParameter();
alpar@953:       }
alpar@953:     };
alpar@954:     ///\ref named-templ-param "Named parameter" for setting PredNodeMap type
alpar@954: 
alpar@954:     ///\ref named-templ-param "Named parameter" for setting PredNodeMap type
alpar@1043:     ///
alpar@953:     template <class T>
alpar@1116:     class DefPredNodeMap : public Dijkstra< Graph,
alpar@953: 					    LengthMap,
alpar@1116: 					    DefPredNodeMapTraits<T> > { };
alpar@953:     
alpar@953:     template <class T>
alpar@1116:     struct DefDistMapTraits : public Traits {
alpar@953:       typedef T DistMap;
alpar@953:       static DistMap *createDistMap(const Graph &G) 
alpar@953:       {
alpar@1126: 	throw UninitializedParameter();
alpar@953:       }
alpar@953:     };
alpar@954:     ///\ref named-templ-param "Named parameter" for setting DistMap type
alpar@954: 
alpar@954:     ///\ref named-templ-param "Named parameter" for setting DistMap type
alpar@1043:     ///
alpar@953:     template <class T>
alpar@1116:     class DefDistMap : public Dijkstra< Graph,
alpar@953: 					LengthMap,
alpar@1116: 					DefDistMapTraits<T> > { };
alpar@953:     
alpar@1128:     template <class T>
alpar@1128:     struct DefReachedMapTraits : public Traits {
alpar@1128:       typedef T ReachedMap;
alpar@1128:       static ReachedMap *createReachedMap(const Graph &G) 
alpar@1128:       {
alpar@1128: 	throw UninitializedParameter();
alpar@1128:       }
alpar@1128:     };
alpar@1128:     ///\ref named-templ-param "Named parameter" for setting ReachedMap type
alpar@1128: 
alpar@1128:     ///\ref named-templ-param "Named parameter" for setting ReachedMap type
alpar@1128:     ///
alpar@1128:     template <class T>
alpar@1128:     class DefReachedMap : public Dijkstra< Graph,
alpar@1128: 					LengthMap,
alpar@1128: 					DefReachedMapTraits<T> > { };
alpar@1128:     
alpar@1128:     struct DefGraphReachedMapTraits : public Traits {
alpar@1128:       typedef typename Graph::NodeMap<bool> ReachedMap;
alpar@1128:       static ReachedMap *createReachedMap(const Graph &G) 
alpar@1128:       {
alpar@1128: 	return new ReachedMap(G);
alpar@1128:       }
alpar@1128:     };
alpar@1128:     ///\brief \ref named-templ-param "Named parameter"
alpar@1128:     ///for setting the ReachedMap type to be Graph::NodeMap<bool>.
alpar@1128:     ///
alpar@1128:     ///\ref named-templ-param "Named parameter"
alpar@1128:     ///for setting the ReachedMap type to be Graph::NodeMap<bool>.
alpar@1128:     ///If you don't set it explicitely, it will be automatically allocated.
alpar@1128:     template <class T>
alpar@1128:     class DefReachedMapToBeDefaultMap :
alpar@1128:       public Dijkstra< Graph,
alpar@1128: 		       LengthMap,
alpar@1128: 		       DefGraphReachedMapTraits> { };
alpar@1128:     
alpar@1128:     ///@}
alpar@1128: 
alpar@1128: 
alpar@1128:   private:
alpar@1128:     typename Graph::template NodeMap<int> _heap_map;
alpar@1128:     Heap _heap;
alpar@1128:   public:      
alpar@1128:     
alpar@802:     ///Constructor.
alpar@255:     
alpar@802:     ///\param _G the graph the algorithm will run on.
alpar@802:     ///\param _length the length map used by the algorithm.
alpar@954:     Dijkstra(const Graph& _G, const LengthMap& _length) :
alpar@688:       G(&_G), length(&_length),
alpar@1119:       _pred(NULL), local_pred(false),
alpar@1130:       _predNode(NULL), local_predNode(false),
alpar@1130:       _dist(NULL), local_dist(false),
alpar@1128:       _reached(NULL), local_reached(false),
alpar@1128:       _heap_map(*G,-1),_heap(_heap_map)
alpar@688:     { }
alpar@688:     
alpar@802:     ///Destructor.
alpar@688:     ~Dijkstra() 
alpar@688:     {
alpar@1119:       if(local_pred) delete _pred;
alpar@1130:       if(local_predNode) delete _predNode;
alpar@1130:       if(local_dist) delete _dist;
alpar@1119:       if(local_reached) delete _reached;
alpar@688:     }
alpar@688: 
alpar@688:     ///Sets the length map.
alpar@688: 
alpar@688:     ///Sets the length map.
alpar@688:     ///\return <tt> (*this) </tt>
alpar@1116:     Dijkstra &lengthMap(const LengthMap &m) 
alpar@688:     {
alpar@688:       length = &m;
alpar@688:       return *this;
alpar@688:     }
alpar@688: 
alpar@688:     ///Sets the map storing the predecessor edges.
alpar@688: 
alpar@688:     ///Sets the map storing the predecessor edges.
alpar@688:     ///If you don't use this function before calling \ref run(),
alpar@688:     ///it will allocate one. The destuctor deallocates this
alpar@688:     ///automatically allocated map, of course.
alpar@688:     ///\return <tt> (*this) </tt>
alpar@1116:     Dijkstra &predMap(PredMap &m) 
alpar@688:     {
alpar@1119:       if(local_pred) {
alpar@1119: 	delete _pred;
alpar@1119: 	local_pred=false;
alpar@688:       }
alpar@1119:       _pred = &m;
alpar@688:       return *this;
alpar@688:     }
alpar@688: 
alpar@688:     ///Sets the map storing the predecessor nodes.
alpar@688: 
alpar@688:     ///Sets the map storing the predecessor nodes.
alpar@688:     ///If you don't use this function before calling \ref run(),
alpar@688:     ///it will allocate one. The destuctor deallocates this
alpar@688:     ///automatically allocated map, of course.
alpar@688:     ///\return <tt> (*this) </tt>
alpar@1116:     Dijkstra &predNodeMap(PredNodeMap &m) 
alpar@688:     {
alpar@1130:       if(local_predNode) {
alpar@1130: 	delete _predNode;
alpar@1130: 	local_predNode=false;
alpar@688:       }
alpar@1130:       _predNode = &m;
alpar@688:       return *this;
alpar@688:     }
alpar@688: 
alpar@688:     ///Sets the map storing the distances calculated by the algorithm.
alpar@688: 
alpar@688:     ///Sets the map storing the distances calculated by the algorithm.
alpar@688:     ///If you don't use this function before calling \ref run(),
alpar@688:     ///it will allocate one. The destuctor deallocates this
alpar@688:     ///automatically allocated map, of course.
alpar@688:     ///\return <tt> (*this) </tt>
alpar@1116:     Dijkstra &distMap(DistMap &m) 
alpar@688:     {
alpar@1130:       if(local_dist) {
alpar@1130: 	delete _dist;
alpar@1130: 	local_dist=false;
alpar@688:       }
alpar@1130:       _dist = &m;
alpar@688:       return *this;
alpar@688:     }
alpar@694: 
alpar@1130:   private:
alpar@1130:     void finalizeNodeData(Node v,Value dst)
alpar@1130:     {
alpar@1130:       _reached->set(v,true);
alpar@1130:       _dist->set(v, dst);
alpar@1130:       _predNode->set(v,G->source((*_pred)[v]));
alpar@1130:     }
alpar@1130: 
alpar@1130:   public:
alpar@1128:     ///\name Excetution control
alpar@1128:     ///The simplest way to execute the algorithm is to use
alpar@1156:     ///one of the member functions called \c run(...).
alpar@1128:     ///\n
alpar@1128:     ///It you need more control on the execution,
alpar@1128:     ///first you must call \ref init(), then you can add several source nodes
alpar@1128:     ///with \ref addSource(). Finally \ref start() will perform the actual path
alpar@1128:     ///computation.
alpar@1128: 
alpar@1128:     ///@{
alpar@1128: 
alpar@1128:     ///Initializes the internal data structures.
alpar@1128: 
alpar@1128:     ///Initializes the internal data structures.
alpar@1128:     ///
alpar@1128:     ///\todo _heap_map's type could also be in the traits class.
alpar@1128:     void init()
alpar@1128:     {
alpar@1128:       create_maps();
alpar@774:       
alpar@774:       for ( NodeIt u(*G) ; u!=INVALID ; ++u ) {
alpar@1119: 	_pred->set(u,INVALID);
alpar@1130: 	_predNode->set(u,INVALID);
alpar@1119: 	///\todo *_reached is not set to false.
alpar@1128: 	_heap_map.set(u,Heap::PRE_HEAP);
alpar@694:       }
alpar@1128:     }
alpar@1128:     
alpar@1128:     ///Adds a new source node.
alpar@1128: 
alpar@1155:     ///Adds a new source node to the priority heap.
alpar@1128:     ///
alpar@1128:     ///The optional second parameter is the initial distance of the node.
alpar@1128:     ///
alpar@1155:     ///It checks if the node has already been added to the heap and
alpar@1155:     ///It is pushed to the heap only if either it was not in the heap
alpar@1155:     ///or the shortest path found till then is longer then \c dst.
alpar@1128:     void addSource(Node s,Value dst=0)
alpar@1128:     {
alpar@1128:       source = s;
alpar@1128:       if(_heap.state(s) != Heap::IN_HEAP) _heap.push(s,dst);
alpar@1155:       else if(_heap[s]<dst) {
alpar@1155: 	_heap.push(s,dst);
alpar@1155: 	_pred->set(s,INVALID);
alpar@1155:       }
alpar@1128:     }
alpar@1128:     
alpar@1155:     ///Processes the next node in the priority heap
alpar@1155: 
alpar@1155:     ///Processes the next node in the priority heap.
alpar@1155:     ///
alpar@1155:     ///\warning The priority heap must not be empty!
alpar@1151:     void processNextNode()
alpar@1128:     {
alpar@1128:       Node v=_heap.top(); 
alpar@1128:       Value oldvalue=_heap[v];
alpar@1128:       _heap.pop();
alpar@1130:       finalizeNodeData(v,oldvalue);
alpar@694:       
alpar@1128:       for(OutEdgeIt e(*G,v); e!=INVALID; ++e) {
alpar@1128: 	Node w=G->target(e); 
alpar@1128: 	switch(_heap.state(w)) {
alpar@1128: 	case Heap::PRE_HEAP:
alpar@1128: 	  _heap.push(w,oldvalue+(*length)[e]); 
alpar@1128: 	  _pred->set(w,e);
alpar@1130: //  	  _predNode->set(w,v);
alpar@1128: 	  break;
alpar@1128: 	case Heap::IN_HEAP:
alpar@1128: 	  if ( oldvalue+(*length)[e] < _heap[w] ) {
alpar@1128: 	    _heap.decrease(w, oldvalue+(*length)[e]); 
alpar@1119: 	    _pred->set(w,e);
alpar@1130: // 	    _predNode->set(w,v);
alpar@694: 	  }
alpar@1128: 	  break;
alpar@1128: 	case Heap::POST_HEAP:
alpar@1128: 	  break;
alpar@694: 	}
alpar@694:       }
alpar@694:     }
alpar@1128: 
alpar@1155:     ///Returns \c false if there are nodes to be processed in the priority heap
alpar@1155: 
alpar@1155:     ///Returns \c false if there are nodes to be processed in the priority heap
alpar@1155:     ///
alpar@1155:     bool emptyHeap() { return heap.empty(); }
alpar@1155:     ///Returns the number of the nodes to be processed in the priority heap
alpar@1155: 
alpar@1155:     ///Returns the number of the nodes to be processed in the priority heap
alpar@1155:     ///
alpar@1155:     int heapSize() { return heap.size(); }
alpar@1155:     
alpar@1130:     ///Executes the algorithm.
alpar@1128: 
alpar@1130:     ///Executes the algorithm.
alpar@1128:     ///
alpar@1130:     ///\pre init() must be called and at least one node should be added
alpar@1130:     ///with addSource() before using this function.
alpar@1128:     ///
alpar@1128:     ///This method runs the %Dijkstra algorithm from the root node(s)
alpar@1128:     ///in order to
alpar@1128:     ///compute the
alpar@1128:     ///shortest path to each node. The algorithm computes
alpar@1128:     ///- The shortest path tree.
alpar@1128:     ///- The distance of each node from the root(s).
alpar@1128:     ///
alpar@1128:     void start()
alpar@1128:     {
alpar@1151:       while ( !_heap.empty() ) processNextNode();
alpar@1128:     }
alpar@255:     
alpar@1130:     ///Executes the algorithm until \c dest is reached.
alpar@1128: 
alpar@1130:     ///Executes the algorithm until \c dest is reached.
alpar@1128:     ///
alpar@1130:     ///\pre init() must be called and at least one node should be added
alpar@1130:     ///with addSource() before using this function.
alpar@1128:     ///
alpar@1128:     ///This method runs the %Dijkstra algorithm from the root node(s)
alpar@1128:     ///in order to
alpar@1128:     ///compute the
alpar@1128:     ///shortest path to \c dest. The algorithm computes
alpar@1128:     ///- The shortest path to \c  dest.
alpar@1128:     ///- The distance of \c dest from the root(s).
alpar@1128:     ///
alpar@1128:     void start(Node dest)
alpar@1128:     {
alpar@1151:       while ( !_heap.empty() && _heap.top()!=dest ) processNextNode();
alpar@1130:       if ( _heap.top()==dest ) finalizeNodeData(_heap.top());
alpar@1130:     }
alpar@1130:     
alpar@1130:     ///Executes the algorithm until a condition is met.
alpar@1130: 
alpar@1130:     ///Executes the algorithm until a condition is met.
alpar@1130:     ///
alpar@1130:     ///\pre init() must be called and at least one node should be added
alpar@1130:     ///with addSource() before using this function.
alpar@1130:     ///
alpar@1130:     ///\param nm must be a bool (or convertible) node map. The algorithm
alpar@1130:     ///will stop when it reaches a node \c v with <tt>nm[v]==true</tt>.
alpar@1130:     template<class NM>
alpar@1130:     void start(const NM &nm)
alpar@1130:     {
alpar@1151:       while ( !_heap.empty() && !mn[_heap.top()] ) processNextNode();
alpar@1130:       if ( !_heap.empty() ) finalizeNodeData(_heap.top());
alpar@1128:     }
alpar@1128:     
alpar@1128:     ///Runs %Dijkstra algorithm from node \c s.
alpar@1128:     
alpar@1128:     ///This method runs the %Dijkstra algorithm from a root node \c s
alpar@1128:     ///in order to
alpar@1128:     ///compute the
alpar@1128:     ///shortest path to each node. The algorithm computes
alpar@1128:     ///- The shortest path tree.
alpar@1128:     ///- The distance of each node from the root.
alpar@1128:     ///
alpar@1128:     ///\note d.run(s) is just a shortcut of the following code.
alpar@1128:     ///\code
alpar@1128:     ///  d.init();
alpar@1128:     ///  d.addSource(s);
alpar@1128:     ///  d.start();
alpar@1128:     ///\endcode
alpar@1128:     void run(Node s) {
alpar@1128:       init();
alpar@1128:       addSource(s);
alpar@1128:       start();
alpar@1128:     }
alpar@1128:     
alpar@1130:     ///Finds the shortest path between \c s and \c t.
alpar@1130:     
alpar@1130:     ///Finds the shortest path between \c s and \c t.
alpar@1130:     ///
alpar@1130:     ///\return The length of the shortest s---t path if there exists one,
alpar@1130:     ///0 otherwise.
alpar@1130:     ///\note Apart from the return value, d.run(s) is
alpar@1130:     ///just a shortcut of the following code.
alpar@1130:     ///\code
alpar@1130:     ///  d.init();
alpar@1130:     ///  d.addSource(s);
alpar@1130:     ///  d.start(t);
alpar@1130:     ///\endcode
alpar@1130:     Value run(Node s,Node t) {
alpar@1130:       init();
alpar@1130:       addSource(s);
alpar@1130:       start(t);
alpar@1130:       return (*_pred)[t]==INVALID?0:(*_dist)[t];
alpar@1130:     }
alpar@1130:     
alpar@1128:     ///@}
alpar@1128: 
alpar@1128:     ///\name Query Functions
alpar@1128:     ///The result of the %Dijkstra algorithm can be obtained using these
alpar@1128:     ///functions.\n
alpar@1128:     ///Before the use of these functions,
alpar@1128:     ///either run() or start() must be called.
alpar@1128:     
alpar@1128:     ///@{
alpar@1128: 
jacint@385:     ///The distance of a node from the root.
alpar@255: 
jacint@385:     ///Returns the distance of a node from the root.
alpar@255:     ///\pre \ref run() must be called before using this function.
jacint@385:     ///\warning If node \c v in unreachable from the root the return value
alpar@255:     ///of this funcion is undefined.
alpar@1130:     Value dist(Node v) const { return (*_dist)[v]; }
jacint@373: 
alpar@584:     ///Returns the 'previous edge' of the shortest path tree.
alpar@255: 
alpar@584:     ///For a node \c v it returns the 'previous edge' of the shortest path tree,
alpar@785:     ///i.e. it returns the last edge of a shortest path from the root to \c
alpar@688:     ///v. It is \ref INVALID
alpar@688:     ///if \c v is unreachable from the root or if \c v=s. The
jacint@385:     ///shortest path tree used here is equal to the shortest path tree used in
jacint@385:     ///\ref predNode(Node v).  \pre \ref run() must be called before using
jacint@385:     ///this function.
alpar@780:     ///\todo predEdge could be a better name.
alpar@1119:     Edge pred(Node v) const { return (*_pred)[v]; }
jacint@373: 
alpar@584:     ///Returns the 'previous node' of the shortest path tree.
alpar@255: 
alpar@584:     ///For a node \c v it returns the 'previous node' of the shortest path tree,
jacint@385:     ///i.e. it returns the last but one node from a shortest path from the
jacint@385:     ///root to \c /v. It is INVALID if \c v is unreachable from the root or if
jacint@385:     ///\c v=s. The shortest path tree used here is equal to the shortest path
jacint@385:     ///tree used in \ref pred(Node v).  \pre \ref run() must be called before
jacint@385:     ///using this function.
alpar@1130:     Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
alpar@1130: 				  G->source((*_pred)[v]); }
alpar@255:     
alpar@255:     ///Returns a reference to the NodeMap of distances.
alpar@255: 
jacint@385:     ///Returns a reference to the NodeMap of distances. \pre \ref run() must
jacint@385:     ///be called before using this function.
alpar@1130:     const DistMap &distMap() const { return *_dist;}
jacint@385:  
alpar@255:     ///Returns a reference to the shortest path tree map.
alpar@255: 
alpar@255:     ///Returns a reference to the NodeMap of the edges of the
alpar@255:     ///shortest path tree.
alpar@255:     ///\pre \ref run() must be called before using this function.
alpar@1119:     const PredMap &predMap() const { return *_pred;}
jacint@385:  
jacint@385:     ///Returns a reference to the map of nodes of shortest paths.
alpar@255: 
alpar@255:     ///Returns a reference to the NodeMap of the last but one nodes of the
jacint@385:     ///shortest path tree.
alpar@255:     ///\pre \ref run() must be called before using this function.
alpar@1130:     const PredNodeMap &predNodeMap() const { return *_predNode;}
alpar@255: 
jacint@385:     ///Checks if a node is reachable from the root.
alpar@255: 
jacint@385:     ///Returns \c true if \c v is reachable from the root.
alpar@1128:     ///\warning If the algorithm is started from multiple nodes,
alpar@1128:     ///this function may give false result for the source nodes.
alpar@255:     ///\pre \ref run() must be called before using this function.
jacint@385:     ///
alpar@1119:     bool reached(Node v) { return v==source || (*_pred)[v]!=INVALID; }
alpar@255:     
alpar@1128:     ///@}
alpar@255:   };
alpar@953: 
hegyi@1123:   /// Default traits used by \ref DijkstraWizard
hegyi@1123: 
alpar@1151:   /// To make it easier to use Dijkstra algorithm
alpar@1151:   ///we have created a wizard class.
alpar@1151:   /// This \ref DijkstraWizard class needs default traits,
alpar@1151:   ///as well as the \ref Dijkstra class.
hegyi@1123:   /// The \ref DijkstraWizardBase is a class to be the default traits of the
hegyi@1123:   /// \ref DijkstraWizard class.
alpar@1116:   template<class GR,class LM>
alpar@1116:   class DijkstraWizardBase : public DijkstraDefaultTraits<GR,LM>
alpar@1116:   {
alpar@1116: 
alpar@1116:     typedef DijkstraDefaultTraits<GR,LM> Base;
alpar@1116:   protected:
alpar@1116:     /// Pointer to the underlying graph.
alpar@1116:     void *_g;
alpar@1116:     /// Pointer to the length map
alpar@1116:     void *_length;
alpar@1116:     ///Pointer to the map of predecessors edges.
alpar@1116:     void *_pred;
alpar@1116:     ///Pointer to the map of predecessors nodes.
alpar@1116:     void *_predNode;
alpar@1116:     ///Pointer to the map of distances.
alpar@1116:     void *_dist;
alpar@1116:     ///Pointer to the source node.
alpar@1116:     void *_source;
alpar@1116: 
hegyi@1123:     /// Type of the nodes in the graph.
alpar@1116:     typedef typename Base::Graph::Node Node;
alpar@1116: 
alpar@1116:     public:
hegyi@1123:     /// Constructor.
hegyi@1123:     
hegyi@1123:     /// This constructor does not require parameters, therefore it initiates
hegyi@1123:     /// all of the attributes to default values (0, INVALID).
alpar@1116:     DijkstraWizardBase() : _g(0), _length(0), _pred(0), _predNode(0),
alpar@1116: 		       _dist(0), _source(INVALID) {}
alpar@1116: 
hegyi@1123:     /// Constructor.
hegyi@1123:     
alpar@1156:     /// This constructor requires some parameters,
alpar@1156:     /// listed in the parameters list.
hegyi@1123:     /// Others are initiated to 0.
hegyi@1123:     /// \param g is the initial value of  \ref _g
hegyi@1123:     /// \param l is the initial value of  \ref _length
hegyi@1123:     /// \param s is the initial value of  \ref _source
alpar@1116:     DijkstraWizardBase(const GR &g,const LM &l, Node s=INVALID) :
alpar@1116:       _g((void *)&g), _length((void *)&l), _pred(0), _predNode(0),
alpar@1116: 		  _dist(0), _source((void *)&s) {}
alpar@1116: 
alpar@1116:   };
alpar@1116:   
hegyi@1123:   /// A class to make easier the usage of Dijkstra algorithm
alpar@953: 
alpar@1151:   /// \ingroup flowalgs
hegyi@1123:   /// This class is created to make it easier to use Dijkstra algorithm.
hegyi@1123:   /// It uses the functions and features of the plain \ref Dijkstra,
alpar@1151:   /// but it is much simpler to use it.
alpar@953:   ///
hegyi@1123:   /// Simplicity means that the way to change the types defined
hegyi@1123:   /// in the traits class is based on functions that returns the new class
alpar@1151:   /// and not on templatable built-in classes.
alpar@1151:   /// When using the plain \ref Dijkstra
alpar@1151:   /// the new class with the modified type comes from
alpar@1151:   /// the original class by using the ::
alpar@1151:   /// operator. In the case of \ref DijkstraWizard only
alpar@1151:   /// a function have to be called and it will
hegyi@1123:   /// return the needed class.
hegyi@1123:   ///
hegyi@1123:   /// It does not have own \ref run method. When its \ref run method is called
hegyi@1123:   /// it initiates a plain \ref Dijkstra class, and calls the \ref Dijkstra::run
hegyi@1123:   /// method of it.
alpar@953:   template<class TR>
alpar@1116:   class DijkstraWizard : public TR
alpar@953:   {
alpar@1116:     typedef TR Base;
alpar@953: 
hegyi@1123:     ///The type of the underlying graph.
alpar@953:     typedef typename TR::Graph Graph;
alpar@1119:     //\e
alpar@953:     typedef typename Graph::Node Node;
alpar@1119:     //\e
alpar@953:     typedef typename Graph::NodeIt NodeIt;
alpar@1119:     //\e
alpar@953:     typedef typename Graph::Edge Edge;
alpar@1119:     //\e
alpar@953:     typedef typename Graph::OutEdgeIt OutEdgeIt;
alpar@953:     
hegyi@1123:     ///The type of the map that stores the edge lengths.
alpar@953:     typedef typename TR::LengthMap LengthMap;
hegyi@1123:     ///The type of the length of the edges.
alpar@987:     typedef typename LengthMap::Value Value;
hegyi@1123:     ///\brief The type of the map that stores the last
hegyi@1123:     ///edges of the shortest paths.
alpar@953:     typedef typename TR::PredMap PredMap;
hegyi@1123:     ///\brief The type of the map that stores the last but one
hegyi@1123:     ///nodes of the shortest paths.
alpar@953:     typedef typename TR::PredNodeMap PredNodeMap;
hegyi@1123:     ///The type of the map that stores the dists of the nodes.
alpar@953:     typedef typename TR::DistMap DistMap;
alpar@953: 
hegyi@1123:     ///The heap type used by the dijkstra algorithm.
alpar@953:     typedef typename TR::Heap Heap;
alpar@1116: public:
hegyi@1123:     /// Constructor.
alpar@1116:     DijkstraWizard() : TR() {}
alpar@953: 
hegyi@1123:     /// Constructor that requires parameters.
hegyi@1124: 
hegyi@1124:     /// Constructor that requires parameters.
hegyi@1123:     /// These parameters will be the default values for the traits class.
alpar@1116:     DijkstraWizard(const Graph &g,const LengthMap &l, Node s=INVALID) :
alpar@1116:       TR(g,l,s) {}
alpar@953: 
hegyi@1123:     ///Copy constructor
alpar@1116:     DijkstraWizard(const TR &b) : TR(b) {}
alpar@953: 
alpar@1116:     ~DijkstraWizard() {}
alpar@1116: 
hegyi@1123:     ///Runs Dijkstra algorithm from a given node.
hegyi@1123:     
hegyi@1123:     ///Runs Dijkstra algorithm from a given node.
hegyi@1123:     ///The node can be given by the \ref source function.
alpar@1116:     void run()
alpar@953:     {
alpar@1126:       if(_source==0) throw UninitializedParameter();
alpar@1116:       Dijkstra<Graph,LengthMap,TR> Dij(*(Graph*)_g,*(LengthMap*)_length);
alpar@1116:       if(_pred) Dij.predMap(*(PredMap*)_pred);
alpar@1116:       if(_predNode) Dij.predNodeMap(*(PredNodeMap*)_predNode);
alpar@1116:       if(_dist) Dij.distMap(*(DistMap*)_dist);
alpar@1116:       Dij.run(*(Node*)_source);
alpar@1116:     }
alpar@1116: 
hegyi@1124:     ///Runs Dijkstra algorithm from the given node.
hegyi@1123: 
hegyi@1124:     ///Runs Dijkstra algorithm from the given node.
hegyi@1123:     ///\param s is the given source.
alpar@1116:     void run(Node s)
alpar@1116:     {
alpar@1116:       _source=(void *)&s;
alpar@1116:       run();
alpar@953:     }
alpar@953: 
alpar@953:     template<class T>
alpar@1116:     struct DefPredMapBase : public Base {
alpar@1116:       typedef T PredMap;
alpar@1117:       static PredMap *createPredMap(const Graph &G) { return 0; };
alpar@1117:       DefPredMapBase(const Base &b) : Base(b) {}
alpar@1116:     };
alpar@953:     
alpar@1156:     ///\brief \ref named-templ-param "Named parameter"
alpar@1156:     ///function for setting PredMap type
alpar@1156:     ///
alpar@1156:     /// \ref named-templ-param "Named parameter"
alpar@1156:     ///function for setting PredMap type
hegyi@1124:     ///
alpar@953:     template<class T>
alpar@1116:     DijkstraWizard<DefPredMapBase<T> > predMap(const T &t) 
alpar@953:     {
alpar@1116:       _pred=(void *)&t;
alpar@1116:       return DijkstraWizard<DefPredMapBase<T> >(*this);
alpar@953:     }
alpar@953:     
alpar@1116: 
alpar@953:     template<class T>
alpar@1116:     struct DefPredNodeMapBase : public Base {
alpar@1116:       typedef T PredNodeMap;
alpar@1117:       static PredNodeMap *createPredNodeMap(const Graph &G) { return 0; };
alpar@1117:       DefPredNodeMapBase(const Base &b) : Base(b) {}
alpar@1116:     };
alpar@1116:     
alpar@1156:     ///\brief \ref named-templ-param "Named parameter"
alpar@1156:     ///function for setting PredNodeMap type
alpar@1156:     ///
alpar@1156:     /// \ref named-templ-param "Named parameter"
alpar@1156:     ///function for setting PredNodeMap type
hegyi@1124:     ///
alpar@953:     template<class T>
alpar@1116:     DijkstraWizard<DefPredNodeMapBase<T> > predNodeMap(const T &t) 
alpar@953:     {
alpar@1116:       _predNode=(void *)&t;
alpar@1116:       return DijkstraWizard<DefPredNodeMapBase<T> >(*this);
alpar@953:     }
alpar@1116:    
alpar@1116:     template<class T>
alpar@1116:     struct DefDistMapBase : public Base {
alpar@1116:       typedef T DistMap;
alpar@1117:       static DistMap *createDistMap(const Graph &G) { return 0; };
alpar@1117:       DefDistMapBase(const Base &b) : Base(b) {}
alpar@1116:     };
alpar@953:     
alpar@1156:     ///\brief \ref named-templ-param "Named parameter"
alpar@1156:     ///function for setting DistMap type
alpar@1156:     ///
alpar@1156:     /// \ref named-templ-param "Named parameter"
alpar@1156:     ///function for setting DistMap type
hegyi@1124:     ///
alpar@953:     template<class T>
alpar@1116:     DijkstraWizard<DefDistMapBase<T> > distMap(const T &t) 
alpar@953:     {
alpar@1116:       _dist=(void *)&t;
alpar@1116:       return DijkstraWizard<DefDistMapBase<T> >(*this);
alpar@953:     }
alpar@1117:     
hegyi@1123:     /// Sets the source node, from which the Dijkstra algorithm runs.
hegyi@1123: 
hegyi@1123:     /// Sets the source node, from which the Dijkstra algorithm runs.
hegyi@1123:     /// \param s is the source node.
alpar@1117:     DijkstraWizard<TR> &source(Node s) 
alpar@953:     {
alpar@1116:       source=(void *)&s;
alpar@953:       return *this;
alpar@953:     }
alpar@953:     
alpar@953:   };
alpar@255:   
alpar@953:   ///\e
alpar@953: 
alpar@1151:   /// \ingroup flowalgs
alpar@954:   ///\todo Please document...
alpar@953:   ///
alpar@953:   template<class GR, class LM>
alpar@1116:   DijkstraWizard<DijkstraWizardBase<GR,LM> >
alpar@1116:   dijkstra(const GR &g,const LM &l,typename GR::Node s=INVALID)
alpar@953:   {
alpar@1116:     return DijkstraWizard<DijkstraWizardBase<GR,LM> >(g,l,s);
alpar@953:   }
alpar@953: 
alpar@430: /// @}
alpar@255:   
alpar@921: } //END OF NAMESPACE LEMON
alpar@255: 
alpar@255: #endif
alpar@255: