Fix compilation error when NDEBUG is defined.
1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
3 * This file is a part of LEMON, a generic C++ optimization library.
5 * Copyright (C) 2003-2008
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
9 * Permission to use, modify and distribute this software is granted
10 * provided that this copyright notice appears in all copies. For
11 * precise terms see the accompanying LICENSE file.
13 * This software is provided "AS IS" with no warranty of any kind,
14 * express or implied, and with no claim as to its suitability for any
19 #ifndef LEMON_DIJKSTRA_H
20 #define LEMON_DIJKSTRA_H
22 ///\ingroup shortest_path
24 ///\brief Dijkstra algorithm.
27 #include <lemon/list_graph.h>
28 #include <lemon/bin_heap.h>
29 #include <lemon/bits/path_dump.h>
30 #include <lemon/bits/invalid.h>
31 #include <lemon/error.h>
32 #include <lemon/maps.h>
36 /// \brief Default OperationTraits for the Dijkstra algorithm class.
38 /// It defines all computational operations and constants which are
39 /// used in the Dijkstra algorithm.
40 template <typename Value>
41 struct DijkstraDefaultOperationTraits {
42 /// \brief Gives back the zero value of the type.
44 return static_cast<Value>(0);
46 /// \brief Gives back the sum of the given two elements.
47 static Value plus(const Value& left, const Value& right) {
50 /// \brief Gives back true only if the first value less than the second.
51 static bool less(const Value& left, const Value& right) {
56 /// \brief Widest path OperationTraits for the Dijkstra algorithm class.
58 /// It defines all computational operations and constants which are
59 /// used in the Dijkstra algorithm for widest path computation.
60 template <typename Value>
61 struct DijkstraWidestPathOperationTraits {
62 /// \brief Gives back the maximum value of the type.
64 return std::numeric_limits<Value>::max();
66 /// \brief Gives back the minimum of the given two elements.
67 static Value plus(const Value& left, const Value& right) {
68 return std::min(left, right);
70 /// \brief Gives back true only if the first value less than the second.
71 static bool less(const Value& left, const Value& right) {
76 ///Default traits class of Dijkstra class.
78 ///Default traits class of Dijkstra class.
79 ///\tparam GR Digraph type.
80 ///\tparam LM Type of length map.
81 template<class GR, class LM>
82 struct DijkstraDefaultTraits
84 ///The digraph type the algorithm runs on.
86 ///The type of the map that stores the arc lengths.
88 ///The type of the map that stores the arc lengths.
89 ///It must meet the \ref concepts::ReadMap "ReadMap" concept.
91 //The type of the length of the arcs.
92 typedef typename LM::Value Value;
93 /// Operation traits for Dijkstra algorithm.
95 /// It defines the used operation by the algorithm.
96 /// \see DijkstraDefaultOperationTraits
97 typedef DijkstraDefaultOperationTraits<Value> OperationTraits;
98 /// The cross reference type used by heap.
101 /// The cross reference type used by heap.
102 /// Usually it is \c Digraph::NodeMap<int>.
103 typedef typename Digraph::template NodeMap<int> HeapCrossRef;
104 ///Instantiates a HeapCrossRef.
106 ///This function instantiates a \c HeapCrossRef.
107 /// \param G is the digraph, to which we would like to define the
109 static HeapCrossRef *createHeapCrossRef(const GR &G)
111 return new HeapCrossRef(G);
114 ///The heap type used by Dijkstra algorithm.
116 ///The heap type used by Dijkstra algorithm.
120 typedef BinHeap<typename LM::Value, HeapCrossRef, std::less<Value> > Heap;
122 static Heap *createHeap(HeapCrossRef& R)
127 ///\brief The type of the map that stores the last
128 ///arcs of the shortest paths.
130 ///The type of the map that stores the last
131 ///arcs of the shortest paths.
132 ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
134 typedef typename Digraph::template NodeMap<typename GR::Arc> PredMap;
135 ///Instantiates a PredMap.
137 ///This function instantiates a \c PredMap.
138 ///\param G is the digraph, to which we would like to define the PredMap.
139 ///\todo The digraph alone may be insufficient for the initialization
140 static PredMap *createPredMap(const GR &G)
142 return new PredMap(G);
145 ///The type of the map that stores whether a nodes is processed.
147 ///The type of the map that stores whether a nodes is processed.
148 ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
149 ///By default it is a NullMap.
150 ///\todo If it is set to a real map,
151 ///Dijkstra::processed() should read this.
152 ///\todo named parameter to set this type, function to read and write.
153 typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
154 ///Instantiates a ProcessedMap.
156 ///This function instantiates a \c ProcessedMap.
157 ///\param g is the digraph, to which
158 ///we would like to define the \c ProcessedMap
160 static ProcessedMap *createProcessedMap(const GR &g)
162 static ProcessedMap *createProcessedMap(const GR &)
165 return new ProcessedMap();
167 ///The type of the map that stores the dists of the nodes.
169 ///The type of the map that stores the dists of the nodes.
170 ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
172 typedef typename Digraph::template NodeMap<typename LM::Value> DistMap;
173 ///Instantiates a DistMap.
175 ///This function instantiates a \ref DistMap.
176 ///\param G is the digraph, to which we would like to define
178 static DistMap *createDistMap(const GR &G)
180 return new DistMap(G);
184 ///%Dijkstra algorithm class.
186 /// \ingroup shortest_path
187 ///This class provides an efficient implementation of %Dijkstra algorithm.
188 ///The arc lengths are passed to the algorithm using a
189 ///\ref concepts::ReadMap "ReadMap",
190 ///so it is easy to change it to any kind of length.
192 ///The type of the length is determined by the
193 ///\ref concepts::ReadMap::Value "Value" of the length map.
195 ///It is also possible to change the underlying priority heap.
197 ///\tparam GR The digraph type the algorithm runs on. The default value
198 ///is \ref ListDigraph. The value of GR is not used directly by
199 ///Dijkstra, it is only passed to \ref DijkstraDefaultTraits.
200 ///\tparam LM This read-only ArcMap determines the lengths of the
201 ///arcs. It is read once for each arc, so the map may involve in
202 ///relatively time consuming process to compute the arc length if
203 ///it is necessary. The default map type is \ref
204 ///concepts::Digraph::ArcMap "Digraph::ArcMap<int>". The value
205 ///of LM is not used directly by Dijkstra, it is only passed to \ref
206 ///DijkstraDefaultTraits.
207 ///\tparam TR Traits class to set
208 ///various data types used by the algorithm. The default traits
209 ///class is \ref DijkstraDefaultTraits
210 ///"DijkstraDefaultTraits<GR,LM>". See \ref
211 ///DijkstraDefaultTraits for the documentation of a Dijkstra traits
215 template <typename GR, typename LM, typename TR>
217 template <typename GR=ListDigraph,
218 typename LM=typename GR::template ArcMap<int>,
219 typename TR=DijkstraDefaultTraits<GR,LM> >
224 * \brief \ref Exception for uninitialized parameters.
226 * This error represents problems in the initialization
227 * of the parameters of the algorithms.
229 class UninitializedParameter : public lemon::UninitializedParameter {
231 virtual const char* what() const throw() {
232 return "lemon::Dijkstra::UninitializedParameter";
237 ///The type of the underlying digraph.
238 typedef typename TR::Digraph Digraph;
240 typedef typename Digraph::Node Node;
242 typedef typename Digraph::NodeIt NodeIt;
244 typedef typename Digraph::Arc Arc;
246 typedef typename Digraph::OutArcIt OutArcIt;
248 ///The type of the length of the arcs.
249 typedef typename TR::LengthMap::Value Value;
250 ///The type of the map that stores the arc lengths.
251 typedef typename TR::LengthMap LengthMap;
252 ///\brief The type of the map that stores the last
253 ///arcs of the shortest paths.
254 typedef typename TR::PredMap PredMap;
255 ///The type of the map indicating if a node is processed.
256 typedef typename TR::ProcessedMap ProcessedMap;
257 ///The type of the map that stores the dists of the nodes.
258 typedef typename TR::DistMap DistMap;
259 ///The cross reference type used for the current heap.
260 typedef typename TR::HeapCrossRef HeapCrossRef;
261 ///The heap type used by the dijkstra algorithm.
262 typedef typename TR::Heap Heap;
263 ///The operation traits.
264 typedef typename TR::OperationTraits OperationTraits;
266 /// Pointer to the underlying digraph.
268 /// Pointer to the length map
269 const LengthMap *length;
270 ///Pointer to the map of predecessors arcs.
272 ///Indicates if \ref _pred is locally allocated (\c true) or not.
274 ///Pointer to the map of distances.
276 ///Indicates if \ref _dist is locally allocated (\c true) or not.
278 ///Pointer to the map of processed status of the nodes.
279 ProcessedMap *_processed;
280 ///Indicates if \ref _processed is locally allocated (\c true) or not.
281 bool local_processed;
282 ///Pointer to the heap cross references.
283 HeapCrossRef *_heap_cross_ref;
284 ///Indicates if \ref _heap_cross_ref is locally allocated (\c true) or not.
285 bool local_heap_cross_ref;
286 ///Pointer to the heap.
288 ///Indicates if \ref _heap is locally allocated (\c true) or not.
291 ///Creates the maps if necessary.
293 ///\todo Better memory allocation (instead of new).
298 _pred = Traits::createPredMap(*G);
302 _dist = Traits::createDistMap(*G);
305 local_processed = true;
306 _processed = Traits::createProcessedMap(*G);
308 if (!_heap_cross_ref) {
309 local_heap_cross_ref = true;
310 _heap_cross_ref = Traits::createHeapCrossRef(*G);
314 _heap = Traits::createHeap(*_heap_cross_ref);
320 typedef Dijkstra Create;
322 ///\name Named template parameters
327 struct DefPredMapTraits : public Traits {
329 static PredMap *createPredMap(const Digraph &)
331 throw UninitializedParameter();
334 ///\ref named-templ-param "Named parameter" for setting PredMap type
336 ///\ref named-templ-param "Named parameter" for setting PredMap type
340 : public Dijkstra< Digraph, LengthMap, DefPredMapTraits<T> > {
341 typedef Dijkstra< Digraph, LengthMap, DefPredMapTraits<T> > Create;
345 struct DefDistMapTraits : public Traits {
347 static DistMap *createDistMap(const Digraph &)
349 throw UninitializedParameter();
352 ///\ref named-templ-param "Named parameter" for setting DistMap type
354 ///\ref named-templ-param "Named parameter" for setting DistMap type
358 : public Dijkstra< Digraph, LengthMap, DefDistMapTraits<T> > {
359 typedef Dijkstra< Digraph, LengthMap, DefDistMapTraits<T> > Create;
363 struct DefProcessedMapTraits : public Traits {
364 typedef T ProcessedMap;
365 static ProcessedMap *createProcessedMap(const Digraph &G)
367 throw UninitializedParameter();
370 ///\ref named-templ-param "Named parameter" for setting ProcessedMap type
372 ///\ref named-templ-param "Named parameter" for setting ProcessedMap type
375 struct DefProcessedMap
376 : public Dijkstra< Digraph, LengthMap, DefProcessedMapTraits<T> > {
377 typedef Dijkstra< Digraph, LengthMap, DefProcessedMapTraits<T> > Create;
380 struct DefDigraphProcessedMapTraits : public Traits {
381 typedef typename Digraph::template NodeMap<bool> ProcessedMap;
382 static ProcessedMap *createProcessedMap(const Digraph &G)
384 return new ProcessedMap(G);
387 ///\brief \ref named-templ-param "Named parameter"
388 ///for setting the ProcessedMap type to be Digraph::NodeMap<bool>.
390 ///\ref named-templ-param "Named parameter"
391 ///for setting the ProcessedMap type to be Digraph::NodeMap<bool>.
392 ///If you don't set it explicitely, it will be automatically allocated.
394 struct DefProcessedMapToBeDefaultMap
395 : public Dijkstra< Digraph, LengthMap, DefDigraphProcessedMapTraits> {
396 typedef Dijkstra< Digraph, LengthMap, DefDigraphProcessedMapTraits>
400 template <class H, class CR>
401 struct DefHeapTraits : public Traits {
402 typedef CR HeapCrossRef;
404 static HeapCrossRef *createHeapCrossRef(const Digraph &) {
405 throw UninitializedParameter();
407 static Heap *createHeap(HeapCrossRef &)
409 throw UninitializedParameter();
412 ///\brief \ref named-templ-param "Named parameter" for setting
413 ///heap and cross reference type
415 ///\ref named-templ-param "Named parameter" for setting heap and cross
418 template <class H, class CR = typename Digraph::template NodeMap<int> >
420 : public Dijkstra< Digraph, LengthMap, DefHeapTraits<H, CR> > {
421 typedef Dijkstra< Digraph, LengthMap, DefHeapTraits<H, CR> > Create;
424 template <class H, class CR>
425 struct DefStandardHeapTraits : public Traits {
426 typedef CR HeapCrossRef;
428 static HeapCrossRef *createHeapCrossRef(const Digraph &G) {
429 return new HeapCrossRef(G);
431 static Heap *createHeap(HeapCrossRef &R)
436 ///\brief \ref named-templ-param "Named parameter" for setting
437 ///heap and cross reference type with automatic allocation
439 ///\ref named-templ-param "Named parameter" for setting heap and cross
440 ///reference type. It can allocate the heap and the cross reference
441 ///object if the cross reference's constructor waits for the digraph as
442 ///parameter and the heap's constructor waits for the cross reference.
443 template <class H, class CR = typename Digraph::template NodeMap<int> >
444 struct DefStandardHeap
445 : public Dijkstra< Digraph, LengthMap, DefStandardHeapTraits<H, CR> > {
446 typedef Dijkstra< Digraph, LengthMap, DefStandardHeapTraits<H, CR> >
451 struct DefOperationTraitsTraits : public Traits {
452 typedef T OperationTraits;
455 /// \brief \ref named-templ-param "Named parameter" for setting
456 /// OperationTraits type
458 /// \ref named-templ-param "Named parameter" for setting OperationTraits
461 struct DefOperationTraits
462 : public Dijkstra<Digraph, LengthMap, DefOperationTraitsTraits<T> > {
463 typedef Dijkstra<Digraph, LengthMap, DefOperationTraitsTraits<T> >
478 ///\param _G the digraph the algorithm will run on.
479 ///\param _length the length map used by the algorithm.
480 Dijkstra(const Digraph& _G, const LengthMap& _length) :
481 G(&_G), length(&_length),
482 _pred(NULL), local_pred(false),
483 _dist(NULL), local_dist(false),
484 _processed(NULL), local_processed(false),
485 _heap_cross_ref(NULL), local_heap_cross_ref(false),
486 _heap(NULL), local_heap(false)
492 if(local_pred) delete _pred;
493 if(local_dist) delete _dist;
494 if(local_processed) delete _processed;
495 if(local_heap_cross_ref) delete _heap_cross_ref;
496 if(local_heap) delete _heap;
499 ///Sets the length map.
501 ///Sets the length map.
502 ///\return <tt> (*this) </tt>
503 Dijkstra &lengthMap(const LengthMap &m)
509 ///Sets the map storing the predecessor arcs.
511 ///Sets the map storing the predecessor arcs.
512 ///If you don't use this function before calling \ref run(),
513 ///it will allocate one. The destuctor deallocates this
514 ///automatically allocated map, of course.
515 ///\return <tt> (*this) </tt>
516 Dijkstra &predMap(PredMap &m)
526 ///Sets the map storing the distances calculated by the algorithm.
528 ///Sets the map storing the distances calculated by the algorithm.
529 ///If you don't use this function before calling \ref run(),
530 ///it will allocate one. The destuctor deallocates this
531 ///automatically allocated map, of course.
532 ///\return <tt> (*this) </tt>
533 Dijkstra &distMap(DistMap &m)
543 ///Sets the heap and the cross reference used by algorithm.
545 ///Sets the heap and the cross reference used by algorithm.
546 ///If you don't use this function before calling \ref run(),
547 ///it will allocate one. The destuctor deallocates this
548 ///automatically allocated heap and cross reference, of course.
549 ///\return <tt> (*this) </tt>
550 Dijkstra &heap(Heap& hp, HeapCrossRef &cr)
552 if(local_heap_cross_ref) {
553 delete _heap_cross_ref;
554 local_heap_cross_ref=false;
556 _heap_cross_ref = &cr;
566 void finalizeNodeData(Node v,Value dst)
568 _processed->set(v,true);
574 typedef PredMapPath<Digraph, PredMap> Path;
576 ///\name Execution control
577 ///The simplest way to execute the algorithm is to use
578 ///one of the member functions called \c run(...).
580 ///If you need more control on the execution,
581 ///first you must call \ref init(), then you can add several source nodes
582 ///with \ref addSource().
583 ///Finally \ref start() will perform the actual path
588 ///Initializes the internal data structures.
590 ///Initializes the internal data structures.
596 for ( NodeIt u(*G) ; u!=INVALID ; ++u ) {
597 _pred->set(u,INVALID);
598 _processed->set(u,false);
599 _heap_cross_ref->set(u,Heap::PRE_HEAP);
603 ///Adds a new source node.
605 ///Adds a new source node to the priority heap.
607 ///The optional second parameter is the initial distance of the node.
609 ///It checks if the node has already been added to the heap and
610 ///it is pushed to the heap only if either it was not in the heap
611 ///or the shortest path found till then is shorter than \c dst.
612 void addSource(Node s,Value dst=OperationTraits::zero())
614 if(_heap->state(s) != Heap::IN_HEAP) {
616 } else if(OperationTraits::less((*_heap)[s], dst)) {
618 _pred->set(s,INVALID);
622 ///Processes the next node in the priority heap
624 ///Processes the next node in the priority heap.
626 ///\return The processed node.
628 ///\warning The priority heap must not be empty!
629 Node processNextNode()
632 Value oldvalue=_heap->prio();
634 finalizeNodeData(v,oldvalue);
636 for(OutArcIt e(*G,v); e!=INVALID; ++e) {
638 switch(_heap->state(w)) {
640 _heap->push(w,OperationTraits::plus(oldvalue, (*length)[e]));
645 Value newvalue = OperationTraits::plus(oldvalue, (*length)[e]);
646 if ( OperationTraits::less(newvalue, (*_heap)[w]) ) {
647 _heap->decrease(w, newvalue);
652 case Heap::POST_HEAP:
659 ///Next node to be processed.
661 ///Next node to be processed.
663 ///\return The next node to be processed or INVALID if the priority heap
667 return !_heap->empty()?_heap->top():INVALID;
670 ///\brief Returns \c false if there are nodes
671 ///to be processed in the priority heap
673 ///Returns \c false if there are nodes
674 ///to be processed in the priority heap
675 bool emptyQueue() { return _heap->empty(); }
676 ///Returns the number of the nodes to be processed in the priority heap
678 ///Returns the number of the nodes to be processed in the priority heap
680 int queueSize() { return _heap->size(); }
682 ///Executes the algorithm.
684 ///Executes the algorithm.
686 ///\pre init() must be called and at least one node should be added
687 ///with addSource() before using this function.
689 ///This method runs the %Dijkstra algorithm from the root node(s)
692 ///shortest path to each node. The algorithm computes
693 ///- The shortest path tree.
694 ///- The distance of each node from the root(s).
698 while ( !_heap->empty() ) processNextNode();
701 ///Executes the algorithm until \c dest is reached.
703 ///Executes the algorithm until \c dest is reached.
705 ///\pre init() must be called and at least one node should be added
706 ///with addSource() before using this function.
708 ///This method runs the %Dijkstra algorithm from the root node(s)
711 ///shortest path to \c dest. The algorithm computes
712 ///- The shortest path to \c dest.
713 ///- The distance of \c dest from the root(s).
715 void start(Node dest)
717 while ( !_heap->empty() && _heap->top()!=dest ) processNextNode();
718 if ( !_heap->empty() ) finalizeNodeData(_heap->top(),_heap->prio());
721 ///Executes the algorithm until a condition is met.
723 ///Executes the algorithm until a condition is met.
725 ///\pre init() must be called and at least one node should be added
726 ///with addSource() before using this function.
728 ///\param nm must be a bool (or convertible) node map. The algorithm
729 ///will stop when it reaches a node \c v with <tt>nm[v]</tt> true.
731 ///\return The reached node \c v with <tt>nm[v]</tt> true or
732 ///\c INVALID if no such node was found.
733 template<class NodeBoolMap>
734 Node start(const NodeBoolMap &nm)
736 while ( !_heap->empty() && !nm[_heap->top()] ) processNextNode();
737 if ( _heap->empty() ) return INVALID;
738 finalizeNodeData(_heap->top(),_heap->prio());
742 ///Runs %Dijkstra algorithm from node \c s.
744 ///This method runs the %Dijkstra algorithm from a root node \c s
747 ///shortest path to each node. The algorithm computes
748 ///- The shortest path tree.
749 ///- The distance of each node from the root.
751 ///\note d.run(s) is just a shortcut of the following code.
763 ///Finds the shortest path between \c s and \c t.
765 ///Finds the shortest path between \c s and \c t.
767 ///\return The length of the shortest s---t path if there exists one,
769 ///\note Apart from the return value, d.run(s) is
770 ///just a shortcut of the following code.
776 Value run(Node s,Node t) {
780 return (*_pred)[t]==INVALID?OperationTraits::zero():(*_dist)[t];
785 ///\name Query Functions
786 ///The result of the %Dijkstra algorithm can be obtained using these
788 ///Before the use of these functions,
789 ///either run() or start() must be called.
793 ///Gives back the shortest path.
795 ///Gives back the shortest path.
796 ///\pre The \c t should be reachable from the source.
799 return Path(*G, *_pred, t);
802 ///The distance of a node from the root.
804 ///Returns the distance of a node from the root.
805 ///\pre \ref run() must be called before using this function.
806 ///\warning If node \c v in unreachable from the root the return value
807 ///of this funcion is undefined.
808 Value dist(Node v) const { return (*_dist)[v]; }
810 ///The current distance of a node from the root.
812 ///Returns the current distance of a node from the root.
813 ///It may be decreased in the following processes.
814 ///\pre \c node should be reached but not processed
815 Value currentDist(Node v) const { return (*_heap)[v]; }
817 ///Returns the 'previous arc' of the shortest path tree.
819 ///For a node \c v it returns the 'previous arc' of the shortest path tree,
820 ///i.e. it returns the last arc of a shortest path from the root to \c
821 ///v. It is \ref INVALID
822 ///if \c v is unreachable from the root or if \c v=s. The
823 ///shortest path tree used here is equal to the shortest path tree used in
824 ///\ref predNode(). \pre \ref run() must be called before using
826 Arc predArc(Node v) const { return (*_pred)[v]; }
828 ///Returns the 'previous node' of the shortest path tree.
830 ///For a node \c v it returns the 'previous node' of the shortest path tree,
831 ///i.e. it returns the last but one node from a shortest path from the
832 ///root to \c /v. It is INVALID if \c v is unreachable from the root or if
833 ///\c v=s. The shortest path tree used here is equal to the shortest path
834 ///tree used in \ref predArc(). \pre \ref run() must be called before
835 ///using this function.
836 Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
837 G->source((*_pred)[v]); }
839 ///Returns a reference to the NodeMap of distances.
841 ///Returns a reference to the NodeMap of distances. \pre \ref run() must
842 ///be called before using this function.
843 const DistMap &distMap() const { return *_dist;}
845 ///Returns a reference to the shortest path tree map.
847 ///Returns a reference to the NodeMap of the arcs of the
848 ///shortest path tree.
849 ///\pre \ref run() must be called before using this function.
850 const PredMap &predMap() const { return *_pred;}
852 ///Checks if a node is reachable from the root.
854 ///Returns \c true if \c v is reachable from the root.
855 ///\warning The source nodes are inditated as unreached.
856 ///\pre \ref run() must be called before using this function.
858 bool reached(Node v) { return (*_heap_cross_ref)[v] != Heap::PRE_HEAP; }
860 ///Checks if a node is processed.
862 ///Returns \c true if \c v is processed, i.e. the shortest
863 ///path to \c v has already found.
864 ///\pre \ref run() must be called before using this function.
866 bool processed(Node v) { return (*_heap_cross_ref)[v] == Heap::POST_HEAP; }
875 ///Default traits class of Dijkstra function.
877 ///Default traits class of Dijkstra function.
878 ///\tparam GR Digraph type.
879 ///\tparam LM Type of length map.
880 template<class GR, class LM>
881 struct DijkstraWizardDefaultTraits
883 ///The digraph type the algorithm runs on.
885 ///The type of the map that stores the arc lengths.
887 ///The type of the map that stores the arc lengths.
888 ///It must meet the \ref concepts::ReadMap "ReadMap" concept.
889 typedef LM LengthMap;
890 //The type of the length of the arcs.
891 typedef typename LM::Value Value;
892 /// Operation traits for Dijkstra algorithm.
894 /// It defines the used operation by the algorithm.
895 /// \see DijkstraDefaultOperationTraits
896 typedef DijkstraDefaultOperationTraits<Value> OperationTraits;
897 ///The heap type used by Dijkstra algorithm.
899 /// The cross reference type used by heap.
901 /// The cross reference type used by heap.
902 /// Usually it is \c Digraph::NodeMap<int>.
903 typedef typename Digraph::template NodeMap<int> HeapCrossRef;
904 ///Instantiates a HeapCrossRef.
906 ///This function instantiates a \ref HeapCrossRef.
907 /// \param G is the digraph, to which we would like to define the
909 /// \todo The digraph alone may be insufficient for the initialization
910 static HeapCrossRef *createHeapCrossRef(const GR &G)
912 return new HeapCrossRef(G);
915 ///The heap type used by Dijkstra algorithm.
917 ///The heap type used by Dijkstra algorithm.
921 typedef BinHeap<typename LM::Value, typename GR::template NodeMap<int>,
922 std::less<Value> > Heap;
924 static Heap *createHeap(HeapCrossRef& R)
929 ///\brief The type of the map that stores the last
930 ///arcs of the shortest paths.
932 ///The type of the map that stores the last
933 ///arcs of the shortest paths.
934 ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
936 typedef NullMap <typename GR::Node,typename GR::Arc> PredMap;
937 ///Instantiates a PredMap.
939 ///This function instantiates a \ref PredMap.
940 ///\param g is the digraph, to which we would like to define the PredMap.
941 ///\todo The digraph alone may be insufficient for the initialization
943 static PredMap *createPredMap(const GR &g)
945 static PredMap *createPredMap(const GR &)
948 return new PredMap();
950 ///The type of the map that stores whether a nodes is processed.
952 ///The type of the map that stores whether a nodes is processed.
953 ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
954 ///By default it is a NullMap.
955 ///\todo If it is set to a real map,
956 ///Dijkstra::processed() should read this.
957 ///\todo named parameter to set this type, function to read and write.
958 typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
959 ///Instantiates a ProcessedMap.
961 ///This function instantiates a \ref ProcessedMap.
962 ///\param g is the digraph, to which
963 ///we would like to define the \ref ProcessedMap
965 static ProcessedMap *createProcessedMap(const GR &g)
967 static ProcessedMap *createProcessedMap(const GR &)
970 return new ProcessedMap();
972 ///The type of the map that stores the dists of the nodes.
974 ///The type of the map that stores the dists of the nodes.
975 ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
977 typedef NullMap<typename Digraph::Node,typename LM::Value> DistMap;
978 ///Instantiates a DistMap.
980 ///This function instantiates a \ref DistMap.
981 ///\param g is the digraph, to which we would like to define
984 static DistMap *createDistMap(const GR &g)
986 static DistMap *createDistMap(const GR &)
989 return new DistMap();
993 /// Default traits used by \ref DijkstraWizard
995 /// To make it easier to use Dijkstra algorithm
996 ///we have created a wizard class.
997 /// This \ref DijkstraWizard class needs default traits,
998 ///as well as the \ref Dijkstra class.
999 /// The \ref DijkstraWizardBase is a class to be the default traits of the
1000 /// \ref DijkstraWizard class.
1001 /// \todo More named parameters are required...
1002 template<class GR,class LM>
1003 class DijkstraWizardBase : public DijkstraWizardDefaultTraits<GR,LM>
1006 typedef DijkstraWizardDefaultTraits<GR,LM> Base;
1008 /// Type of the nodes in the digraph.
1009 typedef typename Base::Digraph::Node Node;
1011 /// Pointer to the underlying digraph.
1013 /// Pointer to the length map
1015 ///Pointer to the map of predecessors arcs.
1017 ///Pointer to the map of distances.
1019 ///Pointer to the source node.
1025 /// This constructor does not require parameters, therefore it initiates
1026 /// all of the attributes to default values (0, INVALID).
1027 DijkstraWizardBase() : _g(0), _length(0), _pred(0),
1028 _dist(0), _source(INVALID) {}
1032 /// This constructor requires some parameters,
1033 /// listed in the parameters list.
1034 /// Others are initiated to 0.
1035 /// \param g is the initial value of \ref _g
1036 /// \param l is the initial value of \ref _length
1037 /// \param s is the initial value of \ref _source
1038 DijkstraWizardBase(const GR &g,const LM &l, Node s=INVALID) :
1039 _g(reinterpret_cast<void*>(const_cast<GR*>(&g))),
1040 _length(reinterpret_cast<void*>(const_cast<LM*>(&l))),
1041 _pred(0), _dist(0), _source(s) {}
1045 /// A class to make the usage of Dijkstra algorithm easier
1047 /// This class is created to make it easier to use Dijkstra algorithm.
1048 /// It uses the functions and features of the plain \ref Dijkstra,
1049 /// but it is much simpler to use it.
1051 /// Simplicity means that the way to change the types defined
1052 /// in the traits class is based on functions that returns the new class
1053 /// and not on templatable built-in classes.
1054 /// When using the plain \ref Dijkstra
1055 /// the new class with the modified type comes from
1056 /// the original class by using the ::
1057 /// operator. In the case of \ref DijkstraWizard only
1058 /// a function have to be called and it will
1059 /// return the needed class.
1061 /// It does not have own \ref run method. When its \ref run method is called
1062 /// it initiates a plain \ref Dijkstra class, and calls the \ref
1063 /// Dijkstra::run method of it.
1065 class DijkstraWizard : public TR
1069 ///The type of the underlying digraph.
1070 typedef typename TR::Digraph Digraph;
1072 typedef typename Digraph::Node Node;
1074 typedef typename Digraph::NodeIt NodeIt;
1076 typedef typename Digraph::Arc Arc;
1078 typedef typename Digraph::OutArcIt OutArcIt;
1080 ///The type of the map that stores the arc lengths.
1081 typedef typename TR::LengthMap LengthMap;
1082 ///The type of the length of the arcs.
1083 typedef typename LengthMap::Value Value;
1084 ///\brief The type of the map that stores the last
1085 ///arcs of the shortest paths.
1086 typedef typename TR::PredMap PredMap;
1087 ///The type of the map that stores the dists of the nodes.
1088 typedef typename TR::DistMap DistMap;
1089 ///The heap type used by the dijkstra algorithm.
1090 typedef typename TR::Heap Heap;
1093 DijkstraWizard() : TR() {}
1095 /// Constructor that requires parameters.
1097 /// Constructor that requires parameters.
1098 /// These parameters will be the default values for the traits class.
1099 DijkstraWizard(const Digraph &g,const LengthMap &l, Node s=INVALID) :
1103 DijkstraWizard(const TR &b) : TR(b) {}
1105 ~DijkstraWizard() {}
1107 ///Runs Dijkstra algorithm from a given node.
1109 ///Runs Dijkstra algorithm from a given node.
1110 ///The node can be given by the \ref source function.
1113 if(Base::_source==INVALID) throw UninitializedParameter();
1114 Dijkstra<Digraph,LengthMap,TR>
1115 dij(*reinterpret_cast<const Digraph*>(Base::_g),
1116 *reinterpret_cast<const LengthMap*>(Base::_length));
1117 if(Base::_pred) dij.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
1118 if(Base::_dist) dij.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
1119 dij.run(Base::_source);
1122 ///Runs Dijkstra algorithm from the given node.
1124 ///Runs Dijkstra algorithm from the given node.
1125 ///\param s is the given source.
1133 struct DefPredMapBase : public Base {
1135 static PredMap *createPredMap(const Digraph &) { return 0; };
1136 DefPredMapBase(const TR &b) : TR(b) {}
1139 ///\brief \ref named-templ-param "Named parameter"
1140 ///function for setting PredMap type
1142 /// \ref named-templ-param "Named parameter"
1143 ///function for setting PredMap type
1146 DijkstraWizard<DefPredMapBase<T> > predMap(const T &t)
1148 Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
1149 return DijkstraWizard<DefPredMapBase<T> >(*this);
1153 struct DefDistMapBase : public Base {
1155 static DistMap *createDistMap(const Digraph &) { return 0; };
1156 DefDistMapBase(const TR &b) : TR(b) {}
1159 ///\brief \ref named-templ-param "Named parameter"
1160 ///function for setting DistMap type
1162 /// \ref named-templ-param "Named parameter"
1163 ///function for setting DistMap type
1166 DijkstraWizard<DefDistMapBase<T> > distMap(const T &t)
1168 Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t));
1169 return DijkstraWizard<DefDistMapBase<T> >(*this);
1172 /// Sets the source node, from which the Dijkstra algorithm runs.
1174 /// Sets the source node, from which the Dijkstra algorithm runs.
1175 /// \param s is the source node.
1176 DijkstraWizard<TR> &source(Node s)
1184 ///Function type interface for Dijkstra algorithm.
1186 /// \ingroup shortest_path
1187 ///Function type interface for Dijkstra algorithm.
1189 ///This function also has several
1190 ///\ref named-templ-func-param "named parameters",
1191 ///they are declared as the members of class \ref DijkstraWizard.
1193 ///example shows how to use these parameters.
1195 /// dijkstra(g,length,source).predMap(preds).run();
1197 ///\warning Don't forget to put the \ref DijkstraWizard::run() "run()"
1198 ///to the end of the parameter list.
1199 ///\sa DijkstraWizard
1201 template<class GR, class LM>
1202 DijkstraWizard<DijkstraWizardBase<GR,LM> >
1203 dijkstra(const GR &g,const LM &l,typename GR::Node s=INVALID)
1205 return DijkstraWizard<DijkstraWizardBase<GR,LM> >(g,l,s);
1208 } //END OF NAMESPACE LEMON