COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/dijkstra.h @ 1220:20b26ee5812b

Last change on this file since 1220:20b26ee5812b was 1220:20b26ee5812b, checked in by Alpar Juttner, 16 years ago
  • Add compilation tests for the function type interface of BFS/DFS/Dijkstra
  • Fix the bugs covered up by these tests
File size: 33.0 KB
Line 
1/* -*- C++ -*-
2 * src/lemon/dijkstra.h - Part of LEMON, a generic C++ optimization library
3 *
4 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Combinatorial Optimization Research Group, EGRES).
6 *
7 * Permission to use, modify and distribute this software is granted
8 * provided that this copyright notice appears in all copies. For
9 * precise terms see the accompanying LICENSE file.
10 *
11 * This software is provided "AS IS" with no warranty of any kind,
12 * express or implied, and with no claim as to its suitability for any
13 * purpose.
14 *
15 */
16
17#ifndef LEMON_DIJKSTRA_H
18#define LEMON_DIJKSTRA_H
19
20///\ingroup flowalgs
21///\file
22///\brief Dijkstra algorithm.
23
24#include <lemon/list_graph.h>
25#include <lemon/bin_heap.h>
26#include <lemon/invalid.h>
27#include <lemon/error.h>
28#include <lemon/maps.h>
29
30namespace lemon {
31
32
33 
34  ///Default traits class of Dijkstra class.
35
36  ///Default traits class of Dijkstra class.
37  ///\param GR Graph type.
38  ///\param LM Type of length map.
39  template<class GR, class LM>
40  struct DijkstraDefaultTraits
41  {
42    ///The graph type the algorithm runs on.
43    typedef GR Graph;
44    ///The type of the map that stores the edge lengths.
45
46    ///The type of the map that stores the edge lengths.
47    ///It must meet the \ref concept::ReadMap "ReadMap" concept.
48    typedef LM LengthMap;
49    //The type of the length of the edges.
50    typedef typename LM::Value Value;
51    ///The heap type used by Dijkstra algorithm.
52
53    ///The heap type used by Dijkstra algorithm.
54    ///
55    ///\sa BinHeap
56    ///\sa Dijkstra
57    typedef BinHeap<typename Graph::Node,
58                    typename LM::Value,
59                    typename GR::template NodeMap<int>,
60                    std::less<Value> > Heap;
61
62    ///\brief The type of the map that stores the last
63    ///edges of the shortest paths.
64    ///
65    ///The type of the map that stores the last
66    ///edges of the shortest paths.
67    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
68    ///
69    typedef typename Graph::template NodeMap<typename GR::Edge> PredMap;
70    ///Instantiates a PredMap.
71 
72    ///This function instantiates a \ref PredMap.
73    ///\param G is the graph, to which we would like to define the PredMap.
74    ///\todo The graph alone may be insufficient for the initialization
75    static PredMap *createPredMap(const GR &G)
76    {
77      return new PredMap(G);
78    }
79//     ///\brief The type of the map that stores the last but one
80//     ///nodes of the shortest paths.
81//     ///
82//     ///The type of the map that stores the last but one
83//     ///nodes of the shortest paths.
84//     ///It must meet the \ref concept::WriteMap "WriteMap" concept.
85//     ///
86//     typedef NullMap<typename Graph::Node,typename Graph::Node> PredNodeMap;
87//     ///Instantiates a PredNodeMap.
88   
89//     ///This function instantiates a \ref PredNodeMap.
90//     ///\param G is the graph, to which
91//     ///we would like to define the \ref PredNodeMap
92//     static PredNodeMap *createPredNodeMap(const GR &G)
93//     {
94//       return new PredNodeMap();
95//     }
96
97    ///The type of the map that stores whether a nodes is processed.
98 
99    ///The type of the map that stores whether a nodes is processed.
100    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
101    ///By default it is a NullMap.
102    ///\todo If it is set to a real map,
103    ///Dijkstra::processed() should read this.
104    ///\todo named parameter to set this type, function to read and write.
105    typedef NullMap<typename Graph::Node,bool> ProcessedMap;
106    ///Instantiates a ProcessedMap.
107 
108    ///This function instantiates a \ref ProcessedMap.
109    ///\param G is the graph, to which
110    ///we would like to define the \ref ProcessedMap
111    static ProcessedMap *createProcessedMap(const GR &G)
112    {
113      return new ProcessedMap();
114    }
115    ///The type of the map that stores the dists of the nodes.
116 
117    ///The type of the map that stores the dists of the nodes.
118    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
119    ///
120    typedef typename Graph::template NodeMap<typename LM::Value> DistMap;
121    ///Instantiates a DistMap.
122 
123    ///This function instantiates a \ref DistMap.
124    ///\param G is the graph, to which we would like to define the \ref DistMap
125    static DistMap *createDistMap(const GR &G)
126    {
127      return new DistMap(G);
128    }
129  };
130 
131  ///%Dijkstra algorithm class.
132 
133  /// \ingroup flowalgs
134  ///This class provides an efficient implementation of %Dijkstra algorithm.
135  ///The edge lengths are passed to the algorithm using a
136  ///\ref concept::ReadMap "ReadMap",
137  ///so it is easy to change it to any kind of length.
138  ///
139  ///The type of the length is determined by the
140  ///\ref concept::ReadMap::Value "Value" of the length map.
141  ///
142  ///It is also possible to change the underlying priority heap.
143  ///
144  ///\param GR The graph type the algorithm runs on. The default value
145  ///is \ref ListGraph. The value of GR is not used directly by
146  ///Dijkstra, it is only passed to \ref DijkstraDefaultTraits.
147  ///\param LM This read-only EdgeMap determines the lengths of the
148  ///edges. It is read once for each edge, so the map may involve in
149  ///relatively time consuming process to compute the edge length if
150  ///it is necessary. The default map type is \ref
151  ///concept::StaticGraph::EdgeMap "Graph::EdgeMap<int>".  The value
152  ///of LM is not used directly by Dijkstra, it is only passed to \ref
153  ///DijkstraDefaultTraits.  \param TR Traits class to set
154  ///various data types used by the algorithm.  The default traits
155  ///class is \ref DijkstraDefaultTraits
156  ///"DijkstraDefaultTraits<GR,LM>".  See \ref
157  ///DijkstraDefaultTraits for the documentation of a Dijkstra traits
158  ///class.
159  ///
160  ///\author Jacint Szabo and Alpar Juttner
161  ///\todo A compare object would be nice.
162
163#ifdef DOXYGEN
164  template <typename GR,
165            typename LM,
166            typename TR>
167#else
168  template <typename GR=ListGraph,
169            typename LM=typename GR::template EdgeMap<int>,
170            typename TR=DijkstraDefaultTraits<GR,LM> >
171#endif
172  class Dijkstra {
173  public:
174    /**
175     * \brief \ref Exception for uninitialized parameters.
176     *
177     * This error represents problems in the initialization
178     * of the parameters of the algorithms.
179     */
180    class UninitializedParameter : public lemon::UninitializedParameter {
181    public:
182      virtual const char* exceptionName() const {
183        return "lemon::Dijkstra::UninitializedParameter";
184      }
185    };
186
187    typedef TR Traits;
188    ///The type of the underlying graph.
189    typedef typename TR::Graph Graph;
190    ///\e
191    typedef typename Graph::Node Node;
192    ///\e
193    typedef typename Graph::NodeIt NodeIt;
194    ///\e
195    typedef typename Graph::Edge Edge;
196    ///\e
197    typedef typename Graph::OutEdgeIt OutEdgeIt;
198   
199    ///The type of the length of the edges.
200    typedef typename TR::LengthMap::Value Value;
201    ///The type of the map that stores the edge lengths.
202    typedef typename TR::LengthMap LengthMap;
203    ///\brief The type of the map that stores the last
204    ///edges of the shortest paths.
205    typedef typename TR::PredMap PredMap;
206//     ///\brief The type of the map that stores the last but one
207//     ///nodes of the shortest paths.
208//     typedef typename TR::PredNodeMap PredNodeMap;
209    ///The type of the map indicating if a node is processed.
210    typedef typename TR::ProcessedMap ProcessedMap;
211    ///The type of the map that stores the dists of the nodes.
212    typedef typename TR::DistMap DistMap;
213    ///The heap type used by the dijkstra algorithm.
214    typedef typename TR::Heap Heap;
215  private:
216    /// Pointer to the underlying graph.
217    const Graph *G;
218    /// Pointer to the length map
219    const LengthMap *length;
220    ///Pointer to the map of predecessors edges.
221    PredMap *_pred;
222    ///Indicates if \ref _pred is locally allocated (\c true) or not.
223    bool local_pred;
224//     ///Pointer to the map of predecessors nodes.
225//     PredNodeMap *_predNode;
226//     ///Indicates if \ref _predNode is locally allocated (\c true) or not.
227//     bool local_predNode;
228    ///Pointer to the map of distances.
229    DistMap *_dist;
230    ///Indicates if \ref _dist is locally allocated (\c true) or not.
231    bool local_dist;
232    ///Pointer to the map of processed status of the nodes.
233    ProcessedMap *_processed;
234    ///Indicates if \ref _processed is locally allocated (\c true) or not.
235    bool local_processed;
236
237//     ///The source node of the last execution.
238//     Node source;
239
240    ///Creates the maps if necessary.
241   
242    ///\todo Error if \c G or are \c NULL. What about \c length?
243    ///\todo Better memory allocation (instead of new).
244    void create_maps()
245    {
246      if(!_pred) {
247        local_pred = true;
248        _pred = Traits::createPredMap(*G);
249      }
250//       if(!_predNode) {
251//      local_predNode = true;
252//      _predNode = Traits::createPredNodeMap(*G);
253//       }
254      if(!_dist) {
255        local_dist = true;
256        _dist = Traits::createDistMap(*G);
257      }
258      if(!_processed) {
259        local_processed = true;
260        _processed = Traits::createProcessedMap(*G);
261      }
262    }
263   
264  public :
265 
266    ///\name Named template parameters
267
268    ///@{
269
270    template <class T>
271    struct DefPredMapTraits : public Traits {
272      typedef T PredMap;
273      static PredMap *createPredMap(const Graph &G)
274      {
275        throw UninitializedParameter();
276      }
277    };
278    ///\ref named-templ-param "Named parameter" for setting PredMap type
279
280    ///\ref named-templ-param "Named parameter" for setting PredMap type
281    ///
282    template <class T>
283    class DefPredMap : public Dijkstra< Graph,
284                                        LengthMap,
285                                        DefPredMapTraits<T> > { };
286   
287//     template <class T>
288//     struct DefPredNodeMapTraits : public Traits {
289//       typedef T PredNodeMap;
290//       static PredNodeMap *createPredNodeMap(const Graph &G)
291//       {
292//      throw UninitializedParameter();
293//       }
294//     };
295//     ///\ref named-templ-param "Named parameter" for setting PredNodeMap type
296
297//     ///\ref named-templ-param "Named parameter" for setting PredNodeMap type
298//     ///
299//     template <class T>
300//     class DefPredNodeMap : public Dijkstra< Graph,
301//                                          LengthMap,
302//                                          DefPredNodeMapTraits<T> > { };
303   
304    template <class T>
305    struct DefDistMapTraits : public Traits {
306      typedef T DistMap;
307      static DistMap *createDistMap(const Graph &G)
308      {
309        throw UninitializedParameter();
310      }
311    };
312    ///\ref named-templ-param "Named parameter" for setting DistMap type
313
314    ///\ref named-templ-param "Named parameter" for setting DistMap type
315    ///
316    template <class T>
317    class DefDistMap : public Dijkstra< Graph,
318                                        LengthMap,
319                                        DefDistMapTraits<T> > { };
320   
321    template <class T>
322    struct DefProcessedMapTraits : public Traits {
323      typedef T ProcessedMap;
324      static ProcessedMap *createProcessedMap(const Graph &G)
325      {
326        throw UninitializedParameter();
327      }
328    };
329    ///\ref named-templ-param "Named parameter" for setting ProcessedMap type
330
331    ///\ref named-templ-param "Named parameter" for setting ProcessedMap type
332    ///
333    template <class T>
334    class DefProcessedMap : public Dijkstra< Graph,
335                                        LengthMap,
336                                        DefProcessedMapTraits<T> > { };
337   
338    struct DefGraphProcessedMapTraits : public Traits {
339      typedef typename Graph::template NodeMap<bool> ProcessedMap;
340      static ProcessedMap *createProcessedMap(const Graph &G)
341      {
342        return new ProcessedMap(G);
343      }
344    };
345    ///\brief \ref named-templ-param "Named parameter"
346    ///for setting the ProcessedMap type to be Graph::NodeMap<bool>.
347    ///
348    ///\ref named-templ-param "Named parameter"
349    ///for setting the ProcessedMap type to be Graph::NodeMap<bool>.
350    ///If you don't set it explicitely, it will be automatically allocated.
351    template <class T>
352    class DefProcessedMapToBeDefaultMap :
353      public Dijkstra< Graph,
354                       LengthMap,
355                       DefGraphProcessedMapTraits> { };
356   
357    ///@}
358
359
360  private:
361    typename Graph::template NodeMap<int> _heap_map;
362    Heap _heap;
363  public:     
364   
365    ///Constructor.
366   
367    ///\param _G the graph the algorithm will run on.
368    ///\param _length the length map used by the algorithm.
369    Dijkstra(const Graph& _G, const LengthMap& _length) :
370      G(&_G), length(&_length),
371      _pred(NULL), local_pred(false),
372//       _predNode(NULL), local_predNode(false),
373      _dist(NULL), local_dist(false),
374      _processed(NULL), local_processed(false),
375      _heap_map(*G,-1),_heap(_heap_map)
376    { }
377   
378    ///Destructor.
379    ~Dijkstra()
380    {
381      if(local_pred) delete _pred;
382//       if(local_predNode) delete _predNode;
383      if(local_dist) delete _dist;
384      if(local_processed) delete _processed;
385    }
386
387    ///Sets the length map.
388
389    ///Sets the length map.
390    ///\return <tt> (*this) </tt>
391    Dijkstra &lengthMap(const LengthMap &m)
392    {
393      length = &m;
394      return *this;
395    }
396
397    ///Sets the map storing the predecessor edges.
398
399    ///Sets the map storing the predecessor edges.
400    ///If you don't use this function before calling \ref run(),
401    ///it will allocate one. The destuctor deallocates this
402    ///automatically allocated map, of course.
403    ///\return <tt> (*this) </tt>
404    Dijkstra &predMap(PredMap &m)
405    {
406      if(local_pred) {
407        delete _pred;
408        local_pred=false;
409      }
410      _pred = &m;
411      return *this;
412    }
413
414//     ///Sets the map storing the predecessor nodes.
415
416//     ///Sets the map storing the predecessor nodes.
417//     ///If you don't use this function before calling \ref run(),
418//     ///it will allocate one. The destuctor deallocates this
419//     ///automatically allocated map, of course.
420//     ///\return <tt> (*this) </tt>
421//     Dijkstra &predNodeMap(PredNodeMap &m)
422//     {
423//       if(local_predNode) {
424//      delete _predNode;
425//      local_predNode=false;
426//       }
427//       _predNode = &m;
428//       return *this;
429//     }
430
431    ///Sets the map storing the distances calculated by the algorithm.
432
433    ///Sets the map storing the distances calculated by the algorithm.
434    ///If you don't use this function before calling \ref run(),
435    ///it will allocate one. The destuctor deallocates this
436    ///automatically allocated map, of course.
437    ///\return <tt> (*this) </tt>
438    Dijkstra &distMap(DistMap &m)
439    {
440      if(local_dist) {
441        delete _dist;
442        local_dist=false;
443      }
444      _dist = &m;
445      return *this;
446    }
447
448  private:
449    void finalizeNodeData(Node v,Value dst)
450    {
451      _processed->set(v,true);
452      _dist->set(v, dst);
453//       if((*_pred)[v]!=INVALID)
454//       _predNode->set(v,G->source((*_pred)[v])); ///\todo What to do?
455    }
456
457  public:
458    ///\name Execution control
459    ///The simplest way to execute the algorithm is to use
460    ///one of the member functions called \c run(...).
461    ///\n
462    ///If you need more control on the execution,
463    ///first you must call \ref init(), then you can add several source nodes
464    ///with \ref addSource().
465    ///Finally \ref start() will perform the actual path
466    ///computation.
467
468    ///@{
469
470    ///Initializes the internal data structures.
471
472    ///Initializes the internal data structures.
473    ///
474    ///\todo _heap_map's type could also be in the traits class.
475    void init()
476    {
477      create_maps();
478     
479      for ( NodeIt u(*G) ; u!=INVALID ; ++u ) {
480        _pred->set(u,INVALID);
481//      _predNode->set(u,INVALID);
482        _processed->set(u,false);
483        _heap_map.set(u,Heap::PRE_HEAP);
484      }
485    }
486   
487    ///Adds a new source node.
488
489    ///Adds a new source node to the priority heap.
490    ///
491    ///The optional second parameter is the initial distance of the node.
492    ///
493    ///It checks if the node has already been added to the heap and
494    ///It is pushed to the heap only if either it was not in the heap
495    ///or the shortest path found till then is longer then \c dst.
496    void addSource(Node s,Value dst=0)
497    {
498//       source = s;
499      if(_heap.state(s) != Heap::IN_HEAP) _heap.push(s,dst);
500      else if(_heap[s]<dst) {
501        _heap.push(s,dst);
502        _pred->set(s,INVALID);
503      }
504    }
505   
506    ///Processes the next node in the priority heap
507
508    ///Processes the next node in the priority heap.
509    ///
510    ///\warning The priority heap must not be empty!
511    void processNextNode()
512    {
513      Node v=_heap.top();
514      Value oldvalue=_heap[v];
515      _heap.pop();
516      finalizeNodeData(v,oldvalue);
517     
518      for(OutEdgeIt e(*G,v); e!=INVALID; ++e) {
519        Node w=G->target(e);
520        switch(_heap.state(w)) {
521        case Heap::PRE_HEAP:
522          _heap.push(w,oldvalue+(*length)[e]);
523          _pred->set(w,e);
524//        _predNode->set(w,v);
525          break;
526        case Heap::IN_HEAP:
527          if ( oldvalue+(*length)[e] < _heap[w] ) {
528            _heap.decrease(w, oldvalue+(*length)[e]);
529            _pred->set(w,e);
530//          _predNode->set(w,v);
531          }
532          break;
533        case Heap::POST_HEAP:
534          break;
535        }
536      }
537    }
538
539    ///\brief Returns \c false if there are nodes
540    ///to be processed in the priority heap
541    ///
542    ///Returns \c false if there are nodes
543    ///to be processed in the priority heap
544    bool emptyQueue() { return _heap.empty(); }
545    ///Returns the number of the nodes to be processed in the priority heap
546
547    ///Returns the number of the nodes to be processed in the priority heap
548    ///
549    int queueSize() { return _heap.size(); }
550   
551    ///Executes the algorithm.
552
553    ///Executes the algorithm.
554    ///
555    ///\pre init() must be called and at least one node should be added
556    ///with addSource() before using this function.
557    ///
558    ///This method runs the %Dijkstra algorithm from the root node(s)
559    ///in order to
560    ///compute the
561    ///shortest path to each node. The algorithm computes
562    ///- The shortest path tree.
563    ///- The distance of each node from the root(s).
564    ///
565    void start()
566    {
567      while ( !_heap.empty() ) processNextNode();
568    }
569   
570    ///Executes the algorithm until \c dest is reached.
571
572    ///Executes the algorithm until \c dest is reached.
573    ///
574    ///\pre init() must be called and at least one node should be added
575    ///with addSource() before using this function.
576    ///
577    ///This method runs the %Dijkstra algorithm from the root node(s)
578    ///in order to
579    ///compute the
580    ///shortest path to \c dest. The algorithm computes
581    ///- The shortest path to \c  dest.
582    ///- The distance of \c dest from the root(s).
583    ///
584    void start(Node dest)
585    {
586      while ( !_heap.empty() && _heap.top()!=dest ) processNextNode();
587      if ( _heap.top()==dest ) finalizeNodeData(_heap.top());
588    }
589   
590    ///Executes the algorithm until a condition is met.
591
592    ///Executes the algorithm until a condition is met.
593    ///
594    ///\pre init() must be called and at least one node should be added
595    ///with addSource() before using this function.
596    ///
597    ///\param nm must be a bool (or convertible) node map. The algorithm
598    ///will stop when it reaches a node \c v with <tt>nm[v]==true</tt>.
599    template<class NM>
600    void start(const NM &nm)
601    {
602      while ( !_heap.empty() && !nm[_heap.top()] ) processNextNode();
603      if ( !_heap.empty() ) finalizeNodeData(_heap.top());
604    }
605   
606    ///Runs %Dijkstra algorithm from node \c s.
607   
608    ///This method runs the %Dijkstra algorithm from a root node \c s
609    ///in order to
610    ///compute the
611    ///shortest path to each node. The algorithm computes
612    ///- The shortest path tree.
613    ///- The distance of each node from the root.
614    ///
615    ///\note d.run(s) is just a shortcut of the following code.
616    ///\code
617    ///  d.init();
618    ///  d.addSource(s);
619    ///  d.start();
620    ///\endcode
621    void run(Node s) {
622      init();
623      addSource(s);
624      start();
625    }
626   
627    ///Finds the shortest path between \c s and \c t.
628   
629    ///Finds the shortest path between \c s and \c t.
630    ///
631    ///\return The length of the shortest s---t path if there exists one,
632    ///0 otherwise.
633    ///\note Apart from the return value, d.run(s) is
634    ///just a shortcut of the following code.
635    ///\code
636    ///  d.init();
637    ///  d.addSource(s);
638    ///  d.start(t);
639    ///\endcode
640    Value run(Node s,Node t) {
641      init();
642      addSource(s);
643      start(t);
644      return (*_pred)[t]==INVALID?0:(*_dist)[t];
645    }
646   
647    ///@}
648
649    ///\name Query Functions
650    ///The result of the %Dijkstra algorithm can be obtained using these
651    ///functions.\n
652    ///Before the use of these functions,
653    ///either run() or start() must be called.
654   
655    ///@{
656
657    ///The distance of a node from the root.
658
659    ///Returns the distance of a node from the root.
660    ///\pre \ref run() must be called before using this function.
661    ///\warning If node \c v in unreachable from the root the return value
662    ///of this funcion is undefined.
663    Value dist(Node v) const { return (*_dist)[v]; }
664
665    ///Returns the 'previous edge' of the shortest path tree.
666
667    ///For a node \c v it returns the 'previous edge' of the shortest path tree,
668    ///i.e. it returns the last edge of a shortest path from the root to \c
669    ///v. It is \ref INVALID
670    ///if \c v is unreachable from the root or if \c v=s. The
671    ///shortest path tree used here is equal to the shortest path tree used in
672    ///\ref predNode(Node v).  \pre \ref run() must be called before using
673    ///this function.
674    ///\todo predEdge could be a better name.
675    Edge pred(Node v) const { return (*_pred)[v]; }
676
677    ///Returns the 'previous node' of the shortest path tree.
678
679    ///For a node \c v it returns the 'previous node' of the shortest path tree,
680    ///i.e. it returns the last but one node from a shortest path from the
681    ///root to \c /v. It is INVALID if \c v is unreachable from the root or if
682    ///\c v=s. The shortest path tree used here is equal to the shortest path
683    ///tree used in \ref pred(Node v).  \pre \ref run() must be called before
684    ///using this function.
685    Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
686                                  G->source((*_pred)[v]); }
687   
688    ///Returns a reference to the NodeMap of distances.
689
690    ///Returns a reference to the NodeMap of distances. \pre \ref run() must
691    ///be called before using this function.
692    const DistMap &distMap() const { return *_dist;}
693 
694    ///Returns a reference to the shortest path tree map.
695
696    ///Returns a reference to the NodeMap of the edges of the
697    ///shortest path tree.
698    ///\pre \ref run() must be called before using this function.
699    const PredMap &predMap() const { return *_pred;}
700 
701//     ///Returns a reference to the map of nodes of shortest paths.
702
703//     ///Returns a reference to the NodeMap of the last but one nodes of the
704//     ///shortest path tree.
705//     ///\pre \ref run() must be called before using this function.
706//     const PredNodeMap &predNodeMap() const { return *_predNode;}
707
708    ///Checks if a node is reachable from the root.
709
710    ///Returns \c true if \c v is reachable from the root.
711    ///\warning The source nodes are inditated as unreached.
712    ///\pre \ref run() must be called before using this function.
713    ///
714    bool reached(Node v) { return _heap_map[v]!=Heap::PRE_HEAP; }
715   
716    ///@}
717  };
718
719
720
721
722 
723  ///Default traits class of Dijkstra function.
724
725  ///Default traits class of Dijkstra function.
726  ///\param GR Graph type.
727  ///\param LM Type of length map.
728  template<class GR, class LM>
729  struct DijkstraWizardDefaultTraits
730  {
731    ///The graph type the algorithm runs on.
732    typedef GR Graph;
733    ///The type of the map that stores the edge lengths.
734
735    ///The type of the map that stores the edge lengths.
736    ///It must meet the \ref concept::ReadMap "ReadMap" concept.
737    typedef LM LengthMap;
738    //The type of the length of the edges.
739    typedef typename LM::Value Value;
740    ///The heap type used by Dijkstra algorithm.
741
742    ///The heap type used by Dijkstra algorithm.
743    ///
744    ///\sa BinHeap
745    ///\sa Dijkstra
746    typedef BinHeap<typename Graph::Node,
747                    typename LM::Value,
748                    typename GR::template NodeMap<int>,
749                    std::less<Value> > Heap;
750
751    ///\brief The type of the map that stores the last
752    ///edges of the shortest paths.
753    ///
754    ///The type of the map that stores the last
755    ///edges of the shortest paths.
756    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
757    ///
758    typedef NullMap <typename GR::Node,typename GR::Edge> PredMap;
759    ///Instantiates a PredMap.
760 
761    ///This function instantiates a \ref PredMap.
762    ///\param G is the graph, to which we would like to define the PredMap.
763    ///\todo The graph alone may be insufficient for the initialization
764    static PredMap *createPredMap(const GR &G)
765    {
766      return new PredMap();
767    }
768    ///The type of the map that stores whether a nodes is processed.
769 
770    ///The type of the map that stores whether a nodes is processed.
771    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
772    ///By default it is a NullMap.
773    ///\todo If it is set to a real map,
774    ///Dijkstra::processed() should read this.
775    ///\todo named parameter to set this type, function to read and write.
776    typedef NullMap<typename Graph::Node,bool> ProcessedMap;
777    ///Instantiates a ProcessedMap.
778 
779    ///This function instantiates a \ref ProcessedMap.
780    ///\param G is the graph, to which
781    ///we would like to define the \ref ProcessedMap
782    static ProcessedMap *createProcessedMap(const GR &G)
783    {
784      return new ProcessedMap();
785    }
786    ///The type of the map that stores the dists of the nodes.
787 
788    ///The type of the map that stores the dists of the nodes.
789    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
790    ///
791    typedef NullMap<typename Graph::Node,typename LM::Value> DistMap;
792    ///Instantiates a DistMap.
793 
794    ///This function instantiates a \ref DistMap.
795    ///\param G is the graph, to which we would like to define the \ref DistMap
796    static DistMap *createDistMap(const GR &G)
797    {
798      return new DistMap();
799    }
800  };
801 
802  /// Default traits used by \ref DijkstraWizard
803
804  /// To make it easier to use Dijkstra algorithm
805  ///we have created a wizard class.
806  /// This \ref DijkstraWizard class needs default traits,
807  ///as well as the \ref Dijkstra class.
808  /// The \ref DijkstraWizardBase is a class to be the default traits of the
809  /// \ref DijkstraWizard class.
810  /// \todo More named parameters are required...
811  template<class GR,class LM>
812  class DijkstraWizardBase : public DijkstraWizardDefaultTraits<GR,LM>
813  {
814
815    typedef DijkstraWizardDefaultTraits<GR,LM> Base;
816  protected:
817    /// Type of the nodes in the graph.
818    typedef typename Base::Graph::Node Node;
819
820    /// Pointer to the underlying graph.
821    void *_g;
822    /// Pointer to the length map
823    void *_length;
824    ///Pointer to the map of predecessors edges.
825    void *_pred;
826//     ///Pointer to the map of predecessors nodes.
827//     void *_predNode;
828    ///Pointer to the map of distances.
829    void *_dist;
830    ///Pointer to the source node.
831    Node _source;
832
833    public:
834    /// Constructor.
835   
836    /// This constructor does not require parameters, therefore it initiates
837    /// all of the attributes to default values (0, INVALID).
838    DijkstraWizardBase() : _g(0), _length(0), _pred(0),
839//                         _predNode(0),
840                           _dist(0), _source(INVALID) {}
841
842    /// Constructor.
843   
844    /// This constructor requires some parameters,
845    /// listed in the parameters list.
846    /// Others are initiated to 0.
847    /// \param g is the initial value of  \ref _g
848    /// \param l is the initial value of  \ref _length
849    /// \param s is the initial value of  \ref _source
850    DijkstraWizardBase(const GR &g,const LM &l, Node s=INVALID) :
851      _g((void *)&g), _length((void *)&l), _pred(0),
852//       _predNode(0),
853      _dist(0), _source(s) {}
854
855  };
856 
857  /// A class to make easier the usage of Dijkstra algorithm
858
859  /// This class is created to make it easier to use Dijkstra algorithm.
860  /// It uses the functions and features of the plain \ref Dijkstra,
861  /// but it is much simpler to use it.
862  ///
863  /// Simplicity means that the way to change the types defined
864  /// in the traits class is based on functions that returns the new class
865  /// and not on templatable built-in classes.
866  /// When using the plain \ref Dijkstra
867  /// the new class with the modified type comes from
868  /// the original class by using the ::
869  /// operator. In the case of \ref DijkstraWizard only
870  /// a function have to be called and it will
871  /// return the needed class.
872  ///
873  /// It does not have own \ref run method. When its \ref run method is called
874  /// it initiates a plain \ref Dijkstra class, and calls the \ref Dijkstra::run
875  /// method of it.
876  template<class TR>
877  class DijkstraWizard : public TR
878  {
879    typedef TR Base;
880
881    ///The type of the underlying graph.
882    typedef typename TR::Graph Graph;
883    //\e
884    typedef typename Graph::Node Node;
885    //\e
886    typedef typename Graph::NodeIt NodeIt;
887    //\e
888    typedef typename Graph::Edge Edge;
889    //\e
890    typedef typename Graph::OutEdgeIt OutEdgeIt;
891   
892    ///The type of the map that stores the edge lengths.
893    typedef typename TR::LengthMap LengthMap;
894    ///The type of the length of the edges.
895    typedef typename LengthMap::Value Value;
896    ///\brief The type of the map that stores the last
897    ///edges of the shortest paths.
898    typedef typename TR::PredMap PredMap;
899//     ///\brief The type of the map that stores the last but one
900//     ///nodes of the shortest paths.
901//     typedef typename TR::PredNodeMap PredNodeMap;
902    ///The type of the map that stores the dists of the nodes.
903    typedef typename TR::DistMap DistMap;
904
905    ///The heap type used by the dijkstra algorithm.
906    typedef typename TR::Heap Heap;
907public:
908    /// Constructor.
909    DijkstraWizard() : TR() {}
910
911    /// Constructor that requires parameters.
912
913    /// Constructor that requires parameters.
914    /// These parameters will be the default values for the traits class.
915    DijkstraWizard(const Graph &g,const LengthMap &l, Node s=INVALID) :
916      TR(g,l,s) {}
917
918    ///Copy constructor
919    DijkstraWizard(const TR &b) : TR(b) {}
920
921    ~DijkstraWizard() {}
922
923    ///Runs Dijkstra algorithm from a given node.
924   
925    ///Runs Dijkstra algorithm from a given node.
926    ///The node can be given by the \ref source function.
927    void run()
928    {
929      if(Base::_source==INVALID) throw UninitializedParameter();
930      Dijkstra<Graph,LengthMap,TR>
931        Dij(*(Graph*)Base::_g,*(LengthMap*)Base::_length);
932      if(Base::_pred) Dij.predMap(*(PredMap*)Base::_pred);
933//       if(Base::_predNode) Dij.predNodeMap(*(PredNodeMap*)Base::_predNode);
934      if(Base::_dist) Dij.distMap(*(DistMap*)Base::_dist);
935      Dij.run(Base::_source);
936    }
937
938    ///Runs Dijkstra algorithm from the given node.
939
940    ///Runs Dijkstra algorithm from the given node.
941    ///\param s is the given source.
942    void run(Node s)
943    {
944      Base::_source=s;
945      run();
946    }
947
948    template<class T>
949    struct DefPredMapBase : public Base {
950      typedef T PredMap;
951      static PredMap *createPredMap(const Graph &G) { return 0; };
952      DefPredMapBase(const Base &b) : Base(b) {}
953    };
954   
955    ///\brief \ref named-templ-param "Named parameter"
956    ///function for setting PredMap type
957    ///
958    /// \ref named-templ-param "Named parameter"
959    ///function for setting PredMap type
960    ///
961    template<class T>
962    DijkstraWizard<DefPredMapBase<T> > predMap(const T &t)
963    {
964      Base::_pred=(void *)&t;
965      return DijkstraWizard<DefPredMapBase<T> >(*this);
966    }
967   
968
969//     template<class T>
970//     struct DefPredNodeMapBase : public Base {
971//       typedef T PredNodeMap;
972//       static PredNodeMap *createPredNodeMap(const Graph &G) { return 0; };
973//       DefPredNodeMapBase(const Base &b) : Base(b) {}
974//     };
975   
976//     ///\brief \ref named-templ-param "Named parameter"
977//     ///function for setting PredNodeMap type
978//     ///
979//     /// \ref named-templ-param "Named parameter"
980//     ///function for setting PredNodeMap type
981//     ///
982//     template<class T>
983//     DijkstraWizard<DefPredNodeMapBase<T> > predNodeMap(const T &t)
984//     {
985//       Base::_predNode=(void *)&t;
986//       return DijkstraWizard<DefPredNodeMapBase<T> >(*this);
987//     }
988   
989    template<class T>
990    struct DefDistMapBase : public Base {
991      typedef T DistMap;
992      static DistMap *createDistMap(const Graph &G) { return 0; };
993      DefDistMapBase(const Base &b) : Base(b) {}
994    };
995   
996    ///\brief \ref named-templ-param "Named parameter"
997    ///function for setting DistMap type
998    ///
999    /// \ref named-templ-param "Named parameter"
1000    ///function for setting DistMap type
1001    ///
1002    template<class T>
1003    DijkstraWizard<DefDistMapBase<T> > distMap(const T &t)
1004    {
1005      Base::_dist=(void *)&t;
1006      return DijkstraWizard<DefDistMapBase<T> >(*this);
1007    }
1008   
1009    /// Sets the source node, from which the Dijkstra algorithm runs.
1010
1011    /// Sets the source node, from which the Dijkstra algorithm runs.
1012    /// \param s is the source node.
1013    DijkstraWizard<TR> &source(Node s)
1014    {
1015      Base::_source=s;
1016      return *this;
1017    }
1018   
1019  };
1020 
1021  ///Function type interface for Dijkstra algorithm.
1022
1023  /// \ingroup flowalgs
1024  ///Function type interface for Dijkstra algorithm.
1025  ///
1026  ///This function also has several
1027  ///\ref named-templ-func-param "named parameters",
1028  ///they are declared as the members of class \ref DijkstraWizard.
1029  ///The following
1030  ///example shows how to use these parameters.
1031  ///\code
1032  ///  dijkstra(g,length,source).predMap(preds).run();
1033  ///\endcode
1034  ///\warning Don't forget to put the \ref DijkstraWizard::run() "run()"
1035  ///to the end of the parameter list.
1036  ///\sa DijkstraWizard
1037  ///\sa Dijkstra
1038  template<class GR, class LM>
1039  DijkstraWizard<DijkstraWizardBase<GR,LM> >
1040  dijkstra(const GR &g,const LM &l,typename GR::Node s=INVALID)
1041  {
1042    return DijkstraWizard<DijkstraWizardBase<GR,LM> >(g,l,s);
1043  }
1044
1045} //END OF NAMESPACE LEMON
1046
1047#endif
1048
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