COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/lemon/dfs.h @ 1218:5331168bbb18

Last change on this file since 1218:5331168bbb18 was 1218:5331168bbb18, checked in by Alpar Juttner, 19 years ago
  • Several updates and clarifications on dijkstra.h
  • bfs.h and dfs.h is synchronized with dijkstra.h
File size: 33.1 KB
Line 
1/* -*- C++ -*-
2 * src/lemon/dfs.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_DFS_H
18#define LEMON_DFS_H
19
20///\ingroup flowalgs
21///\file
22///\brief Dfs algorithm.
23
24#include <lemon/list_graph.h>
25#include <lemon/graph_utils.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 Dfs class.
35
36  ///Default traits class of Dfs class.
37  ///\param GR Graph type.
38  template<class GR>
39  struct DfsDefaultTraits
40  {
41    ///The graph type the algorithm runs on.
42    typedef GR Graph;
43    ///\brief The type of the map that stores the last
44    ///edges of the %DFS paths.
45    ///
46    ///The type of the map that stores the last
47    ///edges of the %DFS paths.
48    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
49    ///
50    typedef typename Graph::template NodeMap<typename GR::Edge> PredMap;
51    ///Instantiates a PredMap.
52 
53    ///This function instantiates a \ref PredMap.
54    ///\param G is the graph, to which we would like to define the PredMap.
55    ///\todo The graph alone may be insufficient to initialize
56    static PredMap *createPredMap(const GR &G)
57    {
58      return new PredMap(G);
59    }
60//     ///\brief The type of the map that stores the last but one
61//     ///nodes of the %DFS paths.
62//     ///
63//     ///The type of the map that stores the last but one
64//     ///nodes of the %DFS paths.
65//     ///It must meet the \ref concept::WriteMap "WriteMap" concept.
66//     ///
67//     typedef NullMap<typename Graph::Node,typename Graph::Node> PredNodeMap;
68//     ///Instantiates a PredNodeMap.
69   
70//     ///This function instantiates a \ref PredNodeMap.
71//     ///\param G is the graph, to which
72//     ///we would like to define the \ref PredNodeMap
73//     static PredNodeMap *createPredNodeMap(const GR &G)
74//     {
75//       return new PredNodeMap();
76//     }
77
78    ///The type of the map that indicates which nodes are processed.
79 
80    ///The type of the map that indicates which nodes are processed.
81    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
82    ///\todo named parameter to set this type, function to read and write.
83    typedef NullMap<typename Graph::Node,bool> ProcessedMap;
84    ///Instantiates a ProcessedMap.
85 
86    ///This function instantiates a \ref ProcessedMap.
87    ///\param G is the graph, to which
88    ///we would like to define the \ref ProcessedMap
89    static ProcessedMap *createProcessedMap(const GR &G)
90    {
91      return new ProcessedMap();
92    }
93    ///The type of the map that indicates which nodes are reached.
94 
95    ///The type of the map that indicates which nodes are reached.
96    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
97    ///\todo named parameter to set this type, function to read and write.
98    typedef typename Graph::template NodeMap<bool> ReachedMap;
99    ///Instantiates a ReachedMap.
100 
101    ///This function instantiates a \ref ReachedMap.
102    ///\param G is the graph, to which
103    ///we would like to define the \ref ReachedMap.
104    static ReachedMap *createReachedMap(const GR &G)
105    {
106      return new ReachedMap(G);
107    }
108    ///The type of the map that stores the dists of the nodes.
109 
110    ///The type of the map that stores the dists of the nodes.
111    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
112    ///
113    typedef typename Graph::template NodeMap<int> DistMap;
114    ///Instantiates a DistMap.
115 
116    ///This function instantiates a \ref DistMap.
117    ///\param G is the graph, to which we would like to define the \ref DistMap
118    static DistMap *createDistMap(const GR &G)
119    {
120      return new DistMap(G);
121    }
122  };
123 
124  ///%DFS algorithm class.
125 
126  ///\ingroup flowalgs
127  ///This class provides an efficient implementation of the %DFS algorithm.
128  ///
129  ///\param GR The graph type the algorithm runs on. The default value is
130  ///\ref ListGraph. The value of GR is not used directly by Dfs, it
131  ///is only passed to \ref DfsDefaultTraits.
132  ///\param TR Traits class to set various data types used by the algorithm.
133  ///The default traits class is
134  ///\ref DfsDefaultTraits "DfsDefaultTraits<GR>".
135  ///See \ref DfsDefaultTraits for the documentation of
136  ///a Dfs traits class.
137  ///
138  ///\author Jacint Szabo and Alpar Juttner
139  ///\todo A compare object would be nice.
140
141#ifdef DOXYGEN
142  template <typename GR,
143            typename TR>
144#else
145  template <typename GR=ListGraph,
146            typename TR=DfsDefaultTraits<GR> >
147#endif
148  class Dfs {
149  public:
150    /**
151     * \brief \ref Exception for uninitialized parameters.
152     *
153     * This error represents problems in the initialization
154     * of the parameters of the algorithms.
155     */
156    class UninitializedParameter : public lemon::UninitializedParameter {
157    public:
158      virtual const char* exceptionName() const {
159        return "lemon::Dfs::UninitializedParameter";
160      }
161    };
162
163    typedef TR Traits;
164    ///The type of the underlying graph.
165    typedef typename TR::Graph Graph;
166    ///\e
167    typedef typename Graph::Node Node;
168    ///\e
169    typedef typename Graph::NodeIt NodeIt;
170    ///\e
171    typedef typename Graph::Edge Edge;
172    ///\e
173    typedef typename Graph::OutEdgeIt OutEdgeIt;
174   
175    ///\brief The type of the map that stores the last
176    ///edges of the %DFS paths.
177    typedef typename TR::PredMap PredMap;
178//     ///\brief The type of the map that stores the last but one
179//     ///nodes of the %DFS paths.
180//     typedef typename TR::PredNodeMap PredNodeMap;
181    ///The type of the map indicating which nodes are reached.
182    typedef typename TR::ReachedMap ReachedMap;
183    ///The type of the map indicating which nodes are processed.
184    typedef typename TR::ProcessedMap ProcessedMap;
185    ///The type of the map that stores the dists of the nodes.
186    typedef typename TR::DistMap DistMap;
187  private:
188    /// Pointer to the underlying graph.
189    const Graph *G;
190    ///Pointer to the map of predecessors edges.
191    PredMap *_pred;
192    ///Indicates if \ref _pred is locally allocated (\c true) or not.
193    bool local_pred;
194//     ///Pointer to the map of predecessors nodes.
195//     PredNodeMap *_predNode;
196//     ///Indicates if \ref _predNode is locally allocated (\c true) or not.
197//     bool local_predNode;
198    ///Pointer to the map of distances.
199    DistMap *_dist;
200    ///Indicates if \ref _dist is locally allocated (\c true) or not.
201    bool local_dist;
202    ///Pointer to the map of reached status of the nodes.
203    ReachedMap *_reached;
204    ///Indicates if \ref _reached is locally allocated (\c true) or not.
205    bool local_reached;
206    ///Pointer to the map of processed status of the nodes.
207    ProcessedMap *_processed;
208    ///Indicates if \ref _processed is locally allocated (\c true) or not.
209    bool local_processed;
210
211    std::vector<typename Graph::OutEdgeIt> _stack;
212    int _stack_head;
213//     ///The source node of the last execution.
214//     Node source;
215
216    ///Creates the maps if necessary.
217   
218    ///\todo Error if \c G are \c NULL.
219    ///\todo Better memory allocation (instead of new).
220    void create_maps()
221    {
222      if(!_pred) {
223        local_pred = true;
224        _pred = Traits::createPredMap(*G);
225      }
226//       if(!_predNode) {
227//      local_predNode = true;
228//      _predNode = Traits::createPredNodeMap(*G);
229//       }
230      if(!_dist) {
231        local_dist = true;
232        _dist = Traits::createDistMap(*G);
233      }
234      if(!_reached) {
235        local_reached = true;
236        _reached = Traits::createReachedMap(*G);
237      }
238      if(!_processed) {
239        local_processed = true;
240        _processed = Traits::createProcessedMap(*G);
241      }
242    }
243   
244  public :
245 
246    ///\name Named template parameters
247
248    ///@{
249
250    template <class T>
251    struct DefPredMapTraits : public Traits {
252      typedef T PredMap;
253      static PredMap *createPredMap(const Graph &G)
254      {
255        throw UninitializedParameter();
256      }
257    };
258    ///\ref named-templ-param "Named parameter" for setting PredMap type
259
260    ///\ref named-templ-param "Named parameter" for setting PredMap type
261    ///
262    template <class T>
263    class DefPredMap : public Dfs< Graph,
264                                        DefPredMapTraits<T> > { };
265   
266//     template <class T>
267//     struct DefPredNodeMapTraits : public Traits {
268//       typedef T PredNodeMap;
269//       static PredNodeMap *createPredNodeMap(const Graph &G)
270//       {
271//      throw UninitializedParameter();
272//       }
273//     };
274//     ///\ref named-templ-param "Named parameter" for setting PredNodeMap type
275
276//     ///\ref named-templ-param "Named parameter" for setting PredNodeMap type
277//     ///
278//     template <class T>
279//     class DefPredNodeMap : public Dfs< Graph,
280//                                          LengthMap,
281//                                          DefPredNodeMapTraits<T> > { };
282   
283    template <class T>
284    struct DefDistMapTraits : public Traits {
285      typedef T DistMap;
286      static DistMap *createDistMap(const Graph &G)
287      {
288        throw UninitializedParameter();
289      }
290    };
291    ///\ref named-templ-param "Named parameter" for setting DistMap type
292
293    ///\ref named-templ-param "Named parameter" for setting DistMap type
294    ///
295    template <class T>
296    class DefDistMap : public Dfs< Graph,
297                                   DefDistMapTraits<T> > { };
298   
299    template <class T>
300    struct DefReachedMapTraits : public Traits {
301      typedef T ReachedMap;
302      static ReachedMap *createReachedMap(const Graph &G)
303      {
304        throw UninitializedParameter();
305      }
306    };
307    ///\ref named-templ-param "Named parameter" for setting ReachedMap type
308
309    ///\ref named-templ-param "Named parameter" for setting ReachedMap type
310    ///
311    template <class T>
312    class DefReachedMap : public Dfs< Graph,
313                                      DefReachedMapTraits<T> > { };
314   
315    struct DefGraphReachedMapTraits : public Traits {
316      typedef typename Graph::template NodeMap<bool> ReachedMap;
317      static ReachedMap *createReachedMap(const Graph &G)
318      {
319        return new ReachedMap(G);
320      }
321    };
322    template <class T>
323    struct DefProcessedMapTraits : public Traits {
324      typedef T ProcessedMap;
325      static ProcessedMap *createProcessedMap(const Graph &G)
326      {
327        throw UninitializedParameter();
328      }
329    };
330    ///\ref named-templ-param "Named parameter" for setting ProcessedMap type
331
332    ///\ref named-templ-param "Named parameter" for setting ProcessedMap type
333    ///
334    template <class T>
335    class DefProcessedMap : public Dfs< Graph,
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 Dfs< Graph,
354                  DefGraphProcessedMapTraits> { };
355   
356    ///@}
357
358  public:     
359   
360    ///Constructor.
361   
362    ///\param _G the graph the algorithm will run on.
363    ///
364    Dfs(const Graph& _G) :
365      G(&_G),
366      _pred(NULL), local_pred(false),
367//       _predNode(NULL), local_predNode(false),
368      _dist(NULL), local_dist(false),
369      _reached(NULL), local_reached(false),
370      _processed(NULL), local_processed(false)
371    { }
372   
373    ///Destructor.
374    ~Dfs()
375    {
376      if(local_pred) delete _pred;
377//       if(local_predNode) delete _predNode;
378      if(local_dist) delete _dist;
379      if(local_reached) delete _reached;
380      if(local_processed) delete _processed;
381    }
382
383    ///Sets the map storing the predecessor edges.
384
385    ///Sets the map storing the predecessor edges.
386    ///If you don't use this function before calling \ref run(),
387    ///it will allocate one. The destuctor deallocates this
388    ///automatically allocated map, of course.
389    ///\return <tt> (*this) </tt>
390    Dfs &predMap(PredMap &m)
391    {
392      if(local_pred) {
393        delete _pred;
394        local_pred=false;
395      }
396      _pred = &m;
397      return *this;
398    }
399
400//     ///Sets the map storing the predecessor nodes.
401
402//     ///Sets the map storing the predecessor nodes.
403//     ///If you don't use this function before calling \ref run(),
404//     ///it will allocate one. The destuctor deallocates this
405//     ///automatically allocated map, of course.
406//     ///\return <tt> (*this) </tt>
407//     Dfs &predNodeMap(PredNodeMap &m)
408//     {
409//       if(local_predNode) {
410//      delete _predNode;
411//      local_predNode=false;
412//       }
413//       _predNode = &m;
414//       return *this;
415//     }
416
417    ///Sets the map storing the distances calculated by the algorithm.
418
419    ///Sets the map storing the distances calculated by the algorithm.
420    ///If you don't use this function before calling \ref run(),
421    ///it will allocate one. The destuctor deallocates this
422    ///automatically allocated map, of course.
423    ///\return <tt> (*this) </tt>
424    Dfs &distMap(DistMap &m)
425    {
426      if(local_dist) {
427        delete _dist;
428        local_dist=false;
429      }
430      _dist = &m;
431      return *this;
432    }
433
434  public:
435    ///\name Execution control
436    ///The simplest way to execute the algorithm is to use
437    ///one of the member functions called \c run(...).
438    ///\n
439    ///If you need more control on the execution,
440    ///first you must call \ref init(), then you can add several source nodes
441    ///with \ref addSource().
442    ///Finally \ref start() will perform the actual path
443    ///computation.
444
445    ///@{
446
447    ///Initializes the internal data structures.
448
449    ///Initializes the internal data structures.
450    ///
451    void init()
452    {
453      create_maps();
454      _stack.resize(countNodes(*G));
455      _stack_head=-1;
456      for ( NodeIt u(*G) ; u!=INVALID ; ++u ) {
457        _pred->set(u,INVALID);
458        // _predNode->set(u,INVALID);
459        _reached->set(u,false);
460        _processed->set(u,false);
461      }
462    }
463   
464    ///Adds a new source node.
465
466    ///Adds a new source node to the set of nodes to be processed.
467    ///
468    ///\bug dist's are wrong (or at least strange) in case of multiple sources.
469    void addSource(Node s)
470    {
471      if(!(*_reached)[s])
472        {
473          _reached->set(s,true);
474          _pred->set(s,INVALID);
475          // _predNode->set(u,INVALID);
476          _stack[++_stack_head]=OutEdgeIt(*G,s);
477          _dist->set(s,_stack_head);
478        }
479    }
480   
481    ///Processes the next node.
482
483    ///Processes the next node.
484    ///
485    ///\warning The stack must not be empty!
486    void processNextEdge()
487    {
488      Node m;
489      Edge e=_stack[_stack_head];
490      if(!(*_reached)[m=G->target(e)]) {
491        _pred->set(m,e);
492        _reached->set(m,true);
493        //        _pred_node->set(m,G->source(e));
494        _stack[++_stack_head] = OutEdgeIt(*G, m);
495        _dist->set(m,_stack_head);
496      }
497      else {
498        Node n;
499        while(_stack_head>=0 &&
500              (n=G->source(_stack[_stack_head]),
501               ++_stack[_stack_head]==INVALID))
502          {
503            _processed->set(n,true);
504            --_stack_head;
505          }
506      }
507    }
508     
509    ///\brief Returns \c false if there are nodes
510    ///to be processed in the queue
511    ///
512    ///Returns \c false if there are nodes
513    ///to be processed in the queue
514    bool emptyQueue() { return _stack_head<0; }
515    ///Returns the number of the nodes to be processed.
516   
517    ///Returns the number of the nodes to be processed in the queue.
518    ///
519    int queueSize() { return _stack_head+1; }
520   
521    ///Executes the algorithm.
522
523    ///Executes the algorithm.
524    ///
525    ///\pre init() must be called and at least one node should be added
526    ///with addSource() before using this function.
527    ///
528    ///This method runs the %DFS algorithm from the root node(s)
529    ///in order to
530    ///compute the
531    ///%DFS path to each node. The algorithm computes
532    ///- The %DFS tree.
533    ///- The distance of each node from the root(s).
534    ///
535    void start()
536    {
537      while ( !emptyQueue() ) processNextEdge();
538    }
539   
540    ///Executes the algorithm until \c dest is reached.
541
542    ///Executes the algorithm until \c dest is reached.
543    ///
544    ///\pre init() must be called and at least one node should be added
545    ///with addSource() before using this function.
546    ///
547    ///This method runs the %DFS algorithm from the root node(s)
548    ///in order to
549    ///compute the
550    ///%DFS path to \c dest. The algorithm computes
551    ///- The %DFS path to \c  dest.
552    ///- The distance of \c dest from the root(s).
553    ///
554    void start(Node dest)
555    {
556      while ( !emptyQueue() && _queue[_queue_tail]!=dest ) processNextEdge();
557    }
558   
559    ///Executes the algorithm until a condition is met.
560
561    ///Executes the algorithm until a condition is met.
562    ///
563    ///\pre init() must be called and at least one node should be added
564    ///with addSource() before using this function.
565    ///
566    ///\param nm must be a bool (or convertible) node map. The algorithm
567    ///will stop when it reaches a node \c v with <tt>nm[v]==true</tt>.
568    template<class NM>
569      void start(const NM &nm)
570      {
571        while ( !emptyQueue() && !nm[_queue[_queue_tail]] ) processNextEdge();
572      }
573   
574    ///Runs %DFS algorithm from node \c s.
575   
576    ///This method runs the %DFS algorithm from a root node \c s
577    ///in order to
578    ///compute the
579    ///%DFS path to each node. The algorithm computes
580    ///- The %DFS tree.
581    ///- The distance of each node from the root.
582    ///
583    ///\note d.run(s) is just a shortcut of the following code.
584    ///\code
585    ///  d.init();
586    ///  d.addSource(s);
587    ///  d.start();
588    ///\endcode
589    void run(Node s) {
590      init();
591      addSource(s);
592      start();
593    }
594   
595    ///Finds the %DFS path between \c s and \c t.
596   
597    ///Finds the %DFS path between \c s and \c t.
598    ///
599    ///\return The length of the %DFS s---t path if there exists one,
600    ///0 otherwise.
601    ///\note Apart from the return value, d.run(s) is
602    ///just a shortcut of the following code.
603    ///\code
604    ///  d.init();
605    ///  d.addSource(s);
606    ///  d.start(t);
607    ///\endcode
608    int run(Node s,Node t) {
609      init();
610      addSource(s);
611      start(t);
612      return reached(t)?_curr_dist-1+(_queue_tail==_queue_next_dist):0;
613    }
614   
615    ///@}
616
617    ///\name Query Functions
618    ///The result of the %DFS algorithm can be obtained using these
619    ///functions.\n
620    ///Before the use of these functions,
621    ///either run() or start() must be called.
622   
623    ///@{
624
625    ///The distance of a node from the root(s).
626
627    ///Returns the distance of a node from the root(s).
628    ///\pre \ref run() must be called before using this function.
629    ///\warning If node \c v in unreachable from the root(s) the return value
630    ///of this funcion is undefined.
631    int dist(Node v) const { return (*_dist)[v]; }
632
633    ///Returns the 'previous edge' of the %DFS tree.
634
635    ///For a node \c v it returns the 'previous edge'
636    ///of the %DFS path,
637    ///i.e. it returns the last edge of a %DFS path from the root(s) to \c
638    ///v. It is \ref INVALID
639    ///if \c v is unreachable from the root(s) or \c v is a root. The
640    ///%DFS tree used here is equal to the %DFS tree used in
641    ///\ref predNode(Node v).
642    ///\pre Either \ref run() or \ref start() must be called before using
643    ///this function.
644    ///\todo predEdge could be a better name.
645    Edge pred(Node v) const { return (*_pred)[v];}
646
647    ///Returns the 'previous node' of the %DFS tree.
648
649    ///For a node \c v it returns the 'previous node'
650    ///of the %DFS tree,
651    ///i.e. it returns the last but one node from a %DFS path from the
652    ///root(a) to \c /v.
653    ///It is INVALID if \c v is unreachable from the root(s) or
654    ///if \c v itself a root.
655    ///The %DFS tree used here is equal to the %DFS
656    ///tree used in \ref pred(Node v).
657    ///\pre Either \ref run() or \ref start() must be called before
658    ///using this function.
659    Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
660                                  G->source((*_pred)[v]); }
661   
662    ///Returns a reference to the NodeMap of distances.
663
664    ///Returns a reference to the NodeMap of distances.
665    ///\pre Either \ref run() or \ref init() must
666    ///be called before using this function.
667    const DistMap &distMap() const { return *_dist;}
668 
669    ///Returns a reference to the %DFS edge-tree map.
670
671    ///Returns a reference to the NodeMap of the edges of the
672    ///%DFS tree.
673    ///\pre Either \ref run() or \ref init()
674    ///must be called before using this function.
675    const PredMap &predMap() const { return *_pred;}
676 
677//     ///Returns a reference to the map of nodes of %DFS paths.
678
679//     ///Returns a reference to the NodeMap of the last but one nodes of the
680//     ///%DFS tree.
681//     ///\pre \ref run() must be called before using this function.
682//     const PredNodeMap &predNodeMap() const { return *_predNode;}
683
684    ///Checks if a node is reachable from the root.
685
686    ///Returns \c true if \c v is reachable from the root.
687    ///\warning The source nodes are inditated as unreached.
688    ///\pre Either \ref run() or \ref start()
689    ///must be called before using this function.
690    ///
691    bool reached(Node v) { return (*_reached)[v]; }
692   
693    ///@}
694  };
695
696  ///Default traits class of Dfs function.
697
698  ///Default traits class of Dfs function.
699  ///\param GR Graph type.
700  template<class GR>
701  struct DfsWizardDefaultTraits
702  {
703    ///The graph type the algorithm runs on.
704    typedef GR Graph;
705    ///\brief The type of the map that stores the last
706    ///edges of the %DFS paths.
707    ///
708    ///The type of the map that stores the last
709    ///edges of the %DFS paths.
710    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
711    ///
712    typedef NullMap<typename Graph::Node,typename GR::Edge> PredMap;
713    ///Instantiates a PredMap.
714 
715    ///This function instantiates a \ref PredMap.
716    ///\param G is the graph, to which we would like to define the PredMap.
717    ///\todo The graph alone may be insufficient to initialize
718    static PredMap *createPredMap(const GR &G)
719    {
720      return new PredMap();
721    }
722//     ///\brief The type of the map that stores the last but one
723//     ///nodes of the %DFS paths.
724//     ///
725//     ///The type of the map that stores the last but one
726//     ///nodes of the %DFS paths.
727//     ///It must meet the \ref concept::WriteMap "WriteMap" concept.
728//     ///
729//     typedef NullMap<typename Graph::Node,typename Graph::Node> PredNodeMap;
730//     ///Instantiates a PredNodeMap.
731   
732//     ///This function instantiates a \ref PredNodeMap.
733//     ///\param G is the graph, to which
734//     ///we would like to define the \ref PredNodeMap
735//     static PredNodeMap *createPredNodeMap(const GR &G)
736//     {
737//       return new PredNodeMap();
738//     }
739
740    ///The type of the map that indicates which nodes are processed.
741 
742    ///The type of the map that indicates which nodes are processed.
743    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
744    ///\todo named parameter to set this type, function to read and write.
745    typedef NullMap<typename Graph::Node,bool> ProcessedMap;
746    ///Instantiates a ProcessedMap.
747 
748    ///This function instantiates a \ref ProcessedMap.
749    ///\param G is the graph, to which
750    ///we would like to define the \ref ProcessedMap
751    static ProcessedMap *createProcessedMap(const GR &G)
752    {
753      return new ProcessedMap();
754    }
755    ///The type of the map that indicates which nodes are reached.
756 
757    ///The type of the map that indicates which nodes are reached.
758    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
759    ///\todo named parameter to set this type, function to read and write.
760    typedef typename Graph::template NodeMap<bool> ReachedMap;
761    ///Instantiates a ReachedMap.
762 
763    ///This function instantiates a \ref ReachedMap.
764    ///\param G is the graph, to which
765    ///we would like to define the \ref ReachedMap.
766    static ReachedMap *createReachedMap(const GR &G)
767    {
768      return new ReachedMap(G);
769    }
770    ///The type of the map that stores the dists of the nodes.
771 
772    ///The type of the map that stores the dists of the nodes.
773    ///It must meet the \ref concept::WriteMap "WriteMap" concept.
774    ///
775    typedef NullMap<typename Graph::Node,int> DistMap;
776    ///Instantiates a DistMap.
777 
778    ///This function instantiates a \ref DistMap.
779    ///\param G is the graph, to which we would like to define the \ref DistMap
780    static DistMap *createDistMap(const GR &G)
781    {
782      return new DistMap();
783    }
784  };
785 
786  /// Default traits used by \ref DfsWizard
787
788  /// To make it easier to use Dfs algorithm
789  ///we have created a wizard class.
790  /// This \ref DfsWizard class needs default traits,
791  ///as well as the \ref Dfs class.
792  /// The \ref DfsWizardBase is a class to be the default traits of the
793  /// \ref DfsWizard class.
794  template<class GR>
795  class DfsWizardBase : public DfsWizardDefaultTraits<GR>
796  {
797
798    typedef DfsWizardDefaultTraits<GR> Base;
799  protected:
800    /// Type of the nodes in the graph.
801    typedef typename Base::Graph::Node Node;
802
803    /// Pointer to the underlying graph.
804    void *_g;
805    ///Pointer to the map of reached nodes.
806    void *_reached;
807    ///Pointer to the map of processed nodes.
808    void *_processed;
809    ///Pointer to the map of predecessors edges.
810    void *_pred;
811//     ///Pointer to the map of predecessors nodes.
812//     void *_predNode;
813    ///Pointer to the map of distances.
814    void *_dist;
815    ///Pointer to the source node.
816    Node _source;
817   
818    public:
819    /// Constructor.
820   
821    /// This constructor does not require parameters, therefore it initiates
822    /// all of the attributes to default values (0, INVALID).
823    DfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0),
824//                         _predNode(0),
825                           _dist(0), _source(INVALID) {}
826
827    /// Constructor.
828   
829    /// This constructor requires some parameters,
830    /// listed in the parameters list.
831    /// Others are initiated to 0.
832    /// \param g is the initial value of  \ref _g
833    /// \param s is the initial value of  \ref _source
834    DfsWizardBase(const GR &g, Node s=INVALID) :
835      _g((void *)&g), _reached(0), _processed(0), _pred(0),
836//       _predNode(0),
837      _dist(0), _source(s) {}
838
839  };
840 
841  /// A class to make the usage of Dfs algorithm easier
842
843  /// This class is created to make it easier to use Dfs algorithm.
844  /// It uses the functions and features of the plain \ref Dfs,
845  /// but it is much simpler to use it.
846  ///
847  /// Simplicity means that the way to change the types defined
848  /// in the traits class is based on functions that returns the new class
849  /// and not on templatable built-in classes.
850  /// When using the plain \ref Dfs
851  /// the new class with the modified type comes from
852  /// the original class by using the ::
853  /// operator. In the case of \ref DfsWizard only
854  /// a function have to be called and it will
855  /// return the needed class.
856  ///
857  /// It does not have own \ref run method. When its \ref run method is called
858  /// it initiates a plain \ref Dfs class, and calls the \ref Dfs::run
859  /// method of it.
860  template<class TR>
861  class DfsWizard : public TR
862  {
863    typedef TR Base;
864
865    ///The type of the underlying graph.
866    typedef typename TR::Graph Graph;
867    //\e
868    typedef typename Graph::Node Node;
869    //\e
870    typedef typename Graph::NodeIt NodeIt;
871    //\e
872    typedef typename Graph::Edge Edge;
873    //\e
874    typedef typename Graph::OutEdgeIt OutEdgeIt;
875   
876    ///\brief The type of the map that stores
877    ///the reached nodes
878    typedef typename TR::ReachedMap ReachedMap;
879    ///\brief The type of the map that stores
880    ///the processed nodes
881    typedef typename TR::ProcessedMap ProcessedMap;
882    ///\brief The type of the map that stores the last
883    ///edges of the %DFS paths.
884    typedef typename TR::PredMap PredMap;
885//     ///\brief The type of the map that stores the last but one
886//     ///nodes of the %DFS paths.
887//     typedef typename TR::PredNodeMap PredNodeMap;
888    ///The type of the map that stores the dists of the nodes.
889    typedef typename TR::DistMap DistMap;
890
891public:
892    /// Constructor.
893    DfsWizard() : TR() {}
894
895    /// Constructor that requires parameters.
896
897    /// Constructor that requires parameters.
898    /// These parameters will be the default values for the traits class.
899    DfsWizard(const Graph &g, Node s=INVALID) :
900      TR(g,s) {}
901
902    ///Copy constructor
903    DfsWizard(const TR &b) : TR(b) {}
904
905    ~DfsWizard() {}
906
907    ///Runs Dfs algorithm from a given node.
908   
909    ///Runs Dfs algorithm from a given node.
910    ///The node can be given by the \ref source function.
911    void run()
912    {
913      if(Base::_source==INVALID) throw UninitializedParameter();
914      Dfs<Graph,TR> alg(*(Graph*)Base::_g);
915      if(Base::_reached) alg.reachedMap(*(ReachedMap*)Base::_reached);
916      if(Base::_processed) alg.processedMap(*(ProcessedMap*)Base::_processed);
917      if(Base::_pred) alg.predMap(*(PredMap*)Base::_pred);
918//       if(Base::_predNode) alg.predNodeMap(*(PredNodeMap*)Base::_predNode);
919      if(Base::_dist) alg.distMap(*(DistMap*)Base::_dist);
920      alg.run(Base::_source);
921    }
922
923    ///Runs Dfs algorithm from the given node.
924
925    ///Runs Dfs algorithm from the given node.
926    ///\param s is the given source.
927    void run(Node s)
928    {
929      Base::_source=s;
930      run();
931    }
932
933    template<class T>
934    struct DefPredMapBase : public Base {
935      typedef T PredMap;
936      static PredMap *createPredMap(const Graph &G) { return 0; };
937      DefPredMapBase(const Base &b) : Base(b) {}
938    };
939   
940    ///\brief \ref named-templ-param "Named parameter"
941    ///function for setting PredMap type
942    ///
943    /// \ref named-templ-param "Named parameter"
944    ///function for setting PredMap type
945    ///
946    template<class T>
947    DfsWizard<DefPredMapBase<T> > predMap(const T &t)
948    {
949      Base::_pred=(void *)&t;
950      return DfsWizard<DefPredMapBase<T> >(*this);
951    }
952   
953 
954    template<class T>
955    struct DefReachedMapBase : public Base {
956      typedef T ReachedMap;
957      static ReachedMap *createReachedMap(const Graph &G) { return 0; };
958      DefReachedMapBase(const Base &b) : Base(b) {}
959    };
960   
961    ///\brief \ref named-templ-param "Named parameter"
962    ///function for setting ReachedMap
963    ///
964    /// \ref named-templ-param "Named parameter"
965    ///function for setting ReachedMap
966    ///
967    template<class T>
968    DfsWizard<DefReachedMapBase<T> > reachedMap(const T &t)
969    {
970      Base::_pred=(void *)&t;
971      return DfsWizard<DefReachedMapBase<T> >(*this);
972    }
973   
974
975    template<class T>
976    struct DefProcessedMapBase : public Base {
977      typedef T ProcessedMap;
978      static ProcessedMap *createProcessedMap(const Graph &G) { return 0; };
979      DefProcessedMapBase(const Base &b) : Base(b) {}
980    };
981   
982    ///\brief \ref named-templ-param "Named parameter"
983    ///function for setting ProcessedMap
984    ///
985    /// \ref named-templ-param "Named parameter"
986    ///function for setting ProcessedMap
987    ///
988    template<class T>
989    DfsWizard<DefProcessedMapBase<T> > processedMap(const T &t)
990    {
991      Base::_pred=(void *)&t;
992      return DfsWizard<DefProcessedMapBase<T> >(*this);
993    }
994   
995
996//     template<class T>
997//     struct DefPredNodeMapBase : public Base {
998//       typedef T PredNodeMap;
999//       static PredNodeMap *createPredNodeMap(const Graph &G) { return 0; };
1000//       DefPredNodeMapBase(const Base &b) : Base(b) {}
1001//     };
1002   
1003//     ///\brief \ref named-templ-param "Named parameter"
1004//     ///function for setting PredNodeMap type
1005//     ///
1006//     /// \ref named-templ-param "Named parameter"
1007//     ///function for setting PredNodeMap type
1008//     ///
1009//     template<class T>
1010//     DfsWizard<DefPredNodeMapBase<T> > predNodeMap(const T &t)
1011//     {
1012//       Base::_predNode=(void *)&t;
1013//       return DfsWizard<DefPredNodeMapBase<T> >(*this);
1014//     }
1015   
1016    template<class T>
1017    struct DefDistMapBase : public Base {
1018      typedef T DistMap;
1019      static DistMap *createDistMap(const Graph &G) { return 0; };
1020      DefDistMapBase(const Base &b) : Base(b) {}
1021    };
1022   
1023    ///\brief \ref named-templ-param "Named parameter"
1024    ///function for setting DistMap type
1025    ///
1026    /// \ref named-templ-param "Named parameter"
1027    ///function for setting DistMap type
1028    ///
1029    template<class T>
1030    DfsWizard<DefDistMapBase<T> > distMap(const T &t)
1031    {
1032      Base::_dist=(void *)&t;
1033      return DfsWizard<DefDistMapBase<T> >(*this);
1034    }
1035   
1036    /// Sets the source node, from which the Dfs algorithm runs.
1037
1038    /// Sets the source node, from which the Dfs algorithm runs.
1039    /// \param s is the source node.
1040    DfsWizard<TR> &source(Node s)
1041    {
1042      Base::_source=s;
1043      return *this;
1044    }
1045   
1046  };
1047 
1048  ///Function type interface for Dfs algorithm.
1049
1050  /// \ingroup flowalgs
1051  ///Function type interface for Dfs algorithm.
1052  ///
1053  ///This function also has several
1054  ///\ref named-templ-func-param "named parameters",
1055  ///they are declared as the members of class \ref DfsWizard.
1056  ///The following
1057  ///example shows how to use these parameters.
1058  ///\code
1059  ///  dfs(g,source).predMap(preds).run();
1060  ///\endcode
1061  ///\warning Don't forget to put the \ref DfsWizard::run() "run()"
1062  ///to the end of the parameter list.
1063  ///\sa DfsWizard
1064  ///\sa Dfs
1065  template<class GR>
1066  DfsWizard<DfsWizardBase<GR> >
1067  dfs(const GR &g,typename GR::Node s=INVALID)
1068  {
1069    return DfsWizard<DfsWizardBase<GR> >(g,s);
1070  }
1071
1072} //END OF NAMESPACE LEMON
1073
1074#endif
1075
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