COIN-OR::LEMON - Graph Library

source: lemon/lemon/max_cardinality_search.h @ 1045:fe283caf6414

Last change on this file since 1045:fe283caf6414 was 1020:70bee017b584, checked in by Antal Nemes <thoneyvazul@…>, 10 years ago

Port max. card. search alg. from svn -r3512 (#397) and (#56)

File size: 25.6 KB
Line 
1/* -*- C++ -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library
4 *
5 * Copyright (C) 2003-2010
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 *
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.
12 *
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
15 * purpose.
16 *
17 */
18
19#ifndef LEMON_MAX_CARDINALITY_SEARCH_H
20#define LEMON_MAX_CARDINALITY_SEARCH_H
21
22
23/// \ingroup search
24/// \file
25/// \brief Maximum cardinality search in undirected digraphs.
26
27#include <lemon/bin_heap.h>
28#include <lemon/bucket_heap.h>
29
30#include <lemon/error.h>
31#include <lemon/maps.h>
32
33#include <functional>
34
35namespace lemon {
36
37  /// \brief Default traits class of MaxCardinalitySearch class.
38  ///
39  /// Default traits class of MaxCardinalitySearch class.
40  /// \param Digraph Digraph type.
41  /// \param CapacityMap Type of capacity map.
42  template <typename GR, typename CAP>
43  struct MaxCardinalitySearchDefaultTraits {
44    /// The digraph type the algorithm runs on.
45    typedef GR Digraph;
46
47    template <typename CM>
48    struct CapMapSelector {
49
50      typedef CM CapacityMap;
51
52      static CapacityMap *createCapacityMap(const Digraph& g) {
53        return new CapacityMap(g);
54      }
55    };
56
57    template <typename CM>
58    struct CapMapSelector<ConstMap<CM, Const<int, 1> > > {
59
60      typedef ConstMap<CM, Const<int, 1> > CapacityMap;
61
62      static CapacityMap *createCapacityMap(const Digraph&) {
63        return new CapacityMap;
64      }
65    };
66
67    /// \brief The type of the map that stores the arc capacities.
68    ///
69    /// The type of the map that stores the arc capacities.
70    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
71    typedef typename CapMapSelector<CAP>::CapacityMap CapacityMap;
72
73    /// \brief The type of the capacity of the arcs.
74    typedef typename CapacityMap::Value Value;
75
76    /// \brief Instantiates a CapacityMap.
77    ///
78    /// This function instantiates a \ref CapacityMap.
79    /// \param digraph is the digraph, to which we would like to define
80    /// the CapacityMap.
81    static CapacityMap *createCapacityMap(const Digraph& digraph) {
82      return CapMapSelector<CapacityMap>::createCapacityMap(digraph);
83    }
84
85    /// \brief The cross reference type used by heap.
86    ///
87    /// The cross reference type used by heap.
88    /// Usually it is \c Digraph::NodeMap<int>.
89    typedef typename Digraph::template NodeMap<int> HeapCrossRef;
90
91    /// \brief Instantiates a HeapCrossRef.
92    ///
93    /// This function instantiates a \ref HeapCrossRef.
94    /// \param digraph is the digraph, to which we would like to define the
95    /// HeapCrossRef.
96    static HeapCrossRef *createHeapCrossRef(const Digraph &digraph) {
97      return new HeapCrossRef(digraph);
98    }
99   
100    template <typename CapacityMap>
101    struct HeapSelector {
102      template <typename Value, typename Ref>
103      struct Selector {
104        typedef BinHeap<Value, Ref, std::greater<Value> > Heap;
105      };
106    };
107
108    template <typename CapacityKey>
109    struct HeapSelector<ConstMap<CapacityKey, Const<int, 1> > > {
110      template <typename Value, typename Ref>
111      struct Selector {
112        typedef BucketHeap<Ref, false > Heap;
113      };
114    };
115
116    /// \brief The heap type used by MaxCardinalitySearch algorithm.
117    ///
118    /// The heap type used by MaxCardinalitySearch algorithm. It should
119    /// maximalize the priorities. The default heap type is
120    /// the \ref BinHeap, but it is specialized when the
121    /// CapacityMap is ConstMap<Digraph::Node, Const<int, 1> >
122    /// to BucketHeap.
123    ///
124    /// \sa MaxCardinalitySearch
125    typedef typename HeapSelector<CapacityMap>
126    ::template Selector<Value, HeapCrossRef>
127    ::Heap Heap;
128
129    /// \brief Instantiates a Heap.
130    ///
131    /// This function instantiates a \ref Heap.
132    /// \param crossref The cross reference of the heap.
133    static Heap *createHeap(HeapCrossRef& crossref) {
134      return new Heap(crossref);
135    }
136
137    /// \brief The type of the map that stores whether a node is processed.
138    ///
139    /// The type of the map that stores whether a node is processed.
140    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
141    /// By default it is a NullMap.
142    typedef NullMap<typename Digraph::Node, bool> ProcessedMap;
143
144    /// \brief Instantiates a ProcessedMap.
145    ///
146    /// This function instantiates a \ref ProcessedMap.
147    /// \param digraph is the digraph, to which
148    /// we would like to define the \ref ProcessedMap
149#ifdef DOXYGEN
150    static ProcessedMap *createProcessedMap(const Digraph &digraph)
151#else
152    static ProcessedMap *createProcessedMap(const Digraph &)
153#endif
154    {
155      return new ProcessedMap();
156    }
157
158    /// \brief The type of the map that stores the cardinalities of the nodes.
159    ///
160    /// The type of the map that stores the cardinalities of the nodes.
161    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
162    typedef typename Digraph::template NodeMap<Value> CardinalityMap;
163
164    /// \brief Instantiates a CardinalityMap.
165    ///
166    /// This function instantiates a \ref CardinalityMap.
167    /// \param digraph is the digraph, to which we would like to define the \ref
168    /// CardinalityMap
169    static CardinalityMap *createCardinalityMap(const Digraph &digraph) {
170      return new CardinalityMap(digraph);
171    }
172
173
174  };
175 
176  /// \ingroup search
177  ///
178  /// \brief Maximum Cardinality Search algorithm class.
179  ///
180  /// This class provides an efficient implementation of Maximum Cardinality
181  /// Search algorithm. The maximum cardinality search first chooses any
182  /// node of the digraph. Then every time it chooses one unprocessed node
183  /// with maximum cardinality, i.e the sum of capacities on out arcs to the nodes
184  /// which were previusly processed.
185  /// If there is a cut in the digraph the algorithm should choose
186  /// again any unprocessed node of the digraph.
187
188  /// The arc capacities are passed to the algorithm using a
189  /// \ref concepts::ReadMap "ReadMap", so it is easy to change it to any
190  /// kind of capacity.
191  ///
192  /// The type of the capacity is determined by the \ref
193  /// concepts::ReadMap::Value "Value" of the capacity map.
194  ///
195  /// It is also possible to change the underlying priority heap.
196  ///
197  ///
198  /// \param GR The digraph type the algorithm runs on. The value of
199  /// Digraph is not used directly by the search algorithm, it
200  /// is only passed to \ref MaxCardinalitySearchDefaultTraits.
201  /// \param CAP This read-only ArcMap determines the capacities of
202  /// the arcs. It is read once for each arc, so the map may involve in
203  /// relatively time consuming process to compute the arc capacity if
204  /// it is necessary. The default map type is \ref
205  /// ConstMap "ConstMap<concepts::Digraph::Arc, Const<int,1> >". The value
206  /// of CapacityMap is not used directly by search algorithm, it is only
207  /// passed to \ref MaxCardinalitySearchDefaultTraits. 
208  /// \param TR Traits class to set various data types used by the
209  /// algorithm.  The default traits class is
210  /// \ref MaxCardinalitySearchDefaultTraits
211  /// "MaxCardinalitySearchDefaultTraits<GR, CAP>". 
212  /// See \ref MaxCardinalitySearchDefaultTraits
213  /// for the documentation of a MaxCardinalitySearch traits class.
214
215#ifdef DOXYGEN
216  template <typename GR, typename CAP, typename TR>
217#else
218  template <typename GR, typename CAP =
219            ConstMap<typename GR::Arc, Const<int,1> >,
220            typename TR =
221            MaxCardinalitySearchDefaultTraits<GR, CAP> >
222#endif
223  class MaxCardinalitySearch {
224  public:
225
226    typedef TR Traits;
227    ///The type of the underlying digraph.
228    typedef typename Traits::Digraph Digraph;
229   
230    ///The type of the capacity of the arcs.
231    typedef typename Traits::CapacityMap::Value Value;
232    ///The type of the map that stores the arc capacities.
233    typedef typename Traits::CapacityMap CapacityMap;
234    ///The type of the map indicating if a node is processed.
235    typedef typename Traits::ProcessedMap ProcessedMap;
236    ///The type of the map that stores the cardinalities of the nodes.
237    typedef typename Traits::CardinalityMap CardinalityMap;
238    ///The cross reference type used for the current heap.
239    typedef typename Traits::HeapCrossRef HeapCrossRef;
240    ///The heap type used by the algorithm. It maximizes the priorities.
241    typedef typename Traits::Heap Heap;
242  private:
243    // Pointer to the underlying digraph.
244    const Digraph *_graph;
245    // Pointer to the capacity map
246    const CapacityMap *_capacity;
247    // Indicates if \ref _capacity is locally allocated (\c true) or not.
248    bool local_capacity;
249    // Pointer to the map of cardinality.
250    CardinalityMap *_cardinality;
251    // Indicates if \ref _cardinality is locally allocated (\c true) or not.
252    bool local_cardinality;
253    // Pointer to the map of processed status of the nodes.
254    ProcessedMap *_processed;
255    // Indicates if \ref _processed is locally allocated (\c true) or not.
256    bool local_processed;
257    // Pointer to the heap cross references.
258    HeapCrossRef *_heap_cross_ref;
259    // Indicates if \ref _heap_cross_ref is locally allocated (\c true) or not.
260    bool local_heap_cross_ref;
261    // Pointer to the heap.
262    Heap *_heap;
263    // Indicates if \ref _heap is locally allocated (\c true) or not.
264    bool local_heap;
265
266  public :
267
268    typedef MaxCardinalitySearch Create;
269 
270    ///\name Named template parameters
271
272    ///@{
273
274    template <class T>
275    struct DefCapacityMapTraits : public Traits {
276      typedef T CapacityMap;
277      static CapacityMap *createCapacityMap(const Digraph &) {
278        LEMON_ASSERT(false,"Uninitialized parameter.");
279        return 0;
280      }
281    };
282    /// \brief \ref named-templ-param "Named parameter" for setting
283    /// CapacityMap type
284    ///
285    /// \ref named-templ-param "Named parameter" for setting CapacityMap type
286    /// for the algorithm.
287    template <class T>
288    struct SetCapacityMap
289      : public MaxCardinalitySearch<Digraph, CapacityMap,
290                                    DefCapacityMapTraits<T> > {
291      typedef MaxCardinalitySearch<Digraph, CapacityMap,
292                                   DefCapacityMapTraits<T> > Create;
293    };
294
295    template <class T>
296    struct DefCardinalityMapTraits : public Traits {
297      typedef T CardinalityMap;
298      static CardinalityMap *createCardinalityMap(const Digraph &)
299      {
300        LEMON_ASSERT(false,"Uninitialized parameter.");
301        return 0;
302      }
303    };
304    /// \brief \ref named-templ-param "Named parameter" for setting
305    /// CardinalityMap type
306    ///
307    /// \ref named-templ-param "Named parameter" for setting CardinalityMap
308    /// type for the algorithm.
309    template <class T>
310    struct SetCardinalityMap
311      : public MaxCardinalitySearch<Digraph, CapacityMap,
312                                    DefCardinalityMapTraits<T> > {
313      typedef MaxCardinalitySearch<Digraph, CapacityMap,
314                                   DefCardinalityMapTraits<T> > Create;
315    };
316   
317    template <class T>
318    struct DefProcessedMapTraits : public Traits {
319      typedef T ProcessedMap;
320      static ProcessedMap *createProcessedMap(const Digraph &) {
321        LEMON_ASSERT(false,"Uninitialized parameter.");
322        return 0;
323      }
324    };
325    /// \brief \ref named-templ-param "Named parameter" for setting
326    /// ProcessedMap type
327    ///
328    /// \ref named-templ-param "Named parameter" for setting ProcessedMap type
329    /// for the algorithm.
330    template <class T>
331    struct SetProcessedMap
332      : public MaxCardinalitySearch<Digraph, CapacityMap,
333                                    DefProcessedMapTraits<T> > {
334      typedef MaxCardinalitySearch<Digraph, CapacityMap,
335                                   DefProcessedMapTraits<T> > Create;
336    };
337   
338    template <class H, class CR>
339    struct DefHeapTraits : public Traits {
340      typedef CR HeapCrossRef;
341      typedef H Heap;
342      static HeapCrossRef *createHeapCrossRef(const Digraph &) {
343        LEMON_ASSERT(false,"Uninitialized parameter.");
344        return 0;
345      }
346      static Heap *createHeap(HeapCrossRef &) {
347        LEMON_ASSERT(false,"Uninitialized parameter.");
348        return 0;
349      }
350    };
351    /// \brief \ref named-templ-param "Named parameter" for setting heap
352    /// and cross reference type
353    ///
354    /// \ref named-templ-param "Named parameter" for setting heap and cross
355    /// reference type for the algorithm.
356    template <class H, class CR = typename Digraph::template NodeMap<int> >
357    struct SetHeap
358      : public MaxCardinalitySearch<Digraph, CapacityMap,
359                                    DefHeapTraits<H, CR> > {
360      typedef MaxCardinalitySearch< Digraph, CapacityMap,
361                                    DefHeapTraits<H, CR> > Create;
362    };
363
364    template <class H, class CR>
365    struct DefStandardHeapTraits : public Traits {
366      typedef CR HeapCrossRef;
367      typedef H Heap;
368      static HeapCrossRef *createHeapCrossRef(const Digraph &digraph) {
369        return new HeapCrossRef(digraph);
370      }
371      static Heap *createHeap(HeapCrossRef &crossref) {
372        return new Heap(crossref);
373      }
374    };
375
376    /// \brief \ref named-templ-param "Named parameter" for setting heap and
377    /// cross reference type with automatic allocation
378    ///
379    /// \ref named-templ-param "Named parameter" for setting heap and cross
380    /// reference type. It can allocate the heap and the cross reference
381    /// object if the cross reference's constructor waits for the digraph as
382    /// parameter and the heap's constructor waits for the cross reference.
383    template <class H, class CR = typename Digraph::template NodeMap<int> >
384    struct SetStandardHeap
385      : public MaxCardinalitySearch<Digraph, CapacityMap,
386                                    DefStandardHeapTraits<H, CR> > {
387      typedef MaxCardinalitySearch<Digraph, CapacityMap,
388                                   DefStandardHeapTraits<H, CR> >
389      Create;
390    };
391   
392    ///@}
393
394
395  protected:
396
397    MaxCardinalitySearch() {}
398
399  public:     
400   
401    /// \brief Constructor.
402    ///
403    ///\param digraph the digraph the algorithm will run on.
404    ///\param capacity the capacity map used by the algorithm.
405    ///When no capacity map given, a constant 1 capacity map will
406    ///be allocated.
407#ifdef DOXYGEN
408    MaxCardinalitySearch(const Digraph& digraph,
409                         const CapacityMap& capacity=0 ) :
410#else
411    MaxCardinalitySearch(const Digraph& digraph,
412                         const CapacityMap& capacity=*static_cast<const CapacityMap*>(0) ) :
413#endif
414      _graph(&digraph),
415      _capacity(&capacity), local_capacity(false),
416      _cardinality(0), local_cardinality(false),
417      _processed(0), local_processed(false),
418      _heap_cross_ref(0), local_heap_cross_ref(false),
419      _heap(0), local_heap(false)
420    { }
421
422    /// \brief Destructor.
423    ~MaxCardinalitySearch() {
424      if(local_capacity) delete _capacity;
425      if(local_cardinality) delete _cardinality;
426      if(local_processed) delete _processed;
427      if(local_heap_cross_ref) delete _heap_cross_ref;
428      if(local_heap) delete _heap;
429    }
430
431    /// \brief Sets the capacity map.
432    ///
433    /// Sets the capacity map.
434    /// \return <tt> (*this) </tt>
435    MaxCardinalitySearch &capacityMap(const CapacityMap &m) {
436      if (local_capacity) {
437        delete _capacity;
438        local_capacity=false;
439      }
440      _capacity=&m;
441      return *this;
442    }
443
444    /// \brief Returns a const reference to the capacity map.
445    ///
446    /// Returns a const reference to the capacity map used by
447    /// the algorithm.
448    const CapacityMap &capacityMap() const {
449      return *_capacity;
450    }
451
452    /// \brief Sets the map storing the cardinalities calculated by the
453    /// algorithm.
454    ///
455    /// Sets the map storing the cardinalities calculated by the algorithm.
456    /// If you don't use this function before calling \ref run(),
457    /// it will allocate one. The destuctor deallocates this
458    /// automatically allocated map, of course.
459    /// \return <tt> (*this) </tt>
460    MaxCardinalitySearch &cardinalityMap(CardinalityMap &m) {
461      if(local_cardinality) {
462        delete _cardinality;
463        local_cardinality=false;
464      }
465      _cardinality = &m;
466      return *this;
467    }
468
469    /// \brief Sets the map storing the processed nodes.
470    ///
471    /// Sets the map storing the processed nodes.
472    /// If you don't use this function before calling \ref run(),
473    /// it will allocate one. The destuctor deallocates this
474    /// automatically allocated map, of course.
475    /// \return <tt> (*this) </tt>
476    MaxCardinalitySearch &processedMap(ProcessedMap &m)
477    {
478      if(local_processed) {
479        delete _processed;
480        local_processed=false;
481      }
482      _processed = &m;
483      return *this;
484    }
485
486    /// \brief Returns a const reference to the cardinality map.
487    ///
488    /// Returns a const reference to the cardinality map used by
489    /// the algorithm.
490    const ProcessedMap &processedMap() const {
491      return *_processed;
492    }
493
494    /// \brief Sets the heap and the cross reference used by algorithm.
495    ///
496    /// Sets the heap and the cross reference used by algorithm.
497    /// If you don't use this function before calling \ref run(),
498    /// it will allocate one. The destuctor deallocates this
499    /// automatically allocated map, of course.
500    /// \return <tt> (*this) </tt>
501    MaxCardinalitySearch &heap(Heap& hp, HeapCrossRef &cr) {
502      if(local_heap_cross_ref) {
503        delete _heap_cross_ref;
504        local_heap_cross_ref = false;
505      }
506      _heap_cross_ref = &cr;
507      if(local_heap) {
508        delete _heap;
509        local_heap = false;
510      }
511      _heap = &hp;
512      return *this;
513    }
514
515    /// \brief Returns a const reference to the heap.
516    ///
517    /// Returns a const reference to the heap used by
518    /// the algorithm.
519    const Heap &heap() const {
520      return *_heap;
521    }
522
523    /// \brief Returns a const reference to the cross reference.
524    ///
525    /// Returns a const reference to the cross reference
526    /// of the heap.
527    const HeapCrossRef &heapCrossRef() const {
528      return *_heap_cross_ref;
529    }
530
531  private:
532
533    typedef typename Digraph::Node Node;
534    typedef typename Digraph::NodeIt NodeIt;
535    typedef typename Digraph::Arc Arc;
536    typedef typename Digraph::InArcIt InArcIt;
537
538    void create_maps() {
539      if(!_capacity) {
540        local_capacity = true;
541        _capacity = Traits::createCapacityMap(*_graph);
542      }
543      if(!_cardinality) {
544        local_cardinality = true;
545        _cardinality = Traits::createCardinalityMap(*_graph);
546      }
547      if(!_processed) {
548        local_processed = true;
549        _processed = Traits::createProcessedMap(*_graph);
550      }
551      if (!_heap_cross_ref) {
552        local_heap_cross_ref = true;
553        _heap_cross_ref = Traits::createHeapCrossRef(*_graph);
554      }
555      if (!_heap) {
556        local_heap = true;
557        _heap = Traits::createHeap(*_heap_cross_ref);
558      }
559    }
560   
561    void finalizeNodeData(Node node, Value capacity) {
562      _processed->set(node, true);
563      _cardinality->set(node, capacity);
564    }
565
566  public:
567    /// \name Execution control
568    /// The simplest way to execute the algorithm is to use
569    /// one of the member functions called \ref run().
570    /// \n
571    /// If you need more control on the execution,
572    /// first you must call \ref init(), then you can add several source nodes
573    /// with \ref addSource().
574    /// Finally \ref start() will perform the computation.
575
576    ///@{
577
578    /// \brief Initializes the internal data structures.
579    ///
580    /// Initializes the internal data structures, and clears the heap.
581    void init() {
582      create_maps();
583      _heap->clear();
584      for (NodeIt it(*_graph) ; it != INVALID ; ++it) {
585        _processed->set(it, false);
586        _heap_cross_ref->set(it, Heap::PRE_HEAP);
587      }
588    }
589   
590    /// \brief Adds a new source node.
591    ///
592    /// Adds a new source node to the priority heap.
593    ///
594    /// It checks if the node has not yet been added to the heap.
595    void addSource(Node source, Value capacity = 0) {
596      if(_heap->state(source) == Heap::PRE_HEAP) {
597        _heap->push(source, capacity);
598      }
599    }
600   
601    /// \brief Processes the next node in the priority heap
602    ///
603    /// Processes the next node in the priority heap.
604    ///
605    /// \return The processed node.
606    ///
607    /// \warning The priority heap must not be empty!
608    Node processNextNode() {
609      Node node = _heap->top();
610      finalizeNodeData(node, _heap->prio());
611      _heap->pop();
612     
613      for (InArcIt it(*_graph, node); it != INVALID; ++it) {
614        Node source = _graph->source(it);
615        switch (_heap->state(source)) {
616        case Heap::PRE_HEAP:
617          _heap->push(source, (*_capacity)[it]);
618          break;
619        case Heap::IN_HEAP:
620          _heap->decrease(source, (*_heap)[source] + (*_capacity)[it]);
621          break;
622        case Heap::POST_HEAP:
623          break;
624        }
625      }
626      return node;
627    }
628
629    /// \brief Next node to be processed.
630    ///
631    /// Next node to be processed.
632    ///
633    /// \return The next node to be processed or INVALID if the
634    /// priority heap is empty.
635    Node nextNode() {
636      return !_heap->empty() ? _heap->top() : INVALID;
637    }
638 
639    /// \brief Returns \c false if there are nodes
640    /// to be processed in the priority heap
641    ///
642    /// Returns \c false if there are nodes
643    /// to be processed in the priority heap
644    bool emptyQueue() { return _heap->empty(); }
645    /// \brief Returns the number of the nodes to be processed
646    /// in the priority heap
647    ///
648    /// Returns the number of the nodes to be processed in the priority heap
649    int emptySize() { return _heap->size(); }
650   
651    /// \brief Executes the algorithm.
652    ///
653    /// Executes the algorithm.
654    ///
655    ///\pre init() must be called and at least one node should be added
656    /// with addSource() before using this function.
657    ///
658    /// This method runs the Maximum Cardinality Search algorithm from the
659    /// source node(s).
660    void start() {
661      while ( !_heap->empty() ) processNextNode();
662    }
663   
664    /// \brief Executes the algorithm until \c dest is reached.
665    ///
666    /// Executes the algorithm until \c dest is reached.
667    ///
668    /// \pre init() must be called and at least one node should be added
669    /// with addSource() before using this function.
670    ///
671    /// This method runs the %MaxCardinalitySearch algorithm from the source
672    /// nodes.
673    void start(Node dest) {
674      while ( !_heap->empty() && _heap->top()!=dest ) processNextNode();
675      if ( !_heap->empty() ) finalizeNodeData(_heap->top(), _heap->prio());
676    }
677   
678    /// \brief Executes the algorithm until a condition is met.
679    ///
680    /// Executes the algorithm until a condition is met.
681    ///
682    /// \pre init() must be called and at least one node should be added
683    /// with addSource() before using this function.
684    ///
685    /// \param nm must be a bool (or convertible) node map. The algorithm
686    /// will stop when it reaches a node \c v with <tt>nm[v]==true</tt>.
687    template <typename NodeBoolMap>
688    void start(const NodeBoolMap &nm) {
689      while ( !_heap->empty() && !nm[_heap->top()] ) processNextNode();
690      if ( !_heap->empty() ) finalizeNodeData(_heap->top(),_heap->prio());
691    }
692   
693    /// \brief Runs the maximum cardinality search algorithm from node \c s.
694    ///
695    /// This method runs the %MaxCardinalitySearch algorithm from a root
696    /// node \c s.
697    ///
698    ///\note d.run(s) is just a shortcut of the following code.
699    ///\code
700    ///  d.init();
701    ///  d.addSource(s);
702    ///  d.start();
703    ///\endcode
704    void run(Node s) {
705      init();
706      addSource(s);
707      start();
708    }
709
710    /// \brief Runs the maximum cardinality search algorithm for the
711    /// whole digraph.
712    ///
713    /// This method runs the %MaxCardinalitySearch algorithm from all
714    /// unprocessed node of the digraph.
715    ///
716    ///\note d.run(s) is just a shortcut of the following code.
717    ///\code
718    ///  d.init();
719    ///  for (NodeIt it(digraph); it != INVALID; ++it) {
720    ///    if (!d.reached(it)) {
721    ///      d.addSource(s);
722    ///      d.start();
723    ///    }
724    ///  }
725    ///\endcode
726    void run() {
727      init();
728      for (NodeIt it(*_graph); it != INVALID; ++it) {
729        if (!reached(it)) {
730          addSource(it);
731          start();
732        }
733      }
734    }
735   
736    ///@}
737
738    /// \name Query Functions
739    /// The results of the maximum cardinality search algorithm can be
740    /// obtained using these functions.
741    /// \n
742    /// Before the use of these functions, either run() or start() must be
743    /// called.
744   
745    ///@{
746
747    /// \brief The cardinality of a node.
748    ///
749    /// Returns the cardinality of a node.
750    /// \pre \ref run() must be called before using this function.
751    /// \warning If node \c v in unreachable from the root the return value
752    /// of this funcion is undefined.
753    Value cardinality(Node node) const { return (*_cardinality)[node]; }
754
755    /// \brief The current cardinality of a node.
756    ///
757    /// Returns the current cardinality of a node.
758    /// \pre the given node should be reached but not processed
759    Value currentCardinality(Node node) const { return (*_heap)[node]; }
760
761    /// \brief Returns a reference to the NodeMap of cardinalities.
762    ///
763    /// Returns a reference to the NodeMap of cardinalities. \pre \ref run()
764    /// must be called before using this function.
765    const CardinalityMap &cardinalityMap() const { return *_cardinality;}
766 
767    /// \brief Checks if a node is reachable from the root.
768    ///
769    /// Returns \c true if \c v is reachable from the root.
770    /// \warning The source nodes are initated as unreached.
771    /// \pre \ref run() must be called before using this function.
772    bool reached(Node v) { return (*_heap_cross_ref)[v] != Heap::PRE_HEAP; }
773
774    /// \brief Checks if a node is processed.
775    ///
776    /// Returns \c true if \c v is processed, i.e. the shortest
777    /// path to \c v has already found.
778    /// \pre \ref run() must be called before using this function.
779    bool processed(Node v) { return (*_heap_cross_ref)[v] == Heap::POST_HEAP; }
780   
781    ///@}
782  };
783
784}
785
786#endif
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