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/* -*- C++ -*-
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 *
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 * This file is a part of LEMON, a generic C++ optimization library
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 *
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 * Copyright (C) 2003-2008
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 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
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 * (Egervary Research Group on Combinatorial Optimization, EGRES).
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 *
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 * Permission to use, modify and distribute this software is granted
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 * provided that this copyright notice appears in all copies. For
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 * precise terms see the accompanying LICENSE file.
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 *
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 * This software is provided "AS IS" with no warranty of any kind,
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 * express or implied, and with no claim as to its suitability for any
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 * purpose.
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 *
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 */
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#ifndef LEMON_BELLMAN_FORD_H
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#define LEMON_BELLMAN_FORD_H
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/// \ingroup shortest_path
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/// \file
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/// \brief Bellman-Ford algorithm.
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#include <lemon/bits/path_dump.h>
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#include <lemon/core.h>
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#include <lemon/error.h>
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#include <lemon/maps.h>
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#include <lemon/path.h>
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#include <limits>
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namespace lemon {
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  /// \brief Default OperationTraits for the BellmanFord algorithm class.
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  ///  
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  /// This operation traits class defines all computational operations
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  /// and constants that are used in the Bellman-Ford algorithm.
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  /// The default implementation is based on the \c numeric_limits class.
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  /// If the numeric type does not have infinity value, then the maximum
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  /// value is used as extremal infinity value.
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  template <
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    typename V, 
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    bool has_inf = std::numeric_limits<V>::has_infinity>
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  struct BellmanFordDefaultOperationTraits {
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    /// \e
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    typedef V Value;
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    /// \brief Gives back the zero value of the type.
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    static Value zero() {
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      return static_cast<Value>(0);
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    }
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    /// \brief Gives back the positive infinity value of the type.
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    static Value infinity() {
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      return std::numeric_limits<Value>::infinity();
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    }
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    /// \brief Gives back the sum of the given two elements.
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    static Value plus(const Value& left, const Value& right) {
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      return left + right;
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    }
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    /// \brief Gives back \c true only if the first value is less than
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    /// the second.
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    static bool less(const Value& left, const Value& right) {
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      return left < right;
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    }
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  };
67

	
68
  template <typename V>
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  struct BellmanFordDefaultOperationTraits<V, false> {
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    typedef V Value;
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    static Value zero() {
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      return static_cast<Value>(0);
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    }
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    static Value infinity() {
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      return std::numeric_limits<Value>::max();
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    }
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    static Value plus(const Value& left, const Value& right) {
78
      if (left == infinity() || right == infinity()) return infinity();
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      return left + right;
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    }
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    static bool less(const Value& left, const Value& right) {
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      return left < right;
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    }
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  };
85
  
86
  /// \brief Default traits class of BellmanFord class.
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  ///
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  /// Default traits class of BellmanFord class.
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  /// \param GR The type of the digraph.
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  /// \param LEN The type of the length map.
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  template<typename GR, typename LEN>
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  struct BellmanFordDefaultTraits {
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    /// The type of the digraph the algorithm runs on. 
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    typedef GR Digraph;
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96
    /// \brief The type of the map that stores the arc lengths.
97
    ///
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    /// The type of the map that stores the arc lengths.
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    /// It must conform to the \ref concepts::ReadMap "ReadMap" concept.
100
    typedef LEN LengthMap;
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102
    /// The type of the arc lengths.
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    typedef typename LEN::Value Value;
104

	
105
    /// \brief Operation traits for Bellman-Ford algorithm.
106
    ///
107
    /// It defines the used operations and the infinity value for the
108
    /// given \c Value type.
109
    /// \see BellmanFordDefaultOperationTraits
110
    typedef BellmanFordDefaultOperationTraits<Value> OperationTraits;
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112
    /// \brief The type of the map that stores the last arcs of the 
113
    /// shortest paths.
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    /// 
115
    /// The type of the map that stores the last
116
    /// arcs of the shortest paths.
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    /// It must conform to the \ref concepts::WriteMap "WriteMap" concept.
118
    typedef typename GR::template NodeMap<typename GR::Arc> PredMap;
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120
    /// \brief Instantiates a \c PredMap.
121
    /// 
122
    /// This function instantiates a \ref PredMap. 
123
    /// \param g is the digraph to which we would like to define the
124
    /// \ref PredMap.
125
    static PredMap *createPredMap(const GR& g) {
126
      return new PredMap(g);
127
    }
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129
    /// \brief The type of the map that stores the distances of the nodes.
130
    ///
131
    /// The type of the map that stores the distances of the nodes.
132
    /// It must conform to the \ref concepts::WriteMap "WriteMap" concept.
133
    typedef typename GR::template NodeMap<typename LEN::Value> DistMap;
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135
    /// \brief Instantiates a \c DistMap.
136
    ///
137
    /// This function instantiates a \ref DistMap. 
138
    /// \param g is the digraph to which we would like to define the 
139
    /// \ref DistMap.
140
    static DistMap *createDistMap(const GR& g) {
141
      return new DistMap(g);
142
    }
143

	
144
  };
145
  
146
  /// \brief %BellmanFord algorithm class.
147
  ///
148
  /// \ingroup shortest_path
149
  /// This class provides an efficient implementation of the Bellman-Ford 
150
  /// algorithm. The maximum time complexity of the algorithm is
151
  /// <tt>O(ne)</tt>.
152
  ///
153
  /// The Bellman-Ford algorithm solves the single-source shortest path
154
  /// problem when the arcs can have negative lengths, but the digraph
155
  /// should not contain directed cycles with negative total length.
156
  /// If all arc costs are non-negative, consider to use the Dijkstra
157
  /// algorithm instead, since it is more efficient.
158
  ///
159
  /// The arc lengths are passed to the algorithm using a
160
  /// \ref concepts::ReadMap "ReadMap", so it is easy to change it to any 
161
  /// kind of length. The type of the length values is determined by the
162
  /// \ref concepts::ReadMap::Value "Value" type of the length map.
163
  ///
164
  /// There is also a \ref bellmanFord() "function-type interface" for the
165
  /// Bellman-Ford algorithm, which is convenient in the simplier cases and
166
  /// it can be used easier.
167
  ///
168
  /// \tparam GR The type of the digraph the algorithm runs on.
169
  /// The default type is \ref ListDigraph.
170
  /// \tparam LEN A \ref concepts::ReadMap "readable" arc map that specifies
171
  /// the lengths of the arcs. The default map type is
172
  /// \ref concepts::Digraph::ArcMap "GR::ArcMap<int>".
173
#ifdef DOXYGEN
174
  template <typename GR, typename LEN, typename TR>
175
#else
176
  template <typename GR=ListDigraph,
177
            typename LEN=typename GR::template ArcMap<int>,
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            typename TR=BellmanFordDefaultTraits<GR,LEN> >
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#endif
180
  class BellmanFord {
181
  public:
182

	
183
    ///The type of the underlying digraph.
184
    typedef typename TR::Digraph Digraph;
185
    
186
    /// \brief The type of the arc lengths.
187
    typedef typename TR::LengthMap::Value Value;
188
    /// \brief The type of the map that stores the arc lengths.
189
    typedef typename TR::LengthMap LengthMap;
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    /// \brief The type of the map that stores the last
191
    /// arcs of the shortest paths.
192
    typedef typename TR::PredMap PredMap;
193
    /// \brief The type of the map that stores the distances of the nodes.
194
    typedef typename TR::DistMap DistMap;
195
    /// The type of the paths.
196
    typedef PredMapPath<Digraph, PredMap> Path;
197
    ///\brief The \ref BellmanFordDefaultOperationTraits
198
    /// "operation traits class" of the algorithm.
199
    typedef typename TR::OperationTraits OperationTraits;
200

	
201
    ///The \ref BellmanFordDefaultTraits "traits class" of the algorithm.
202
    typedef TR Traits;
203

	
204
  private:
205

	
206
    typedef typename Digraph::Node Node;
207
    typedef typename Digraph::NodeIt NodeIt;
208
    typedef typename Digraph::Arc Arc;
209
    typedef typename Digraph::OutArcIt OutArcIt;
210

	
211
    // Pointer to the underlying digraph.
212
    const Digraph *_gr;
213
    // Pointer to the length map
214
    const LengthMap *_length;
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    // Pointer to the map of predecessors arcs.
216
    PredMap *_pred;
217
    // Indicates if _pred is locally allocated (true) or not.
218
    bool _local_pred;
219
    // Pointer to the map of distances.
220
    DistMap *_dist;
221
    // Indicates if _dist is locally allocated (true) or not.
222
    bool _local_dist;
223

	
224
    typedef typename Digraph::template NodeMap<bool> MaskMap;
225
    MaskMap *_mask;
226

	
227
    std::vector<Node> _process;
228

	
229
    // Creates the maps if necessary.
230
    void create_maps() {
231
      if(!_pred) {
232
	_local_pred = true;
233
	_pred = Traits::createPredMap(*_gr);
234
      }
235
      if(!_dist) {
236
	_local_dist = true;
237
	_dist = Traits::createDistMap(*_gr);
238
      }
239
      _mask = new MaskMap(*_gr, false);
240
    }
241
    
242
  public :
243
 
244
    typedef BellmanFord Create;
245

	
246
    /// \name Named Template Parameters
247

	
248
    ///@{
249

	
250
    template <class T>
251
    struct SetPredMapTraits : public Traits {
252
      typedef T PredMap;
253
      static PredMap *createPredMap(const Digraph&) {
254
        LEMON_ASSERT(false, "PredMap is not initialized");
255
        return 0; // ignore warnings
256
      }
257
    };
258

	
259
    /// \brief \ref named-templ-param "Named parameter" for setting
260
    /// \c PredMap type.
261
    ///
262
    /// \ref named-templ-param "Named parameter" for setting
263
    /// \c PredMap type.
264
    /// It must conform to the \ref concepts::WriteMap "WriteMap" concept.
265
    template <class T>
266
    struct SetPredMap 
267
      : public BellmanFord< Digraph, LengthMap, SetPredMapTraits<T> > {
268
      typedef BellmanFord< Digraph, LengthMap, SetPredMapTraits<T> > Create;
269
    };
270
    
271
    template <class T>
272
    struct SetDistMapTraits : public Traits {
273
      typedef T DistMap;
274
      static DistMap *createDistMap(const Digraph&) {
275
        LEMON_ASSERT(false, "DistMap is not initialized");
276
        return 0; // ignore warnings
277
      }
278
    };
279

	
280
    /// \brief \ref named-templ-param "Named parameter" for setting
281
    /// \c DistMap type.
282
    ///
283
    /// \ref named-templ-param "Named parameter" for setting
284
    /// \c DistMap type.
285
    /// It must conform to the \ref concepts::WriteMap "WriteMap" concept.
286
    template <class T>
287
    struct SetDistMap 
288
      : public BellmanFord< Digraph, LengthMap, SetDistMapTraits<T> > {
289
      typedef BellmanFord< Digraph, LengthMap, SetDistMapTraits<T> > Create;
290
    };
291

	
292
    template <class T>
293
    struct SetOperationTraitsTraits : public Traits {
294
      typedef T OperationTraits;
295
    };
296
    
297
    /// \brief \ref named-templ-param "Named parameter" for setting 
298
    /// \c OperationTraits type.
299
    ///
300
    /// \ref named-templ-param "Named parameter" for setting
301
    /// \c OperationTraits type.
302
    /// For more information see \ref BellmanFordDefaultOperationTraits.
303
    template <class T>
304
    struct SetOperationTraits
305
      : public BellmanFord< Digraph, LengthMap, SetOperationTraitsTraits<T> > {
306
      typedef BellmanFord< Digraph, LengthMap, SetOperationTraitsTraits<T> >
307
      Create;
308
    };
309
    
310
    ///@}
311

	
312
  protected:
313
    
314
    BellmanFord() {}
315

	
316
  public:      
317
    
318
    /// \brief Constructor.
319
    ///
320
    /// Constructor.
321
    /// \param g The digraph the algorithm runs on.
322
    /// \param length The length map used by the algorithm.
323
    BellmanFord(const Digraph& g, const LengthMap& length) :
324
      _gr(&g), _length(&length),
325
      _pred(0), _local_pred(false),
326
      _dist(0), _local_dist(false), _mask(0) {}
327
    
328
    ///Destructor.
329
    ~BellmanFord() {
330
      if(_local_pred) delete _pred;
331
      if(_local_dist) delete _dist;
332
      if(_mask) delete _mask;
333
    }
334

	
335
    /// \brief Sets the length map.
336
    ///
337
    /// Sets the length map.
338
    /// \return <tt>(*this)</tt>
339
    BellmanFord &lengthMap(const LengthMap &map) {
340
      _length = &map;
341
      return *this;
342
    }
343

	
344
    /// \brief Sets the map that stores the predecessor arcs.
345
    ///
346
    /// Sets the map that stores the predecessor arcs.
347
    /// If you don't use this function before calling \ref run()
348
    /// or \ref init(), an instance will be allocated automatically.
349
    /// The destructor deallocates this automatically allocated map,
350
    /// of course.
351
    /// \return <tt>(*this)</tt>
352
    BellmanFord &predMap(PredMap &map) {
353
      if(_local_pred) {
354
	delete _pred;
355
	_local_pred=false;
356
      }
357
      _pred = &map;
358
      return *this;
359
    }
360

	
361
    /// \brief Sets the map that stores the distances of the nodes.
362
    ///
363
    /// Sets the map that stores the distances of the nodes calculated
364
    /// by the algorithm.
365
    /// If you don't use this function before calling \ref run()
366
    /// or \ref init(), an instance will be allocated automatically.
367
    /// The destructor deallocates this automatically allocated map,
368
    /// of course.
369
    /// \return <tt>(*this)</tt>
370
    BellmanFord &distMap(DistMap &map) {
371
      if(_local_dist) {
372
	delete _dist;
373
	_local_dist=false;
374
      }
375
      _dist = &map;
376
      return *this;
377
    }
378

	
379
    /// \name Execution Control
380
    /// The simplest way to execute the Bellman-Ford algorithm is to use
381
    /// one of the member functions called \ref run().\n
382
    /// If you need better control on the execution, you have to call
383
    /// \ref init() first, then you can add several source nodes
384
    /// with \ref addSource(). Finally the actual path computation can be
385
    /// performed with \ref start(), \ref checkedStart() or
386
    /// \ref limitedStart().
387

	
388
    ///@{
389

	
390
    /// \brief Initializes the internal data structures.
391
    /// 
392
    /// Initializes the internal data structures. The optional parameter
393
    /// is the initial distance of each node.
394
    void init(const Value value = OperationTraits::infinity()) {
395
      create_maps();
396
      for (NodeIt it(*_gr); it != INVALID; ++it) {
397
	_pred->set(it, INVALID);
398
	_dist->set(it, value);
399
      }
400
      _process.clear();
401
      if (OperationTraits::less(value, OperationTraits::infinity())) {
402
	for (NodeIt it(*_gr); it != INVALID; ++it) {
403
	  _process.push_back(it);
404
	  _mask->set(it, true);
405
	}
406
      }
407
    }
408
    
409
    /// \brief Adds a new source node.
410
    ///
411
    /// This function adds a new source node. The optional second parameter
412
    /// is the initial distance of the node.
413
    void addSource(Node source, Value dst = OperationTraits::zero()) {
414
      _dist->set(source, dst);
415
      if (!(*_mask)[source]) {
416
	_process.push_back(source);
417
	_mask->set(source, true);
418
      }
419
    }
420

	
421
    /// \brief Executes one round from the Bellman-Ford algorithm.
422
    ///
423
    /// If the algoritm calculated the distances in the previous round
424
    /// exactly for the paths of at most \c k arcs, then this function
425
    /// will calculate the distances exactly for the paths of at most
426
    /// <tt>k+1</tt> arcs. Performing \c k iterations using this function
427
    /// calculates the shortest path distances exactly for the paths
428
    /// consisting of at most \c k arcs.
429
    ///
430
    /// \warning The paths with limited arc number cannot be retrieved
431
    /// easily with \ref path() or \ref predArc() functions. If you also
432
    /// need the shortest paths and not only the distances, you should
433
    /// store the \ref predMap() "predecessor map" after each iteration
434
    /// and build the path manually.
435
    ///
436
    /// \return \c true when the algorithm have not found more shorter
437
    /// paths.
438
    ///
439
    /// \see ActiveIt
440
    bool processNextRound() {
441
      for (int i = 0; i < int(_process.size()); ++i) {
442
	_mask->set(_process[i], false);
443
      }
444
      std::vector<Node> nextProcess;
445
      std::vector<Value> values(_process.size());
446
      for (int i = 0; i < int(_process.size()); ++i) {
447
	values[i] = (*_dist)[_process[i]];
448
      }
449
      for (int i = 0; i < int(_process.size()); ++i) {
450
	for (OutArcIt it(*_gr, _process[i]); it != INVALID; ++it) {
451
	  Node target = _gr->target(it);
452
	  Value relaxed = OperationTraits::plus(values[i], (*_length)[it]);
453
	  if (OperationTraits::less(relaxed, (*_dist)[target])) {
454
	    _pred->set(target, it);
455
	    _dist->set(target, relaxed);
456
	    if (!(*_mask)[target]) {
457
	      _mask->set(target, true);
458
	      nextProcess.push_back(target);
459
	    }
460
	  }	  
461
	}
462
      }
463
      _process.swap(nextProcess);
464
      return _process.empty();
465
    }
466

	
467
    /// \brief Executes one weak round from the Bellman-Ford algorithm.
468
    ///
469
    /// If the algorithm calculated the distances in the previous round
470
    /// at least for the paths of at most \c k arcs, then this function
471
    /// will calculate the distances at least for the paths of at most
472
    /// <tt>k+1</tt> arcs.
473
    /// This function does not make it possible to calculate the shortest
474
    /// path distances exactly for paths consisting of at most \c k arcs,
475
    /// this is why it is called weak round.
476
    ///
477
    /// \return \c true when the algorithm have not found more shorter
478
    /// paths.
479
    ///
480
    /// \see ActiveIt
481
    bool processNextWeakRound() {
482
      for (int i = 0; i < int(_process.size()); ++i) {
483
	_mask->set(_process[i], false);
484
      }
485
      std::vector<Node> nextProcess;
486
      for (int i = 0; i < int(_process.size()); ++i) {
487
	for (OutArcIt it(*_gr, _process[i]); it != INVALID; ++it) {
488
	  Node target = _gr->target(it);
489
	  Value relaxed = 
490
	    OperationTraits::plus((*_dist)[_process[i]], (*_length)[it]);
491
	  if (OperationTraits::less(relaxed, (*_dist)[target])) {
492
	    _pred->set(target, it);
493
	    _dist->set(target, relaxed);
494
	    if (!(*_mask)[target]) {
495
	      _mask->set(target, true);
496
	      nextProcess.push_back(target);
497
	    }
498
	  }	  
499
	}
500
      }
501
      _process.swap(nextProcess);
502
      return _process.empty();
503
    }
504

	
505
    /// \brief Executes the algorithm.
506
    ///
507
    /// Executes the algorithm.
508
    ///
509
    /// This method runs the Bellman-Ford algorithm from the root node(s)
510
    /// in order to compute the shortest path to each node.
511
    ///
512
    /// The algorithm computes
513
    /// - the shortest path tree (forest),
514
    /// - the distance of each node from the root(s).
515
    ///
516
    /// \pre init() must be called and at least one root node should be
517
    /// added with addSource() before using this function.
518
    void start() {
519
      int num = countNodes(*_gr) - 1;
520
      for (int i = 0; i < num; ++i) {
521
	if (processNextWeakRound()) break;
522
      }
523
    }
524

	
525
    /// \brief Executes the algorithm and checks the negative cycles.
526
    ///
527
    /// Executes the algorithm and checks the negative cycles.
528
    ///
529
    /// This method runs the Bellman-Ford algorithm from the root node(s)
530
    /// in order to compute the shortest path to each node and also checks
531
    /// if the digraph contains cycles with negative total length.
532
    ///
533
    /// The algorithm computes 
534
    /// - the shortest path tree (forest),
535
    /// - the distance of each node from the root(s).
536
    /// 
537
    /// \return \c false if there is a negative cycle in the digraph.
538
    ///
539
    /// \pre init() must be called and at least one root node should be
540
    /// added with addSource() before using this function. 
541
    bool checkedStart() {
542
      int num = countNodes(*_gr);
543
      for (int i = 0; i < num; ++i) {
544
	if (processNextWeakRound()) return true;
545
      }
546
      return _process.empty();
547
    }
548

	
549
    /// \brief Executes the algorithm with arc number limit.
550
    ///
551
    /// Executes the algorithm with arc number limit.
552
    ///
553
    /// This method runs the Bellman-Ford algorithm from the root node(s)
554
    /// in order to compute the shortest path distance for each node
555
    /// using only the paths consisting of at most \c num arcs.
556
    ///
557
    /// The algorithm computes
558
    /// - the limited distance of each node from the root(s),
559
    /// - the predecessor arc for each node.
560
    ///
561
    /// \warning The paths with limited arc number cannot be retrieved
562
    /// easily with \ref path() or \ref predArc() functions. If you also
563
    /// need the shortest paths and not only the distances, you should
564
    /// store the \ref predMap() "predecessor map" after each iteration
565
    /// and build the path manually.
566
    ///
567
    /// \pre init() must be called and at least one root node should be
568
    /// added with addSource() before using this function. 
569
    void limitedStart(int num) {
570
      for (int i = 0; i < num; ++i) {
571
	if (processNextRound()) break;
572
      }
573
    }
574
    
575
    /// \brief Runs the algorithm from the given root node.
576
    ///    
577
    /// This method runs the Bellman-Ford algorithm from the given root
578
    /// node \c s in order to compute the shortest path to each node.
579
    ///
580
    /// The algorithm computes
581
    /// - the shortest path tree (forest),
582
    /// - the distance of each node from the root(s).
583
    ///
584
    /// \note bf.run(s) is just a shortcut of the following code.
585
    /// \code
586
    ///   bf.init();
587
    ///   bf.addSource(s);
588
    ///   bf.start();
589
    /// \endcode
590
    void run(Node s) {
591
      init();
592
      addSource(s);
593
      start();
594
    }
595
    
596
    /// \brief Runs the algorithm from the given root node with arc
597
    /// number limit.
598
    ///    
599
    /// This method runs the Bellman-Ford algorithm from the given root
600
    /// node \c s in order to compute the shortest path distance for each
601
    /// node using only the paths consisting of at most \c num arcs.
602
    ///
603
    /// The algorithm computes
604
    /// - the limited distance of each node from the root(s),
605
    /// - the predecessor arc for each node.
606
    ///
607
    /// \warning The paths with limited arc number cannot be retrieved
608
    /// easily with \ref path() or \ref predArc() functions. If you also
609
    /// need the shortest paths and not only the distances, you should
610
    /// store the \ref predMap() "predecessor map" after each iteration
611
    /// and build the path manually.
612
    ///
613
    /// \note bf.run(s, num) is just a shortcut of the following code.
614
    /// \code
615
    ///   bf.init();
616
    ///   bf.addSource(s);
617
    ///   bf.limitedStart(num);
618
    /// \endcode
619
    void run(Node s, int num) {
620
      init();
621
      addSource(s);
622
      limitedStart(num);
623
    }
624
    
625
    ///@}
626

	
627
    /// \brief LEMON iterator for getting the active nodes.
628
    ///
629
    /// This class provides a common style LEMON iterator that traverses
630
    /// the active nodes of the Bellman-Ford algorithm after the last
631
    /// phase. These nodes should be checked in the next phase to
632
    /// find augmenting arcs outgoing from them.
633
    class ActiveIt {
634
    public:
635

	
636
      /// \brief Constructor.
637
      ///
638
      /// Constructor for getting the active nodes of the given BellmanFord
639
      /// instance. 
640
      ActiveIt(const BellmanFord& algorithm) : _algorithm(&algorithm)
641
      {
642
        _index = _algorithm->_process.size() - 1;
643
      }
644

	
645
      /// \brief Invalid constructor.
646
      ///
647
      /// Invalid constructor.
648
      ActiveIt(Invalid) : _algorithm(0), _index(-1) {}
649

	
650
      /// \brief Conversion to \c Node.
651
      ///
652
      /// Conversion to \c Node.
653
      operator Node() const { 
654
        return _index >= 0 ? _algorithm->_process[_index] : INVALID;
655
      }
656

	
657
      /// \brief Increment operator.
658
      ///
659
      /// Increment operator.
660
      ActiveIt& operator++() {
661
        --_index;
662
        return *this; 
663
      }
664

	
665
      bool operator==(const ActiveIt& it) const { 
666
        return static_cast<Node>(*this) == static_cast<Node>(it); 
667
      }
668
      bool operator!=(const ActiveIt& it) const { 
669
        return static_cast<Node>(*this) != static_cast<Node>(it); 
670
      }
671
      bool operator<(const ActiveIt& it) const { 
672
        return static_cast<Node>(*this) < static_cast<Node>(it); 
673
      }
674
      
675
    private:
676
      const BellmanFord* _algorithm;
677
      int _index;
678
    };
679
    
680
    /// \name Query Functions
681
    /// The result of the Bellman-Ford algorithm can be obtained using these
682
    /// functions.\n
683
    /// Either \ref run() or \ref init() should be called before using them.
684
    
685
    ///@{
686

	
687
    /// \brief The shortest path to the given node.
688
    ///    
689
    /// Gives back the shortest path to the given node from the root(s).
690
    ///
691
    /// \warning \c t should be reached from the root(s).
692
    ///
693
    /// \pre Either \ref run() or \ref init() must be called before
694
    /// using this function.
695
    Path path(Node t) const
696
    {
697
      return Path(*_gr, *_pred, t);
698
    }
699
	  
700
    /// \brief The distance of the given node from the root(s).
701
    ///
702
    /// Returns the distance of the given node from the root(s).
703
    ///
704
    /// \warning If node \c v is not reached from the root(s), then
705
    /// the return value of this function is undefined.
706
    ///
707
    /// \pre Either \ref run() or \ref init() must be called before
708
    /// using this function.
709
    Value dist(Node v) const { return (*_dist)[v]; }
710

	
711
    /// \brief Returns the 'previous arc' of the shortest path tree for
712
    /// the given node.
713
    ///
714
    /// This function returns the 'previous arc' of the shortest path
715
    /// tree for node \c v, i.e. it returns the last arc of a
716
    /// shortest path from a root to \c v. It is \c INVALID if \c v
717
    /// is not reached from the root(s) or if \c v is a root.
718
    ///
719
    /// The shortest path tree used here is equal to the shortest path
720
    /// tree used in \ref predNode() and \predMap().
721
    ///
722
    /// \pre Either \ref run() or \ref init() must be called before
723
    /// using this function.
724
    Arc predArc(Node v) const { return (*_pred)[v]; }
725

	
726
    /// \brief Returns the 'previous node' of the shortest path tree for
727
    /// the given node.
728
    ///
729
    /// This function returns the 'previous node' of the shortest path
730
    /// tree for node \c v, i.e. it returns the last but one node of
731
    /// a shortest path from a root to \c v. It is \c INVALID if \c v
732
    /// is not reached from the root(s) or if \c v is a root.
733
    ///
734
    /// The shortest path tree used here is equal to the shortest path
735
    /// tree used in \ref predArc() and \predMap().
736
    ///
737
    /// \pre Either \ref run() or \ref init() must be called before
738
    /// using this function.
739
    Node predNode(Node v) const { 
740
      return (*_pred)[v] == INVALID ? INVALID : _gr->source((*_pred)[v]); 
741
    }
742
    
743
    /// \brief Returns a const reference to the node map that stores the
744
    /// distances of the nodes.
745
    ///
746
    /// Returns a const reference to the node map that stores the distances
747
    /// of the nodes calculated by the algorithm.
748
    ///
749
    /// \pre Either \ref run() or \ref init() must be called before
750
    /// using this function.
751
    const DistMap &distMap() const { return *_dist;}
752
 
753
    /// \brief Returns a const reference to the node map that stores the
754
    /// predecessor arcs.
755
    ///
756
    /// Returns a const reference to the node map that stores the predecessor
757
    /// arcs, which form the shortest path tree (forest).
758
    ///
759
    /// \pre Either \ref run() or \ref init() must be called before
760
    /// using this function.
761
    const PredMap &predMap() const { return *_pred; }
762
 
763
    /// \brief Checks if a node is reached from the root(s).
764
    ///
765
    /// Returns \c true if \c v is reached from the root(s).
766
    ///
767
    /// \pre Either \ref run() or \ref init() must be called before
768
    /// using this function.
769
    bool reached(Node v) const {
770
      return (*_dist)[v] != OperationTraits::infinity();
771
    }
772

	
773
    /// \brief Gives back a negative cycle.
774
    ///    
775
    /// This function gives back a directed cycle with negative total
776
    /// length if the algorithm has already found one.
777
    /// Otherwise it gives back an empty path.
778
    lemon::Path<Digraph> negativeCycle() {
779
      typename Digraph::template NodeMap<int> state(*_gr, -1);
780
      lemon::Path<Digraph> cycle;
781
      for (int i = 0; i < int(_process.size()); ++i) {
782
        if (state[_process[i]] != -1) continue;
783
        for (Node v = _process[i]; (*_pred)[v] != INVALID;
784
             v = _gr->source((*_pred)[v])) {
785
          if (state[v] == i) {
786
            cycle.addFront((*_pred)[v]);
787
            for (Node u = _gr->source((*_pred)[v]); u != v;
788
                 u = _gr->source((*_pred)[u])) {
789
              cycle.addFront((*_pred)[u]);
790
            }
791
            return cycle;
792
          }
793
          else if (state[v] >= 0) {
794
            break;
795
          }
796
          state[v] = i;
797
        }
798
      }
799
      return cycle;
800
    }
801
    
802
    ///@}
803
  };
804
 
805
  /// \brief Default traits class of bellmanFord() function.
806
  ///
807
  /// Default traits class of bellmanFord() function.
808
  /// \tparam GR The type of the digraph.
809
  /// \tparam LEN The type of the length map.
810
  template <typename GR, typename LEN>
811
  struct BellmanFordWizardDefaultTraits {
812
    /// The type of the digraph the algorithm runs on. 
813
    typedef GR Digraph;
814

	
815
    /// \brief The type of the map that stores the arc lengths.
816
    ///
817
    /// The type of the map that stores the arc lengths.
818
    /// It must meet the \ref concepts::ReadMap "ReadMap" concept.
819
    typedef LEN LengthMap;
820

	
821
    /// The type of the arc lengths.
822
    typedef typename LEN::Value Value;
823

	
824
    /// \brief Operation traits for Bellman-Ford algorithm.
825
    ///
826
    /// It defines the used operations and the infinity value for the
827
    /// given \c Value type.
828
    /// \see BellmanFordDefaultOperationTraits
829
    typedef BellmanFordDefaultOperationTraits<Value> OperationTraits;
830

	
831
    /// \brief The type of the map that stores the last
832
    /// arcs of the shortest paths.
833
    /// 
834
    /// The type of the map that stores the last arcs of the shortest paths.
835
    /// It must conform to the \ref concepts::WriteMap "WriteMap" concept.
836
    typedef typename GR::template NodeMap<typename GR::Arc> PredMap;
837

	
838
    /// \brief Instantiates a \c PredMap.
839
    /// 
840
    /// This function instantiates a \ref PredMap.
841
    /// \param g is the digraph to which we would like to define the
842
    /// \ref PredMap.
843
    static PredMap *createPredMap(const GR &g) {
844
      return new PredMap(g);
845
    }
846

	
847
    /// \brief The type of the map that stores the distances of the nodes.
848
    ///
849
    /// The type of the map that stores the distances of the nodes.
850
    /// It must conform to the \ref concepts::WriteMap "WriteMap" concept.
851
    typedef typename GR::template NodeMap<Value> DistMap;
852

	
853
    /// \brief Instantiates a \c DistMap.
854
    ///
855
    /// This function instantiates a \ref DistMap. 
856
    /// \param g is the digraph to which we would like to define the
857
    /// \ref DistMap.
858
    static DistMap *createDistMap(const GR &g) {
859
      return new DistMap(g);
860
    }
861

	
862
    ///The type of the shortest paths.
863

	
864
    ///The type of the shortest paths.
865
    ///It must meet the \ref concepts::Path "Path" concept.
866
    typedef lemon::Path<Digraph> Path;
867
  };
868
  
869
  /// \brief Default traits class used by BellmanFordWizard.
870
  ///
871
  /// Default traits class used by BellmanFordWizard.
872
  /// \tparam GR The type of the digraph.
873
  /// \tparam LEN The type of the length map.
874
  template <typename GR, typename LEN>
875
  class BellmanFordWizardBase 
876
    : public BellmanFordWizardDefaultTraits<GR, LEN> {
877

	
878
    typedef BellmanFordWizardDefaultTraits<GR, LEN> Base;
879
  protected:
880
    // Type of the nodes in the digraph.
881
    typedef typename Base::Digraph::Node Node;
882

	
883
    // Pointer to the underlying digraph.
884
    void *_graph;
885
    // Pointer to the length map
886
    void *_length;
887
    // Pointer to the map of predecessors arcs.
888
    void *_pred;
889
    // Pointer to the map of distances.
890
    void *_dist;
891
    //Pointer to the shortest path to the target node.
892
    void *_path;
893
    //Pointer to the distance of the target node.
894
    void *_di;
895

	
896
    public:
897
    /// Constructor.
898
    
899
    /// This constructor does not require parameters, it initiates
900
    /// all of the attributes to default values \c 0.
901
    BellmanFordWizardBase() :
902
      _graph(0), _length(0), _pred(0), _dist(0), _path(0), _di(0) {}
903

	
904
    /// Constructor.
905
    
906
    /// This constructor requires two parameters,
907
    /// others are initiated to \c 0.
908
    /// \param gr The digraph the algorithm runs on.
909
    /// \param len The length map.
910
    BellmanFordWizardBase(const GR& gr, 
911
			  const LEN& len) :
912
      _graph(reinterpret_cast<void*>(const_cast<GR*>(&gr))), 
913
      _length(reinterpret_cast<void*>(const_cast<LEN*>(&len))), 
914
      _pred(0), _dist(0), _path(0), _di(0) {}
915

	
916
  };
917
  
918
  /// \brief Auxiliary class for the function-type interface of the
919
  /// \ref BellmanFord "Bellman-Ford" algorithm.
920
  ///
921
  /// This auxiliary class is created to implement the
922
  /// \ref bellmanFord() "function-type interface" of the
923
  /// \ref BellmanFord "Bellman-Ford" algorithm.
924
  /// It does not have own \ref run() method, it uses the
925
  /// functions and features of the plain \ref BellmanFord.
926
  ///
927
  /// This class should only be used through the \ref bellmanFord()
928
  /// function, which makes it easier to use the algorithm.
929
  template<class TR>
930
  class BellmanFordWizard : public TR {
931
    typedef TR Base;
932

	
933
    typedef typename TR::Digraph Digraph;
934

	
935
    typedef typename Digraph::Node Node;
936
    typedef typename Digraph::NodeIt NodeIt;
937
    typedef typename Digraph::Arc Arc;
938
    typedef typename Digraph::OutArcIt ArcIt;
939
    
940
    typedef typename TR::LengthMap LengthMap;
941
    typedef typename LengthMap::Value Value;
942
    typedef typename TR::PredMap PredMap;
943
    typedef typename TR::DistMap DistMap;
944
    typedef typename TR::Path Path;
945

	
946
  public:
947
    /// Constructor.
948
    BellmanFordWizard() : TR() {}
949

	
950
    /// \brief Constructor that requires parameters.
951
    ///
952
    /// Constructor that requires parameters.
953
    /// These parameters will be the default values for the traits class.
954
    /// \param gr The digraph the algorithm runs on.
955
    /// \param len The length map.
956
    BellmanFordWizard(const Digraph& gr, const LengthMap& len) 
957
      : TR(gr, len) {}
958

	
959
    /// \brief Copy constructor
960
    BellmanFordWizard(const TR &b) : TR(b) {}
961

	
962
    ~BellmanFordWizard() {}
963

	
964
    /// \brief Runs the Bellman-Ford algorithm from the given source node.
965
    ///    
966
    /// This method runs the Bellman-Ford algorithm from the given source
967
    /// node in order to compute the shortest path to each node.
968
    void run(Node s) {
969
      BellmanFord<Digraph,LengthMap,TR> 
970
	bf(*reinterpret_cast<const Digraph*>(Base::_graph), 
971
           *reinterpret_cast<const LengthMap*>(Base::_length));
972
      if (Base::_pred) bf.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
973
      if (Base::_dist) bf.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
974
      bf.run(s);
975
    }
976

	
977
    /// \brief Runs the Bellman-Ford algorithm to find the shortest path
978
    /// between \c s and \c t.
979
    ///
980
    /// This method runs the Bellman-Ford algorithm from node \c s
981
    /// in order to compute the shortest path to node \c t.
982
    /// Actually, it computes the shortest path to each node, but using
983
    /// this function you can retrieve the distance and the shortest path
984
    /// for a single target node easier.
985
    ///
986
    /// \return \c true if \c t is reachable form \c s.
987
    bool run(Node s, Node t) {
988
      BellmanFord<Digraph,LengthMap,TR>
989
        bf(*reinterpret_cast<const Digraph*>(Base::_graph),
990
           *reinterpret_cast<const LengthMap*>(Base::_length));
991
      if (Base::_pred) bf.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
992
      if (Base::_dist) bf.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
993
      bf.run(s);
994
      if (Base::_path) *reinterpret_cast<Path*>(Base::_path) = bf.path(t);
995
      if (Base::_di) *reinterpret_cast<Value*>(Base::_di) = bf.dist(t);
996
      return bf.reached(t);
997
    }
998

	
999
    template<class T>
1000
    struct SetPredMapBase : public Base {
1001
      typedef T PredMap;
1002
      static PredMap *createPredMap(const Digraph &) { return 0; };
1003
      SetPredMapBase(const TR &b) : TR(b) {}
1004
    };
1005
    
1006
    /// \brief \ref named-templ-param "Named parameter" for setting
1007
    /// the predecessor map.
1008
    ///
1009
    /// \ref named-templ-param "Named parameter" for setting
1010
    /// the map that stores the predecessor arcs of the nodes.
1011
    template<class T>
1012
    BellmanFordWizard<SetPredMapBase<T> > predMap(const T &t) {
1013
      Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
1014
      return BellmanFordWizard<SetPredMapBase<T> >(*this);
1015
    }
1016
    
1017
    template<class T>
1018
    struct SetDistMapBase : public Base {
1019
      typedef T DistMap;
1020
      static DistMap *createDistMap(const Digraph &) { return 0; };
1021
      SetDistMapBase(const TR &b) : TR(b) {}
1022
    };
1023
    
1024
    /// \brief \ref named-templ-param "Named parameter" for setting
1025
    /// the distance map.
1026
    ///
1027
    /// \ref named-templ-param "Named parameter" for setting
1028
    /// the map that stores the distances of the nodes calculated
1029
    /// by the algorithm.
1030
    template<class T>
1031
    BellmanFordWizard<SetDistMapBase<T> > distMap(const T &t) {
1032
      Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t));
1033
      return BellmanFordWizard<SetDistMapBase<T> >(*this);
1034
    }
1035

	
1036
    template<class T>
1037
    struct SetPathBase : public Base {
1038
      typedef T Path;
1039
      SetPathBase(const TR &b) : TR(b) {}
1040
    };
1041

	
1042
    /// \brief \ref named-func-param "Named parameter" for getting
1043
    /// the shortest path to the target node.
1044
    ///
1045
    /// \ref named-func-param "Named parameter" for getting
1046
    /// the shortest path to the target node.
1047
    template<class T>
1048
    BellmanFordWizard<SetPathBase<T> > path(const T &t)
1049
    {
1050
      Base::_path=reinterpret_cast<void*>(const_cast<T*>(&t));
1051
      return BellmanFordWizard<SetPathBase<T> >(*this);
1052
    }
1053

	
1054
    /// \brief \ref named-func-param "Named parameter" for getting
1055
    /// the distance of the target node.
1056
    ///
1057
    /// \ref named-func-param "Named parameter" for getting
1058
    /// the distance of the target node.
1059
    BellmanFordWizard dist(const Value &d)
1060
    {
1061
      Base::_di=reinterpret_cast<void*>(const_cast<Value*>(&d));
1062
      return *this;
1063
    }
1064
    
1065
  };
1066
  
1067
  /// \brief Function type interface for the \ref BellmanFord "Bellman-Ford"
1068
  /// algorithm.
1069
  ///
1070
  /// \ingroup shortest_path
1071
  /// Function type interface for the \ref BellmanFord "Bellman-Ford"
1072
  /// algorithm.
1073
  ///
1074
  /// This function also has several \ref named-templ-func-param 
1075
  /// "named parameters", they are declared as the members of class 
1076
  /// \ref BellmanFordWizard.
1077
  /// The following examples show how to use these parameters.
1078
  /// \code
1079
  ///   // Compute shortest path from node s to each node
1080
  ///   bellmanFord(g,length).predMap(preds).distMap(dists).run(s);
1081
  ///
1082
  ///   // Compute shortest path from s to t
1083
  ///   bool reached = bellmanFord(g,length).path(p).dist(d).run(s,t);
1084
  /// \endcode
1085
  /// \warning Don't forget to put the \ref BellmanFordWizard::run() "run()"
1086
  /// to the end of the parameter list.
1087
  /// \sa BellmanFordWizard
1088
  /// \sa BellmanFord
1089
  template<typename GR, typename LEN>
1090
  BellmanFordWizard<BellmanFordWizardBase<GR,LEN> >
1091
  bellmanFord(const GR& digraph,
1092
	      const LEN& length)
1093
  {
1094
    return BellmanFordWizard<BellmanFordWizardBase<GR,LEN> >(digraph, length);
1095
  }
1096

	
1097
} //END OF NAMESPACE LEMON
1098

	
1099
#endif
1100

	
Ignore white space 384 line context
1
/* -*- mode: C++; indent-tabs-mode: nil; -*-
2
 *
3
 * This file is a part of LEMON, a generic C++ optimization library.
4
 *
5
 * Copyright (C) 2003-2009
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_BINOM_HEAP_H
20
#define LEMON_BINOM_HEAP_H
21

	
22
///\file
23
///\ingroup heaps
24
///\brief Binomial Heap implementation.
25

	
26
#include <vector>
27
#include <utility>
28
#include <functional>
29
#include <lemon/math.h>
30
#include <lemon/counter.h>
31

	
32
namespace lemon {
33

	
34
  /// \ingroup heaps
35
  ///
36
  ///\brief Binomial heap data structure.
37
  ///
38
  /// This class implements the \e binomial \e heap data structure.
39
  /// It fully conforms to the \ref concepts::Heap "heap concept".
40
  ///
41
  /// The methods \ref increase() and \ref erase() are not efficient
42
  /// in a binomial heap. In case of many calls of these operations,
43
  /// it is better to use other heap structure, e.g. \ref BinHeap
44
  /// "binary heap".
45
  ///
46
  /// \tparam PR Type of the priorities of the items.
47
  /// \tparam IM A read-writable item map with \c int values, used
48
  /// internally to handle the cross references.
49
  /// \tparam CMP A functor class for comparing the priorities.
50
  /// The default is \c std::less<PR>.
51
#ifdef DOXYGEN
52
  template <typename PR, typename IM, typename CMP>
53
#else
54
  template <typename PR, typename IM, typename CMP = std::less<PR> >
55
#endif
56
  class BinomHeap {
57
  public:
58
    /// Type of the item-int map.
59
    typedef IM ItemIntMap;
60
    /// Type of the priorities.
61
    typedef PR Prio;
62
    /// Type of the items stored in the heap.
63
    typedef typename ItemIntMap::Key Item;
64
    /// Functor type for comparing the priorities.
65
    typedef CMP Compare;
66

	
67
    /// \brief Type to represent the states of the items.
68
    ///
69
    /// Each item has a state associated to it. It can be "in heap",
70
    /// "pre-heap" or "post-heap". The latter two are indifferent from the
71
    /// heap's point of view, but may be useful to the user.
72
    ///
73
    /// The item-int map must be initialized in such way that it assigns
74
    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
75
    enum State {
76
      IN_HEAP = 0,    ///< = 0.
77
      PRE_HEAP = -1,  ///< = -1.
78
      POST_HEAP = -2  ///< = -2.
79
    };
80

	
81
  private:
82
    class Store;
83

	
84
    std::vector<Store> _data;
85
    int _min, _head;
86
    ItemIntMap &_iim;
87
    Compare _comp;
88
    int _num_items;
89

	
90
  public:
91
    /// \brief Constructor.
92
    ///
93
    /// Constructor.
94
    /// \param map A map that assigns \c int values to the items.
95
    /// It is used internally to handle the cross references.
96
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
97
    explicit BinomHeap(ItemIntMap &map)
98
      : _min(0), _head(-1), _iim(map), _num_items(0) {}
99

	
100
    /// \brief Constructor.
101
    ///
102
    /// Constructor.
103
    /// \param map A map that assigns \c int values to the items.
104
    /// It is used internally to handle the cross references.
105
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
106
    /// \param comp The function object used for comparing the priorities.
107
    BinomHeap(ItemIntMap &map, const Compare &comp)
108
      : _min(0), _head(-1), _iim(map), _comp(comp), _num_items(0) {}
109

	
110
    /// \brief The number of items stored in the heap.
111
    ///
112
    /// This function returns the number of items stored in the heap.
113
    int size() const { return _num_items; }
114

	
115
    /// \brief Check if the heap is empty.
116
    ///
117
    /// This function returns \c true if the heap is empty.
118
    bool empty() const { return _num_items==0; }
119

	
120
    /// \brief Make the heap empty.
121
    ///
122
    /// This functon makes the heap empty.
123
    /// It does not change the cross reference map. If you want to reuse
124
    /// a heap that is not surely empty, you should first clear it and
125
    /// then you should set the cross reference map to \c PRE_HEAP
126
    /// for each item.
127
    void clear() {
128
      _data.clear(); _min=0; _num_items=0; _head=-1;
129
    }
130

	
131
    /// \brief Set the priority of an item or insert it, if it is
132
    /// not stored in the heap.
133
    ///
134
    /// This method sets the priority of the given item if it is
135
    /// already stored in the heap. Otherwise it inserts the given
136
    /// item into the heap with the given priority.
137
    /// \param item The item.
138
    /// \param value The priority.
139
    void set (const Item& item, const Prio& value) {
140
      int i=_iim[item];
141
      if ( i >= 0 && _data[i].in ) {
142
        if ( _comp(value, _data[i].prio) ) decrease(item, value);
143
        if ( _comp(_data[i].prio, value) ) increase(item, value);
144
      } else push(item, value);
145
    }
146

	
147
    /// \brief Insert an item into the heap with the given priority.
148
    ///
149
    /// This function inserts the given item into the heap with the
150
    /// given priority.
151
    /// \param item The item to insert.
152
    /// \param value The priority of the item.
153
    /// \pre \e item must not be stored in the heap.
154
    void push (const Item& item, const Prio& value) {
155
      int i=_iim[item];
156
      if ( i<0 ) {
157
        int s=_data.size();
158
        _iim.set( item,s );
159
        Store st;
160
        st.name=item;
161
        st.prio=value;
162
        _data.push_back(st);
163
        i=s;
164
      }
165
      else {
166
        _data[i].parent=_data[i].right_neighbor=_data[i].child=-1;
167
        _data[i].degree=0;
168
        _data[i].in=true;
169
        _data[i].prio=value;
170
      }
171

	
172
      if( 0==_num_items ) {
173
        _head=i;
174
        _min=i;
175
      } else {
176
        merge(i);
177
        if( _comp(_data[i].prio, _data[_min].prio) ) _min=i;
178
      }
179
      ++_num_items;
180
    }
181

	
182
    /// \brief Return the item having minimum priority.
183
    ///
184
    /// This function returns the item having minimum priority.
185
    /// \pre The heap must be non-empty.
186
    Item top() const { return _data[_min].name; }
187

	
188
    /// \brief The minimum priority.
189
    ///
190
    /// This function returns the minimum priority.
191
    /// \pre The heap must be non-empty.
192
    Prio prio() const { return _data[_min].prio; }
193

	
194
    /// \brief The priority of the given item.
195
    ///
196
    /// This function returns the priority of the given item.
197
    /// \param item The item.
198
    /// \pre \e item must be in the heap.
199
    const Prio& operator[](const Item& item) const {
200
      return _data[_iim[item]].prio;
201
    }
202

	
203
    /// \brief Remove the item having minimum priority.
204
    ///
205
    /// This function removes the item having minimum priority.
206
    /// \pre The heap must be non-empty.
207
    void pop() {
208
      _data[_min].in=false;
209

	
210
      int head_child=-1;
211
      if ( _data[_min].child!=-1 ) {
212
        int child=_data[_min].child;
213
        int neighb;
214
        while( child!=-1 ) {
215
          neighb=_data[child].right_neighbor;
216
          _data[child].parent=-1;
217
          _data[child].right_neighbor=head_child;
218
          head_child=child;
219
          child=neighb;
220
        }
221
      }
222

	
223
      if ( _data[_head].right_neighbor==-1 ) {
224
        // there was only one root
225
        _head=head_child;
226
      }
227
      else {
228
        // there were more roots
229
        if( _head!=_min )  { unlace(_min); }
230
        else { _head=_data[_head].right_neighbor; }
231
        merge(head_child);
232
      }
233
      _min=findMin();
234
      --_num_items;
235
    }
236

	
237
    /// \brief Remove the given item from the heap.
238
    ///
239
    /// This function removes the given item from the heap if it is
240
    /// already stored.
241
    /// \param item The item to delete.
242
    /// \pre \e item must be in the heap.
243
    void erase (const Item& item) {
244
      int i=_iim[item];
245
      if ( i >= 0 && _data[i].in ) {
246
        decrease( item, _data[_min].prio-1 );
247
        pop();
248
      }
249
    }
250

	
251
    /// \brief Decrease the priority of an item to the given value.
252
    ///
253
    /// This function decreases the priority of an item to the given value.
254
    /// \param item The item.
255
    /// \param value The priority.
256
    /// \pre \e item must be stored in the heap with priority at least \e value.
257
    void decrease (Item item, const Prio& value) {
258
      int i=_iim[item];
259
      int p=_data[i].parent;
260
      _data[i].prio=value;
261
      
262
      while( p!=-1 && _comp(value, _data[p].prio) ) {
263
        _data[i].name=_data[p].name;
264
        _data[i].prio=_data[p].prio;
265
        _data[p].name=item;
266
        _data[p].prio=value;
267
        _iim[_data[i].name]=i;
268
        i=p;
269
        p=_data[p].parent;
270
      }
271
      _iim[item]=i;
272
      if ( _comp(value, _data[_min].prio) ) _min=i;
273
    }
274

	
275
    /// \brief Increase the priority of an item to the given value.
276
    ///
277
    /// This function increases the priority of an item to the given value.
278
    /// \param item The item.
279
    /// \param value The priority.
280
    /// \pre \e item must be stored in the heap with priority at most \e value.
281
    void increase (Item item, const Prio& value) {
282
      erase(item);
283
      push(item, value);
284
    }
285

	
286
    /// \brief Return the state of an item.
287
    ///
288
    /// This method returns \c PRE_HEAP if the given item has never
289
    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
290
    /// and \c POST_HEAP otherwise.
291
    /// In the latter case it is possible that the item will get back
292
    /// to the heap again.
293
    /// \param item The item.
294
    State state(const Item &item) const {
295
      int i=_iim[item];
296
      if( i>=0 ) {
297
        if ( _data[i].in ) i=0;
298
        else i=-2;
299
      }
300
      return State(i);
301
    }
302

	
303
    /// \brief Set the state of an item in the heap.
304
    ///
305
    /// This function sets the state of the given item in the heap.
306
    /// It can be used to manually clear the heap when it is important
307
    /// to achive better time complexity.
308
    /// \param i The item.
309
    /// \param st The state. It should not be \c IN_HEAP.
310
    void state(const Item& i, State st) {
311
      switch (st) {
312
      case POST_HEAP:
313
      case PRE_HEAP:
314
        if (state(i) == IN_HEAP) {
315
          erase(i);
316
        }
317
        _iim[i] = st;
318
        break;
319
      case IN_HEAP:
320
        break;
321
      }
322
    }
323

	
324
  private:
325
    
326
    // Find the minimum of the roots
327
    int findMin() {
328
      if( _head!=-1 ) {
329
        int min_loc=_head, min_val=_data[_head].prio;
330
        for( int x=_data[_head].right_neighbor; x!=-1;
331
             x=_data[x].right_neighbor ) {
332
          if( _comp( _data[x].prio,min_val ) ) {
333
            min_val=_data[x].prio;
334
            min_loc=x;
335
          }
336
        }
337
        return min_loc;
338
      }
339
      else return -1;
340
    }
341

	
342
    // Merge the heap with another heap starting at the given position
343
    void merge(int a) {
344
      if( _head==-1 || a==-1 ) return;
345
      if( _data[a].right_neighbor==-1 &&
346
          _data[a].degree<=_data[_head].degree ) {
347
        _data[a].right_neighbor=_head;
348
        _head=a;
349
      } else {
350
        interleave(a);
351
      }
352
      if( _data[_head].right_neighbor==-1 ) return;
353
      
354
      int x=_head;
355
      int x_prev=-1, x_next=_data[x].right_neighbor;
356
      while( x_next!=-1 ) {
357
        if( _data[x].degree!=_data[x_next].degree ||
358
            ( _data[x_next].right_neighbor!=-1 &&
359
              _data[_data[x_next].right_neighbor].degree==_data[x].degree ) ) {
360
          x_prev=x;
361
          x=x_next;
362
        }
363
        else {
364
          if( _comp(_data[x_next].prio,_data[x].prio) ) {
365
            if( x_prev==-1 ) {
366
              _head=x_next;
367
            } else {
368
              _data[x_prev].right_neighbor=x_next;
369
            }
370
            fuse(x,x_next);
371
            x=x_next;
372
          }
373
          else {
374
            _data[x].right_neighbor=_data[x_next].right_neighbor;
375
            fuse(x_next,x);
376
          }
377
        }
378
        x_next=_data[x].right_neighbor;
379
      }
380
    }
381

	
382
    // Interleave the elements of the given list into the list of the roots
383
    void interleave(int a) {
384
      int p=_head, q=a;
385
      int curr=_data.size();
386
      _data.push_back(Store());
387
      
388
      while( p!=-1 || q!=-1 ) {
389
        if( q==-1 || ( p!=-1 && _data[p].degree<_data[q].degree ) ) {
390
          _data[curr].right_neighbor=p;
391
          curr=p;
392
          p=_data[p].right_neighbor;
393
        }
394
        else {
395
          _data[curr].right_neighbor=q;
396
          curr=q;
397
          q=_data[q].right_neighbor;
398
        }
399
      }
400
      
401
      _head=_data.back().right_neighbor;
402
      _data.pop_back();
403
    }
404

	
405
    // Lace node a under node b
406
    void fuse(int a, int b) {
407
      _data[a].parent=b;
408
      _data[a].right_neighbor=_data[b].child;
409
      _data[b].child=a;
410

	
411
      ++_data[b].degree;
412
    }
413

	
414
    // Unlace node a (if it has siblings)
415
    void unlace(int a) {
416
      int neighb=_data[a].right_neighbor;
417
      int other=_head;
418

	
419
      while( _data[other].right_neighbor!=a )
420
        other=_data[other].right_neighbor;
421
      _data[other].right_neighbor=neighb;
422
    }
423

	
424
  private:
425

	
426
    class Store {
427
      friend class BinomHeap;
428

	
429
      Item name;
430
      int parent;
431
      int right_neighbor;
432
      int child;
433
      int degree;
434
      bool in;
435
      Prio prio;
436

	
437
      Store() : parent(-1), right_neighbor(-1), child(-1), degree(0),
438
        in(true) {}
439
    };
440
  };
441

	
442
} //namespace lemon
443

	
444
#endif //LEMON_BINOM_HEAP_H
445

	
Ignore white space 384 line context
1
/* -*- mode: C++; indent-tabs-mode: nil; -*-
2
 *
3
 * This file is a part of LEMON, a generic C++ optimization library.
4
 *
5
 * Copyright (C) 2003-2009
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_FOURARY_HEAP_H
20
#define LEMON_FOURARY_HEAP_H
21

	
22
///\ingroup heaps
23
///\file
24
///\brief Fourary heap implementation.
25

	
26
#include <vector>
27
#include <utility>
28
#include <functional>
29

	
30
namespace lemon {
31

	
32
  /// \ingroup heaps
33
  ///
34
  ///\brief Fourary heap data structure.
35
  ///
36
  /// This class implements the \e fourary \e heap data structure.
37
  /// It fully conforms to the \ref concepts::Heap "heap concept".
38
  ///
39
  /// The fourary heap is a specialization of the \ref KaryHeap "K-ary heap"
40
  /// for <tt>K=4</tt>. It is similar to the \ref BinHeap "binary heap",
41
  /// but its nodes have at most four children, instead of two.
42
  ///
43
  /// \tparam PR Type of the priorities of the items.
44
  /// \tparam IM A read-writable item map with \c int values, used
45
  /// internally to handle the cross references.
46
  /// \tparam CMP A functor class for comparing the priorities.
47
  /// The default is \c std::less<PR>.
48
  ///
49
  ///\sa BinHeap
50
  ///\sa KaryHeap
51
#ifdef DOXYGEN
52
  template <typename PR, typename IM, typename CMP>
53
#else
54
  template <typename PR, typename IM, typename CMP = std::less<PR> >
55
#endif
56
  class FouraryHeap {
57
  public:
58
    /// Type of the item-int map.
59
    typedef IM ItemIntMap;
60
    /// Type of the priorities.
61
    typedef PR Prio;
62
    /// Type of the items stored in the heap.
63
    typedef typename ItemIntMap::Key Item;
64
    /// Type of the item-priority pairs.
65
    typedef std::pair<Item,Prio> Pair;
66
    /// Functor type for comparing the priorities.
67
    typedef CMP Compare;
68

	
69
    /// \brief Type to represent the states of the items.
70
    ///
71
    /// Each item has a state associated to it. It can be "in heap",
72
    /// "pre-heap" or "post-heap". The latter two are indifferent from the
73
    /// heap's point of view, but may be useful to the user.
74
    ///
75
    /// The item-int map must be initialized in such way that it assigns
76
    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
77
    enum State {
78
      IN_HEAP = 0,    ///< = 0.
79
      PRE_HEAP = -1,  ///< = -1.
80
      POST_HEAP = -2  ///< = -2.
81
    };
82

	
83
  private:
84
    std::vector<Pair> _data;
85
    Compare _comp;
86
    ItemIntMap &_iim;
87

	
88
  public:
89
    /// \brief Constructor.
90
    ///
91
    /// Constructor.
92
    /// \param map A map that assigns \c int values to the items.
93
    /// It is used internally to handle the cross references.
94
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
95
    explicit FouraryHeap(ItemIntMap &map) : _iim(map) {}
96

	
97
    /// \brief Constructor.
98
    ///
99
    /// Constructor.
100
    /// \param map A map that assigns \c int values to the items.
101
    /// It is used internally to handle the cross references.
102
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
103
    /// \param comp The function object used for comparing the priorities.
104
    FouraryHeap(ItemIntMap &map, const Compare &comp)
105
      : _iim(map), _comp(comp) {}
106

	
107
    /// \brief The number of items stored in the heap.
108
    ///
109
    /// This function returns the number of items stored in the heap.
110
    int size() const { return _data.size(); }
111

	
112
    /// \brief Check if the heap is empty.
113
    ///
114
    /// This function returns \c true if the heap is empty.
115
    bool empty() const { return _data.empty(); }
116

	
117
    /// \brief Make the heap empty.
118
    ///
119
    /// This functon makes the heap empty.
120
    /// It does not change the cross reference map. If you want to reuse
121
    /// a heap that is not surely empty, you should first clear it and
122
    /// then you should set the cross reference map to \c PRE_HEAP
123
    /// for each item.
124
    void clear() { _data.clear(); }
125

	
126
  private:
127
    static int parent(int i) { return (i-1)/4; }
128
    static int firstChild(int i) { return 4*i+1; }
129

	
130
    bool less(const Pair &p1, const Pair &p2) const {
131
      return _comp(p1.second, p2.second);
132
    }
133

	
134
    void bubbleUp(int hole, Pair p) {
135
      int par = parent(hole);
136
      while( hole>0 && less(p,_data[par]) ) {
137
        move(_data[par],hole);
138
        hole = par;
139
        par = parent(hole);
140
      }
141
      move(p, hole);
142
    }
143

	
144
    void bubbleDown(int hole, Pair p, int length) {
145
      if( length>1 ) {
146
        int child = firstChild(hole);
147
        while( child+3<length ) {
148
          int min=child;
149
          if( less(_data[++child], _data[min]) ) min=child;
150
          if( less(_data[++child], _data[min]) ) min=child;
151
          if( less(_data[++child], _data[min]) ) min=child;
152
          if( !less(_data[min], p) )
153
            goto ok;
154
          move(_data[min], hole);
155
          hole = min;
156
          child = firstChild(hole);
157
        }
158
        if ( child<length ) {
159
          int min = child;
160
          if( ++child<length && less(_data[child], _data[min]) ) min=child;
161
          if( ++child<length && less(_data[child], _data[min]) ) min=child;
162
          if( less(_data[min], p) ) {
163
            move(_data[min], hole);
164
            hole = min;
165
          }
166
        }
167
      }
168
    ok:
169
      move(p, hole);
170
    }
171

	
172
    void move(const Pair &p, int i) {
173
      _data[i] = p;
174
      _iim.set(p.first, i);
175
    }
176

	
177
  public:
178
    /// \brief Insert a pair of item and priority into the heap.
179
    ///
180
    /// This function inserts \c p.first to the heap with priority
181
    /// \c p.second.
182
    /// \param p The pair to insert.
183
    /// \pre \c p.first must not be stored in the heap.
184
    void push(const Pair &p) {
185
      int n = _data.size();
186
      _data.resize(n+1);
187
      bubbleUp(n, p);
188
    }
189

	
190
    /// \brief Insert an item into the heap with the given priority.
191
    ///
192
    /// This function inserts the given item into the heap with the
193
    /// given priority.
194
    /// \param i The item to insert.
195
    /// \param p The priority of the item.
196
    /// \pre \e i must not be stored in the heap.
197
    void push(const Item &i, const Prio &p) { push(Pair(i,p)); }
198

	
199
    /// \brief Return the item having minimum priority.
200
    ///
201
    /// This function returns the item having minimum priority.
202
    /// \pre The heap must be non-empty.
203
    Item top() const { return _data[0].first; }
204

	
205
    /// \brief The minimum priority.
206
    ///
207
    /// This function returns the minimum priority.
208
    /// \pre The heap must be non-empty.
209
    Prio prio() const { return _data[0].second; }
210

	
211
    /// \brief Remove the item having minimum priority.
212
    ///
213
    /// This function removes the item having minimum priority.
214
    /// \pre The heap must be non-empty.
215
    void pop() {
216
      int n = _data.size()-1;
217
      _iim.set(_data[0].first, POST_HEAP);
218
      if (n>0) bubbleDown(0, _data[n], n);
219
      _data.pop_back();
220
    }
221

	
222
    /// \brief Remove the given item from the heap.
223
    ///
224
    /// This function removes the given item from the heap if it is
225
    /// already stored.
226
    /// \param i The item to delete.
227
    /// \pre \e i must be in the heap.
228
    void erase(const Item &i) {
229
      int h = _iim[i];
230
      int n = _data.size()-1;
231
      _iim.set(_data[h].first, POST_HEAP);
232
      if( h<n ) {
233
        if( less(_data[parent(h)], _data[n]) )
234
          bubbleDown(h, _data[n], n);
235
        else
236
          bubbleUp(h, _data[n]);
237
      }
238
      _data.pop_back();
239
    }
240

	
241
    /// \brief The priority of the given item.
242
    ///
243
    /// This function returns the priority of the given item.
244
    /// \param i The item.
245
    /// \pre \e i must be in the heap.
246
    Prio operator[](const Item &i) const {
247
      int idx = _iim[i];
248
      return _data[idx].second;
249
    }
250

	
251
    /// \brief Set the priority of an item or insert it, if it is
252
    /// not stored in the heap.
253
    ///
254
    /// This method sets the priority of the given item if it is
255
    /// already stored in the heap. Otherwise it inserts the given
256
    /// item into the heap with the given priority.
257
    /// \param i The item.
258
    /// \param p The priority.
259
    void set(const Item &i, const Prio &p) {
260
      int idx = _iim[i];
261
      if( idx < 0 )
262
        push(i,p);
263
      else if( _comp(p, _data[idx].second) )
264
        bubbleUp(idx, Pair(i,p));
265
      else
266
        bubbleDown(idx, Pair(i,p), _data.size());
267
    }
268

	
269
    /// \brief Decrease the priority of an item to the given value.
270
    ///
271
    /// This function decreases the priority of an item to the given value.
272
    /// \param i The item.
273
    /// \param p The priority.
274
    /// \pre \e i must be stored in the heap with priority at least \e p.
275
    void decrease(const Item &i, const Prio &p) {
276
      int idx = _iim[i];
277
      bubbleUp(idx, Pair(i,p));
278
    }
279

	
280
    /// \brief Increase the priority of an item to the given value.
281
    ///
282
    /// This function increases the priority of an item to the given value.
283
    /// \param i The item.
284
    /// \param p The priority.
285
    /// \pre \e i must be stored in the heap with priority at most \e p.
286
    void increase(const Item &i, const Prio &p) {
287
      int idx = _iim[i];
288
      bubbleDown(idx, Pair(i,p), _data.size());
289
    }
290

	
291
    /// \brief Return the state of an item.
292
    ///
293
    /// This method returns \c PRE_HEAP if the given item has never
294
    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
295
    /// and \c POST_HEAP otherwise.
296
    /// In the latter case it is possible that the item will get back
297
    /// to the heap again.
298
    /// \param i The item.
299
    State state(const Item &i) const {
300
      int s = _iim[i];
301
      if (s>=0) s=0;
302
      return State(s);
303
    }
304

	
305
    /// \brief Set the state of an item in the heap.
306
    ///
307
    /// This function sets the state of the given item in the heap.
308
    /// It can be used to manually clear the heap when it is important
309
    /// to achive better time complexity.
310
    /// \param i The item.
311
    /// \param st The state. It should not be \c IN_HEAP.
312
    void state(const Item& i, State st) {
313
      switch (st) {
314
        case POST_HEAP:
315
        case PRE_HEAP:
316
          if (state(i) == IN_HEAP) erase(i);
317
          _iim[i] = st;
318
          break;
319
        case IN_HEAP:
320
          break;
321
      }
322
    }
323

	
324
    /// \brief Replace an item in the heap.
325
    ///
326
    /// This function replaces item \c i with item \c j.
327
    /// Item \c i must be in the heap, while \c j must be out of the heap.
328
    /// After calling this method, item \c i will be out of the
329
    /// heap and \c j will be in the heap with the same prioriority
330
    /// as item \c i had before.
331
    void replace(const Item& i, const Item& j) {
332
      int idx = _iim[i];
333
      _iim.set(i, _iim[j]);
334
      _iim.set(j, idx);
335
      _data[idx].first = j;
336
    }
337

	
338
  }; // class FouraryHeap
339

	
340
} // namespace lemon
341

	
342
#endif // LEMON_FOURARY_HEAP_H
Ignore white space 384 line context
1
/* -*- mode: C++; indent-tabs-mode: nil; -*-
2
 *
3
 * This file is a part of LEMON, a generic C++ optimization library.
4
 *
5
 * Copyright (C) 2003-2009
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_KARY_HEAP_H
20
#define LEMON_KARY_HEAP_H
21

	
22
///\ingroup heaps
23
///\file
24
///\brief Fourary heap implementation.
25

	
26
#include <vector>
27
#include <utility>
28
#include <functional>
29

	
30
namespace lemon {
31

	
32
  /// \ingroup heaps
33
  ///
34
  ///\brief K-ary heap data structure.
35
  ///
36
  /// This class implements the \e K-ary \e heap data structure.
37
  /// It fully conforms to the \ref concepts::Heap "heap concept".
38
  ///
39
  /// The \ref KaryHeap "K-ary heap" is a generalization of the
40
  /// \ref BinHeap "binary heap" structure, its nodes have at most
41
  /// \c K children, instead of two.
42
  /// \ref BinHeap and \ref FouraryHeap are specialized implementations
43
  /// of this structure for <tt>K=2</tt> and <tt>K=4</tt>, respectively.
44
  ///
45
  /// \tparam PR Type of the priorities of the items.
46
  /// \tparam IM A read-writable item map with \c int values, used
47
  /// internally to handle the cross references.
48
  /// \tparam K The degree of the heap, each node have at most \e K
49
  /// children. The default is 16. Powers of two are suggested to use
50
  /// so that the multiplications and divisions needed to traverse the
51
  /// nodes of the heap could be performed faster.
52
  /// \tparam CMP A functor class for comparing the priorities.
53
  /// The default is \c std::less<PR>.
54
  ///
55
  ///\sa BinHeap
56
  ///\sa FouraryHeap
57
#ifdef DOXYGEN
58
  template <typename PR, typename IM, int K, typename CMP>
59
#else
60
  template <typename PR, typename IM, int K = 16,
61
            typename CMP = std::less<PR> >
62
#endif
63
  class KaryHeap {
64
  public:
65
    /// Type of the item-int map.
66
    typedef IM ItemIntMap;
67
    /// Type of the priorities.
68
    typedef PR Prio;
69
    /// Type of the items stored in the heap.
70
    typedef typename ItemIntMap::Key Item;
71
    /// Type of the item-priority pairs.
72
    typedef std::pair<Item,Prio> Pair;
73
    /// Functor type for comparing the priorities.
74
    typedef CMP Compare;
75

	
76
    /// \brief Type to represent the states of the items.
77
    ///
78
    /// Each item has a state associated to it. It can be "in heap",
79
    /// "pre-heap" or "post-heap". The latter two are indifferent from the
80
    /// heap's point of view, but may be useful to the user.
81
    ///
82
    /// The item-int map must be initialized in such way that it assigns
83
    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
84
    enum State {
85
      IN_HEAP = 0,    ///< = 0.
86
      PRE_HEAP = -1,  ///< = -1.
87
      POST_HEAP = -2  ///< = -2.
88
    };
89

	
90
  private:
91
    std::vector<Pair> _data;
92
    Compare _comp;
93
    ItemIntMap &_iim;
94

	
95
  public:
96
    /// \brief Constructor.
97
    ///
98
    /// Constructor.
99
    /// \param map A map that assigns \c int values to the items.
100
    /// It is used internally to handle the cross references.
101
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
102
    explicit KaryHeap(ItemIntMap &map) : _iim(map) {}
103

	
104
    /// \brief Constructor.
105
    ///
106
    /// Constructor.
107
    /// \param map A map that assigns \c int values to the items.
108
    /// It is used internally to handle the cross references.
109
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
110
    /// \param comp The function object used for comparing the priorities.
111
    KaryHeap(ItemIntMap &map, const Compare &comp)
112
      : _iim(map), _comp(comp) {}
113

	
114
    /// \brief The number of items stored in the heap.
115
    ///
116
    /// This function returns the number of items stored in the heap.
117
    int size() const { return _data.size(); }
118

	
119
    /// \brief Check if the heap is empty.
120
    ///
121
    /// This function returns \c true if the heap is empty.
122
    bool empty() const { return _data.empty(); }
123

	
124
    /// \brief Make the heap empty.
125
    ///
126
    /// This functon makes the heap empty.
127
    /// It does not change the cross reference map. If you want to reuse
128
    /// a heap that is not surely empty, you should first clear it and
129
    /// then you should set the cross reference map to \c PRE_HEAP
130
    /// for each item.
131
    void clear() { _data.clear(); }
132

	
133
  private:
134
    int parent(int i) { return (i-1)/K; }
135
    int firstChild(int i) { return K*i+1; }
136

	
137
    bool less(const Pair &p1, const Pair &p2) const {
138
      return _comp(p1.second, p2.second);
139
    }
140

	
141
    void bubbleUp(int hole, Pair p) {
142
      int par = parent(hole);
143
      while( hole>0 && less(p,_data[par]) ) {
144
        move(_data[par],hole);
145
        hole = par;
146
        par = parent(hole);
147
      }
148
      move(p, hole);
149
    }
150

	
151
    void bubbleDown(int hole, Pair p, int length) {
152
      if( length>1 ) {
153
        int child = firstChild(hole);
154
        while( child+K<=length ) {
155
          int min=child;
156
          for (int i=1; i<K; ++i) {
157
            if( less(_data[child+i], _data[min]) )
158
              min=child+i;
159
          }
160
          if( !less(_data[min], p) )
161
            goto ok;
162
          move(_data[min], hole);
163
          hole = min;
164
          child = firstChild(hole);
165
        }
166
        if ( child<length ) {
167
          int min = child;
168
          while (++child < length) {
169
            if( less(_data[child], _data[min]) )
170
              min=child;
171
          }
172
          if( less(_data[min], p) ) {
173
            move(_data[min], hole);
174
            hole = min;
175
          }
176
        }
177
      }
178
    ok:
179
      move(p, hole);
180
    }
181

	
182
    void move(const Pair &p, int i) {
183
      _data[i] = p;
184
      _iim.set(p.first, i);
185
    }
186

	
187
  public:
188
    /// \brief Insert a pair of item and priority into the heap.
189
    ///
190
    /// This function inserts \c p.first to the heap with priority
191
    /// \c p.second.
192
    /// \param p The pair to insert.
193
    /// \pre \c p.first must not be stored in the heap.
194
    void push(const Pair &p) {
195
      int n = _data.size();
196
      _data.resize(n+1);
197
      bubbleUp(n, p);
198
    }
199

	
200
    /// \brief Insert an item into the heap with the given priority.
201
    ///
202
    /// This function inserts the given item into the heap with the
203
    /// given priority.
204
    /// \param i The item to insert.
205
    /// \param p The priority of the item.
206
    /// \pre \e i must not be stored in the heap.
207
    void push(const Item &i, const Prio &p) { push(Pair(i,p)); }
208

	
209
    /// \brief Return the item having minimum priority.
210
    ///
211
    /// This function returns the item having minimum priority.
212
    /// \pre The heap must be non-empty.
213
    Item top() const { return _data[0].first; }
214

	
215
    /// \brief The minimum priority.
216
    ///
217
    /// This function returns the minimum priority.
218
    /// \pre The heap must be non-empty.
219
    Prio prio() const { return _data[0].second; }
220

	
221
    /// \brief Remove the item having minimum priority.
222
    ///
223
    /// This function removes the item having minimum priority.
224
    /// \pre The heap must be non-empty.
225
    void pop() {
226
      int n = _data.size()-1;
227
      _iim.set(_data[0].first, POST_HEAP);
228
      if (n>0) bubbleDown(0, _data[n], n);
229
      _data.pop_back();
230
    }
231

	
232
    /// \brief Remove the given item from the heap.
233
    ///
234
    /// This function removes the given item from the heap if it is
235
    /// already stored.
236
    /// \param i The item to delete.
237
    /// \pre \e i must be in the heap.
238
    void erase(const Item &i) {
239
      int h = _iim[i];
240
      int n = _data.size()-1;
241
      _iim.set(_data[h].first, POST_HEAP);
242
      if( h<n ) {
243
        if( less(_data[parent(h)], _data[n]) )
244
          bubbleDown(h, _data[n], n);
245
        else
246
          bubbleUp(h, _data[n]);
247
      }
248
      _data.pop_back();
249
    }
250

	
251
    /// \brief The priority of the given item.
252
    ///
253
    /// This function returns the priority of the given item.
254
    /// \param i The item.
255
    /// \pre \e i must be in the heap.
256
    Prio operator[](const Item &i) const {
257
      int idx = _iim[i];
258
      return _data[idx].second;
259
    }
260

	
261
    /// \brief Set the priority of an item or insert it, if it is
262
    /// not stored in the heap.
263
    ///
264
    /// This method sets the priority of the given item if it is
265
    /// already stored in the heap. Otherwise it inserts the given
266
    /// item into the heap with the given priority.
267
    /// \param i The item.
268
    /// \param p The priority.
269
    void set(const Item &i, const Prio &p) {
270
      int idx = _iim[i];
271
      if( idx<0 )
272
        push(i,p);
273
      else if( _comp(p, _data[idx].second) )
274
        bubbleUp(idx, Pair(i,p));
275
      else
276
        bubbleDown(idx, Pair(i,p), _data.size());
277
    }
278

	
279
    /// \brief Decrease the priority of an item to the given value.
280
    ///
281
    /// This function decreases the priority of an item to the given value.
282
    /// \param i The item.
283
    /// \param p The priority.
284
    /// \pre \e i must be stored in the heap with priority at least \e p.
285
    void decrease(const Item &i, const Prio &p) {
286
      int idx = _iim[i];
287
      bubbleUp(idx, Pair(i,p));
288
    }
289

	
290
    /// \brief Increase the priority of an item to the given value.
291
    ///
292
    /// This function increases the priority of an item to the given value.
293
    /// \param i The item.
294
    /// \param p The priority.
295
    /// \pre \e i must be stored in the heap with priority at most \e p.
296
    void increase(const Item &i, const Prio &p) {
297
      int idx = _iim[i];
298
      bubbleDown(idx, Pair(i,p), _data.size());
299
    }
300

	
301
    /// \brief Return the state of an item.
302
    ///
303
    /// This method returns \c PRE_HEAP if the given item has never
304
    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
305
    /// and \c POST_HEAP otherwise.
306
    /// In the latter case it is possible that the item will get back
307
    /// to the heap again.
308
    /// \param i The item.
309
    State state(const Item &i) const {
310
      int s = _iim[i];
311
      if (s>=0) s=0;
312
      return State(s);
313
    }
314

	
315
    /// \brief Set the state of an item in the heap.
316
    ///
317
    /// This function sets the state of the given item in the heap.
318
    /// It can be used to manually clear the heap when it is important
319
    /// to achive better time complexity.
320
    /// \param i The item.
321
    /// \param st The state. It should not be \c IN_HEAP.
322
    void state(const Item& i, State st) {
323
      switch (st) {
324
        case POST_HEAP:
325
        case PRE_HEAP:
326
          if (state(i) == IN_HEAP) erase(i);
327
          _iim[i] = st;
328
          break;
329
        case IN_HEAP:
330
          break;
331
      }
332
    }
333

	
334
    /// \brief Replace an item in the heap.
335
    ///
336
    /// This function replaces item \c i with item \c j.
337
    /// Item \c i must be in the heap, while \c j must be out of the heap.
338
    /// After calling this method, item \c i will be out of the
339
    /// heap and \c j will be in the heap with the same prioriority
340
    /// as item \c i had before.
341
    void replace(const Item& i, const Item& j) {
342
      int idx=_iim[i];
343
      _iim.set(i, _iim[j]);
344
      _iim.set(j, idx);
345
      _data[idx].first=j;
346
    }
347

	
348
  }; // class KaryHeap
349

	
350
} // namespace lemon
351

	
352
#endif // LEMON_KARY_HEAP_H
Ignore white space 384 line context
... ...
@@ -49,385 +49,414 @@
49 49
arcs have to be hidden or the reverse oriented graph have to be used, then
50 50
this is the case. It also may happen that in a flow implementation
51 51
the residual graph can be accessed by another algorithm, or a node-set
52 52
is to be shrunk for another algorithm.
53 53
LEMON also provides a variety of graphs for these requirements called
54 54
\ref graph_adaptors "graph adaptors". Adaptors cannot be used alone but only
55 55
in conjunction with other graph representations.
56 56

	
57 57
You are free to use the graph structure that fit your requirements
58 58
the best, most graph algorithms and auxiliary data structures can be used
59 59
with any graph structure.
60 60

	
61 61
<b>See also:</b> \ref graph_concepts "Graph Structure Concepts".
62 62
*/
63 63

	
64 64
/**
65 65
@defgroup graph_adaptors Adaptor Classes for Graphs
66 66
@ingroup graphs
67 67
\brief Adaptor classes for digraphs and graphs
68 68

	
69 69
This group contains several useful adaptor classes for digraphs and graphs.
70 70

	
71 71
The main parts of LEMON are the different graph structures, generic
72 72
graph algorithms, graph concepts, which couple them, and graph
73 73
adaptors. While the previous notions are more or less clear, the
74 74
latter one needs further explanation. Graph adaptors are graph classes
75 75
which serve for considering graph structures in different ways.
76 76

	
77 77
A short example makes this much clearer.  Suppose that we have an
78 78
instance \c g of a directed graph type, say ListDigraph and an algorithm
79 79
\code
80 80
template <typename Digraph>
81 81
int algorithm(const Digraph&);
82 82
\endcode
83 83
is needed to run on the reverse oriented graph.  It may be expensive
84 84
(in time or in memory usage) to copy \c g with the reversed
85 85
arcs.  In this case, an adaptor class is used, which (according
86 86
to LEMON \ref concepts::Digraph "digraph concepts") works as a digraph.
87 87
The adaptor uses the original digraph structure and digraph operations when
88 88
methods of the reversed oriented graph are called.  This means that the adaptor
89 89
have minor memory usage, and do not perform sophisticated algorithmic
90 90
actions.  The purpose of it is to give a tool for the cases when a
91 91
graph have to be used in a specific alteration.  If this alteration is
92 92
obtained by a usual construction like filtering the node or the arc set or
93 93
considering a new orientation, then an adaptor is worthwhile to use.
94 94
To come back to the reverse oriented graph, in this situation
95 95
\code
96 96
template<typename Digraph> class ReverseDigraph;
97 97
\endcode
98 98
template class can be used. The code looks as follows
99 99
\code
100 100
ListDigraph g;
101 101
ReverseDigraph<ListDigraph> rg(g);
102 102
int result = algorithm(rg);
103 103
\endcode
104 104
During running the algorithm, the original digraph \c g is untouched.
105 105
This techniques give rise to an elegant code, and based on stable
106 106
graph adaptors, complex algorithms can be implemented easily.
107 107

	
108 108
In flow, circulation and matching problems, the residual
109 109
graph is of particular importance. Combining an adaptor implementing
110 110
this with shortest path algorithms or minimum mean cycle algorithms,
111 111
a range of weighted and cardinality optimization algorithms can be
112 112
obtained. For other examples, the interested user is referred to the
113 113
detailed documentation of particular adaptors.
114 114

	
115 115
The behavior of graph adaptors can be very different. Some of them keep
116 116
capabilities of the original graph while in other cases this would be
117 117
meaningless. This means that the concepts that they meet depend
118 118
on the graph adaptor, and the wrapped graph.
119 119
For example, if an arc of a reversed digraph is deleted, this is carried
120 120
out by deleting the corresponding arc of the original digraph, thus the
121 121
adaptor modifies the original digraph.
122 122
However in case of a residual digraph, this operation has no sense.
123 123

	
124 124
Let us stand one more example here to simplify your work.
125 125
ReverseDigraph has constructor
126 126
\code
127 127
ReverseDigraph(Digraph& digraph);
128 128
\endcode
129 129
This means that in a situation, when a <tt>const %ListDigraph&</tt>
130 130
reference to a graph is given, then it have to be instantiated with
131 131
<tt>Digraph=const %ListDigraph</tt>.
132 132
\code
133 133
int algorithm1(const ListDigraph& g) {
134 134
  ReverseDigraph<const ListDigraph> rg(g);
135 135
  return algorithm2(rg);
136 136
}
137 137
\endcode
138 138
*/
139 139

	
140 140
/**
141 141
@defgroup maps Maps
142 142
@ingroup datas
143 143
\brief Map structures implemented in LEMON.
144 144

	
145 145
This group contains the map structures implemented in LEMON.
146 146

	
147 147
LEMON provides several special purpose maps and map adaptors that e.g. combine
148 148
new maps from existing ones.
149 149

	
150 150
<b>See also:</b> \ref map_concepts "Map Concepts".
151 151
*/
152 152

	
153 153
/**
154 154
@defgroup graph_maps Graph Maps
155 155
@ingroup maps
156 156
\brief Special graph-related maps.
157 157

	
158 158
This group contains maps that are specifically designed to assign
159 159
values to the nodes and arcs/edges of graphs.
160 160

	
161 161
If you are looking for the standard graph maps (\c NodeMap, \c ArcMap,
162 162
\c EdgeMap), see the \ref graph_concepts "Graph Structure Concepts".
163 163
*/
164 164

	
165 165
/**
166 166
\defgroup map_adaptors Map Adaptors
167 167
\ingroup maps
168 168
\brief Tools to create new maps from existing ones
169 169

	
170 170
This group contains map adaptors that are used to create "implicit"
171 171
maps from other maps.
172 172

	
173 173
Most of them are \ref concepts::ReadMap "read-only maps".
174 174
They can make arithmetic and logical operations between one or two maps
175 175
(negation, shifting, addition, multiplication, logical 'and', 'or',
176 176
'not' etc.) or e.g. convert a map to another one of different Value type.
177 177

	
178 178
The typical usage of this classes is passing implicit maps to
179 179
algorithms.  If a function type algorithm is called then the function
180 180
type map adaptors can be used comfortable. For example let's see the
181 181
usage of map adaptors with the \c graphToEps() function.
182 182
\code
183 183
  Color nodeColor(int deg) {
184 184
    if (deg >= 2) {
185 185
      return Color(0.5, 0.0, 0.5);
186 186
    } else if (deg == 1) {
187 187
      return Color(1.0, 0.5, 1.0);
188 188
    } else {
189 189
      return Color(0.0, 0.0, 0.0);
190 190
    }
191 191
  }
192 192

	
193 193
  Digraph::NodeMap<int> degree_map(graph);
194 194

	
195 195
  graphToEps(graph, "graph.eps")
196 196
    .coords(coords).scaleToA4().undirected()
197 197
    .nodeColors(composeMap(functorToMap(nodeColor), degree_map))
198 198
    .run();
199 199
\endcode
200 200
The \c functorToMap() function makes an \c int to \c Color map from the
201 201
\c nodeColor() function. The \c composeMap() compose the \c degree_map
202 202
and the previously created map. The composed map is a proper function to
203 203
get the color of each node.
204 204

	
205 205
The usage with class type algorithms is little bit harder. In this
206 206
case the function type map adaptors can not be used, because the
207 207
function map adaptors give back temporary objects.
208 208
\code
209 209
  Digraph graph;
210 210

	
211 211
  typedef Digraph::ArcMap<double> DoubleArcMap;
212 212
  DoubleArcMap length(graph);
213 213
  DoubleArcMap speed(graph);
214 214

	
215 215
  typedef DivMap<DoubleArcMap, DoubleArcMap> TimeMap;
216 216
  TimeMap time(length, speed);
217 217

	
218 218
  Dijkstra<Digraph, TimeMap> dijkstra(graph, time);
219 219
  dijkstra.run(source, target);
220 220
\endcode
221 221
We have a length map and a maximum speed map on the arcs of a digraph.
222 222
The minimum time to pass the arc can be calculated as the division of
223 223
the two maps which can be done implicitly with the \c DivMap template
224 224
class. We use the implicit minimum time map as the length map of the
225 225
\c Dijkstra algorithm.
226 226
*/
227 227

	
228 228
/**
229 229
@defgroup paths Path Structures
230 230
@ingroup datas
231 231
\brief %Path structures implemented in LEMON.
232 232

	
233 233
This group contains the path structures implemented in LEMON.
234 234

	
235 235
LEMON provides flexible data structures to work with paths.
236 236
All of them have similar interfaces and they can be copied easily with
237 237
assignment operators and copy constructors. This makes it easy and
238 238
efficient to have e.g. the Dijkstra algorithm to store its result in
239 239
any kind of path structure.
240 240

	
241
\sa lemon::concepts::Path
241
\sa \ref concepts::Path "Path concept"
242
*/
243

	
244
/**
245
@defgroup heaps Heap Structures
246
@ingroup datas
247
\brief %Heap structures implemented in LEMON.
248

	
249
This group contains the heap structures implemented in LEMON.
250

	
251
LEMON provides several heap classes. They are efficient implementations
252
of the abstract data type \e priority \e queue. They store items with
253
specified values called \e priorities in such a way that finding and
254
removing the item with minimum priority are efficient.
255
The basic operations are adding and erasing items, changing the priority
256
of an item, etc.
257

	
258
Heaps are crucial in several algorithms, such as Dijkstra and Prim.
259
The heap implementations have the same interface, thus any of them can be
260
used easily in such algorithms.
261

	
262
\sa \ref concepts::Heap "Heap concept"
263
*/
264

	
265
/**
266
@defgroup matrices Matrices
267
@ingroup datas
268
\brief Two dimensional data storages implemented in LEMON.
269

	
270
This group contains two dimensional data storages implemented in LEMON.
242 271
*/
243 272

	
244 273
/**
245 274
@defgroup auxdat Auxiliary Data Structures
246 275
@ingroup datas
247 276
\brief Auxiliary data structures implemented in LEMON.
248 277

	
249 278
This group contains some data structures implemented in LEMON in
250 279
order to make it easier to implement combinatorial algorithms.
251 280
*/
252 281

	
253 282
/**
254 283
@defgroup geomdat Geometric Data Structures
255 284
@ingroup auxdat
256 285
\brief Geometric data structures implemented in LEMON.
257 286

	
258 287
This group contains geometric data structures implemented in LEMON.
259 288

	
260 289
 - \ref lemon::dim2::Point "dim2::Point" implements a two dimensional
261 290
   vector with the usual operations.
262 291
 - \ref lemon::dim2::Box "dim2::Box" can be used to determine the
263 292
   rectangular bounding box of a set of \ref lemon::dim2::Point
264 293
   "dim2::Point"'s.
265 294
*/
266 295

	
267 296
/**
268 297
@defgroup matrices Matrices
269 298
@ingroup auxdat
270 299
\brief Two dimensional data storages implemented in LEMON.
271 300

	
272 301
This group contains two dimensional data storages implemented in LEMON.
273 302
*/
274 303

	
275 304
/**
276 305
@defgroup algs Algorithms
277 306
\brief This group contains the several algorithms
278 307
implemented in LEMON.
279 308

	
280 309
This group contains the several algorithms
281 310
implemented in LEMON.
282 311
*/
283 312

	
284 313
/**
285 314
@defgroup search Graph Search
286 315
@ingroup algs
287 316
\brief Common graph search algorithms.
288 317

	
289 318
This group contains the common graph search algorithms, namely
290 319
\e breadth-first \e search (BFS) and \e depth-first \e search (DFS).
291 320
*/
292 321

	
293 322
/**
294 323
@defgroup shortest_path Shortest Path Algorithms
295 324
@ingroup algs
296 325
\brief Algorithms for finding shortest paths.
297 326

	
298 327
This group contains the algorithms for finding shortest paths in digraphs.
299 328

	
300 329
 - \ref Dijkstra algorithm for finding shortest paths from a source node
301 330
   when all arc lengths are non-negative.
302 331
 - \ref BellmanFord "Bellman-Ford" algorithm for finding shortest paths
303 332
   from a source node when arc lenghts can be either positive or negative,
304 333
   but the digraph should not contain directed cycles with negative total
305 334
   length.
306 335
 - \ref FloydWarshall "Floyd-Warshall" and \ref Johnson "Johnson" algorithms
307 336
   for solving the \e all-pairs \e shortest \e paths \e problem when arc
308 337
   lenghts can be either positive or negative, but the digraph should
309 338
   not contain directed cycles with negative total length.
310 339
 - \ref Suurballe A successive shortest path algorithm for finding
311 340
   arc-disjoint paths between two nodes having minimum total length.
312 341
*/
313 342

	
314 343
/**
315 344
@defgroup spantree Minimum Spanning Tree Algorithms
316 345
@ingroup algs
317 346
\brief Algorithms for finding minimum cost spanning trees and arborescences.
318 347

	
319 348
This group contains the algorithms for finding minimum cost spanning
320 349
trees and arborescences.
321 350
*/
322 351

	
323 352
/**
324 353
@defgroup max_flow Maximum Flow Algorithms
325 354
@ingroup algs
326 355
\brief Algorithms for finding maximum flows.
327 356

	
328 357
This group contains the algorithms for finding maximum flows and
329 358
feasible circulations.
330 359

	
331 360
The \e maximum \e flow \e problem is to find a flow of maximum value between
332 361
a single source and a single target. Formally, there is a \f$G=(V,A)\f$
333 362
digraph, a \f$cap: A\rightarrow\mathbf{R}^+_0\f$ capacity function and
334 363
\f$s, t \in V\f$ source and target nodes.
335 364
A maximum flow is an \f$f: A\rightarrow\mathbf{R}^+_0\f$ solution of the
336 365
following optimization problem.
337 366

	
338 367
\f[ \max\sum_{sv\in A} f(sv) - \sum_{vs\in A} f(vs) \f]
339 368
\f[ \sum_{uv\in A} f(uv) = \sum_{vu\in A} f(vu)
340 369
    \quad \forall u\in V\setminus\{s,t\} \f]
341 370
\f[ 0 \leq f(uv) \leq cap(uv) \quad \forall uv\in A \f]
342 371

	
343 372
LEMON contains several algorithms for solving maximum flow problems:
344 373
- \ref EdmondsKarp Edmonds-Karp algorithm.
345 374
- \ref Preflow Goldberg-Tarjan's preflow push-relabel algorithm.
346 375
- \ref DinitzSleatorTarjan Dinitz's blocking flow algorithm with dynamic trees.
347 376
- \ref GoldbergTarjan Preflow push-relabel algorithm with dynamic trees.
348 377

	
349 378
In most cases the \ref Preflow "Preflow" algorithm provides the
350 379
fastest method for computing a maximum flow. All implementations
351 380
also provide functions to query the minimum cut, which is the dual
352 381
problem of maximum flow.
353 382

	
354 383
\ref Circulation is a preflow push-relabel algorithm implemented directly 
355 384
for finding feasible circulations, which is a somewhat different problem,
356 385
but it is strongly related to maximum flow.
357 386
For more information, see \ref Circulation.
358 387
*/
359 388

	
360 389
/**
361 390
@defgroup min_cost_flow_algs Minimum Cost Flow Algorithms
362 391
@ingroup algs
363 392

	
364 393
\brief Algorithms for finding minimum cost flows and circulations.
365 394

	
366 395
This group contains the algorithms for finding minimum cost flows and
367 396
circulations. For more information about this problem and its dual
368 397
solution see \ref min_cost_flow "Minimum Cost Flow Problem".
369 398

	
370 399
LEMON contains several algorithms for this problem.
371 400
 - \ref NetworkSimplex Primal Network Simplex algorithm with various
372 401
   pivot strategies.
373 402
 - \ref CostScaling Push-Relabel and Augment-Relabel algorithms based on
374 403
   cost scaling.
375 404
 - \ref CapacityScaling Successive Shortest %Path algorithm with optional
376 405
   capacity scaling.
377 406
 - \ref CancelAndTighten The Cancel and Tighten algorithm.
378 407
 - \ref CycleCanceling Cycle-Canceling algorithms.
379 408

	
380 409
In general NetworkSimplex is the most efficient implementation,
381 410
but in special cases other algorithms could be faster.
382 411
For example, if the total supply and/or capacities are rather small,
383 412
CapacityScaling is usually the fastest algorithm (without effective scaling).
384 413
*/
385 414

	
386 415
/**
387 416
@defgroup min_cut Minimum Cut Algorithms
388 417
@ingroup algs
389 418

	
390 419
\brief Algorithms for finding minimum cut in graphs.
391 420

	
392 421
This group contains the algorithms for finding minimum cut in graphs.
393 422

	
394 423
The \e minimum \e cut \e problem is to find a non-empty and non-complete
395 424
\f$X\f$ subset of the nodes with minimum overall capacity on
396 425
outgoing arcs. Formally, there is a \f$G=(V,A)\f$ digraph, a
397 426
\f$cap: A\rightarrow\mathbf{R}^+_0\f$ capacity function. The minimum
398 427
cut is the \f$X\f$ solution of the next optimization problem:
399 428

	
400 429
\f[ \min_{X \subset V, X\not\in \{\emptyset, V\}}
401 430
    \sum_{uv\in A: u\in X, v\not\in X}cap(uv) \f]
402 431

	
403 432
LEMON contains several algorithms related to minimum cut problems:
404 433

	
405 434
- \ref HaoOrlin "Hao-Orlin algorithm" for calculating minimum cut
406 435
  in directed graphs.
407 436
- \ref NagamochiIbaraki "Nagamochi-Ibaraki algorithm" for
408 437
  calculating minimum cut in undirected graphs.
409 438
- \ref GomoryHu "Gomory-Hu tree computation" for calculating
410 439
  all-pairs minimum cut in undirected graphs.
411 440

	
412 441
If you want to find minimum cut just between two distinict nodes,
413 442
see the \ref max_flow "maximum flow problem".
414 443
*/
415 444

	
416 445
/**
417 446
@defgroup matching Matching Algorithms
418 447
@ingroup algs
419 448
\brief Algorithms for finding matchings in graphs and bipartite graphs.
420 449

	
421 450
This group contains the algorithms for calculating
422 451
matchings in graphs and bipartite graphs. The general matching problem is
423 452
finding a subset of the edges for which each node has at most one incident
424 453
edge.
425 454

	
426 455
There are several different algorithms for calculate matchings in
427 456
graphs.  The matching problems in bipartite graphs are generally
428 457
easier than in general graphs. The goal of the matching optimization
429 458
can be finding maximum cardinality, maximum weight or minimum cost
430 459
matching. The search can be constrained to find perfect or
431 460
maximum cardinality matching.
432 461

	
433 462
The matching algorithms implemented in LEMON:
Ignore white space 384 line context
1 1
EXTRA_DIST += \
2 2
	lemon/lemon.pc.in \
3 3
	lemon/CMakeLists.txt \
4 4
	lemon/config.h.cmake
5 5

	
6 6
pkgconfig_DATA += lemon/lemon.pc
7 7

	
8 8
lib_LTLIBRARIES += lemon/libemon.la
9 9

	
10 10
lemon_libemon_la_SOURCES = \
11 11
	lemon/arg_parser.cc \
12 12
	lemon/base.cc \
13 13
	lemon/color.cc \
14 14
	lemon/lp_base.cc \
15 15
	lemon/lp_skeleton.cc \
16 16
	lemon/random.cc \
17 17
	lemon/bits/windows.cc
18 18

	
19 19
nodist_lemon_HEADERS = lemon/config.h	
20 20

	
21 21
lemon_libemon_la_CXXFLAGS = \
22 22
	$(AM_CXXFLAGS) \
23 23
	$(GLPK_CFLAGS) \
24 24
	$(CPLEX_CFLAGS) \
25 25
	$(SOPLEX_CXXFLAGS) \
26 26
	$(CLP_CXXFLAGS) \
27 27
	$(CBC_CXXFLAGS)
28 28

	
29 29
lemon_libemon_la_LDFLAGS = \
30 30
	$(GLPK_LIBS) \
31 31
	$(CPLEX_LIBS) \
32 32
	$(SOPLEX_LIBS) \
33 33
	$(CLP_LIBS) \
34 34
	$(CBC_LIBS)
35 35

	
36 36
if HAVE_GLPK
37 37
lemon_libemon_la_SOURCES += lemon/glpk.cc
38 38
endif
39 39

	
40 40
if HAVE_CPLEX
41 41
lemon_libemon_la_SOURCES += lemon/cplex.cc
42 42
endif
43 43

	
44 44
if HAVE_SOPLEX
45 45
lemon_libemon_la_SOURCES += lemon/soplex.cc
46 46
endif
47 47

	
48 48
if HAVE_CLP
49 49
lemon_libemon_la_SOURCES += lemon/clp.cc
50 50
endif
51 51

	
52 52
if HAVE_CBC
53 53
lemon_libemon_la_SOURCES += lemon/cbc.cc
54 54
endif
55 55

	
56 56
lemon_HEADERS += \
57 57
	lemon/adaptors.h \
58 58
	lemon/arg_parser.h \
59 59
	lemon/assert.h \
60
	lemon/bellman_ford.h \
60 61
	lemon/bfs.h \
61 62
	lemon/bin_heap.h \
63
	lemon/binom_heap.h \
62 64
	lemon/bucket_heap.h \
63 65
	lemon/cbc.h \
64 66
	lemon/circulation.h \
65 67
	lemon/clp.h \
66 68
	lemon/color.h \
67 69
	lemon/concept_check.h \
68 70
	lemon/connectivity.h \
69 71
	lemon/counter.h \
70 72
	lemon/core.h \
71 73
	lemon/cplex.h \
72 74
	lemon/dfs.h \
73 75
	lemon/dijkstra.h \
74 76
	lemon/dim2.h \
75 77
	lemon/dimacs.h \
76 78
	lemon/edge_set.h \
77 79
	lemon/elevator.h \
78 80
	lemon/error.h \
79 81
	lemon/euler.h \
80 82
	lemon/fib_heap.h \
83
	lemon/fourary_heap.h \
81 84
	lemon/full_graph.h \
82 85
	lemon/glpk.h \
83 86
	lemon/gomory_hu.h \
84 87
	lemon/graph_to_eps.h \
85 88
	lemon/grid_graph.h \
86 89
	lemon/hypercube_graph.h \
90
	lemon/kary_heap.h \
87 91
	lemon/kruskal.h \
88 92
	lemon/hao_orlin.h \
89 93
	lemon/lgf_reader.h \
90 94
	lemon/lgf_writer.h \
91 95
	lemon/list_graph.h \
92 96
	lemon/lp.h \
93 97
	lemon/lp_base.h \
94 98
	lemon/lp_skeleton.h \
95
	lemon/list_graph.h \
96 99
	lemon/maps.h \
97 100
	lemon/matching.h \
98 101
	lemon/math.h \
99 102
	lemon/min_cost_arborescence.h \
100 103
	lemon/nauty_reader.h \
101 104
	lemon/network_simplex.h \
105
	lemon/pairing_heap.h \
102 106
	lemon/path.h \
103 107
	lemon/preflow.h \
104 108
	lemon/radix_heap.h \
105 109
	lemon/radix_sort.h \
106 110
	lemon/random.h \
107 111
	lemon/smart_graph.h \
108 112
	lemon/soplex.h \
109 113
	lemon/suurballe.h \
110 114
	lemon/time_measure.h \
111 115
	lemon/tolerance.h \
112 116
	lemon/unionfind.h \
113 117
	lemon/bits/windows.h
114 118

	
115 119
bits_HEADERS += \
116 120
	lemon/bits/alteration_notifier.h \
117 121
	lemon/bits/array_map.h \
118 122
	lemon/bits/bezier.h \
119 123
	lemon/bits/default_map.h \
120 124
	lemon/bits/edge_set_extender.h \
121 125
	lemon/bits/enable_if.h \
122 126
	lemon/bits/graph_adaptor_extender.h \
123 127
	lemon/bits/graph_extender.h \
124 128
	lemon/bits/map_extender.h \
125 129
	lemon/bits/path_dump.h \
126 130
	lemon/bits/solver_bits.h \
127 131
	lemon/bits/traits.h \
128 132
	lemon/bits/variant.h \
129 133
	lemon/bits/vector_map.h
130 134

	
131 135
concept_HEADERS += \
132 136
	lemon/concepts/digraph.h \
133 137
	lemon/concepts/graph.h \
134 138
	lemon/concepts/graph_components.h \
135 139
	lemon/concepts/heap.h \
136 140
	lemon/concepts/maps.h \
137 141
	lemon/concepts/path.h
Ignore white space 384 line context
1 1
/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 2
 *
3 3
 * This file is a part of LEMON, a generic C++ optimization library.
4 4
 *
5 5
 * Copyright (C) 2003-2009
6 6
 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 7
 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 8
 *
9 9
 * Permission to use, modify and distribute this software is granted
10 10
 * provided that this copyright notice appears in all copies. For
11 11
 * precise terms see the accompanying LICENSE file.
12 12
 *
13 13
 * This software is provided "AS IS" with no warranty of any kind,
14 14
 * express or implied, and with no claim as to its suitability for any
15 15
 * purpose.
16 16
 *
17 17
 */
18 18

	
19 19
#ifndef LEMON_BIN_HEAP_H
20 20
#define LEMON_BIN_HEAP_H
21 21

	
22
///\ingroup auxdat
22
///\ingroup heaps
23 23
///\file
24
///\brief Binary Heap implementation.
24
///\brief Binary heap implementation.
25 25

	
26 26
#include <vector>
27 27
#include <utility>
28 28
#include <functional>
29 29

	
30 30
namespace lemon {
31 31

	
32
  ///\ingroup auxdat
32
  /// \ingroup heaps
33 33
  ///
34
  ///\brief A Binary Heap implementation.
34
  /// \brief Binary heap data structure.
35 35
  ///
36
  ///This class implements the \e binary \e heap data structure.
36
  /// This class implements the \e binary \e heap data structure.
37
  /// It fully conforms to the \ref concepts::Heap "heap concept".
37 38
  ///
38
  ///A \e heap is a data structure for storing items with specified values
39
  ///called \e priorities in such a way that finding the item with minimum
40
  ///priority is efficient. \c CMP specifies the ordering of the priorities.
41
  ///In a heap one can change the priority of an item, add or erase an
42
  ///item, etc.
43
  ///
44
  ///\tparam PR Type of the priority of the items.
45
  ///\tparam IM A read and writable item map with int values, used internally
46
  ///to handle the cross references.
47
  ///\tparam CMP A functor class for the ordering of the priorities.
48
  ///The default is \c std::less<PR>.
49
  ///
50
  ///\sa FibHeap
51
  ///\sa Dijkstra
39
  /// \tparam PR Type of the priorities of the items.
40
  /// \tparam IM A read-writable item map with \c int values, used
41
  /// internally to handle the cross references.
42
  /// \tparam CMP A functor class for comparing the priorities.
43
  /// The default is \c std::less<PR>.
44
#ifdef DOXYGEN
45
  template <typename PR, typename IM, typename CMP>
46
#else
52 47
  template <typename PR, typename IM, typename CMP = std::less<PR> >
48
#endif
53 49
  class BinHeap {
50
  public:
54 51

	
55
  public:
56
    ///\e
52
    /// Type of the item-int map.
57 53
    typedef IM ItemIntMap;
58
    ///\e
54
    /// Type of the priorities.
59 55
    typedef PR Prio;
60
    ///\e
56
    /// Type of the items stored in the heap.
61 57
    typedef typename ItemIntMap::Key Item;
62
    ///\e
58
    /// Type of the item-priority pairs.
63 59
    typedef std::pair<Item,Prio> Pair;
64
    ///\e
60
    /// Functor type for comparing the priorities.
65 61
    typedef CMP Compare;
66 62

	
67
    /// \brief Type to represent the items states.
63
    /// \brief Type to represent the states of the items.
68 64
    ///
69
    /// Each Item element have a state associated to it. It may be "in heap",
70
    /// "pre heap" or "post heap". The latter two are indifferent from the
65
    /// Each item has a state associated to it. It can be "in heap",
66
    /// "pre-heap" or "post-heap". The latter two are indifferent from the
71 67
    /// heap's point of view, but may be useful to the user.
72 68
    ///
73 69
    /// The item-int map must be initialized in such way that it assigns
74 70
    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
75 71
    enum State {
76 72
      IN_HEAP = 0,    ///< = 0.
77 73
      PRE_HEAP = -1,  ///< = -1.
78 74
      POST_HEAP = -2  ///< = -2.
79 75
    };
80 76

	
81 77
  private:
82 78
    std::vector<Pair> _data;
83 79
    Compare _comp;
84 80
    ItemIntMap &_iim;
85 81

	
86 82
  public:
87
    /// \brief The constructor.
83

	
84
    /// \brief Constructor.
88 85
    ///
89
    /// The constructor.
90
    /// \param map should be given to the constructor, since it is used
91
    /// internally to handle the cross references. The value of the map
92
    /// must be \c PRE_HEAP (<tt>-1</tt>) for every item.
86
    /// Constructor.
87
    /// \param map A map that assigns \c int values to the items.
88
    /// It is used internally to handle the cross references.
89
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
93 90
    explicit BinHeap(ItemIntMap &map) : _iim(map) {}
94 91

	
95
    /// \brief The constructor.
92
    /// \brief Constructor.
96 93
    ///
97
    /// The constructor.
98
    /// \param map should be given to the constructor, since it is used
99
    /// internally to handle the cross references. The value of the map
100
    /// should be PRE_HEAP (-1) for each element.
101
    ///
102
    /// \param comp The comparator function object.
94
    /// Constructor.
95
    /// \param map A map that assigns \c int values to the items.
96
    /// It is used internally to handle the cross references.
97
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
98
    /// \param comp The function object used for comparing the priorities.
103 99
    BinHeap(ItemIntMap &map, const Compare &comp)
104 100
      : _iim(map), _comp(comp) {}
105 101

	
106 102

	
107
    /// The number of items stored in the heap.
103
    /// \brief The number of items stored in the heap.
108 104
    ///
109
    /// \brief Returns the number of items stored in the heap.
105
    /// This function returns the number of items stored in the heap.
110 106
    int size() const { return _data.size(); }
111 107

	
112
    /// \brief Checks if the heap stores no items.
108
    /// \brief Check if the heap is empty.
113 109
    ///
114
    /// Returns \c true if and only if the heap stores no items.
110
    /// This function returns \c true if the heap is empty.
115 111
    bool empty() const { return _data.empty(); }
116 112

	
117
    /// \brief Make empty this heap.
113
    /// \brief Make the heap empty.
118 114
    ///
119
    /// Make empty this heap. It does not change the cross reference map.
120
    /// If you want to reuse what is not surely empty you should first clear
121
    /// the heap and after that you should set the cross reference map for
122
    /// each item to \c PRE_HEAP.
115
    /// This functon makes the heap empty.
116
    /// It does not change the cross reference map. If you want to reuse
117
    /// a heap that is not surely empty, you should first clear it and
118
    /// then you should set the cross reference map to \c PRE_HEAP
119
    /// for each item.
123 120
    void clear() {
124 121
      _data.clear();
125 122
    }
126 123

	
127 124
  private:
128 125
    static int parent(int i) { return (i-1)/2; }
129 126

	
130
    static int second_child(int i) { return 2*i+2; }
127
    static int secondChild(int i) { return 2*i+2; }
131 128
    bool less(const Pair &p1, const Pair &p2) const {
132 129
      return _comp(p1.second, p2.second);
133 130
    }
134 131

	
135
    int bubble_up(int hole, Pair p) {
132
    int bubbleUp(int hole, Pair p) {
136 133
      int par = parent(hole);
137 134
      while( hole>0 && less(p,_data[par]) ) {
138 135
        move(_data[par],hole);
139 136
        hole = par;
140 137
        par = parent(hole);
141 138
      }
142 139
      move(p, hole);
143 140
      return hole;
144 141
    }
145 142

	
146
    int bubble_down(int hole, Pair p, int length) {
147
      int child = second_child(hole);
143
    int bubbleDown(int hole, Pair p, int length) {
144
      int child = secondChild(hole);
148 145
      while(child < length) {
149 146
        if( less(_data[child-1], _data[child]) ) {
150 147
          --child;
151 148
        }
152 149
        if( !less(_data[child], p) )
153 150
          goto ok;
154 151
        move(_data[child], hole);
155 152
        hole = child;
156
        child = second_child(hole);
153
        child = secondChild(hole);
157 154
      }
158 155
      child--;
159 156
      if( child<length && less(_data[child], p) ) {
160 157
        move(_data[child], hole);
161 158
        hole=child;
162 159
      }
163 160
    ok:
164 161
      move(p, hole);
165 162
      return hole;
166 163
    }
167 164

	
168 165
    void move(const Pair &p, int i) {
169 166
      _data[i] = p;
170 167
      _iim.set(p.first, i);
171 168
    }
172 169

	
173 170
  public:
171

	
174 172
    /// \brief Insert a pair of item and priority into the heap.
175 173
    ///
176
    /// Adds \c p.first to the heap with priority \c p.second.
174
    /// This function inserts \c p.first to the heap with priority
175
    /// \c p.second.
177 176
    /// \param p The pair to insert.
177
    /// \pre \c p.first must not be stored in the heap.
178 178
    void push(const Pair &p) {
179 179
      int n = _data.size();
180 180
      _data.resize(n+1);
181
      bubble_up(n, p);
181
      bubbleUp(n, p);
182 182
    }
183 183

	
184
    /// \brief Insert an item into the heap with the given heap.
184
    /// \brief Insert an item into the heap with the given priority.
185 185
    ///
186
    /// Adds \c i to the heap with priority \c p.
186
    /// This function inserts the given item into the heap with the
187
    /// given priority.
187 188
    /// \param i The item to insert.
188 189
    /// \param p The priority of the item.
190
    /// \pre \e i must not be stored in the heap.
189 191
    void push(const Item &i, const Prio &p) { push(Pair(i,p)); }
190 192

	
191
    /// \brief Returns the item with minimum priority relative to \c Compare.
193
    /// \brief Return the item having minimum priority.
192 194
    ///
193
    /// This method returns the item with minimum priority relative to \c
194
    /// Compare.
195
    /// \pre The heap must be nonempty.
195
    /// This function returns the item having minimum priority.
196
    /// \pre The heap must be non-empty.
196 197
    Item top() const {
197 198
      return _data[0].first;
198 199
    }
199 200

	
200
    /// \brief Returns the minimum priority relative to \c Compare.
201
    /// \brief The minimum priority.
201 202
    ///
202
    /// It returns the minimum priority relative to \c Compare.
203
    /// \pre The heap must be nonempty.
203
    /// This function returns the minimum priority.
204
    /// \pre The heap must be non-empty.
204 205
    Prio prio() const {
205 206
      return _data[0].second;
206 207
    }
207 208

	
208
    /// \brief Deletes the item with minimum priority relative to \c Compare.
209
    /// \brief Remove the item having minimum priority.
209 210
    ///
210
    /// This method deletes the item with minimum priority relative to \c
211
    /// Compare from the heap.
211
    /// This function removes the item having minimum priority.
212 212
    /// \pre The heap must be non-empty.
213 213
    void pop() {
214 214
      int n = _data.size()-1;
215 215
      _iim.set(_data[0].first, POST_HEAP);
216 216
      if (n > 0) {
217
        bubble_down(0, _data[n], n);
217
        bubbleDown(0, _data[n], n);
218 218
      }
219 219
      _data.pop_back();
220 220
    }
221 221

	
222
    /// \brief Deletes \c i from the heap.
222
    /// \brief Remove the given item from the heap.
223 223
    ///
224
    /// This method deletes item \c i from the heap.
225
    /// \param i The item to erase.
226
    /// \pre The item should be in the heap.
224
    /// This function removes the given item from the heap if it is
225
    /// already stored.
226
    /// \param i The item to delete.
227
    /// \pre \e i must be in the heap.
227 228
    void erase(const Item &i) {
228 229
      int h = _iim[i];
229 230
      int n = _data.size()-1;
230 231
      _iim.set(_data[h].first, POST_HEAP);
231 232
      if( h < n ) {
232
        if ( bubble_up(h, _data[n]) == h) {
233
          bubble_down(h, _data[n], n);
233
        if ( bubbleUp(h, _data[n]) == h) {
234
          bubbleDown(h, _data[n], n);
234 235
        }
235 236
      }
236 237
      _data.pop_back();
237 238
    }
238 239

	
239

	
240
    /// \brief Returns the priority of \c i.
240
    /// \brief The priority of the given item.
241 241
    ///
242
    /// This function returns the priority of item \c i.
242
    /// This function returns the priority of the given item.
243 243
    /// \param i The item.
244
    /// \pre \c i must be in the heap.
244
    /// \pre \e i must be in the heap.
245 245
    Prio operator[](const Item &i) const {
246 246
      int idx = _iim[i];
247 247
      return _data[idx].second;
248 248
    }
249 249

	
250
    /// \brief \c i gets to the heap with priority \c p independently
251
    /// if \c i was already there.
250
    /// \brief Set the priority of an item or insert it, if it is
251
    /// not stored in the heap.
252 252
    ///
253
    /// This method calls \ref push(\c i, \c p) if \c i is not stored
254
    /// in the heap and sets the priority of \c i to \c p otherwise.
253
    /// This method sets the priority of the given item if it is
254
    /// already stored in the heap. Otherwise it inserts the given
255
    /// item into the heap with the given priority.
255 256
    /// \param i The item.
256 257
    /// \param p The priority.
257 258
    void set(const Item &i, const Prio &p) {
258 259
      int idx = _iim[i];
259 260
      if( idx < 0 ) {
260 261
        push(i,p);
261 262
      }
262 263
      else if( _comp(p, _data[idx].second) ) {
263
        bubble_up(idx, Pair(i,p));
264
        bubbleUp(idx, Pair(i,p));
264 265
      }
265 266
      else {
266
        bubble_down(idx, Pair(i,p), _data.size());
267
        bubbleDown(idx, Pair(i,p), _data.size());
267 268
      }
268 269
    }
269 270

	
270
    /// \brief Decreases the priority of \c i to \c p.
271
    /// \brief Decrease the priority of an item to the given value.
271 272
    ///
272
    /// This method decreases the priority of item \c i to \c p.
273
    /// This function decreases the priority of an item to the given value.
273 274
    /// \param i The item.
274 275
    /// \param p The priority.
275
    /// \pre \c i must be stored in the heap with priority at least \c
276
    /// p relative to \c Compare.
276
    /// \pre \e i must be stored in the heap with priority at least \e p.
277 277
    void decrease(const Item &i, const Prio &p) {
278 278
      int idx = _iim[i];
279
      bubble_up(idx, Pair(i,p));
279
      bubbleUp(idx, Pair(i,p));
280 280
    }
281 281

	
282
    /// \brief Increases the priority of \c i to \c p.
282
    /// \brief Increase the priority of an item to the given value.
283 283
    ///
284
    /// This method sets the priority of item \c i to \c p.
284
    /// This function increases the priority of an item to the given value.
285 285
    /// \param i The item.
286 286
    /// \param p The priority.
287
    /// \pre \c i must be stored in the heap with priority at most \c
288
    /// p relative to \c Compare.
287
    /// \pre \e i must be stored in the heap with priority at most \e p.
289 288
    void increase(const Item &i, const Prio &p) {
290 289
      int idx = _iim[i];
291
      bubble_down(idx, Pair(i,p), _data.size());
290
      bubbleDown(idx, Pair(i,p), _data.size());
292 291
    }
293 292

	
294
    /// \brief Returns if \c item is in, has already been in, or has
295
    /// never been in the heap.
293
    /// \brief Return the state of an item.
296 294
    ///
297
    /// This method returns PRE_HEAP if \c item has never been in the
298
    /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
299
    /// otherwise. In the latter case it is possible that \c item will
300
    /// get back to the heap again.
295
    /// This method returns \c PRE_HEAP if the given item has never
296
    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
297
    /// and \c POST_HEAP otherwise.
298
    /// In the latter case it is possible that the item will get back
299
    /// to the heap again.
301 300
    /// \param i The item.
302 301
    State state(const Item &i) const {
303 302
      int s = _iim[i];
304 303
      if( s>=0 )
305 304
        s=0;
306 305
      return State(s);
307 306
    }
308 307

	
309
    /// \brief Sets the state of the \c item in the heap.
308
    /// \brief Set the state of an item in the heap.
310 309
    ///
311
    /// Sets the state of the \c item in the heap. It can be used to
312
    /// manually clear the heap when it is important to achive the
313
    /// better time complexity.
310
    /// This function sets the state of the given item in the heap.
311
    /// It can be used to manually clear the heap when it is important
312
    /// to achive better time complexity.
314 313
    /// \param i The item.
315 314
    /// \param st The state. It should not be \c IN_HEAP.
316 315
    void state(const Item& i, State st) {
317 316
      switch (st) {
318 317
      case POST_HEAP:
319 318
      case PRE_HEAP:
320 319
        if (state(i) == IN_HEAP) {
321 320
          erase(i);
322 321
        }
323 322
        _iim[i] = st;
324 323
        break;
325 324
      case IN_HEAP:
326 325
        break;
327 326
      }
328 327
    }
329 328

	
330
    /// \brief Replaces an item in the heap.
329
    /// \brief Replace an item in the heap.
331 330
    ///
332
    /// The \c i item is replaced with \c j item. The \c i item should
333
    /// be in the heap, while the \c j should be out of the heap. The
334
    /// \c i item will out of the heap and \c j will be in the heap
335
    /// with the same prioriority as prevoiusly the \c i item.
331
    /// This function replaces item \c i with item \c j.
332
    /// Item \c i must be in the heap, while \c j must be out of the heap.
333
    /// After calling this method, item \c i will be out of the
334
    /// heap and \c j will be in the heap with the same prioriority
335
    /// as item \c i had before.
336 336
    void replace(const Item& i, const Item& j) {
337 337
      int idx = _iim[i];
338 338
      _iim.set(i, _iim[j]);
339 339
      _iim.set(j, idx);
340 340
      _data[idx].first = j;
341 341
    }
342 342

	
343 343
  }; // class BinHeap
344 344

	
345 345
} // namespace lemon
346 346

	
347 347
#endif // LEMON_BIN_HEAP_H
Ignore white space 384 line context
... ...
@@ -348,278 +348,278 @@
348 348
    }
349 349

	
350 350

	
351 351
    class NodeIt : public Node { 
352 352
      const Graph* graph;
353 353
    public:
354 354

	
355 355
      NodeIt() {}
356 356

	
357 357
      NodeIt(Invalid i) : Node(i) { }
358 358

	
359 359
      explicit NodeIt(const Graph& _graph) : graph(&_graph) {
360 360
	_graph.first(static_cast<Node&>(*this));
361 361
      }
362 362

	
363 363
      NodeIt(const Graph& _graph, const Node& node) 
364 364
	: Node(node), graph(&_graph) {}
365 365

	
366 366
      NodeIt& operator++() { 
367 367
	graph->next(*this);
368 368
	return *this; 
369 369
      }
370 370

	
371 371
    };
372 372

	
373 373

	
374 374
    class ArcIt : public Arc { 
375 375
      const Graph* graph;
376 376
    public:
377 377

	
378 378
      ArcIt() { }
379 379

	
380 380
      ArcIt(Invalid i) : Arc(i) { }
381 381

	
382 382
      explicit ArcIt(const Graph& _graph) : graph(&_graph) {
383 383
	_graph.first(static_cast<Arc&>(*this));
384 384
      }
385 385

	
386 386
      ArcIt(const Graph& _graph, const Arc& e) : 
387 387
	Arc(e), graph(&_graph) { }
388 388

	
389 389
      ArcIt& operator++() { 
390 390
	graph->next(*this);
391 391
	return *this; 
392 392
      }
393 393

	
394 394
    };
395 395

	
396 396

	
397 397
    class OutArcIt : public Arc { 
398 398
      const Graph* graph;
399 399
    public:
400 400

	
401 401
      OutArcIt() { }
402 402

	
403 403
      OutArcIt(Invalid i) : Arc(i) { }
404 404

	
405 405
      OutArcIt(const Graph& _graph, const Node& node) 
406 406
	: graph(&_graph) {
407 407
	_graph.firstOut(*this, node);
408 408
      }
409 409

	
410 410
      OutArcIt(const Graph& _graph, const Arc& arc) 
411 411
	: Arc(arc), graph(&_graph) {}
412 412

	
413 413
      OutArcIt& operator++() { 
414 414
	graph->nextOut(*this);
415 415
	return *this; 
416 416
      }
417 417

	
418 418
    };
419 419

	
420 420

	
421 421
    class InArcIt : public Arc { 
422 422
      const Graph* graph;
423 423
    public:
424 424

	
425 425
      InArcIt() { }
426 426

	
427 427
      InArcIt(Invalid i) : Arc(i) { }
428 428

	
429 429
      InArcIt(const Graph& _graph, const Node& node) 
430 430
	: graph(&_graph) {
431 431
	_graph.firstIn(*this, node);
432 432
      }
433 433

	
434 434
      InArcIt(const Graph& _graph, const Arc& arc) : 
435 435
	Arc(arc), graph(&_graph) {}
436 436

	
437 437
      InArcIt& operator++() { 
438 438
	graph->nextIn(*this);
439 439
	return *this; 
440 440
      }
441 441

	
442 442
    };
443 443

	
444 444

	
445 445
    class EdgeIt : public Parent::Edge { 
446 446
      const Graph* graph;
447 447
    public:
448 448

	
449 449
      EdgeIt() { }
450 450

	
451 451
      EdgeIt(Invalid i) : Edge(i) { }
452 452

	
453 453
      explicit EdgeIt(const Graph& _graph) : graph(&_graph) {
454 454
	_graph.first(static_cast<Edge&>(*this));
455 455
      }
456 456

	
457 457
      EdgeIt(const Graph& _graph, const Edge& e) : 
458 458
	Edge(e), graph(&_graph) { }
459 459

	
460 460
      EdgeIt& operator++() { 
461 461
	graph->next(*this);
462 462
	return *this; 
463 463
      }
464 464

	
465 465
    };
466 466

	
467 467
    class IncEdgeIt : public Parent::Edge {
468 468
      friend class EdgeSetExtender;
469 469
      const Graph* graph;
470 470
      bool direction;
471 471
    public:
472 472

	
473 473
      IncEdgeIt() { }
474 474

	
475 475
      IncEdgeIt(Invalid i) : Edge(i), direction(false) { }
476 476

	
477 477
      IncEdgeIt(const Graph& _graph, const Node &n) : graph(&_graph) {
478 478
	_graph.firstInc(*this, direction, n);
479 479
      }
480 480

	
481 481
      IncEdgeIt(const Graph& _graph, const Edge &ue, const Node &n)
482 482
	: graph(&_graph), Edge(ue) {
483 483
	direction = (_graph.source(ue) == n);
484 484
      }
485 485

	
486 486
      IncEdgeIt& operator++() {
487 487
	graph->nextInc(*this, direction);
488 488
	return *this; 
489 489
      }
490 490
    };
491 491

	
492 492
    // \brief Base node of the iterator
493 493
    //
494 494
    // Returns the base node (ie. the source in this case) of the iterator
495 495
    Node baseNode(const OutArcIt &e) const {
496 496
      return Parent::source(static_cast<const Arc&>(e));
497 497
    }
498 498
    // \brief Running node of the iterator
499 499
    //
500 500
    // Returns the running node (ie. the target in this case) of the
501 501
    // iterator
502 502
    Node runningNode(const OutArcIt &e) const {
503 503
      return Parent::target(static_cast<const Arc&>(e));
504 504
    }
505 505

	
506 506
    // \brief Base node of the iterator
507 507
    //
508 508
    // Returns the base node (ie. the target in this case) of the iterator
509 509
    Node baseNode(const InArcIt &e) const {
510 510
      return Parent::target(static_cast<const Arc&>(e));
511 511
    }
512 512
    // \brief Running node of the iterator
513 513
    //
514 514
    // Returns the running node (ie. the source in this case) of the
515 515
    // iterator
516 516
    Node runningNode(const InArcIt &e) const {
517 517
      return Parent::source(static_cast<const Arc&>(e));
518 518
    }
519 519

	
520 520
    // Base node of the iterator
521 521
    //
522 522
    // Returns the base node of the iterator
523 523
    Node baseNode(const IncEdgeIt &e) const {
524 524
      return e.direction ? u(e) : v(e);
525 525
    }
526 526
    // Running node of the iterator
527 527
    //
528 528
    // Returns the running node of the iterator
529 529
    Node runningNode(const IncEdgeIt &e) const {
530 530
      return e.direction ? v(e) : u(e);
531 531
    }
532 532

	
533 533

	
534 534
    template <typename _Value>
535 535
    class ArcMap 
536 536
      : public MapExtender<DefaultMap<Graph, Arc, _Value> > {
537 537
      typedef MapExtender<DefaultMap<Graph, Arc, _Value> > Parent;
538 538

	
539 539
    public:
540
      ArcMap(const Graph& _g) 
540
      explicit ArcMap(const Graph& _g) 
541 541
	: Parent(_g) {}
542 542
      ArcMap(const Graph& _g, const _Value& _v) 
543 543
	: Parent(_g, _v) {}
544 544

	
545 545
      ArcMap& operator=(const ArcMap& cmap) {
546 546
	return operator=<ArcMap>(cmap);
547 547
      }
548 548

	
549 549
      template <typename CMap>
550 550
      ArcMap& operator=(const CMap& cmap) {
551 551
        Parent::operator=(cmap);
552 552
	return *this;
553 553
      }
554 554

	
555 555
    };
556 556

	
557 557

	
558 558
    template <typename _Value>
559 559
    class EdgeMap 
560 560
      : public MapExtender<DefaultMap<Graph, Edge, _Value> > {
561 561
      typedef MapExtender<DefaultMap<Graph, Edge, _Value> > Parent;
562 562

	
563 563
    public:
564
      EdgeMap(const Graph& _g) 
564
      explicit EdgeMap(const Graph& _g) 
565 565
	: Parent(_g) {}
566 566

	
567 567
      EdgeMap(const Graph& _g, const _Value& _v) 
568 568
	: Parent(_g, _v) {}
569 569

	
570 570
      EdgeMap& operator=(const EdgeMap& cmap) {
571 571
	return operator=<EdgeMap>(cmap);
572 572
      }
573 573

	
574 574
      template <typename CMap>
575 575
      EdgeMap& operator=(const CMap& cmap) {
576 576
        Parent::operator=(cmap);
577 577
	return *this;
578 578
      }
579 579

	
580 580
    };
581 581

	
582 582

	
583 583
    // Alteration extension
584 584

	
585 585
    Edge addEdge(const Node& from, const Node& to) {
586 586
      Edge edge = Parent::addEdge(from, to);
587 587
      notifier(Edge()).add(edge);
588 588
      std::vector<Arc> arcs;
589 589
      arcs.push_back(Parent::direct(edge, true));
590 590
      arcs.push_back(Parent::direct(edge, false));
591 591
      notifier(Arc()).add(arcs);
592 592
      return edge;
593 593
    }
594 594
    
595 595
    void clear() {
596 596
      notifier(Arc()).clear();
597 597
      notifier(Edge()).clear();
598 598
      Parent::clear();
599 599
    }
600 600

	
601 601
    void erase(const Edge& edge) {
602 602
      std::vector<Arc> arcs;
603 603
      arcs.push_back(Parent::direct(edge, true));
604 604
      arcs.push_back(Parent::direct(edge, false));
605 605
      notifier(Arc()).erase(arcs);
606 606
      notifier(Edge()).erase(edge);
607 607
      Parent::erase(edge);
608 608
    }
609 609

	
610 610

	
611 611
    EdgeSetExtender() {
612 612
      arc_notifier.setContainer(*this);
613 613
      edge_notifier.setContainer(*this);
614 614
    }
615 615

	
616 616
    ~EdgeSetExtender() {
617 617
      edge_notifier.clear();
618 618
      arc_notifier.clear();
619 619
    }
620 620
    
621 621
  };
622 622

	
623 623
}
624 624

	
625 625
#endif
Ignore white space 384 line context
... ...
@@ -415,337 +415,337 @@
415 415

	
416 416

	
417 417
    class NodeIt : public Node {
418 418
      const Graph* _graph;
419 419
    public:
420 420

	
421 421
      NodeIt() {}
422 422

	
423 423
      NodeIt(Invalid i) : Node(i) { }
424 424

	
425 425
      explicit NodeIt(const Graph& graph) : _graph(&graph) {
426 426
        _graph->first(static_cast<Node&>(*this));
427 427
      }
428 428

	
429 429
      NodeIt(const Graph& graph, const Node& node)
430 430
        : Node(node), _graph(&graph) {}
431 431

	
432 432
      NodeIt& operator++() {
433 433
        _graph->next(*this);
434 434
        return *this;
435 435
      }
436 436

	
437 437
    };
438 438

	
439 439

	
440 440
    class ArcIt : public Arc {
441 441
      const Graph* _graph;
442 442
    public:
443 443

	
444 444
      ArcIt() { }
445 445

	
446 446
      ArcIt(Invalid i) : Arc(i) { }
447 447

	
448 448
      explicit ArcIt(const Graph& graph) : _graph(&graph) {
449 449
        _graph->first(static_cast<Arc&>(*this));
450 450
      }
451 451

	
452 452
      ArcIt(const Graph& graph, const Arc& arc) :
453 453
        Arc(arc), _graph(&graph) { }
454 454

	
455 455
      ArcIt& operator++() {
456 456
        _graph->next(*this);
457 457
        return *this;
458 458
      }
459 459

	
460 460
    };
461 461

	
462 462

	
463 463
    class OutArcIt : public Arc {
464 464
      const Graph* _graph;
465 465
    public:
466 466

	
467 467
      OutArcIt() { }
468 468

	
469 469
      OutArcIt(Invalid i) : Arc(i) { }
470 470

	
471 471
      OutArcIt(const Graph& graph, const Node& node)
472 472
        : _graph(&graph) {
473 473
        _graph->firstOut(*this, node);
474 474
      }
475 475

	
476 476
      OutArcIt(const Graph& graph, const Arc& arc)
477 477
        : Arc(arc), _graph(&graph) {}
478 478

	
479 479
      OutArcIt& operator++() {
480 480
        _graph->nextOut(*this);
481 481
        return *this;
482 482
      }
483 483

	
484 484
    };
485 485

	
486 486

	
487 487
    class InArcIt : public Arc {
488 488
      const Graph* _graph;
489 489
    public:
490 490

	
491 491
      InArcIt() { }
492 492

	
493 493
      InArcIt(Invalid i) : Arc(i) { }
494 494

	
495 495
      InArcIt(const Graph& graph, const Node& node)
496 496
        : _graph(&graph) {
497 497
        _graph->firstIn(*this, node);
498 498
      }
499 499

	
500 500
      InArcIt(const Graph& graph, const Arc& arc) :
501 501
        Arc(arc), _graph(&graph) {}
502 502

	
503 503
      InArcIt& operator++() {
504 504
        _graph->nextIn(*this);
505 505
        return *this;
506 506
      }
507 507

	
508 508
    };
509 509

	
510 510

	
511 511
    class EdgeIt : public Parent::Edge {
512 512
      const Graph* _graph;
513 513
    public:
514 514

	
515 515
      EdgeIt() { }
516 516

	
517 517
      EdgeIt(Invalid i) : Edge(i) { }
518 518

	
519 519
      explicit EdgeIt(const Graph& graph) : _graph(&graph) {
520 520
        _graph->first(static_cast<Edge&>(*this));
521 521
      }
522 522

	
523 523
      EdgeIt(const Graph& graph, const Edge& edge) :
524 524
        Edge(edge), _graph(&graph) { }
525 525

	
526 526
      EdgeIt& operator++() {
527 527
        _graph->next(*this);
528 528
        return *this;
529 529
      }
530 530

	
531 531
    };
532 532

	
533 533
    class IncEdgeIt : public Parent::Edge {
534 534
      friend class GraphExtender;
535 535
      const Graph* _graph;
536 536
      bool _direction;
537 537
    public:
538 538

	
539 539
      IncEdgeIt() { }
540 540

	
541 541
      IncEdgeIt(Invalid i) : Edge(i), _direction(false) { }
542 542

	
543 543
      IncEdgeIt(const Graph& graph, const Node &node) : _graph(&graph) {
544 544
        _graph->firstInc(*this, _direction, node);
545 545
      }
546 546

	
547 547
      IncEdgeIt(const Graph& graph, const Edge &edge, const Node &node)
548 548
        : _graph(&graph), Edge(edge) {
549 549
        _direction = (_graph->source(edge) == node);
550 550
      }
551 551

	
552 552
      IncEdgeIt& operator++() {
553 553
        _graph->nextInc(*this, _direction);
554 554
        return *this;
555 555
      }
556 556
    };
557 557

	
558 558
    // \brief Base node of the iterator
559 559
    //
560 560
    // Returns the base node (ie. the source in this case) of the iterator
561 561
    Node baseNode(const OutArcIt &arc) const {
562 562
      return Parent::source(static_cast<const Arc&>(arc));
563 563
    }
564 564
    // \brief Running node of the iterator
565 565
    //
566 566
    // Returns the running node (ie. the target in this case) of the
567 567
    // iterator
568 568
    Node runningNode(const OutArcIt &arc) const {
569 569
      return Parent::target(static_cast<const Arc&>(arc));
570 570
    }
571 571

	
572 572
    // \brief Base node of the iterator
573 573
    //
574 574
    // Returns the base node (ie. the target in this case) of the iterator
575 575
    Node baseNode(const InArcIt &arc) const {
576 576
      return Parent::target(static_cast<const Arc&>(arc));
577 577
    }
578 578
    // \brief Running node of the iterator
579 579
    //
580 580
    // Returns the running node (ie. the source in this case) of the
581 581
    // iterator
582 582
    Node runningNode(const InArcIt &arc) const {
583 583
      return Parent::source(static_cast<const Arc&>(arc));
584 584
    }
585 585

	
586 586
    // Base node of the iterator
587 587
    //
588 588
    // Returns the base node of the iterator
589 589
    Node baseNode(const IncEdgeIt &edge) const {
590 590
      return edge._direction ? u(edge) : v(edge);
591 591
    }
592 592
    // Running node of the iterator
593 593
    //
594 594
    // Returns the running node of the iterator
595 595
    Node runningNode(const IncEdgeIt &edge) const {
596 596
      return edge._direction ? v(edge) : u(edge);
597 597
    }
598 598

	
599 599
    // Mappable extension
600 600

	
601 601
    template <typename _Value>
602 602
    class NodeMap
603 603
      : public MapExtender<DefaultMap<Graph, Node, _Value> > {
604 604
      typedef MapExtender<DefaultMap<Graph, Node, _Value> > Parent;
605 605

	
606 606
    public:
607
      NodeMap(const Graph& graph)
607
      explicit NodeMap(const Graph& graph)
608 608
        : Parent(graph) {}
609 609
      NodeMap(const Graph& graph, const _Value& value)
610 610
        : Parent(graph, value) {}
611 611

	
612 612
    private:
613 613
      NodeMap& operator=(const NodeMap& cmap) {
614 614
        return operator=<NodeMap>(cmap);
615 615
      }
616 616

	
617 617
      template <typename CMap>
618 618
      NodeMap& operator=(const CMap& cmap) {
619 619
        Parent::operator=(cmap);
620 620
        return *this;
621 621
      }
622 622

	
623 623
    };
624 624

	
625 625
    template <typename _Value>
626 626
    class ArcMap
627 627
      : public MapExtender<DefaultMap<Graph, Arc, _Value> > {
628 628
      typedef MapExtender<DefaultMap<Graph, Arc, _Value> > Parent;
629 629

	
630 630
    public:
631
      ArcMap(const Graph& graph)
631
      explicit ArcMap(const Graph& graph)
632 632
        : Parent(graph) {}
633 633
      ArcMap(const Graph& graph, const _Value& value)
634 634
        : Parent(graph, value) {}
635 635

	
636 636
    private:
637 637
      ArcMap& operator=(const ArcMap& cmap) {
638 638
        return operator=<ArcMap>(cmap);
639 639
      }
640 640

	
641 641
      template <typename CMap>
642 642
      ArcMap& operator=(const CMap& cmap) {
643 643
        Parent::operator=(cmap);
644 644
        return *this;
645 645
      }
646 646
    };
647 647

	
648 648

	
649 649
    template <typename _Value>
650 650
    class EdgeMap
651 651
      : public MapExtender<DefaultMap<Graph, Edge, _Value> > {
652 652
      typedef MapExtender<DefaultMap<Graph, Edge, _Value> > Parent;
653 653

	
654 654
    public:
655
      EdgeMap(const Graph& graph)
655
      explicit EdgeMap(const Graph& graph)
656 656
        : Parent(graph) {}
657 657

	
658 658
      EdgeMap(const Graph& graph, const _Value& value)
659 659
        : Parent(graph, value) {}
660 660

	
661 661
    private:
662 662
      EdgeMap& operator=(const EdgeMap& cmap) {
663 663
        return operator=<EdgeMap>(cmap);
664 664
      }
665 665

	
666 666
      template <typename CMap>
667 667
      EdgeMap& operator=(const CMap& cmap) {
668 668
        Parent::operator=(cmap);
669 669
        return *this;
670 670
      }
671 671

	
672 672
    };
673 673

	
674 674
    // Alteration extension
675 675

	
676 676
    Node addNode() {
677 677
      Node node = Parent::addNode();
678 678
      notifier(Node()).add(node);
679 679
      return node;
680 680
    }
681 681

	
682 682
    Edge addEdge(const Node& from, const Node& to) {
683 683
      Edge edge = Parent::addEdge(from, to);
684 684
      notifier(Edge()).add(edge);
685 685
      std::vector<Arc> ev;
686 686
      ev.push_back(Parent::direct(edge, true));
687 687
      ev.push_back(Parent::direct(edge, false));
688 688
      notifier(Arc()).add(ev);
689 689
      return edge;
690 690
    }
691 691

	
692 692
    void clear() {
693 693
      notifier(Arc()).clear();
694 694
      notifier(Edge()).clear();
695 695
      notifier(Node()).clear();
696 696
      Parent::clear();
697 697
    }
698 698

	
699 699
    template <typename Graph, typename NodeRefMap, typename EdgeRefMap>
700 700
    void build(const Graph& graph, NodeRefMap& nodeRef,
701 701
               EdgeRefMap& edgeRef) {
702 702
      Parent::build(graph, nodeRef, edgeRef);
703 703
      notifier(Node()).build();
704 704
      notifier(Edge()).build();
705 705
      notifier(Arc()).build();
706 706
    }
707 707

	
708 708
    void erase(const Node& node) {
709 709
      Arc arc;
710 710
      Parent::firstOut(arc, node);
711 711
      while (arc != INVALID ) {
712 712
        erase(arc);
713 713
        Parent::firstOut(arc, node);
714 714
      }
715 715

	
716 716
      Parent::firstIn(arc, node);
717 717
      while (arc != INVALID ) {
718 718
        erase(arc);
719 719
        Parent::firstIn(arc, node);
720 720
      }
721 721

	
722 722
      notifier(Node()).erase(node);
723 723
      Parent::erase(node);
724 724
    }
725 725

	
726 726
    void erase(const Edge& edge) {
727 727
      std::vector<Arc> av;
728 728
      av.push_back(Parent::direct(edge, true));
729 729
      av.push_back(Parent::direct(edge, false));
730 730
      notifier(Arc()).erase(av);
731 731
      notifier(Edge()).erase(edge);
732 732
      Parent::erase(edge);
733 733
    }
734 734

	
735 735
    GraphExtender() {
736 736
      node_notifier.setContainer(*this);
737 737
      arc_notifier.setContainer(*this);
738 738
      edge_notifier.setContainer(*this);
739 739
    }
740 740

	
741 741
    ~GraphExtender() {
742 742
      edge_notifier.clear();
743 743
      arc_notifier.clear();
744 744
      node_notifier.clear();
745 745
    }
746 746

	
747 747
  };
748 748

	
749 749
}
750 750

	
751 751
#endif
Ignore white space 384 line context
1 1
/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 2
 *
3 3
 * This file is a part of LEMON, a generic C++ optimization library.
4 4
 *
5 5
 * Copyright (C) 2003-2009
6 6
 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 7
 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 8
 *
9 9
 * Permission to use, modify and distribute this software is granted
10 10
 * provided that this copyright notice appears in all copies. For
11 11
 * precise terms see the accompanying LICENSE file.
12 12
 *
13 13
 * This software is provided "AS IS" with no warranty of any kind,
14 14
 * express or implied, and with no claim as to its suitability for any
15 15
 * purpose.
16 16
 *
17 17
 */
18 18

	
19 19
#ifndef LEMON_BUCKET_HEAP_H
20 20
#define LEMON_BUCKET_HEAP_H
21 21

	
22
///\ingroup auxdat
22
///\ingroup heaps
23 23
///\file
24
///\brief Bucket Heap implementation.
24
///\brief Bucket heap implementation.
25 25

	
26 26
#include <vector>
27 27
#include <utility>
28 28
#include <functional>
29 29

	
30 30
namespace lemon {
31 31

	
32 32
  namespace _bucket_heap_bits {
33 33

	
34 34
    template <bool MIN>
35 35
    struct DirectionTraits {
36 36
      static bool less(int left, int right) {
37 37
        return left < right;
38 38
      }
39 39
      static void increase(int& value) {
40 40
        ++value;
41 41
      }
42 42
    };
43 43

	
44 44
    template <>
45 45
    struct DirectionTraits<false> {
46 46
      static bool less(int left, int right) {
47 47
        return left > right;
48 48
      }
49 49
      static void increase(int& value) {
50 50
        --value;
51 51
      }
52 52
    };
53 53

	
54 54
  }
55 55

	
56
  /// \ingroup auxdat
56
  /// \ingroup heaps
57 57
  ///
58
  /// \brief A Bucket Heap implementation.
58
  /// \brief Bucket heap data structure.
59 59
  ///
60
  /// This class implements the \e bucket \e heap data structure. A \e heap
61
  /// is a data structure for storing items with specified values called \e
62
  /// priorities in such a way that finding the item with minimum priority is
63
  /// efficient. The bucket heap is very simple implementation, it can store
64
  /// only integer priorities and it stores for each priority in the
65
  /// \f$ [0..C) \f$ range a list of items. So it should be used only when
66
  /// the priorities are small. It is not intended to use as dijkstra heap.
60
  /// This class implements the \e bucket \e heap data structure.
61
  /// It practically conforms to the \ref concepts::Heap "heap concept",
62
  /// but it has some limitations.
67 63
  ///
68
  /// \param IM A read and write Item int map, used internally
69
  /// to handle the cross references.
70
  /// \param MIN If the given parameter is false then instead of the
71
  /// minimum value the maximum can be retrivied with the top() and
72
  /// prio() member functions.
64
  /// The bucket heap is a very simple structure. It can store only
65
  /// \c int priorities and it maintains a list of items for each priority
66
  /// in the range <tt>[0..C)</tt>. So it should only be used when the
67
  /// priorities are small. It is not intended to use as a Dijkstra heap.
68
  ///
69
  /// \tparam IM A read-writable item map with \c int values, used
70
  /// internally to handle the cross references.
71
  /// \tparam MIN Indicate if the heap is a \e min-heap or a \e max-heap.
72
  /// The default is \e min-heap. If this parameter is set to \c false,
73
  /// then the comparison is reversed, so the top(), prio() and pop()
74
  /// functions deal with the item having maximum priority instead of the
75
  /// minimum.
76
  ///
77
  /// \sa SimpleBucketHeap
73 78
  template <typename IM, bool MIN = true>
74 79
  class BucketHeap {
75 80

	
76 81
  public:
77
    /// \e
78
    typedef typename IM::Key Item;
79
    /// \e
82

	
83
    /// Type of the item-int map.
84
    typedef IM ItemIntMap;
85
    /// Type of the priorities.
80 86
    typedef int Prio;
81
    /// \e
82
    typedef std::pair<Item, Prio> Pair;
83
    /// \e
84
    typedef IM ItemIntMap;
87
    /// Type of the items stored in the heap.
88
    typedef typename ItemIntMap::Key Item;
89
    /// Type of the item-priority pairs.
90
    typedef std::pair<Item,Prio> Pair;
85 91

	
86 92
  private:
87 93

	
88 94
    typedef _bucket_heap_bits::DirectionTraits<MIN> Direction;
89 95

	
90 96
  public:
91 97

	
92
    /// \brief Type to represent the items states.
98
    /// \brief Type to represent the states of the items.
93 99
    ///
94
    /// Each Item element have a state associated to it. It may be "in heap",
95
    /// "pre heap" or "post heap". The latter two are indifferent from the
100
    /// Each item has a state associated to it. It can be "in heap",
101
    /// "pre-heap" or "post-heap". The latter two are indifferent from the
96 102
    /// heap's point of view, but may be useful to the user.
97 103
    ///
98 104
    /// The item-int map must be initialized in such way that it assigns
99 105
    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
100 106
    enum State {
101 107
      IN_HEAP = 0,    ///< = 0.
102 108
      PRE_HEAP = -1,  ///< = -1.
103 109
      POST_HEAP = -2  ///< = -2.
104 110
    };
105 111

	
106 112
  public:
107
    /// \brief The constructor.
113

	
114
    /// \brief Constructor.
108 115
    ///
109
    /// The constructor.
110
    /// \param map should be given to the constructor, since it is used
111
    /// internally to handle the cross references. The value of the map
112
    /// should be PRE_HEAP (-1) for each element.
116
    /// Constructor.
117
    /// \param map A map that assigns \c int values to the items.
118
    /// It is used internally to handle the cross references.
119
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
113 120
    explicit BucketHeap(ItemIntMap &map) : _iim(map), _minimum(0) {}
114 121

	
115
    /// The number of items stored in the heap.
122
    /// \brief The number of items stored in the heap.
116 123
    ///
117
    /// \brief Returns the number of items stored in the heap.
124
    /// This function returns the number of items stored in the heap.
118 125
    int size() const { return _data.size(); }
119 126

	
120
    /// \brief Checks if the heap stores no items.
127
    /// \brief Check if the heap is empty.
121 128
    ///
122
    /// Returns \c true if and only if the heap stores no items.
129
    /// This function returns \c true if the heap is empty.
123 130
    bool empty() const { return _data.empty(); }
124 131

	
125
    /// \brief Make empty this heap.
132
    /// \brief Make the heap empty.
126 133
    ///
127
    /// Make empty this heap. It does not change the cross reference
128
    /// map.  If you want to reuse a heap what is not surely empty you
129
    /// should first clear the heap and after that you should set the
130
    /// cross reference map for each item to \c PRE_HEAP.
134
    /// This functon makes the heap empty.
135
    /// It does not change the cross reference map. If you want to reuse
136
    /// a heap that is not surely empty, you should first clear it and
137
    /// then you should set the cross reference map to \c PRE_HEAP
138
    /// for each item.
131 139
    void clear() {
132 140
      _data.clear(); _first.clear(); _minimum = 0;
133 141
    }
134 142

	
135 143
  private:
136 144

	
137
    void relocate_last(int idx) {
145
    void relocateLast(int idx) {
138 146
      if (idx + 1 < int(_data.size())) {
139 147
        _data[idx] = _data.back();
140 148
        if (_data[idx].prev != -1) {
141 149
          _data[_data[idx].prev].next = idx;
142 150
        } else {
143 151
          _first[_data[idx].value] = idx;
144 152
        }
145 153
        if (_data[idx].next != -1) {
146 154
          _data[_data[idx].next].prev = idx;
147 155
        }
148 156
        _iim[_data[idx].item] = idx;
149 157
      }
150 158
      _data.pop_back();
151 159
    }
152 160

	
153 161
    void unlace(int idx) {
154 162
      if (_data[idx].prev != -1) {
155 163
        _data[_data[idx].prev].next = _data[idx].next;
156 164
      } else {
157 165
        _first[_data[idx].value] = _data[idx].next;
158 166
      }
159 167
      if (_data[idx].next != -1) {
160 168
        _data[_data[idx].next].prev = _data[idx].prev;
161 169
      }
162 170
    }
163 171

	
164 172
    void lace(int idx) {
165 173
      if (int(_first.size()) <= _data[idx].value) {
166 174
        _first.resize(_data[idx].value + 1, -1);
167 175
      }
168 176
      _data[idx].next = _first[_data[idx].value];
169 177
      if (_data[idx].next != -1) {
170 178
        _data[_data[idx].next].prev = idx;
171 179
      }
172 180
      _first[_data[idx].value] = idx;
173 181
      _data[idx].prev = -1;
174 182
    }
175 183

	
176 184
  public:
185

	
177 186
    /// \brief Insert a pair of item and priority into the heap.
178 187
    ///
179
    /// Adds \c p.first to the heap with priority \c p.second.
188
    /// This function inserts \c p.first to the heap with priority
189
    /// \c p.second.
180 190
    /// \param p The pair to insert.
191
    /// \pre \c p.first must not be stored in the heap.
181 192
    void push(const Pair& p) {
182 193
      push(p.first, p.second);
183 194
    }
184 195

	
185 196
    /// \brief Insert an item into the heap with the given priority.
186 197
    ///
187
    /// Adds \c i to the heap with priority \c p.
198
    /// This function inserts the given item into the heap with the
199
    /// given priority.
188 200
    /// \param i The item to insert.
189 201
    /// \param p The priority of the item.
202
    /// \pre \e i must not be stored in the heap.
190 203
    void push(const Item &i, const Prio &p) {
191 204
      int idx = _data.size();
192 205
      _iim[i] = idx;
193 206
      _data.push_back(BucketItem(i, p));
194 207
      lace(idx);
195 208
      if (Direction::less(p, _minimum)) {
196 209
        _minimum = p;
197 210
      }
198 211
    }
199 212

	
200
    /// \brief Returns the item with minimum priority.
213
    /// \brief Return the item having minimum priority.
201 214
    ///
202
    /// This method returns the item with minimum priority.
203
    /// \pre The heap must be nonempty.
215
    /// This function returns the item having minimum priority.
216
    /// \pre The heap must be non-empty.
204 217
    Item top() const {
205 218
      while (_first[_minimum] == -1) {
206 219
        Direction::increase(_minimum);
207 220
      }
208 221
      return _data[_first[_minimum]].item;
209 222
    }
210 223

	
211
    /// \brief Returns the minimum priority.
224
    /// \brief The minimum priority.
212 225
    ///
213
    /// It returns the minimum priority.
214
    /// \pre The heap must be nonempty.
226
    /// This function returns the minimum priority.
227
    /// \pre The heap must be non-empty.
215 228
    Prio prio() const {
216 229
      while (_first[_minimum] == -1) {
217 230
        Direction::increase(_minimum);
218 231
      }
219 232
      return _minimum;
220 233
    }
221 234

	
222
    /// \brief Deletes the item with minimum priority.
235
    /// \brief Remove the item having minimum priority.
223 236
    ///
224
    /// This method deletes the item with minimum priority from the heap.
237
    /// This function removes the item having minimum priority.
225 238
    /// \pre The heap must be non-empty.
226 239
    void pop() {
227 240
      while (_first[_minimum] == -1) {
228 241
        Direction::increase(_minimum);
229 242
      }
230 243
      int idx = _first[_minimum];
231 244
      _iim[_data[idx].item] = -2;
232 245
      unlace(idx);
233
      relocate_last(idx);
246
      relocateLast(idx);
234 247
    }
235 248

	
236
    /// \brief Deletes \c i from the heap.
249
    /// \brief Remove the given item from the heap.
237 250
    ///
238
    /// This method deletes item \c i from the heap, if \c i was
239
    /// already stored in the heap.
240
    /// \param i The item to erase.
251
    /// This function removes the given item from the heap if it is
252
    /// already stored.
253
    /// \param i The item to delete.
254
    /// \pre \e i must be in the heap.
241 255
    void erase(const Item &i) {
242 256
      int idx = _iim[i];
243 257
      _iim[_data[idx].item] = -2;
244 258
      unlace(idx);
245
      relocate_last(idx);
259
      relocateLast(idx);
246 260
    }
247 261

	
248

	
249
    /// \brief Returns the priority of \c i.
262
    /// \brief The priority of the given item.
250 263
    ///
251
    /// This function returns the priority of item \c i.
252
    /// \pre \c i must be in the heap.
264
    /// This function returns the priority of the given item.
253 265
    /// \param i The item.
266
    /// \pre \e i must be in the heap.
254 267
    Prio operator[](const Item &i) const {
255 268
      int idx = _iim[i];
256 269
      return _data[idx].value;
257 270
    }
258 271

	
259
    /// \brief \c i gets to the heap with priority \c p independently
260
    /// if \c i was already there.
272
    /// \brief Set the priority of an item or insert it, if it is
273
    /// not stored in the heap.
261 274
    ///
262
    /// This method calls \ref push(\c i, \c p) if \c i is not stored
263
    /// in the heap and sets the priority of \c i to \c p otherwise.
275
    /// This method sets the priority of the given item if it is
276
    /// already stored in the heap. Otherwise it inserts the given
277
    /// item into the heap with the given priority.
264 278
    /// \param i The item.
265 279
    /// \param p The priority.
266 280
    void set(const Item &i, const Prio &p) {
267 281
      int idx = _iim[i];
268 282
      if (idx < 0) {
269 283
        push(i, p);
270 284
      } else if (Direction::less(p, _data[idx].value)) {
271 285
        decrease(i, p);
272 286
      } else {
273 287
        increase(i, p);
274 288
      }
275 289
    }
276 290

	
277
    /// \brief Decreases the priority of \c i to \c p.
291
    /// \brief Decrease the priority of an item to the given value.
278 292
    ///
279
    /// This method decreases the priority of item \c i to \c p.
280
    /// \pre \c i must be stored in the heap with priority at least \c
281
    /// p relative to \c Compare.
293
    /// This function decreases the priority of an item to the given value.
282 294
    /// \param i The item.
283 295
    /// \param p The priority.
296
    /// \pre \e i must be stored in the heap with priority at least \e p.
284 297
    void decrease(const Item &i, const Prio &p) {
285 298
      int idx = _iim[i];
286 299
      unlace(idx);
287 300
      _data[idx].value = p;
288 301
      if (Direction::less(p, _minimum)) {
289 302
        _minimum = p;
290 303
      }
291 304
      lace(idx);
292 305
    }
293 306

	
294
    /// \brief Increases the priority of \c i to \c p.
307
    /// \brief Increase the priority of an item to the given value.
295 308
    ///
296
    /// This method sets the priority of item \c i to \c p.
297
    /// \pre \c i must be stored in the heap with priority at most \c
298
    /// p relative to \c Compare.
309
    /// This function increases the priority of an item to the given value.
299 310
    /// \param i The item.
300 311
    /// \param p The priority.
312
    /// \pre \e i must be stored in the heap with priority at most \e p.
301 313
    void increase(const Item &i, const Prio &p) {
302 314
      int idx = _iim[i];
303 315
      unlace(idx);
304 316
      _data[idx].value = p;
305 317
      lace(idx);
306 318
    }
307 319

	
308
    /// \brief Returns if \c item is in, has already been in, or has
309
    /// never been in the heap.
320
    /// \brief Return the state of an item.
310 321
    ///
311
    /// This method returns PRE_HEAP if \c item has never been in the
312
    /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
313
    /// otherwise. In the latter case it is possible that \c item will
314
    /// get back to the heap again.
322
    /// This method returns \c PRE_HEAP if the given item has never
323
    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
324
    /// and \c POST_HEAP otherwise.
325
    /// In the latter case it is possible that the item will get back
326
    /// to the heap again.
315 327
    /// \param i The item.
316 328
    State state(const Item &i) const {
317 329
      int idx = _iim[i];
318 330
      if (idx >= 0) idx = 0;
319 331
      return State(idx);
320 332
    }
321 333

	
322
    /// \brief Sets the state of the \c item in the heap.
334
    /// \brief Set the state of an item in the heap.
323 335
    ///
324
    /// Sets the state of the \c item in the heap. It can be used to
325
    /// manually clear the heap when it is important to achive the
326
    /// better time complexity.
336
    /// This function sets the state of the given item in the heap.
337
    /// It can be used to manually clear the heap when it is important
338
    /// to achive better time complexity.
327 339
    /// \param i The item.
328 340
    /// \param st The state. It should not be \c IN_HEAP.
329 341
    void state(const Item& i, State st) {
330 342
      switch (st) {
331 343
      case POST_HEAP:
332 344
      case PRE_HEAP:
333 345
        if (state(i) == IN_HEAP) {
334 346
          erase(i);
335 347
        }
336 348
        _iim[i] = st;
337 349
        break;
338 350
      case IN_HEAP:
339 351
        break;
340 352
      }
341 353
    }
342 354

	
343 355
  private:
344 356

	
345 357
    struct BucketItem {
346 358
      BucketItem(const Item& _item, int _value)
347 359
        : item(_item), value(_value) {}
348 360

	
349 361
      Item item;
350 362
      int value;
351 363

	
352 364
      int prev, next;
353 365
    };
354 366

	
355 367
    ItemIntMap& _iim;
356 368
    std::vector<int> _first;
357 369
    std::vector<BucketItem> _data;
358 370
    mutable int _minimum;
359 371

	
360 372
  }; // class BucketHeap
361 373

	
362
  /// \ingroup auxdat
374
  /// \ingroup heaps
363 375
  ///
364
  /// \brief A Simplified Bucket Heap implementation.
376
  /// \brief Simplified bucket heap data structure.
365 377
  ///
366 378
  /// This class implements a simplified \e bucket \e heap data
367
  /// structure.  It does not provide some functionality but it faster
368
  /// and simplier data structure than the BucketHeap. The main
369
  /// difference is that the BucketHeap stores for every key a double
370
  /// linked list while this class stores just simple lists. In the
371
  /// other way it does not support erasing each elements just the
372
  /// minimal and it does not supports key increasing, decreasing.
379
  /// structure. It does not provide some functionality, but it is
380
  /// faster and simpler than BucketHeap. The main difference is
381
  /// that BucketHeap stores a doubly-linked list for each key while
382
  /// this class stores only simply-linked lists. It supports erasing
383
  /// only for the item having minimum priority and it does not support
384
  /// key increasing and decreasing.
373 385
  ///
374
  /// \param IM A read and write Item int map, used internally
375
  /// to handle the cross references.
376
  /// \param MIN If the given parameter is false then instead of the
377
  /// minimum value the maximum can be retrivied with the top() and
378
  /// prio() member functions.
386
  /// Note that this implementation does not conform to the
387
  /// \ref concepts::Heap "heap concept" due to the lack of some 
388
  /// functionality.
389
  ///
390
  /// \tparam IM A read-writable item map with \c int values, used
391
  /// internally to handle the cross references.
392
  /// \tparam MIN Indicate if the heap is a \e min-heap or a \e max-heap.
393
  /// The default is \e min-heap. If this parameter is set to \c false,
394
  /// then the comparison is reversed, so the top(), prio() and pop()
395
  /// functions deal with the item having maximum priority instead of the
396
  /// minimum.
379 397
  ///
380 398
  /// \sa BucketHeap
381 399
  template <typename IM, bool MIN = true >
382 400
  class SimpleBucketHeap {
383 401

	
384 402
  public:
385
    typedef typename IM::Key Item;
403

	
404
    /// Type of the item-int map.
405
    typedef IM ItemIntMap;
406
    /// Type of the priorities.
386 407
    typedef int Prio;
387
    typedef std::pair<Item, Prio> Pair;
388
    typedef IM ItemIntMap;
408
    /// Type of the items stored in the heap.
409
    typedef typename ItemIntMap::Key Item;
410
    /// Type of the item-priority pairs.
411
    typedef std::pair<Item,Prio> Pair;
389 412

	
390 413
  private:
391 414

	
392 415
    typedef _bucket_heap_bits::DirectionTraits<MIN> Direction;
393 416

	
394 417
  public:
395 418

	
396
    /// \brief Type to represent the items states.
419
    /// \brief Type to represent the states of the items.
397 420
    ///
398
    /// Each Item element have a state associated to it. It may be "in heap",
399
    /// "pre heap" or "post heap". The latter two are indifferent from the
421
    /// Each item has a state associated to it. It can be "in heap",
422
    /// "pre-heap" or "post-heap". The latter two are indifferent from the
400 423
    /// heap's point of view, but may be useful to the user.
401 424
    ///
402 425
    /// The item-int map must be initialized in such way that it assigns
403 426
    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
404 427
    enum State {
405 428
      IN_HEAP = 0,    ///< = 0.
406 429
      PRE_HEAP = -1,  ///< = -1.
407 430
      POST_HEAP = -2  ///< = -2.
408 431
    };
409 432

	
410 433
  public:
411 434

	
412
    /// \brief The constructor.
435
    /// \brief Constructor.
413 436
    ///
414
    /// The constructor.
415
    /// \param map should be given to the constructor, since it is used
416
    /// internally to handle the cross references. The value of the map
417
    /// should be PRE_HEAP (-1) for each element.
437
    /// Constructor.
438
    /// \param map A map that assigns \c int values to the items.
439
    /// It is used internally to handle the cross references.
440
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
418 441
    explicit SimpleBucketHeap(ItemIntMap &map)
419 442
      : _iim(map), _free(-1), _num(0), _minimum(0) {}
420 443

	
421
    /// \brief Returns the number of items stored in the heap.
444
    /// \brief The number of items stored in the heap.
422 445
    ///
423
    /// The number of items stored in the heap.
446
    /// This function returns the number of items stored in the heap.
424 447
    int size() const { return _num; }
425 448

	
426
    /// \brief Checks if the heap stores no items.
449
    /// \brief Check if the heap is empty.
427 450
    ///
428
    /// Returns \c true if and only if the heap stores no items.
451
    /// This function returns \c true if the heap is empty.
429 452
    bool empty() const { return _num == 0; }
430 453

	
431
    /// \brief Make empty this heap.
454
    /// \brief Make the heap empty.
432 455
    ///
433
    /// Make empty this heap. It does not change the cross reference
434
    /// map.  If you want to reuse a heap what is not surely empty you
435
    /// should first clear the heap and after that you should set the
436
    /// cross reference map for each item to \c PRE_HEAP.
456
    /// This functon makes the heap empty.
457
    /// It does not change the cross reference map. If you want to reuse
458
    /// a heap that is not surely empty, you should first clear it and
459
    /// then you should set the cross reference map to \c PRE_HEAP
460
    /// for each item.
437 461
    void clear() {
438 462
      _data.clear(); _first.clear(); _free = -1; _num = 0; _minimum = 0;
439 463
    }
440 464

	
441 465
    /// \brief Insert a pair of item and priority into the heap.
442 466
    ///
443
    /// Adds \c p.first to the heap with priority \c p.second.
467
    /// This function inserts \c p.first to the heap with priority
468
    /// \c p.second.
444 469
    /// \param p The pair to insert.
470
    /// \pre \c p.first must not be stored in the heap.
445 471
    void push(const Pair& p) {
446 472
      push(p.first, p.second);
447 473
    }
448 474

	
449 475
    /// \brief Insert an item into the heap with the given priority.
450 476
    ///
451
    /// Adds \c i to the heap with priority \c p.
477
    /// This function inserts the given item into the heap with the
478
    /// given priority.
452 479
    /// \param i The item to insert.
453 480
    /// \param p The priority of the item.
481
    /// \pre \e i must not be stored in the heap.
454 482
    void push(const Item &i, const Prio &p) {
455 483
      int idx;
456 484
      if (_free == -1) {
457 485
        idx = _data.size();
458 486
        _data.push_back(BucketItem(i));
459 487
      } else {
460 488
        idx = _free;
461 489
        _free = _data[idx].next;
462 490
        _data[idx].item = i;
463 491
      }
464 492
      _iim[i] = idx;
465 493
      if (p >= int(_first.size())) _first.resize(p + 1, -1);
466 494
      _data[idx].next = _first[p];
467 495
      _first[p] = idx;
468 496
      if (Direction::less(p, _minimum)) {
469 497
        _minimum = p;
470 498
      }
471 499
      ++_num;
472 500
    }
473 501

	
474
    /// \brief Returns the item with minimum priority.
502
    /// \brief Return the item having minimum priority.
475 503
    ///
476
    /// This method returns the item with minimum priority.
477
    /// \pre The heap must be nonempty.
504
    /// This function returns the item having minimum priority.
505
    /// \pre The heap must be non-empty.
478 506
    Item top() const {
479 507
      while (_first[_minimum] == -1) {
480 508
        Direction::increase(_minimum);
481 509
      }
482 510
      return _data[_first[_minimum]].item;
483 511
    }
484 512

	
485
    /// \brief Returns the minimum priority.
513
    /// \brief The minimum priority.
486 514
    ///
487
    /// It returns the minimum priority.
488
    /// \pre The heap must be nonempty.
515
    /// This function returns the minimum priority.
516
    /// \pre The heap must be non-empty.
489 517
    Prio prio() const {
490 518
      while (_first[_minimum] == -1) {
491 519
        Direction::increase(_minimum);
492 520
      }
493 521
      return _minimum;
494 522
    }
495 523

	
496
    /// \brief Deletes the item with minimum priority.
524
    /// \brief Remove the item having minimum priority.
497 525
    ///
498
    /// This method deletes the item with minimum priority from the heap.
526
    /// This function removes the item having minimum priority.
499 527
    /// \pre The heap must be non-empty.
500 528
    void pop() {
501 529
      while (_first[_minimum] == -1) {
502 530
        Direction::increase(_minimum);
503 531
      }
504 532
      int idx = _first[_minimum];
505 533
      _iim[_data[idx].item] = -2;
506 534
      _first[_minimum] = _data[idx].next;
507 535
      _data[idx].next = _free;
508 536
      _free = idx;
509 537
      --_num;
510 538
    }
511 539

	
512
    /// \brief Returns the priority of \c i.
540
    /// \brief The priority of the given item.
513 541
    ///
514
    /// This function returns the priority of item \c i.
515
    /// \warning This operator is not a constant time function
516
    /// because it scans the whole data structure to find the proper
517
    /// value.
518
    /// \pre \c i must be in the heap.
542
    /// This function returns the priority of the given item.
519 543
    /// \param i The item.
544
    /// \pre \e i must be in the heap.
545
    /// \warning This operator is not a constant time function because
546
    /// it scans the whole data structure to find the proper value.
520 547
    Prio operator[](const Item &i) const {
521
      for (int k = 0; k < _first.size(); ++k) {
548
      for (int k = 0; k < int(_first.size()); ++k) {
522 549
        int idx = _first[k];
523 550
        while (idx != -1) {
524 551
          if (_data[idx].item == i) {
525 552
            return k;
526 553
          }
527 554
          idx = _data[idx].next;
528 555
        }
529 556
      }
530 557
      return -1;
531 558
    }
532 559

	
533
    /// \brief Returns if \c item is in, has already been in, or has
534
    /// never been in the heap.
560
    /// \brief Return the state of an item.
535 561
    ///
536
    /// This method returns PRE_HEAP if \c item has never been in the
537
    /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
538
    /// otherwise. In the latter case it is possible that \c item will
539
    /// get back to the heap again.
562
    /// This method returns \c PRE_HEAP if the given item has never
563
    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
564
    /// and \c POST_HEAP otherwise.
565
    /// In the latter case it is possible that the item will get back
566
    /// to the heap again.
540 567
    /// \param i The item.
541 568
    State state(const Item &i) const {
542 569
      int idx = _iim[i];
543 570
      if (idx >= 0) idx = 0;
544 571
      return State(idx);
545 572
    }
546 573

	
547 574
  private:
548 575

	
549 576
    struct BucketItem {
550 577
      BucketItem(const Item& _item)
551 578
        : item(_item) {}
552 579

	
553 580
      Item item;
554 581
      int next;
555 582
    };
556 583

	
557 584
    ItemIntMap& _iim;
558 585
    std::vector<int> _first;
559 586
    std::vector<BucketItem> _data;
560 587
    int _free, _num;
561 588
    mutable int _minimum;
562 589

	
563 590
  }; // class SimpleBucketHeap
564 591

	
565 592
}
566 593

	
567 594
#endif
Ignore white space 384 line context
... ...
@@ -268,397 +268,399 @@
268 268
    struct SetElevatorTraits : public Traits {
269 269
      typedef T Elevator;
270 270
      static Elevator *createElevator(const Digraph&, int) {
271 271
        LEMON_ASSERT(false, "Elevator is not initialized");
272 272
        return 0; // ignore warnings
273 273
      }
274 274
    };
275 275

	
276 276
    /// \brief \ref named-templ-param "Named parameter" for setting
277 277
    /// Elevator type
278 278
    ///
279 279
    /// \ref named-templ-param "Named parameter" for setting Elevator
280 280
    /// type. If this named parameter is used, then an external
281 281
    /// elevator object must be passed to the algorithm using the
282 282
    /// \ref elevator(Elevator&) "elevator()" function before calling
283 283
    /// \ref run() or \ref init().
284 284
    /// \sa SetStandardElevator
285 285
    template <typename T>
286 286
    struct SetElevator
287 287
      : public Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
288 288
                           SetElevatorTraits<T> > {
289 289
      typedef Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
290 290
                          SetElevatorTraits<T> > Create;
291 291
    };
292 292

	
293 293
    template <typename T>
294 294
    struct SetStandardElevatorTraits : public Traits {
295 295
      typedef T Elevator;
296 296
      static Elevator *createElevator(const Digraph& digraph, int max_level) {
297 297
        return new Elevator(digraph, max_level);
298 298
      }
299 299
    };
300 300

	
301 301
    /// \brief \ref named-templ-param "Named parameter" for setting
302 302
    /// Elevator type with automatic allocation
303 303
    ///
304 304
    /// \ref named-templ-param "Named parameter" for setting Elevator
305 305
    /// type with automatic allocation.
306 306
    /// The Elevator should have standard constructor interface to be
307 307
    /// able to automatically created by the algorithm (i.e. the
308 308
    /// digraph and the maximum level should be passed to it).
309 309
    /// However an external elevator object could also be passed to the
310 310
    /// algorithm with the \ref elevator(Elevator&) "elevator()" function
311 311
    /// before calling \ref run() or \ref init().
312 312
    /// \sa SetElevator
313 313
    template <typename T>
314 314
    struct SetStandardElevator
315 315
      : public Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
316 316
                       SetStandardElevatorTraits<T> > {
317 317
      typedef Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
318 318
                      SetStandardElevatorTraits<T> > Create;
319 319
    };
320 320

	
321 321
    /// @}
322 322

	
323 323
  protected:
324 324

	
325 325
    Circulation() {}
326 326

	
327 327
  public:
328 328

	
329 329
    /// Constructor.
330 330

	
331 331
    /// The constructor of the class.
332 332
    ///
333 333
    /// \param graph The digraph the algorithm runs on.
334 334
    /// \param lower The lower bounds for the flow values on the arcs.
335 335
    /// \param upper The upper bounds (capacities) for the flow values 
336 336
    /// on the arcs.
337 337
    /// \param supply The signed supply values of the nodes.
338 338
    Circulation(const Digraph &graph, const LowerMap &lower,
339 339
                const UpperMap &upper, const SupplyMap &supply)
340 340
      : _g(graph), _lo(&lower), _up(&upper), _supply(&supply),
341 341
        _flow(NULL), _local_flow(false), _level(NULL), _local_level(false),
342 342
        _excess(NULL) {}
343 343

	
344 344
    /// Destructor.
345 345
    ~Circulation() {
346 346
      destroyStructures();
347 347
    }
348 348

	
349 349

	
350 350
  private:
351 351

	
352 352
    bool checkBoundMaps() {
353 353
      for (ArcIt e(_g);e!=INVALID;++e) {
354 354
        if (_tol.less((*_up)[e], (*_lo)[e])) return false;
355 355
      }
356 356
      return true;
357 357
    }
358 358

	
359 359
    void createStructures() {
360 360
      _node_num = _el = countNodes(_g);
361 361

	
362 362
      if (!_flow) {
363 363
        _flow = Traits::createFlowMap(_g);
364 364
        _local_flow = true;
365 365
      }
366 366
      if (!_level) {
367 367
        _level = Traits::createElevator(_g, _node_num);
368 368
        _local_level = true;
369 369
      }
370 370
      if (!_excess) {
371 371
        _excess = new ExcessMap(_g);
372 372
      }
373 373
    }
374 374

	
375 375
    void destroyStructures() {
376 376
      if (_local_flow) {
377 377
        delete _flow;
378 378
      }
379 379
      if (_local_level) {
380 380
        delete _level;
381 381
      }
382 382
      if (_excess) {
383 383
        delete _excess;
384 384
      }
385 385
    }
386 386

	
387 387
  public:
388 388

	
389 389
    /// Sets the lower bound map.
390 390

	
391 391
    /// Sets the lower bound map.
392 392
    /// \return <tt>(*this)</tt>
393 393
    Circulation& lowerMap(const LowerMap& map) {
394 394
      _lo = &map;
395 395
      return *this;
396 396
    }
397 397

	
398 398
    /// Sets the upper bound (capacity) map.
399 399

	
400 400
    /// Sets the upper bound (capacity) map.
401 401
    /// \return <tt>(*this)</tt>
402 402
    Circulation& upperMap(const UpperMap& map) {
403 403
      _up = &map;
404 404
      return *this;
405 405
    }
406 406

	
407 407
    /// Sets the supply map.
408 408

	
409 409
    /// Sets the supply map.
410 410
    /// \return <tt>(*this)</tt>
411 411
    Circulation& supplyMap(const SupplyMap& map) {
412 412
      _supply = &map;
413 413
      return *this;
414 414
    }
415 415

	
416 416
    /// \brief Sets the flow map.
417 417
    ///
418 418
    /// Sets the flow map.
419 419
    /// If you don't use this function before calling \ref run() or
420 420
    /// \ref init(), an instance will be allocated automatically.
421 421
    /// The destructor deallocates this automatically allocated map,
422 422
    /// of course.
423 423
    /// \return <tt>(*this)</tt>
424 424
    Circulation& flowMap(FlowMap& map) {
425 425
      if (_local_flow) {
426 426
        delete _flow;
427 427
        _local_flow = false;
428 428
      }
429 429
      _flow = &map;
430 430
      return *this;
431 431
    }
432 432

	
433 433
    /// \brief Sets the elevator used by algorithm.
434 434
    ///
435 435
    /// Sets the elevator used by algorithm.
436 436
    /// If you don't use this function before calling \ref run() or
437 437
    /// \ref init(), an instance will be allocated automatically.
438 438
    /// The destructor deallocates this automatically allocated elevator,
439 439
    /// of course.
440 440
    /// \return <tt>(*this)</tt>
441 441
    Circulation& elevator(Elevator& elevator) {
442 442
      if (_local_level) {
443 443
        delete _level;
444 444
        _local_level = false;
445 445
      }
446 446
      _level = &elevator;
447 447
      return *this;
448 448
    }
449 449

	
450 450
    /// \brief Returns a const reference to the elevator.
451 451
    ///
452 452
    /// Returns a const reference to the elevator.
453 453
    ///
454 454
    /// \pre Either \ref run() or \ref init() must be called before
455 455
    /// using this function.
456 456
    const Elevator& elevator() const {
457 457
      return *_level;
458 458
    }
459 459

	
460
    /// \brief Sets the tolerance used by algorithm.
460
    /// \brief Sets the tolerance used by the algorithm.
461 461
    ///
462
    /// Sets the tolerance used by algorithm.
463
    Circulation& tolerance(const Tolerance& tolerance) const {
462
    /// Sets the tolerance object used by the algorithm.
463
    /// \return <tt>(*this)</tt>
464
    Circulation& tolerance(const Tolerance& tolerance) {
464 465
      _tol = tolerance;
465 466
      return *this;
466 467
    }
467 468

	
468 469
    /// \brief Returns a const reference to the tolerance.
469 470
    ///
470
    /// Returns a const reference to the tolerance.
471
    /// Returns a const reference to the tolerance object used by
472
    /// the algorithm.
471 473
    const Tolerance& tolerance() const {
472
      return tolerance;
474
      return _tol;
473 475
    }
474 476

	
475 477
    /// \name Execution Control
476 478
    /// The simplest way to execute the algorithm is to call \ref run().\n
477 479
    /// If you need better control on the initial solution or the execution,
478 480
    /// you have to call one of the \ref init() functions first, then
479 481
    /// the \ref start() function.
480 482

	
481 483
    ///@{
482 484

	
483 485
    /// Initializes the internal data structures.
484 486

	
485 487
    /// Initializes the internal data structures and sets all flow values
486 488
    /// to the lower bound.
487 489
    void init()
488 490
    {
489 491
      LEMON_DEBUG(checkBoundMaps(),
490 492
        "Upper bounds must be greater or equal to the lower bounds");
491 493

	
492 494
      createStructures();
493 495

	
494 496
      for(NodeIt n(_g);n!=INVALID;++n) {
495 497
        (*_excess)[n] = (*_supply)[n];
496 498
      }
497 499

	
498 500
      for (ArcIt e(_g);e!=INVALID;++e) {
499 501
        _flow->set(e, (*_lo)[e]);
500 502
        (*_excess)[_g.target(e)] += (*_flow)[e];
501 503
        (*_excess)[_g.source(e)] -= (*_flow)[e];
502 504
      }
503 505

	
504 506
      // global relabeling tested, but in general case it provides
505 507
      // worse performance for random digraphs
506 508
      _level->initStart();
507 509
      for(NodeIt n(_g);n!=INVALID;++n)
508 510
        _level->initAddItem(n);
509 511
      _level->initFinish();
510 512
      for(NodeIt n(_g);n!=INVALID;++n)
511 513
        if(_tol.positive((*_excess)[n]))
512 514
          _level->activate(n);
513 515
    }
514 516

	
515 517
    /// Initializes the internal data structures using a greedy approach.
516 518

	
517 519
    /// Initializes the internal data structures using a greedy approach
518 520
    /// to construct the initial solution.
519 521
    void greedyInit()
520 522
    {
521 523
      LEMON_DEBUG(checkBoundMaps(),
522 524
        "Upper bounds must be greater or equal to the lower bounds");
523 525

	
524 526
      createStructures();
525 527

	
526 528
      for(NodeIt n(_g);n!=INVALID;++n) {
527 529
        (*_excess)[n] = (*_supply)[n];
528 530
      }
529 531

	
530 532
      for (ArcIt e(_g);e!=INVALID;++e) {
531 533
        if (!_tol.less(-(*_excess)[_g.target(e)], (*_up)[e])) {
532 534
          _flow->set(e, (*_up)[e]);
533 535
          (*_excess)[_g.target(e)] += (*_up)[e];
534 536
          (*_excess)[_g.source(e)] -= (*_up)[e];
535 537
        } else if (_tol.less(-(*_excess)[_g.target(e)], (*_lo)[e])) {
536 538
          _flow->set(e, (*_lo)[e]);
537 539
          (*_excess)[_g.target(e)] += (*_lo)[e];
538 540
          (*_excess)[_g.source(e)] -= (*_lo)[e];
539 541
        } else {
540 542
          Value fc = -(*_excess)[_g.target(e)];
541 543
          _flow->set(e, fc);
542 544
          (*_excess)[_g.target(e)] = 0;
543 545
          (*_excess)[_g.source(e)] -= fc;
544 546
        }
545 547
      }
546 548

	
547 549
      _level->initStart();
548 550
      for(NodeIt n(_g);n!=INVALID;++n)
549 551
        _level->initAddItem(n);
550 552
      _level->initFinish();
551 553
      for(NodeIt n(_g);n!=INVALID;++n)
552 554
        if(_tol.positive((*_excess)[n]))
553 555
          _level->activate(n);
554 556
    }
555 557

	
556 558
    ///Executes the algorithm
557 559

	
558 560
    ///This function executes the algorithm.
559 561
    ///
560 562
    ///\return \c true if a feasible circulation is found.
561 563
    ///
562 564
    ///\sa barrier()
563 565
    ///\sa barrierMap()
564 566
    bool start()
565 567
    {
566 568

	
567 569
      Node act;
568 570
      Node bact=INVALID;
569 571
      Node last_activated=INVALID;
570 572
      while((act=_level->highestActive())!=INVALID) {
571 573
        int actlevel=(*_level)[act];
572 574
        int mlevel=_node_num;
573 575
        Value exc=(*_excess)[act];
574 576

	
575 577
        for(OutArcIt e(_g,act);e!=INVALID; ++e) {
576 578
          Node v = _g.target(e);
577 579
          Value fc=(*_up)[e]-(*_flow)[e];
578 580
          if(!_tol.positive(fc)) continue;
579 581
          if((*_level)[v]<actlevel) {
580 582
            if(!_tol.less(fc, exc)) {
581 583
              _flow->set(e, (*_flow)[e] + exc);
582 584
              (*_excess)[v] += exc;
583 585
              if(!_level->active(v) && _tol.positive((*_excess)[v]))
584 586
                _level->activate(v);
585 587
              (*_excess)[act] = 0;
586 588
              _level->deactivate(act);
587 589
              goto next_l;
588 590
            }
589 591
            else {
590 592
              _flow->set(e, (*_up)[e]);
591 593
              (*_excess)[v] += fc;
592 594
              if(!_level->active(v) && _tol.positive((*_excess)[v]))
593 595
                _level->activate(v);
594 596
              exc-=fc;
595 597
            }
596 598
          }
597 599
          else if((*_level)[v]<mlevel) mlevel=(*_level)[v];
598 600
        }
599 601
        for(InArcIt e(_g,act);e!=INVALID; ++e) {
600 602
          Node v = _g.source(e);
601 603
          Value fc=(*_flow)[e]-(*_lo)[e];
602 604
          if(!_tol.positive(fc)) continue;
603 605
          if((*_level)[v]<actlevel) {
604 606
            if(!_tol.less(fc, exc)) {
605 607
              _flow->set(e, (*_flow)[e] - exc);
606 608
              (*_excess)[v] += exc;
607 609
              if(!_level->active(v) && _tol.positive((*_excess)[v]))
608 610
                _level->activate(v);
609 611
              (*_excess)[act] = 0;
610 612
              _level->deactivate(act);
611 613
              goto next_l;
612 614
            }
613 615
            else {
614 616
              _flow->set(e, (*_lo)[e]);
615 617
              (*_excess)[v] += fc;
616 618
              if(!_level->active(v) && _tol.positive((*_excess)[v]))
617 619
                _level->activate(v);
618 620
              exc-=fc;
619 621
            }
620 622
          }
621 623
          else if((*_level)[v]<mlevel) mlevel=(*_level)[v];
622 624
        }
623 625

	
624 626
        (*_excess)[act] = exc;
625 627
        if(!_tol.positive(exc)) _level->deactivate(act);
626 628
        else if(mlevel==_node_num) {
627 629
          _level->liftHighestActiveToTop();
628 630
          _el = _node_num;
629 631
          return false;
630 632
        }
631 633
        else {
632 634
          _level->liftHighestActive(mlevel+1);
633 635
          if(_level->onLevel(actlevel)==0) {
634 636
            _el = actlevel;
635 637
            return false;
636 638
          }
637 639
        }
638 640
      next_l:
639 641
        ;
640 642
      }
641 643
      return true;
642 644
    }
643 645

	
644 646
    /// Runs the algorithm.
645 647

	
646 648
    /// This function runs the algorithm.
647 649
    ///
648 650
    /// \return \c true if a feasible circulation is found.
649 651
    ///
650 652
    /// \note Apart from the return value, c.run() is just a shortcut of
651 653
    /// the following code.
652 654
    /// \code
653 655
    ///   c.greedyInit();
654 656
    ///   c.start();
655 657
    /// \endcode
656 658
    bool run() {
657 659
      greedyInit();
658 660
      return start();
659 661
    }
660 662

	
661 663
    /// @}
662 664

	
663 665
    /// \name Query Functions
664 666
    /// The results of the circulation algorithm can be obtained using
Ignore white space 384 line context
1 1
/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 2
 *
3 3
 * This file is a part of LEMON, a generic C++ optimization library.
4 4
 *
5 5
 * Copyright (C) 2003-2009
6 6
 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 7
 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 8
 *
9 9
 * Permission to use, modify and distribute this software is granted
10 10
 * provided that this copyright notice appears in all copies. For
11 11
 * precise terms see the accompanying LICENSE file.
12 12
 *
13 13
 * This software is provided "AS IS" with no warranty of any kind,
14 14
 * express or implied, and with no claim as to its suitability for any
15 15
 * purpose.
16 16
 *
17 17
 */
18 18

	
19
#ifndef LEMON_CONCEPTS_HEAP_H
20
#define LEMON_CONCEPTS_HEAP_H
21

	
19 22
///\ingroup concept
20 23
///\file
21 24
///\brief The concept of heaps.
22 25

	
23
#ifndef LEMON_CONCEPTS_HEAP_H
24
#define LEMON_CONCEPTS_HEAP_H
25

	
26 26
#include <lemon/core.h>
27 27
#include <lemon/concept_check.h>
28 28

	
29 29
namespace lemon {
30 30

	
31 31
  namespace concepts {
32 32

	
33 33
    /// \addtogroup concept
34 34
    /// @{
35 35

	
36 36
    /// \brief The heap concept.
37 37
    ///
38
    /// Concept class describing the main interface of heaps. A \e heap
39
    /// is a data structure for storing items with specified values called
40
    /// \e priorities in such a way that finding the item with minimum
41
    /// priority is efficient. In a heap one can change the priority of an
42
    /// item, add or erase an item, etc.
38
    /// This concept class describes the main interface of heaps.
39
    /// The various \ref heaps "heap structures" are efficient
40
    /// implementations of the abstract data type \e priority \e queue.
41
    /// They store items with specified values called \e priorities
42
    /// in such a way that finding and removing the item with minimum
43
    /// priority are efficient. The basic operations are adding and
44
    /// erasing items, changing the priority of an item, etc.
43 45
    ///
44
    /// \tparam PR Type of the priority of the items.
45
    /// \tparam IM A read and writable item map with int values, used
46
    /// Heaps are crucial in several algorithms, such as Dijkstra and Prim.
47
    /// Any class that conforms to this concept can be used easily in such
48
    /// algorithms.
49
    ///
50
    /// \tparam PR Type of the priorities of the items.
51
    /// \tparam IM A read-writable item map with \c int values, used
46 52
    /// internally to handle the cross references.
47
    /// \tparam Comp A functor class for the ordering of the priorities.
53
    /// \tparam CMP A functor class for comparing the priorities.
48 54
    /// The default is \c std::less<PR>.
49 55
#ifdef DOXYGEN
50
    template <typename PR, typename IM, typename Comp = std::less<PR> >
56
    template <typename PR, typename IM, typename CMP>
51 57
#else
52
    template <typename PR, typename IM>
58
    template <typename PR, typename IM, typename CMP = std::less<PR> >
53 59
#endif
54 60
    class Heap {
55 61
    public:
56 62

	
57 63
      /// Type of the item-int map.
58 64
      typedef IM ItemIntMap;
59 65
      /// Type of the priorities.
60 66
      typedef PR Prio;
61 67
      /// Type of the items stored in the heap.
62 68
      typedef typename ItemIntMap::Key Item;
63 69

	
64 70
      /// \brief Type to represent the states of the items.
65 71
      ///
66 72
      /// Each item has a state associated to it. It can be "in heap",
67
      /// "pre heap" or "post heap". The later two are indifferent
68
      /// from the point of view of the heap, but may be useful for
69
      /// the user.
73
      /// "pre-heap" or "post-heap". The latter two are indifferent from the
74
      /// heap's point of view, but may be useful to the user.
70 75
      ///
71 76
      /// The item-int map must be initialized in such way that it assigns
72 77
      /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
73 78
      enum State {
74 79
        IN_HEAP = 0,    ///< = 0. The "in heap" state constant.
75
        PRE_HEAP = -1,  ///< = -1. The "pre heap" state constant.
76
        POST_HEAP = -2  ///< = -2. The "post heap" state constant.
80
        PRE_HEAP = -1,  ///< = -1. The "pre-heap" state constant.
81
        POST_HEAP = -2  ///< = -2. The "post-heap" state constant.
77 82
      };
78 83

	
79
      /// \brief The constructor.
84
      /// \brief Constructor.
80 85
      ///
81
      /// The constructor.
86
      /// Constructor.
82 87
      /// \param map A map that assigns \c int values to keys of type
83 88
      /// \c Item. It is used internally by the heap implementations to
84 89
      /// handle the cross references. The assigned value must be
85
      /// \c PRE_HEAP (<tt>-1</tt>) for every item.
90
      /// \c PRE_HEAP (<tt>-1</tt>) for each item.
86 91
      explicit Heap(ItemIntMap &map) {}
87 92

	
93
      /// \brief Constructor.
94
      ///
95
      /// Constructor.
96
      /// \param map A map that assigns \c int values to keys of type
97
      /// \c Item. It is used internally by the heap implementations to
98
      /// handle the cross references. The assigned value must be
99
      /// \c PRE_HEAP (<tt>-1</tt>) for each item.
100
      /// \param comp The function object used for comparing the priorities.
101
      explicit Heap(ItemIntMap &map, const CMP &comp) {}
102

	
88 103
      /// \brief The number of items stored in the heap.
89 104
      ///
90
      /// Returns the number of items stored in the heap.
105
      /// This function returns the number of items stored in the heap.
91 106
      int size() const { return 0; }
92 107

	
93
      /// \brief Checks if the heap is empty.
108
      /// \brief Check if the heap is empty.
94 109
      ///
95
      /// Returns \c true if the heap is empty.
110
      /// This function returns \c true if the heap is empty.
96 111
      bool empty() const { return false; }
97 112

	
98
      /// \brief Makes the heap empty.
113
      /// \brief Make the heap empty.
99 114
      ///
100
      /// Makes the heap empty.
101
      void clear();
115
      /// This functon makes the heap empty.
116
      /// It does not change the cross reference map. If you want to reuse
117
      /// a heap that is not surely empty, you should first clear it and
118
      /// then you should set the cross reference map to \c PRE_HEAP
119
      /// for each item.
120
      void clear() {}
102 121

	
103
      /// \brief Inserts an item into the heap with the given priority.
122
      /// \brief Insert an item into the heap with the given priority.
104 123
      ///
105
      /// Inserts the given item into the heap with the given priority.
124
      /// This function inserts the given item into the heap with the
125
      /// given priority.
106 126
      /// \param i The item to insert.
107 127
      /// \param p The priority of the item.
128
      /// \pre \e i must not be stored in the heap.
108 129
      void push(const Item &i, const Prio &p) {}
109 130

	
110
      /// \brief Returns the item having minimum priority.
131
      /// \brief Return the item having minimum priority.
111 132
      ///
112
      /// Returns the item having minimum priority.
133
      /// This function returns the item having minimum priority.
113 134
      /// \pre The heap must be non-empty.
114 135
      Item top() const {}
115 136

	
116 137
      /// \brief The minimum priority.
117 138
      ///
118
      /// Returns the minimum priority.
139
      /// This function returns the minimum priority.
119 140
      /// \pre The heap must be non-empty.
120 141
      Prio prio() const {}
121 142

	
122
      /// \brief Removes the item having minimum priority.
143
      /// \brief Remove the item having minimum priority.
123 144
      ///
124
      /// Removes the item having minimum priority.
145
      /// This function removes the item having minimum priority.
125 146
      /// \pre The heap must be non-empty.
126 147
      void pop() {}
127 148

	
128
      /// \brief Removes an item from the heap.
149
      /// \brief Remove the given item from the heap.
129 150
      ///
130
      /// Removes the given item from the heap if it is already stored.
151
      /// This function removes the given item from the heap if it is
152
      /// already stored.
131 153
      /// \param i The item to delete.
154
      /// \pre \e i must be in the heap.
132 155
      void erase(const Item &i) {}
133 156

	
134
      /// \brief The priority of an item.
157
      /// \brief The priority of the given item.
135 158
      ///
136
      /// Returns the priority of the given item.
159
      /// This function returns the priority of the given item.
137 160
      /// \param i The item.
138
      /// \pre \c i must be in the heap.
161
      /// \pre \e i must be in the heap.
139 162
      Prio operator[](const Item &i) const {}
140 163

	
141
      /// \brief Sets the priority of an item or inserts it, if it is
164
      /// \brief Set the priority of an item or insert it, if it is
142 165
      /// not stored in the heap.
143 166
      ///
144 167
      /// This method sets the priority of the given item if it is
145
      /// already stored in the heap.
146
      /// Otherwise it inserts the given item with the given priority.
168
      /// already stored in the heap. Otherwise it inserts the given
169
      /// item into the heap with the given priority.
147 170
      ///
148 171
      /// \param i The item.
149 172
      /// \param p The priority.
150 173
      void set(const Item &i, const Prio &p) {}
151 174

	
152
      /// \brief Decreases the priority of an item to the given value.
175
      /// \brief Decrease the priority of an item to the given value.
153 176
      ///
154
      /// Decreases the priority of an item to the given value.
177
      /// This function decreases the priority of an item to the given value.
155 178
      /// \param i The item.
156 179
      /// \param p The priority.
157
      /// \pre \c i must be stored in the heap with priority at least \c p.
180
      /// \pre \e i must be stored in the heap with priority at least \e p.
158 181
      void decrease(const Item &i, const Prio &p) {}
159 182

	
160
      /// \brief Increases the priority of an item to the given value.
183
      /// \brief Increase the priority of an item to the given value.
161 184
      ///
162
      /// Increases the priority of an item to the given value.
185
      /// This function increases the priority of an item to the given value.
163 186
      /// \param i The item.
164 187
      /// \param p The priority.
165
      /// \pre \c i must be stored in the heap with priority at most \c p.
188
      /// \pre \e i must be stored in the heap with priority at most \e p.
166 189
      void increase(const Item &i, const Prio &p) {}
167 190

	
168
      /// \brief Returns if an item is in, has already been in, or has
169
      /// never been in the heap.
191
      /// \brief Return the state of an item.
170 192
      ///
171 193
      /// This method returns \c PRE_HEAP if the given item has never
172 194
      /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
173 195
      /// and \c POST_HEAP otherwise.
174 196
      /// In the latter case it is possible that the item will get back
175 197
      /// to the heap again.
176 198
      /// \param i The item.
177 199
      State state(const Item &i) const {}
178 200

	
179
      /// \brief Sets the state of an item in the heap.
201
      /// \brief Set the state of an item in the heap.
180 202
      ///
181
      /// Sets the state of the given item in the heap. It can be used
182
      /// to manually clear the heap when it is important to achive the
183
      /// better time complexity.
203
      /// This function sets the state of the given item in the heap.
204
      /// It can be used to manually clear the heap when it is important
205
      /// to achive better time complexity.
184 206
      /// \param i The item.
185 207
      /// \param st The state. It should not be \c IN_HEAP.
186 208
      void state(const Item& i, State st) {}
187 209

	
188 210

	
189 211
      template <typename _Heap>
190 212
      struct Constraints {
191 213
      public:
192 214
        void constraints() {
193 215
          typedef typename _Heap::Item OwnItem;
194 216
          typedef typename _Heap::Prio OwnPrio;
195 217
          typedef typename _Heap::State OwnState;
196 218

	
197 219
          Item item;
198 220
          Prio prio;
199 221
          item=Item();
200 222
          prio=Prio();
201 223
          ignore_unused_variable_warning(item);
202 224
          ignore_unused_variable_warning(prio);
203 225

	
204 226
          OwnItem own_item;
205 227
          OwnPrio own_prio;
206 228
          OwnState own_state;
207 229
          own_item=Item();
208 230
          own_prio=Prio();
209 231
          ignore_unused_variable_warning(own_item);
210 232
          ignore_unused_variable_warning(own_prio);
211 233
          ignore_unused_variable_warning(own_state);
212 234

	
213 235
          _Heap heap1(map);
214 236
          _Heap heap2 = heap1;
215 237
          ignore_unused_variable_warning(heap1);
216 238
          ignore_unused_variable_warning(heap2);
217 239

	
218 240
          int s = heap.size();
219 241
          ignore_unused_variable_warning(s);
220 242
          bool e = heap.empty();
221 243
          ignore_unused_variable_warning(e);
222 244

	
223 245
          prio = heap.prio();
224 246
          item = heap.top();
225 247
          prio = heap[item];
226 248
          own_prio = heap.prio();
227 249
          own_item = heap.top();
228 250
          own_prio = heap[own_item];
229 251

	
230 252
          heap.push(item, prio);
231 253
          heap.push(own_item, own_prio);
232 254
          heap.pop();
233 255

	
234 256
          heap.set(item, prio);
235 257
          heap.decrease(item, prio);
236 258
          heap.increase(item, prio);
237 259
          heap.set(own_item, own_prio);
238 260
          heap.decrease(own_item, own_prio);
239 261
          heap.increase(own_item, own_prio);
240 262

	
241 263
          heap.erase(item);
242 264
          heap.erase(own_item);
243 265
          heap.clear();
244 266

	
245 267
          own_state = heap.state(own_item);
246 268
          heap.state(own_item, own_state);
247 269

	
248 270
          own_state = _Heap::PRE_HEAP;
249 271
          own_state = _Heap::IN_HEAP;
250 272
          own_state = _Heap::POST_HEAP;
251 273
        }
252 274

	
253 275
        _Heap& heap;
254 276
        ItemIntMap& map;
255 277
      };
256 278
    };
257 279

	
258 280
    /// @}
259 281
  } // namespace lemon
260 282
}
261 283
#endif
Ignore white space 384 line context
1 1
/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 2
 *
3 3
 * This file is a part of LEMON, a generic C++ optimization library.
4 4
 *
5 5
 * Copyright (C) 2003-2009
6 6
 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 7
 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 8
 *
9 9
 * Permission to use, modify and distribute this software is granted
10 10
 * provided that this copyright notice appears in all copies. For
11 11
 * precise terms see the accompanying LICENSE file.
12 12
 *
13 13
 * This software is provided "AS IS" with no warranty of any kind,
14 14
 * express or implied, and with no claim as to its suitability for any
15 15
 * purpose.
16 16
 *
17 17
 */
18 18

	
19 19
#ifndef LEMON_FIB_HEAP_H
20 20
#define LEMON_FIB_HEAP_H
21 21

	
22 22
///\file
23
///\ingroup auxdat
24
///\brief Fibonacci Heap implementation.
23
///\ingroup heaps
24
///\brief Fibonacci heap implementation.
25 25

	
26 26
#include <vector>
27
#include <utility>
27 28
#include <functional>
28 29
#include <lemon/math.h>
29 30

	
30 31
namespace lemon {
31 32

	
32
  /// \ingroup auxdat
33
  /// \ingroup heaps
33 34
  ///
34
  ///\brief Fibonacci Heap.
35
  /// \brief Fibonacci heap data structure.
35 36
  ///
36
  ///This class implements the \e Fibonacci \e heap data structure. A \e heap
37
  ///is a data structure for storing items with specified values called \e
38
  ///priorities in such a way that finding the item with minimum priority is
39
  ///efficient. \c CMP specifies the ordering of the priorities. In a heap
40
  ///one can change the priority of an item, add or erase an item, etc.
37
  /// This class implements the \e Fibonacci \e heap data structure.
38
  /// It fully conforms to the \ref concepts::Heap "heap concept".
41 39
  ///
42
  ///The methods \ref increase and \ref erase are not efficient in a Fibonacci
43
  ///heap. In case of many calls to these operations, it is better to use a
44
  ///\ref BinHeap "binary heap".
40
  /// The methods \ref increase() and \ref erase() are not efficient in a
41
  /// Fibonacci heap. In case of many calls of these operations, it is
42
  /// better to use other heap structure, e.g. \ref BinHeap "binary heap".
45 43
  ///
46
  ///\param PRIO Type of the priority of the items.
47
  ///\param IM A read and writable Item int map, used internally
48
  ///to handle the cross references.
49
  ///\param CMP A class for the ordering of the priorities. The
50
  ///default is \c std::less<PRIO>.
51
  ///
52
  ///\sa BinHeap
53
  ///\sa Dijkstra
44
  /// \tparam PR Type of the priorities of the items.
45
  /// \tparam IM A read-writable item map with \c int values, used
46
  /// internally to handle the cross references.
47
  /// \tparam CMP A functor class for comparing the priorities.
48
  /// The default is \c std::less<PR>.
54 49
#ifdef DOXYGEN
55
  template <typename PRIO, typename IM, typename CMP>
50
  template <typename PR, typename IM, typename CMP>
56 51
#else
57
  template <typename PRIO, typename IM, typename CMP = std::less<PRIO> >
52
  template <typename PR, typename IM, typename CMP = std::less<PR> >
58 53
#endif
59 54
  class FibHeap {
60 55
  public:
61
    ///\e
56

	
57
    /// Type of the item-int map.
62 58
    typedef IM ItemIntMap;
63
    ///\e
64
    typedef PRIO Prio;
65
    ///\e
59
    /// Type of the priorities.
60
    typedef PR Prio;
61
    /// Type of the items stored in the heap.
66 62
    typedef typename ItemIntMap::Key Item;
67
    ///\e
63
    /// Type of the item-priority pairs.
68 64
    typedef std::pair<Item,Prio> Pair;
69
    ///\e
65
    /// Functor type for comparing the priorities.
70 66
    typedef CMP Compare;
71 67

	
72 68
  private:
73 69
    class Store;
74 70

	
75 71
    std::vector<Store> _data;
76 72
    int _minimum;
77 73
    ItemIntMap &_iim;
78 74
    Compare _comp;
79 75
    int _num;
80 76

	
81 77
  public:
82 78

	
83
    /// \brief Type to represent the items states.
79
    /// \brief Type to represent the states of the items.
84 80
    ///
85
    /// Each Item element have a state associated to it. It may be "in heap",
86
    /// "pre heap" or "post heap". The latter two are indifferent from the
81
    /// Each item has a state associated to it. It can be "in heap",
82
    /// "pre-heap" or "post-heap". The latter two are indifferent from the
87 83
    /// heap's point of view, but may be useful to the user.
88 84
    ///
89 85
    /// The item-int map must be initialized in such way that it assigns
90 86
    /// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap.
91 87
    enum State {
92 88
      IN_HEAP = 0,    ///< = 0.
93 89
      PRE_HEAP = -1,  ///< = -1.
94 90
      POST_HEAP = -2  ///< = -2.
95 91
    };
96 92

	
97
    /// \brief The constructor
93
    /// \brief Constructor.
98 94
    ///
99
    /// \c map should be given to the constructor, since it is
100
    ///   used internally to handle the cross references.
95
    /// Constructor.
96
    /// \param map A map that assigns \c int values to the items.
97
    /// It is used internally to handle the cross references.
98
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
101 99
    explicit FibHeap(ItemIntMap &map)
102 100
      : _minimum(0), _iim(map), _num() {}
103 101

	
104
    /// \brief The constructor
102
    /// \brief Constructor.
105 103
    ///
106
    /// \c map should be given to the constructor, since it is used
107
    /// internally to handle the cross references. \c comp is an
108
    /// object for ordering of the priorities.
104
    /// Constructor.
105
    /// \param map A map that assigns \c int values to the items.
106
    /// It is used internally to handle the cross references.
107
    /// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item.
108
    /// \param comp The function object used for comparing the priorities.
109 109
    FibHeap(ItemIntMap &map, const Compare &comp)
110 110
      : _minimum(0), _iim(map), _comp(comp), _num() {}
111 111

	
112 112
    /// \brief The number of items stored in the heap.
113 113
    ///
114
    /// Returns the number of items stored in the heap.
114
    /// This function returns the number of items stored in the heap.
115 115
    int size() const { return _num; }
116 116

	
117
    /// \brief Checks if the heap stores no items.
117
    /// \brief Check if the heap is empty.
118 118
    ///
119
    ///   Returns \c true if and only if the heap stores no items.
119
    /// This function returns \c true if the heap is empty.
120 120
    bool empty() const { return _num==0; }
121 121

	
122
    /// \brief Make empty this heap.
122
    /// \brief Make the heap empty.
123 123
    ///
124
    /// Make empty this heap. It does not change the cross reference
125
    /// map.  If you want to reuse a heap what is not surely empty you
126
    /// should first clear the heap and after that you should set the
127
    /// cross reference map for each item to \c PRE_HEAP.
124
    /// This functon makes the heap empty.
125
    /// It does not change the cross reference map. If you want to reuse
126
    /// a heap that is not surely empty, you should first clear it and
127
    /// then you should set the cross reference map to \c PRE_HEAP
128
    /// for each item.
128 129
    void clear() {
129 130
      _data.clear(); _minimum = 0; _num = 0;
130 131
    }
131 132

	
132
    /// \brief \c item gets to the heap with priority \c value independently
133
    /// if \c item was already there.
133
    /// \brief Insert an item into the heap with the given priority.
134 134
    ///
135
    /// This method calls \ref push(\c item, \c value) if \c item is not
136
    /// stored in the heap and it calls \ref decrease(\c item, \c value) or
137
    /// \ref increase(\c item, \c value) otherwise.
138
    void set (const Item& item, const Prio& value) {
139
      int i=_iim[item];
140
      if ( i >= 0 && _data[i].in ) {
141
        if ( _comp(value, _data[i].prio) ) decrease(item, value);
142
        if ( _comp(_data[i].prio, value) ) increase(item, value);
143
      } else push(item, value);
144
    }
145

	
146
    /// \brief Adds \c item to the heap with priority \c value.
147
    ///
148
    /// Adds \c item to the heap with priority \c value.
149
    /// \pre \c item must not be stored in the heap.
150
    void push (const Item& item, const Prio& value) {
135
    /// This function inserts the given item into the heap with the
136
    /// given priority.
137
    /// \param item The item to insert.
138
    /// \param prio The priority of the item.
139
    /// \pre \e item must not be stored in the heap.
140
    void push (const Item& item, const Prio& prio) {
151 141
      int i=_iim[item];
152 142
      if ( i < 0 ) {
153 143
        int s=_data.size();
154 144
        _iim.set( item, s );
155 145
        Store st;
156 146
        st.name=item;
157 147
        _data.push_back(st);
158 148
        i=s;
159 149
      } else {
160 150
        _data[i].parent=_data[i].child=-1;
161 151
        _data[i].degree=0;
162 152
        _data[i].in=true;
163 153
        _data[i].marked=false;
164 154
      }
165 155

	
166 156
      if ( _num ) {
167 157
        _data[_data[_minimum].right_neighbor].left_neighbor=i;
168 158
        _data[i].right_neighbor=_data[_minimum].right_neighbor;
169 159
        _data[_minimum].right_neighbor=i;
170 160
        _data[i].left_neighbor=_minimum;
171
        if ( _comp( value, _data[_minimum].prio) ) _minimum=i;
161
        if ( _comp( prio, _data[_minimum].prio) ) _minimum=i;
172 162
      } else {
173 163
        _data[i].right_neighbor=_data[i].left_neighbor=i;
174 164
        _minimum=i;
175 165
      }
176
      _data[i].prio=value;
166
      _data[i].prio=prio;
177 167
      ++_num;
178 168
    }
179 169

	
180
    /// \brief Returns the item with minimum priority relative to \c Compare.
170
    /// \brief Return the item having minimum priority.
181 171
    ///
182
    /// This method returns the item with minimum priority relative to \c
183
    /// Compare.
184
    /// \pre The heap must be nonempty.
172
    /// This function returns the item having minimum priority.
173
    /// \pre The heap must be non-empty.
185 174
    Item top() const { return _data[_minimum].name; }
186 175

	
187
    /// \brief Returns the minimum priority relative to \c Compare.
176
    /// \brief The minimum priority.
188 177
    ///
189
    /// It returns the minimum priority relative to \c Compare.
190
    /// \pre The heap must be nonempty.
191
    const Prio& prio() const { return _data[_minimum].prio; }
178
    /// This function returns the minimum priority.
179
    /// \pre The heap must be non-empty.
180
    Prio prio() const { return _data[_minimum].prio; }
192 181

	
193
    /// \brief Returns the priority of \c item.
182
    /// \brief Remove the item having minimum priority.
194 183
    ///
195
    /// It returns the priority of \c item.
196
    /// \pre \c item must be in the heap.
197
    const Prio& operator[](const Item& item) const {
198
      return _data[_iim[item]].prio;
199
    }
200

	
201
    /// \brief Deletes the item with minimum priority relative to \c Compare.
202
    ///
203
    /// This method deletes the item with minimum priority relative to \c
204
    /// Compare from the heap.
184
    /// This function removes the item having minimum priority.
205 185
    /// \pre The heap must be non-empty.
206 186
    void pop() {
207 187
      /*The first case is that there are only one root.*/
208 188
      if ( _data[_minimum].left_neighbor==_minimum ) {
209 189
        _data[_minimum].in=false;
210 190
        if ( _data[_minimum].degree!=0 ) {
211
          makeroot(_data[_minimum].child);
191
          makeRoot(_data[_minimum].child);
212 192
          _minimum=_data[_minimum].child;
213 193
          balance();
214 194
        }
215 195
      } else {
216 196
        int right=_data[_minimum].right_neighbor;
217 197
        unlace(_minimum);
218 198
        _data[_minimum].in=false;
219 199
        if ( _data[_minimum].degree > 0 ) {
220 200
          int left=_data[_minimum].left_neighbor;
221 201
          int child=_data[_minimum].child;
222 202
          int last_child=_data[child].left_neighbor;
223 203

	
224
          makeroot(child);
204
          makeRoot(child);
225 205

	
226 206
          _data[left].right_neighbor=child;
227 207
          _data[child].left_neighbor=left;
228 208
          _data[right].left_neighbor=last_child;
229 209
          _data[last_child].right_neighbor=right;
230 210
        }
231 211
        _minimum=right;
232 212
        balance();
233 213
      } // the case where there are more roots
234 214
      --_num;
235 215
    }
236 216

	
237
    /// \brief Deletes \c item from the heap.
217
    /// \brief Remove the given item from the heap.
238 218
    ///
239
    /// This method deletes \c item from the heap, if \c item was already
240
    /// stored in the heap. It is quite inefficient in Fibonacci heaps.
219
    /// This function removes the given item from the heap if it is
220
    /// already stored.
221
    /// \param item The item to delete.
222
    /// \pre \e item must be in the heap.
241 223
    void erase (const Item& item) {
242 224
      int i=_iim[item];
243 225

	
244 226
      if ( i >= 0 && _data[i].in ) {
245 227
        if ( _data[i].parent!=-1 ) {
246 228
          int p=_data[i].parent;
247 229
          cut(i,p);
248 230
          cascade(p);
249 231
        }
250 232
        _minimum=i;     //As if its prio would be -infinity
251 233
        pop();
252 234
      }
253 235
    }
254 236

	
255
    /// \brief Decreases the priority of \c item to \c value.
237
    /// \brief The priority of the given item.
256 238
    ///
257
    /// This method decreases the priority of \c item to \c value.
258
    /// \pre \c item must be stored in the heap with priority at least \c
259
    ///   value relative to \c Compare.
260
    void decrease (Item item, const Prio& value) {
239
    /// This function returns the priority of the given item.
240
    /// \param item The item.
241
    /// \pre \e item must be in the heap.
242
    Prio operator[](const Item& item) const {
243
      return _data[_iim[item]].prio;
244
    }
245

	
246
    /// \brief Set the priority of an item or insert it, if it is
247
    /// not stored in the heap.
248
    ///
249
    /// This method sets the priority of the given item if it is
250
    /// already stored in the heap. Otherwise it inserts the given
251
    /// item into the heap with the given priority.
252
    /// \param item The item.
253
    /// \param prio The priority.
254
    void set (const Item& item, const Prio& prio) {
261 255
      int i=_iim[item];
262
      _data[i].prio=value;
256
      if ( i >= 0 && _data[i].in ) {
257
        if ( _comp(prio, _data[i].prio) ) decrease(item, prio);
258
        if ( _comp(_data[i].prio, prio) ) increase(item, prio);
259
      } else push(item, prio);
260
    }
261

	
262
    /// \brief Decrease the priority of an item to the given value.
263
    ///
264
    /// This function decreases the priority of an item to the given value.
265
    /// \param item The item.
266
    /// \param prio The priority.
267
    /// \pre \e item must be stored in the heap with priority at least \e prio.
268
    void decrease (const Item& item, const Prio& prio) {
269
      int i=_iim[item];
270
      _data[i].prio=prio;
263 271
      int p=_data[i].parent;
264 272

	
265
      if ( p!=-1 && _comp(value, _data[p].prio) ) {
273
      if ( p!=-1 && _comp(prio, _data[p].prio) ) {
266 274
        cut(i,p);
267 275
        cascade(p);
268 276
      }
269
      if ( _comp(value, _data[_minimum].prio) ) _minimum=i;
277
      if ( _comp(prio, _data[_minimum].prio) ) _minimum=i;
270 278
    }
271 279

	
272
    /// \brief Increases the priority of \c item to \c value.
280
    /// \brief Increase the priority of an item to the given value.
273 281
    ///
274
    /// This method sets the priority of \c item to \c value. Though
275
    /// there is no precondition on the priority of \c item, this
276
    /// method should be used only if it is indeed necessary to increase
277
    /// (relative to \c Compare) the priority of \c item, because this
278
    /// method is inefficient.
279
    void increase (Item item, const Prio& value) {
282
    /// This function increases the priority of an item to the given value.
283
    /// \param item The item.
284
    /// \param prio The priority.
285
    /// \pre \e item must be stored in the heap with priority at most \e prio.
286
    void increase (const Item& item, const Prio& prio) {
280 287
      erase(item);
281
      push(item, value);
288
      push(item, prio);
282 289
    }
283 290

	
284

	
285
    /// \brief Returns if \c item is in, has already been in, or has never
286
    /// been in the heap.
291
    /// \brief Return the state of an item.
287 292
    ///
288
    /// This method returns PRE_HEAP if \c item has never been in the
289
    /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
290
    /// otherwise. In the latter case it is possible that \c item will
291
    /// get back to the heap again.
293
    /// This method returns \c PRE_HEAP if the given item has never
294
    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
295
    /// and \c POST_HEAP otherwise.
296
    /// In the latter case it is possible that the item will get back
297
    /// to the heap again.
298
    /// \param item The item.
292 299
    State state(const Item &item) const {
293 300
      int i=_iim[item];
294 301
      if( i>=0 ) {
295 302
        if ( _data[i].in ) i=0;
296 303
        else i=-2;
297 304
      }
298 305
      return State(i);
299 306
    }
300 307

	
301
    /// \brief Sets the state of the \c item in the heap.
308
    /// \brief Set the state of an item in the heap.
302 309
    ///
303
    /// Sets the state of the \c item in the heap. It can be used to
304
    /// manually clear the heap when it is important to achive the
305
    /// better time _complexity.
310
    /// This function sets the state of the given item in the heap.
311
    /// It can be used to manually clear the heap when it is important
312
    /// to achive better time complexity.
306 313
    /// \param i The item.
307 314
    /// \param st The state. It should not be \c IN_HEAP.
308 315
    void state(const Item& i, State st) {
309 316
      switch (st) {
310 317
      case POST_HEAP:
311 318
      case PRE_HEAP:
312 319
        if (state(i) == IN_HEAP) {
313 320
          erase(i);
314 321
        }
315 322
        _iim[i] = st;
316 323
        break;
317 324
      case IN_HEAP:
318 325
        break;
319 326
      }
320 327
    }
321 328

	
322 329
  private:
323 330

	
324 331
    void balance() {
325 332

	
326 333
      int maxdeg=int( std::floor( 2.08*log(double(_data.size()))))+1;
327 334

	
328 335
      std::vector<int> A(maxdeg,-1);
329 336

	
330 337
      /*
331 338
       *Recall that now minimum does not point to the minimum prio element.
332 339
       *We set minimum to this during balance().
333 340
       */
334 341
      int anchor=_data[_minimum].left_neighbor;
335 342
      int next=_minimum;
336 343
      bool end=false;
337 344

	
338 345
      do {
339 346
        int active=next;
340 347
        if ( anchor==active ) end=true;
341 348
        int d=_data[active].degree;
342 349
        next=_data[active].right_neighbor;
343 350

	
344 351
        while (A[d]!=-1) {
345 352
          if( _comp(_data[active].prio, _data[A[d]].prio) ) {
346 353
            fuse(active,A[d]);
347 354
          } else {
348 355
            fuse(A[d],active);
349 356
            active=A[d];
350 357
          }
351 358
          A[d]=-1;
352 359
          ++d;
353 360
        }
354 361
        A[d]=active;
355 362
      } while ( !end );
356 363

	
357 364

	
358 365
      while ( _data[_minimum].parent >=0 )
359 366
        _minimum=_data[_minimum].parent;
360 367
      int s=_minimum;
361 368
      int m=_minimum;
362 369
      do {
363 370
        if ( _comp(_data[s].prio, _data[_minimum].prio) ) _minimum=s;
364 371
        s=_data[s].right_neighbor;
365 372
      } while ( s != m );
366 373
    }
367 374

	
368
    void makeroot(int c) {
375
    void makeRoot(int c) {
369 376
      int s=c;
370 377
      do {
371 378
        _data[s].parent=-1;
372 379
        s=_data[s].right_neighbor;
373 380
      } while ( s != c );
374 381
    }
375 382

	
376 383
    void cut(int a, int b) {
377 384
      /*
378 385
       *Replacing a from the children of b.
379 386
       */
380 387
      --_data[b].degree;
381 388

	
382 389
      if ( _data[b].degree !=0 ) {
383 390
        int child=_data[b].child;
384 391
        if ( child==a )
385 392
          _data[b].child=_data[child].right_neighbor;
386 393
        unlace(a);
387 394
      }
388 395

	
389 396

	
390 397
      /*Lacing a to the roots.*/
391 398
      int right=_data[_minimum].right_neighbor;
392 399
      _data[_minimum].right_neighbor=a;
393 400
      _data[a].left_neighbor=_minimum;
394 401
      _data[a].right_neighbor=right;
395 402
      _data[right].left_neighbor=a;
396 403

	
397 404
      _data[a].parent=-1;
398 405
      _data[a].marked=false;
399 406
    }
400 407

	
401 408
    void cascade(int a) {
402 409
      if ( _data[a].parent!=-1 ) {
403 410
        int p=_data[a].parent;
404 411

	
405 412
        if ( _data[a].marked==false ) _data[a].marked=true;
406 413
        else {
407 414
          cut(a,p);
408 415
          cascade(p);
409 416
        }
410 417
      }
411 418
    }
412 419

	
413 420
    void fuse(int a, int b) {
414 421
      unlace(b);
415 422

	
416 423
      /*Lacing b under a.*/
417 424
      _data[b].parent=a;
418 425

	
419 426
      if (_data[a].degree==0) {
420 427
        _data[b].left_neighbor=b;
421 428
        _data[b].right_neighbor=b;
422 429
        _data[a].child=b;
423 430
      } else {
424 431
        int child=_data[a].child;
425 432
        int last_child=_data[child].left_neighbor;
426 433
        _data[child].left_neighbor=b;
427 434
        _data[b].right_neighbor=child;
428 435
        _data[last_child].right_neighbor=b;
429 436
        _data[b].left_neighbor=last_child;
430 437
      }
431 438

	
432 439
      ++_data[a].degree;
433 440

	
434 441
      _data[b].marked=false;
435 442
    }
436 443

	
437 444
    /*
438 445
     *It is invoked only if a has siblings.
439 446
     */
440 447
    void unlace(int a) {
441 448
      int leftn=_data[a].left_neighbor;
442 449
      int rightn=_data[a].right_neighbor;
443 450
      _data[leftn].right_neighbor=rightn;
444 451
      _data[rightn].left_neighbor=leftn;
445 452
    }
446 453

	
447 454

	
448 455
    class Store {
449 456
      friend class FibHeap;
450 457

	
451 458
      Item name;
452 459
      int parent;
453 460
      int left_neighbor;
454 461
      int right_neighbor;
455 462
      int child;
456 463
      int degree;
457 464
      bool marked;
458 465
      bool in;
459 466
      Prio prio;
460 467

	
461 468
      Store() : parent(-1), child(-1), degree(), marked(false), in(true) {}
462 469
    };
463 470
  };
464 471

	
465 472
} //namespace lemon
466 473

	
467 474
#endif //LEMON_FIB_HEAP_H
468 475

	

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