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alpar (Alpar Juttner)
alpar@cs.elte.hu
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@@ -101,277 +101,298 @@
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
@defgroup matrices Matrices
230
@ingroup datas
231
\brief Two dimensional data storages implemented in LEMON.
232

	
233
This group contains two dimensional data storages implemented in LEMON.
234
*/
235

	
236
/**
237 229
@defgroup paths Path Structures
238 230
@ingroup datas
239 231
\brief %Path structures implemented in LEMON.
240 232

	
241 233
This group contains the path structures implemented in LEMON.
242 234

	
243 235
LEMON provides flexible data structures to work with paths.
244 236
All of them have similar interfaces and they can be copied easily with
245 237
assignment operators and copy constructors. This makes it easy and
246 238
efficient to have e.g. the Dijkstra algorithm to store its result in
247 239
any kind of path structure.
248 240

	
249
\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.
250 271
*/
251 272

	
252 273
/**
253 274
@defgroup auxdat Auxiliary Data Structures
254 275
@ingroup datas
255 276
\brief Auxiliary data structures implemented in LEMON.
256 277

	
257 278
This group contains some data structures implemented in LEMON in
258 279
order to make it easier to implement combinatorial algorithms.
259 280
*/
260 281

	
261 282
/**
262 283
@defgroup algs Algorithms
263 284
\brief This group contains the several algorithms
264 285
implemented in LEMON.
265 286

	
266 287
This group contains the several algorithms
267 288
implemented in LEMON.
268 289
*/
269 290

	
270 291
/**
271 292
@defgroup search Graph Search
272 293
@ingroup algs
273 294
\brief Common graph search algorithms.
274 295

	
275 296
This group contains the common graph search algorithms, namely
276 297
\e breadth-first \e search (BFS) and \e depth-first \e search (DFS).
277 298
*/
278 299

	
279 300
/**
280 301
@defgroup shortest_path Shortest Path Algorithms
281 302
@ingroup algs
282 303
\brief Algorithms for finding shortest paths.
283 304

	
284 305
This group contains the algorithms for finding shortest paths in digraphs.
285 306

	
286 307
 - \ref Dijkstra algorithm for finding shortest paths from a source node
287 308
   when all arc lengths are non-negative.
288 309
 - \ref BellmanFord "Bellman-Ford" algorithm for finding shortest paths
289 310
   from a source node when arc lenghts can be either positive or negative,
290 311
   but the digraph should not contain directed cycles with negative total
291 312
   length.
292 313
 - \ref FloydWarshall "Floyd-Warshall" and \ref Johnson "Johnson" algorithms
293 314
   for solving the \e all-pairs \e shortest \e paths \e problem when arc
294 315
   lenghts can be either positive or negative, but the digraph should
295 316
   not contain directed cycles with negative total length.
296 317
 - \ref Suurballe A successive shortest path algorithm for finding
297 318
   arc-disjoint paths between two nodes having minimum total length.
298 319
*/
299 320

	
300 321
/**
301 322
@defgroup max_flow Maximum Flow Algorithms
302 323
@ingroup algs
303 324
\brief Algorithms for finding maximum flows.
304 325

	
305 326
This group contains the algorithms for finding maximum flows and
306 327
feasible circulations.
307 328

	
308 329
The \e maximum \e flow \e problem is to find a flow of maximum value between
309 330
a single source and a single target. Formally, there is a \f$G=(V,A)\f$
310 331
digraph, a \f$cap: A\rightarrow\mathbf{R}^+_0\f$ capacity function and
311 332
\f$s, t \in V\f$ source and target nodes.
312 333
A maximum flow is an \f$f: A\rightarrow\mathbf{R}^+_0\f$ solution of the
313 334
following optimization problem.
314 335

	
315 336
\f[ \max\sum_{sv\in A} f(sv) - \sum_{vs\in A} f(vs) \f]
316 337
\f[ \sum_{uv\in A} f(uv) = \sum_{vu\in A} f(vu)
317 338
    \quad \forall u\in V\setminus\{s,t\} \f]
318 339
\f[ 0 \leq f(uv) \leq cap(uv) \quad \forall uv\in A \f]
319 340

	
320 341
LEMON contains several algorithms for solving maximum flow problems:
321 342
- \ref EdmondsKarp Edmonds-Karp algorithm.
322 343
- \ref Preflow Goldberg-Tarjan's preflow push-relabel algorithm.
323 344
- \ref DinitzSleatorTarjan Dinitz's blocking flow algorithm with dynamic trees.
324 345
- \ref GoldbergTarjan Preflow push-relabel algorithm with dynamic trees.
325 346

	
326 347
In most cases the \ref Preflow "Preflow" algorithm provides the
327 348
fastest method for computing a maximum flow. All implementations
328 349
also provide functions to query the minimum cut, which is the dual
329 350
problem of maximum flow.
330 351

	
331 352
\ref Circulation is a preflow push-relabel algorithm implemented directly 
332 353
for finding feasible circulations, which is a somewhat different problem,
333 354
but it is strongly related to maximum flow.
334 355
For more information, see \ref Circulation.
335 356
*/
336 357

	
337 358
/**
338 359
@defgroup min_cost_flow_algs Minimum Cost Flow Algorithms
339 360
@ingroup algs
340 361

	
341 362
\brief Algorithms for finding minimum cost flows and circulations.
342 363

	
343 364
This group contains the algorithms for finding minimum cost flows and
344 365
circulations. For more information about this problem and its dual
345 366
solution see \ref min_cost_flow "Minimum Cost Flow Problem".
346 367

	
347 368
LEMON contains several algorithms for this problem.
348 369
 - \ref NetworkSimplex Primal Network Simplex algorithm with various
349 370
   pivot strategies.
350 371
 - \ref CostScaling Push-Relabel and Augment-Relabel algorithms based on
351 372
   cost scaling.
352 373
 - \ref CapacityScaling Successive Shortest %Path algorithm with optional
353 374
   capacity scaling.
354 375
 - \ref CancelAndTighten The Cancel and Tighten algorithm.
355 376
 - \ref CycleCanceling Cycle-Canceling algorithms.
356 377

	
357 378
In general NetworkSimplex is the most efficient implementation,
358 379
but in special cases other algorithms could be faster.
359 380
For example, if the total supply and/or capacities are rather small,
360 381
CapacityScaling is usually the fastest algorithm (without effective scaling).
361 382
*/
362 383

	
363 384
/**
364 385
@defgroup min_cut Minimum Cut Algorithms
365 386
@ingroup algs
366 387

	
367 388
\brief Algorithms for finding minimum cut in graphs.
368 389

	
369 390
This group contains the algorithms for finding minimum cut in graphs.
370 391

	
371 392
The \e minimum \e cut \e problem is to find a non-empty and non-complete
372 393
\f$X\f$ subset of the nodes with minimum overall capacity on
373 394
outgoing arcs. Formally, there is a \f$G=(V,A)\f$ digraph, a
374 395
\f$cap: A\rightarrow\mathbf{R}^+_0\f$ capacity function. The minimum
375 396
cut is the \f$X\f$ solution of the next optimization problem:
376 397

	
377 398
\f[ \min_{X \subset V, X\not\in \{\emptyset, V\}}
Ignore white space 6 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 6 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 256 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 6 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

	
Ignore white space 6 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_RADIX_HEAP_H
20 20
#define LEMON_RADIX_HEAP_H
21 21

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

	
26 26
#include <vector>
27 27
#include <lemon/error.h>
28 28

	
29 29
namespace lemon {
30 30

	
31 31

	
32
  /// \ingroup auxdata
32
  /// \ingroup heaps
33 33
  ///
34
  /// \brief A Radix Heap implementation.
34
  /// \brief Radix heap data structure.
35 35
  ///
36
  /// This class implements the \e radix \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. This heap type can store only items with \e int priority.
40
  /// In a heap one can change the priority of an item, add or erase an
41
  /// item, but the priority cannot be decreased under the last removed
42
  /// item's priority.
36
  /// This class implements the \e radix \e heap data structure.
37
  /// It practically conforms to the \ref concepts::Heap "heap concept",
38
  /// but it has some limitations due its special implementation.
39
  /// The type of the priorities must be \c int and the priority of an
40
  /// item cannot be decreased under the priority of the last removed item.
43 41
  ///
44
  /// \param IM A read and writable Item int map, used internally
45
  /// to handle the cross references.
46
  ///
47
  /// \see BinHeap
48
  /// \see Dijkstra
42
  /// \tparam IM A read-writable item map with \c int values, used
43
  /// internally to handle the cross references.
49 44
  template <typename IM>
50 45
  class RadixHeap {
51 46

	
52 47
  public:
53
    typedef typename IM::Key Item;
48

	
49
    /// Type of the item-int map.
50
    typedef IM ItemIntMap;
51
    /// Type of the priorities.
54 52
    typedef int Prio;
55
    typedef IM ItemIntMap;
53
    /// Type of the items stored in the heap.
54
    typedef typename ItemIntMap::Key Item;
56 55

	
57 56
    /// \brief Exception thrown by RadixHeap.
58 57
    ///
59
    /// This Exception is thrown when a smaller priority
60
    /// is inserted into the \e RadixHeap then the last time erased.
58
    /// This exception is thrown when an item is inserted into a
59
    /// RadixHeap with a priority smaller than the last erased one.
61 60
    /// \see RadixHeap
62

	
63
    class UnderFlowPriorityError : public Exception {
61
    class PriorityUnderflowError : public Exception {
64 62
    public:
65 63
      virtual const char* what() const throw() {
66
        return "lemon::RadixHeap::UnderFlowPriorityError";
64
        return "lemon::RadixHeap::PriorityUnderflowError";
67 65
      }
68 66
    };
69 67

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

	
84 82
  private:
85 83

	
86 84
    struct RadixItem {
87 85
      int prev, next, box;
88 86
      Item item;
89 87
      int prio;
90 88
      RadixItem(Item _item, int _prio) : item(_item), prio(_prio) {}
91 89
    };
92 90

	
93 91
    struct RadixBox {
94 92
      int first;
95 93
      int min, size;
96 94
      RadixBox(int _min, int _size) : first(-1), min(_min), size(_size) {}
97 95
    };
98 96

	
99
    std::vector<RadixItem> data;
100
    std::vector<RadixBox> boxes;
97
    std::vector<RadixItem> _data;
98
    std::vector<RadixBox> _boxes;
101 99

	
102 100
    ItemIntMap &_iim;
103 101

	
102
  public:
104 103

	
105
  public:
106
    /// \brief The constructor.
104
    /// \brief Constructor.
107 105
    ///
108
    /// The constructor.
109
    ///
110
    /// \param map It 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.
113
    ///
114
    /// \param minimal The initial minimal value of the heap.
115
    /// \param capacity It determines the initial capacity of the heap.
116
    RadixHeap(ItemIntMap &map, int minimal = 0, int capacity = 0)
117
      : _iim(map) {
118
      boxes.push_back(RadixBox(minimal, 1));
119
      boxes.push_back(RadixBox(minimal + 1, 1));
120
      while (lower(boxes.size() - 1, capacity + minimal - 1)) {
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 minimum The initial minimum value of the heap.
111
    /// \param capacity The initial capacity of the heap.
112
    RadixHeap(ItemIntMap &map, int minimum = 0, int capacity = 0)
113
      : _iim(map)
114
    {
115
      _boxes.push_back(RadixBox(minimum, 1));
116
      _boxes.push_back(RadixBox(minimum + 1, 1));
117
      while (lower(_boxes.size() - 1, capacity + minimum - 1)) {
121 118
        extend();
122 119
      }
123 120
    }
124 121

	
125
    /// The number of items stored in the heap.
122
    /// \brief The number of items stored in the heap.
126 123
    ///
127
    /// \brief Returns the number of items stored in the heap.
128
    int size() const { return data.size(); }
129
    /// \brief Checks if the heap stores no items.
124
    /// This function returns the number of items stored in the heap.
125
    int size() const { return _data.size(); }
126

	
127
    /// \brief Check if the heap is empty.
130 128
    ///
131
    /// Returns \c true if and only if the heap stores no items.
132
    bool empty() const { return data.empty(); }
129
    /// This function returns \c true if the heap is empty.
130
    bool empty() const { return _data.empty(); }
133 131

	
134
    /// \brief Make empty this heap.
132
    /// \brief Make the heap empty.
135 133
    ///
136
    /// Make empty this heap. It does not change the cross reference
137
    /// map.  If you want to reuse a heap what is not surely empty you
138
    /// should first clear the heap and after that you should set the
139
    /// cross reference map for each item to \c PRE_HEAP.
140
    void clear(int minimal = 0, int capacity = 0) {
141
      data.clear(); boxes.clear();
142
      boxes.push_back(RadixBox(minimal, 1));
143
      boxes.push_back(RadixBox(minimal + 1, 1));
144
      while (lower(boxes.size() - 1, capacity + minimal - 1)) {
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.
139
    /// \param minimum The minimum value of the heap.
140
    /// \param capacity The capacity of the heap.
141
    void clear(int minimum = 0, int capacity = 0) {
142
      _data.clear(); _boxes.clear();
143
      _boxes.push_back(RadixBox(minimum, 1));
144
      _boxes.push_back(RadixBox(minimum + 1, 1));
145
      while (lower(_boxes.size() - 1, capacity + minimum - 1)) {
145 146
        extend();
146 147
      }
147 148
    }
148 149

	
149 150
  private:
150 151

	
151 152
    bool upper(int box, Prio pr) {
152
      return pr < boxes[box].min;
153
      return pr < _boxes[box].min;
153 154
    }
154 155

	
155 156
    bool lower(int box, Prio pr) {
156
      return pr >= boxes[box].min + boxes[box].size;
157
      return pr >= _boxes[box].min + _boxes[box].size;
157 158
    }
158 159

	
159
    /// \brief Remove item from the box list.
160
    // Remove item from the box list
160 161
    void remove(int index) {
161
      if (data[index].prev >= 0) {
162
        data[data[index].prev].next = data[index].next;
162
      if (_data[index].prev >= 0) {
163
        _data[_data[index].prev].next = _data[index].next;
163 164
      } else {
164
        boxes[data[index].box].first = data[index].next;
165
        _boxes[_data[index].box].first = _data[index].next;
165 166
      }
166
      if (data[index].next >= 0) {
167
        data[data[index].next].prev = data[index].prev;
167
      if (_data[index].next >= 0) {
168
        _data[_data[index].next].prev = _data[index].prev;
168 169
      }
169 170
    }
170 171

	
171
    /// \brief Insert item into the box list.
172
    // Insert item into the box list
172 173
    void insert(int box, int index) {
173
      if (boxes[box].first == -1) {
174
        boxes[box].first = index;
175
        data[index].next = data[index].prev = -1;
174
      if (_boxes[box].first == -1) {
175
        _boxes[box].first = index;
176
        _data[index].next = _data[index].prev = -1;
176 177
      } else {
177
        data[index].next = boxes[box].first;
178
        data[boxes[box].first].prev = index;
179
        data[index].prev = -1;
180
        boxes[box].first = index;
178
        _data[index].next = _boxes[box].first;
179
        _data[_boxes[box].first].prev = index;
180
        _data[index].prev = -1;
181
        _boxes[box].first = index;
181 182
      }
182
      data[index].box = box;
183
      _data[index].box = box;
183 184
    }
184 185

	
185
    /// \brief Add a new box to the box list.
186
    // Add a new box to the box list
186 187
    void extend() {
187
      int min = boxes.back().min + boxes.back().size;
188
      int bs = 2 * boxes.back().size;
189
      boxes.push_back(RadixBox(min, bs));
188
      int min = _boxes.back().min + _boxes.back().size;
189
      int bs = 2 * _boxes.back().size;
190
      _boxes.push_back(RadixBox(min, bs));
190 191
    }
191 192

	
192
    /// \brief Move an item up into the proper box.
193
    void bubble_up(int index) {
194
      if (!lower(data[index].box, data[index].prio)) return;
193
    // Move an item up into the proper box.
194
    void bubbleUp(int index) {
195
      if (!lower(_data[index].box, _data[index].prio)) return;
195 196
      remove(index);
196
      int box = findUp(data[index].box, data[index].prio);
197
      int box = findUp(_data[index].box, _data[index].prio);
197 198
      insert(box, index);
198 199
    }
199 200

	
200
    /// \brief Find up the proper box for the item with the given prio.
201
    // Find up the proper box for the item with the given priority
201 202
    int findUp(int start, int pr) {
202 203
      while (lower(start, pr)) {
203
        if (++start == int(boxes.size())) {
204
        if (++start == int(_boxes.size())) {
204 205
          extend();
205 206
        }
206 207
      }
207 208
      return start;
208 209
    }
209 210

	
210
    /// \brief Move an item down into the proper box.
211
    void bubble_down(int index) {
212
      if (!upper(data[index].box, data[index].prio)) return;
211
    // Move an item down into the proper box
212
    void bubbleDown(int index) {
213
      if (!upper(_data[index].box, _data[index].prio)) return;
213 214
      remove(index);
214
      int box = findDown(data[index].box, data[index].prio);
215
      int box = findDown(_data[index].box, _data[index].prio);
215 216
      insert(box, index);
216 217
    }
217 218

	
218
    /// \brief Find up the proper box for the item with the given prio.
219
    // Find down the proper box for the item with the given priority
219 220
    int findDown(int start, int pr) {
220 221
      while (upper(start, pr)) {
221
        if (--start < 0) throw UnderFlowPriorityError();
222
        if (--start < 0) throw PriorityUnderflowError();
222 223
      }
223 224
      return start;
224 225
    }
225 226

	
226
    /// \brief Find the first not empty box.
227
    // Find the first non-empty box
227 228
    int findFirst() {
228 229
      int first = 0;
229
      while (boxes[first].first == -1) ++first;
230
      while (_boxes[first].first == -1) ++first;
230 231
      return first;
231 232
    }
232 233

	
233
    /// \brief Gives back the minimal prio of the box.
234
    // Gives back the minimum priority of the given box
234 235
    int minValue(int box) {
235
      int min = data[boxes[box].first].prio;
236
      for (int k = boxes[box].first; k != -1; k = data[k].next) {
237
        if (data[k].prio < min) min = data[k].prio;
236
      int min = _data[_boxes[box].first].prio;
237
      for (int k = _boxes[box].first; k != -1; k = _data[k].next) {
238
        if (_data[k].prio < min) min = _data[k].prio;
238 239
      }
239 240
      return min;
240 241
    }
241 242

	
242
    /// \brief Rearrange the items of the heap and makes the
243
    /// first box not empty.
243
    // Rearrange the items of the heap and make the first box non-empty
244 244
    void moveDown() {
245 245
      int box = findFirst();
246 246
      if (box == 0) return;
247 247
      int min = minValue(box);
248 248
      for (int i = 0; i <= box; ++i) {
249
        boxes[i].min = min;
250
        min += boxes[i].size;
249
        _boxes[i].min = min;
250
        min += _boxes[i].size;
251 251
      }
252
      int curr = boxes[box].first, next;
252
      int curr = _boxes[box].first, next;
253 253
      while (curr != -1) {
254
        next = data[curr].next;
255
        bubble_down(curr);
254
        next = _data[curr].next;
255
        bubbleDown(curr);
256 256
        curr = next;
257 257
      }
258 258
    }
259 259

	
260
    void relocate_last(int index) {
261
      if (index != int(data.size()) - 1) {
262
        data[index] = data.back();
263
        if (data[index].prev != -1) {
264
          data[data[index].prev].next = index;
260
    void relocateLast(int index) {
261
      if (index != int(_data.size()) - 1) {
262
        _data[index] = _data.back();
263
        if (_data[index].prev != -1) {
264
          _data[_data[index].prev].next = index;
265 265
        } else {
266
          boxes[data[index].box].first = index;
266
          _boxes[_data[index].box].first = index;
267 267
        }
268
        if (data[index].next != -1) {
269
          data[data[index].next].prev = index;
268
        if (_data[index].next != -1) {
269
          _data[_data[index].next].prev = index;
270 270
        }
271
        _iim[data[index].item] = index;
271
        _iim[_data[index].item] = index;
272 272
      }
273
      data.pop_back();
273
      _data.pop_back();
274 274
    }
275 275

	
276 276
  public:
277 277

	
278 278
    /// \brief Insert an item into the heap with the given priority.
279 279
    ///
280
    /// Adds \c i to the heap with priority \c p.
280
    /// This function inserts the given item into the heap with the
281
    /// given priority.
281 282
    /// \param i The item to insert.
282 283
    /// \param p The priority of the item.
284
    /// \pre \e i must not be stored in the heap.
285
    /// \warning This method may throw an \c UnderFlowPriorityException.
283 286
    void push(const Item &i, const Prio &p) {
284
      int n = data.size();
287
      int n = _data.size();
285 288
      _iim.set(i, n);
286
      data.push_back(RadixItem(i, p));
287
      while (lower(boxes.size() - 1, p)) {
289
      _data.push_back(RadixItem(i, p));
290
      while (lower(_boxes.size() - 1, p)) {
288 291
        extend();
289 292
      }
290
      int box = findDown(boxes.size() - 1, p);
293
      int box = findDown(_boxes.size() - 1, p);
291 294
      insert(box, n);
292 295
    }
293 296

	
294
    /// \brief Returns the item with minimum priority.
297
    /// \brief Return the item having minimum priority.
295 298
    ///
296
    /// This method returns the item with minimum priority.
297
    /// \pre The heap must be nonempty.
299
    /// This function returns the item having minimum priority.
300
    /// \pre The heap must be non-empty.
298 301
    Item top() const {
299 302
      const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown();
300
      return data[boxes[0].first].item;
303
      return _data[_boxes[0].first].item;
301 304
    }
302 305

	
303
    /// \brief Returns the minimum priority.
306
    /// \brief The minimum priority.
304 307
    ///
305
    /// It returns the minimum priority.
306
    /// \pre The heap must be nonempty.
308
    /// This function returns the minimum priority.
309
    /// \pre The heap must be non-empty.
307 310
    Prio prio() const {
308 311
      const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown();
309
      return data[boxes[0].first].prio;
312
      return _data[_boxes[0].first].prio;
310 313
     }
311 314

	
312
    /// \brief Deletes the item with minimum priority.
315
    /// \brief Remove the item having minimum priority.
313 316
    ///
314
    /// This method deletes the item with minimum priority.
317
    /// This function removes the item having minimum priority.
315 318
    /// \pre The heap must be non-empty.
316 319
    void pop() {
317 320
      moveDown();
318
      int index = boxes[0].first;
319
      _iim[data[index].item] = POST_HEAP;
321
      int index = _boxes[0].first;
322
      _iim[_data[index].item] = POST_HEAP;
320 323
      remove(index);
321
      relocate_last(index);
324
      relocateLast(index);
322 325
    }
323 326

	
324
    /// \brief Deletes \c i from the heap.
327
    /// \brief Remove the given item from the heap.
325 328
    ///
326
    /// This method deletes item \c i from the heap, if \c i was
327
    /// already stored in the heap.
328
    /// \param i The item to erase.
329
    /// This function removes the given item from the heap if it is
330
    /// already stored.
331
    /// \param i The item to delete.
332
    /// \pre \e i must be in the heap.
329 333
    void erase(const Item &i) {
330 334
      int index = _iim[i];
331 335
      _iim[i] = POST_HEAP;
332 336
      remove(index);
333
      relocate_last(index);
337
      relocateLast(index);
334 338
   }
335 339

	
336
    /// \brief Returns the priority of \c i.
340
    /// \brief The priority of the given item.
337 341
    ///
338
    /// This function returns the priority of item \c i.
339
    /// \pre \c i must be in the heap.
342
    /// This function returns the priority of the given item.
340 343
    /// \param i The item.
344
    /// \pre \e i must be in the heap.
341 345
    Prio operator[](const Item &i) const {
342 346
      int idx = _iim[i];
343
      return data[idx].prio;
347
      return _data[idx].prio;
344 348
    }
345 349

	
346
    /// \brief \c i gets to the heap with priority \c p independently
347
    /// if \c i was already there.
350
    /// \brief Set the priority of an item or insert it, if it is
351
    /// not stored in the heap.
348 352
    ///
349
    /// This method calls \ref push(\c i, \c p) if \c i is not stored
350
    /// in the heap and sets the priority of \c i to \c p otherwise.
351
    /// It may throw an \e UnderFlowPriorityException.
353
    /// This method sets the priority of the given item if it is
354
    /// already stored in the heap. Otherwise it inserts the given
355
    /// item into the heap with the given priority.
352 356
    /// \param i The item.
353 357
    /// \param p The priority.
358
    /// \pre \e i must be in the heap.
359
    /// \warning This method may throw an \c UnderFlowPriorityException.
354 360
    void set(const Item &i, const Prio &p) {
355 361
      int idx = _iim[i];
356 362
      if( idx < 0 ) {
357 363
        push(i, p);
358 364
      }
359
      else if( p >= data[idx].prio ) {
360
        data[idx].prio = p;
361
        bubble_up(idx);
365
      else if( p >= _data[idx].prio ) {
366
        _data[idx].prio = p;
367
        bubbleUp(idx);
362 368
      } else {
363
        data[idx].prio = p;
364
        bubble_down(idx);
369
        _data[idx].prio = p;
370
        bubbleDown(idx);
365 371
      }
366 372
    }
367 373

	
368

	
369
    /// \brief Decreases the priority of \c i to \c p.
374
    /// \brief Decrease the priority of an item to the given value.
370 375
    ///
371
    /// This method decreases the priority of item \c i to \c p.
372
    /// \pre \c i must be stored in the heap with priority at least \c p, and
373
    /// \c should be greater or equal to the last removed item's priority.
376
    /// This function decreases the priority of an item to the given value.
374 377
    /// \param i The item.
375 378
    /// \param p The priority.
379
    /// \pre \e i must be stored in the heap with priority at least \e p.
380
    /// \warning This method may throw an \c UnderFlowPriorityException.
376 381
    void decrease(const Item &i, const Prio &p) {
377 382
      int idx = _iim[i];
378
      data[idx].prio = p;
379
      bubble_down(idx);
383
      _data[idx].prio = p;
384
      bubbleDown(idx);
380 385
    }
381 386

	
382
    /// \brief Increases the priority of \c i to \c p.
387
    /// \brief Increase the priority of an item to the given value.
383 388
    ///
384
    /// This method sets the priority of item \c i to \c p.
385
    /// \pre \c i must be stored in the heap with priority at most \c p
389
    /// This function increases the priority of an item to the given value.
386 390
    /// \param i The item.
387 391
    /// \param p The priority.
392
    /// \pre \e i must be stored in the heap with priority at most \e p.
388 393
    void increase(const Item &i, const Prio &p) {
389 394
      int idx = _iim[i];
390
      data[idx].prio = p;
391
      bubble_up(idx);
395
      _data[idx].prio = p;
396
      bubbleUp(idx);
392 397
    }
393 398

	
394
    /// \brief Returns if \c item is in, has already been in, or has
395
    /// never been in the heap.
399
    /// \brief Return the state of an item.
396 400
    ///
397
    /// This method returns PRE_HEAP if \c item has never been in the
398
    /// heap, IN_HEAP if it is in the heap at the moment, and POST_HEAP
399
    /// otherwise. In the latter case it is possible that \c item will
400
    /// get back to the heap again.
401
    /// This method returns \c PRE_HEAP if the given item has never
402
    /// been in the heap, \c IN_HEAP if it is in the heap at the moment,
403
    /// and \c POST_HEAP otherwise.
404
    /// In the latter case it is possible that the item will get back
405
    /// to the heap again.
401 406
    /// \param i The item.
402 407
    State state(const Item &i) const {
403 408
      int s = _iim[i];
404 409
      if( s >= 0 ) s = 0;
405 410
      return State(s);
406 411
    }
407 412

	
408
    /// \brief Sets the state of the \c item in the heap.
413
    /// \brief Set the state of an item in the heap.
409 414
    ///
410
    /// Sets the state of the \c item in the heap. It can be used to
411
    /// manually clear the heap when it is important to achive the
412
    /// better time complexity.
415
    /// This function sets the state of the given item in the heap.
416
    /// It can be used to manually clear the heap when it is important
417
    /// to achive better time complexity.
413 418
    /// \param i The item.
414 419
    /// \param st The state. It should not be \c IN_HEAP.
415 420
    void state(const Item& i, State st) {
416 421
      switch (st) {
417 422
      case POST_HEAP:
418 423
      case PRE_HEAP:
419 424
        if (state(i) == IN_HEAP) {
420 425
          erase(i);
421 426
        }
422 427
        _iim[i] = st;
423 428
        break;
424 429
      case IN_HEAP:
425 430
        break;
426 431
      }
427 432
    }
428 433

	
429 434
  }; // class RadixHeap
430 435

	
431 436
} // namespace lemon
432 437

	
433 438
#endif // LEMON_RADIX_HEAP_H
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