gravatar
kpeter (Peter Kovacs)
kpeter@inf.elte.hu
Small doc fixes in several files (#331)
0 21 0
default
21 files changed:
↑ Collapse diff ↑
Show white space 768 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
namespace lemon {
20 20

	
21 21
/**
22 22
\page min_cost_flow Minimum Cost Flow Problem
23 23

	
24 24
\section mcf_def Definition (GEQ form)
25 25

	
26 26
The \e minimum \e cost \e flow \e problem is to find a feasible flow of
27 27
minimum total cost from a set of supply nodes to a set of demand nodes
28 28
in a network with capacity constraints (lower and upper bounds)
29 29
and arc costs.
30 30

	
31 31
Formally, let \f$G=(V,A)\f$ be a digraph, \f$lower: A\rightarrow\mathbf{R}\f$,
32 32
\f$upper: A\rightarrow\mathbf{R}\cup\{+\infty\}\f$ denote the lower and
33 33
upper bounds for the flow values on the arcs, for which
34 34
\f$lower(uv) \leq upper(uv)\f$ must hold for all \f$uv\in A\f$,
35 35
\f$cost: A\rightarrow\mathbf{R}\f$ denotes the cost per unit flow
36 36
on the arcs and \f$sup: V\rightarrow\mathbf{R}\f$ denotes the
37 37
signed supply values of the nodes.
38 38
If \f$sup(u)>0\f$, then \f$u\f$ is a supply node with \f$sup(u)\f$
39 39
supply, if \f$sup(u)<0\f$, then \f$u\f$ is a demand node with
40 40
\f$-sup(u)\f$ demand.
41 41
A minimum cost flow is an \f$f: A\rightarrow\mathbf{R}\f$ solution
42 42
of the following optimization problem.
43 43

	
44 44
\f[ \min\sum_{uv\in A} f(uv) \cdot cost(uv) \f]
45 45
\f[ \sum_{uv\in A} f(uv) - \sum_{vu\in A} f(vu) \geq
46 46
    sup(u) \quad \forall u\in V \f]
47 47
\f[ lower(uv) \leq f(uv) \leq upper(uv) \quad \forall uv\in A \f]
48 48

	
49 49
The sum of the supply values, i.e. \f$\sum_{u\in V} sup(u)\f$ must be
50 50
zero or negative in order to have a feasible solution (since the sum
51 51
of the expressions on the left-hand side of the inequalities is zero).
52 52
It means that the total demand must be greater or equal to the total
53 53
supply and all the supplies have to be carried out from the supply nodes,
54 54
but there could be demands that are not satisfied.
55 55
If \f$\sum_{u\in V} sup(u)\f$ is zero, then all the supply/demand
56 56
constraints have to be satisfied with equality, i.e. all demands
57 57
have to be satisfied and all supplies have to be used.
58 58

	
59 59

	
60 60
\section mcf_algs Algorithms
61 61

	
62 62
LEMON contains several algorithms for solving this problem, for more
63 63
information see \ref min_cost_flow_algs "Minimum Cost Flow Algorithms".
64 64

	
65 65
A feasible solution for this problem can be found using \ref Circulation.
66 66

	
67 67

	
68 68
\section mcf_dual Dual Solution
69 69

	
70 70
The dual solution of the minimum cost flow problem is represented by
71 71
node potentials \f$\pi: V\rightarrow\mathbf{R}\f$.
72 72
An \f$f: A\rightarrow\mathbf{R}\f$ primal feasible solution is optimal
73 73
if and only if for some \f$\pi: V\rightarrow\mathbf{R}\f$ node potentials
74 74
the following \e complementary \e slackness optimality conditions hold.
75 75

	
76 76
 - For all \f$uv\in A\f$ arcs:
77 77
   - if \f$cost^\pi(uv)>0\f$, then \f$f(uv)=lower(uv)\f$;
78 78
   - if \f$lower(uv)<f(uv)<upper(uv)\f$, then \f$cost^\pi(uv)=0\f$;
79 79
   - if \f$cost^\pi(uv)<0\f$, then \f$f(uv)=upper(uv)\f$.
80 80
 - For all \f$u\in V\f$ nodes:
81
   - \f$\pi(u)<=0\f$;
81
   - \f$\pi(u)\leq 0\f$;
82 82
   - if \f$\sum_{uv\in A} f(uv) - \sum_{vu\in A} f(vu) \neq sup(u)\f$,
83 83
     then \f$\pi(u)=0\f$.
84 84
 
85 85
Here \f$cost^\pi(uv)\f$ denotes the \e reduced \e cost of the arc
86 86
\f$uv\in A\f$ with respect to the potential function \f$\pi\f$, i.e.
87 87
\f[ cost^\pi(uv) = cost(uv) + \pi(u) - \pi(v).\f]
88 88

	
89 89
All algorithms provide dual solution (node potentials), as well,
90 90
if an optimal flow is found.
91 91

	
92 92

	
93 93
\section mcf_eq Equality Form
94 94

	
95 95
The above \ref mcf_def "definition" is actually more general than the
96 96
usual formulation of the minimum cost flow problem, in which strict
97 97
equalities are required in the supply/demand contraints.
98 98

	
99 99
\f[ \min\sum_{uv\in A} f(uv) \cdot cost(uv) \f]
100 100
\f[ \sum_{uv\in A} f(uv) - \sum_{vu\in A} f(vu) =
101 101
    sup(u) \quad \forall u\in V \f]
102 102
\f[ lower(uv) \leq f(uv) \leq upper(uv) \quad \forall uv\in A \f]
103 103

	
104 104
However if the sum of the supply values is zero, then these two problems
105 105
are equivalent.
106 106
The \ref min_cost_flow_algs "algorithms" in LEMON support the general
107 107
form, so if you need the equality form, you have to ensure this additional
108 108
contraint manually.
109 109

	
110 110

	
111 111
\section mcf_leq Opposite Inequalites (LEQ Form)
112 112

	
113 113
Another possible definition of the minimum cost flow problem is
114 114
when there are <em>"less or equal"</em> (LEQ) supply/demand constraints,
115 115
instead of the <em>"greater or equal"</em> (GEQ) constraints.
116 116

	
117 117
\f[ \min\sum_{uv\in A} f(uv) \cdot cost(uv) \f]
118 118
\f[ \sum_{uv\in A} f(uv) - \sum_{vu\in A} f(vu) \leq
119 119
    sup(u) \quad \forall u\in V \f]
120 120
\f[ lower(uv) \leq f(uv) \leq upper(uv) \quad \forall uv\in A \f]
121 121

	
122 122
It means that the total demand must be less or equal to the 
123 123
total supply (i.e. \f$\sum_{u\in V} sup(u)\f$ must be zero or
124 124
positive) and all the demands have to be satisfied, but there
125 125
could be supplies that are not carried out from the supply
126 126
nodes.
127 127
The equality form is also a special case of this form, of course.
128 128

	
129 129
You could easily transform this case to the \ref mcf_def "GEQ form"
130 130
of the problem by reversing the direction of the arcs and taking the
131 131
negative of the supply values (e.g. using \ref ReverseDigraph and
132 132
\ref NegMap adaptors).
133 133
However \ref NetworkSimplex algorithm also supports this form directly
134 134
for the sake of convenience.
135 135

	
136 136
Note that the optimality conditions for this supply constraint type are
137 137
slightly differ from the conditions that are discussed for the GEQ form,
138 138
namely the potentials have to be non-negative instead of non-positive.
139 139
An \f$f: A\rightarrow\mathbf{R}\f$ feasible solution of this problem
140 140
is optimal if and only if for some \f$\pi: V\rightarrow\mathbf{R}\f$
141 141
node potentials the following conditions hold.
142 142

	
143 143
 - For all \f$uv\in A\f$ arcs:
144 144
   - if \f$cost^\pi(uv)>0\f$, then \f$f(uv)=lower(uv)\f$;
145 145
   - if \f$lower(uv)<f(uv)<upper(uv)\f$, then \f$cost^\pi(uv)=0\f$;
146 146
   - if \f$cost^\pi(uv)<0\f$, then \f$f(uv)=upper(uv)\f$.
147 147
 - For all \f$u\in V\f$ nodes:
148
   - \f$\pi(u)>=0\f$;
148
   - \f$\pi(u)\geq 0\f$;
149 149
   - if \f$\sum_{uv\in A} f(uv) - \sum_{vu\in A} f(vu) \neq sup(u)\f$,
150 150
     then \f$\pi(u)=0\f$.
151 151

	
152 152
*/
153 153
}
Show white space 768 line context
1 1
/* -*- C++ -*-
2 2
 *
3 3
 * This file is a part of LEMON, a generic C++ optimization library
4 4
 *
5 5
 * Copyright (C) 2003-2008
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_BELLMAN_FORD_H
20 20
#define LEMON_BELLMAN_FORD_H
21 21

	
22 22
/// \ingroup shortest_path
23 23
/// \file
24 24
/// \brief Bellman-Ford algorithm.
25 25

	
26 26
#include <lemon/bits/path_dump.h>
27 27
#include <lemon/core.h>
28 28
#include <lemon/error.h>
29 29
#include <lemon/maps.h>
30 30
#include <lemon/path.h>
31 31

	
32 32
#include <limits>
33 33

	
34 34
namespace lemon {
35 35

	
36 36
  /// \brief Default OperationTraits for the BellmanFord algorithm class.
37 37
  ///  
38 38
  /// This operation traits class defines all computational operations
39 39
  /// and constants that are used in the Bellman-Ford algorithm.
40 40
  /// The default implementation is based on the \c numeric_limits class.
41 41
  /// If the numeric type does not have infinity value, then the maximum
42 42
  /// value is used as extremal infinity value.
43 43
  template <
44 44
    typename V, 
45 45
    bool has_inf = std::numeric_limits<V>::has_infinity>
46 46
  struct BellmanFordDefaultOperationTraits {
47 47
    /// \e
48 48
    typedef V Value;
49 49
    /// \brief Gives back the zero value of the type.
50 50
    static Value zero() {
51 51
      return static_cast<Value>(0);
52 52
    }
53 53
    /// \brief Gives back the positive infinity value of the type.
54 54
    static Value infinity() {
55 55
      return std::numeric_limits<Value>::infinity();
56 56
    }
57 57
    /// \brief Gives back the sum of the given two elements.
58 58
    static Value plus(const Value& left, const Value& right) {
59 59
      return left + right;
60 60
    }
61 61
    /// \brief Gives back \c true only if the first value is less than
62 62
    /// the second.
63 63
    static bool less(const Value& left, const Value& right) {
64 64
      return left < right;
65 65
    }
66 66
  };
67 67

	
68 68
  template <typename V>
69 69
  struct BellmanFordDefaultOperationTraits<V, false> {
70 70
    typedef V Value;
71 71
    static Value zero() {
72 72
      return static_cast<Value>(0);
73 73
    }
74 74
    static Value infinity() {
75 75
      return std::numeric_limits<Value>::max();
76 76
    }
77 77
    static Value plus(const Value& left, const Value& right) {
78 78
      if (left == infinity() || right == infinity()) return infinity();
79 79
      return left + right;
80 80
    }
81 81
    static bool less(const Value& left, const Value& right) {
82 82
      return left < right;
83 83
    }
84 84
  };
85 85
  
86 86
  /// \brief Default traits class of BellmanFord class.
87 87
  ///
88 88
  /// Default traits class of BellmanFord class.
89 89
  /// \param GR The type of the digraph.
90 90
  /// \param LEN The type of the length map.
91 91
  template<typename GR, typename LEN>
92 92
  struct BellmanFordDefaultTraits {
93 93
    /// The type of the digraph the algorithm runs on. 
94 94
    typedef GR Digraph;
95 95

	
96 96
    /// \brief The type of the map that stores the arc lengths.
97 97
    ///
98 98
    /// The type of the map that stores the arc lengths.
99 99
    /// It must conform to the \ref concepts::ReadMap "ReadMap" concept.
100 100
    typedef LEN LengthMap;
101 101

	
102 102
    /// The type of the arc lengths.
103 103
    typedef typename LEN::Value Value;
104 104

	
105 105
    /// \brief Operation traits for Bellman-Ford algorithm.
106 106
    ///
107 107
    /// It defines the used operations and the infinity value for the
108 108
    /// given \c Value type.
109 109
    /// \see BellmanFordDefaultOperationTraits
110 110
    typedef BellmanFordDefaultOperationTraits<Value> OperationTraits;
111 111
 
112 112
    /// \brief The type of the map that stores the last arcs of the 
113 113
    /// shortest paths.
114 114
    /// 
115 115
    /// The type of the map that stores the last
116 116
    /// arcs of the shortest paths.
117 117
    /// It must conform to the \ref concepts::WriteMap "WriteMap" concept.
118 118
    typedef typename GR::template NodeMap<typename GR::Arc> PredMap;
119 119

	
120 120
    /// \brief Instantiates a \c PredMap.
121 121
    /// 
122 122
    /// This function instantiates a \ref PredMap. 
123 123
    /// \param g is the digraph to which we would like to define the
124 124
    /// \ref PredMap.
125 125
    static PredMap *createPredMap(const GR& g) {
126 126
      return new PredMap(g);
127 127
    }
128 128

	
129 129
    /// \brief The type of the map that stores the distances of the nodes.
130 130
    ///
131 131
    /// The type of the map that stores the distances of the nodes.
132 132
    /// It must conform to the \ref concepts::WriteMap "WriteMap" concept.
133 133
    typedef typename GR::template NodeMap<typename LEN::Value> DistMap;
134 134

	
135 135
    /// \brief Instantiates a \c DistMap.
136 136
    ///
137 137
    /// This function instantiates a \ref DistMap. 
138 138
    /// \param g is the digraph to which we would like to define the 
139 139
    /// \ref DistMap.
140 140
    static DistMap *createDistMap(const GR& g) {
141 141
      return new DistMap(g);
142 142
    }
143 143

	
144 144
  };
145 145
  
146 146
  /// \brief %BellmanFord algorithm class.
147 147
  ///
148 148
  /// \ingroup shortest_path
149 149
  /// This class provides an efficient implementation of the Bellman-Ford 
150 150
  /// algorithm. The maximum time complexity of the algorithm is
151 151
  /// <tt>O(ne)</tt>.
152 152
  ///
153 153
  /// The Bellman-Ford algorithm solves the single-source shortest path
154 154
  /// problem when the arcs can have negative lengths, but the digraph
155 155
  /// should not contain directed cycles with negative total length.
156 156
  /// If all arc costs are non-negative, consider to use the Dijkstra
157 157
  /// algorithm instead, since it is more efficient.
158 158
  ///
159 159
  /// The arc lengths are passed to the algorithm using a
160 160
  /// \ref concepts::ReadMap "ReadMap", so it is easy to change it to any 
161 161
  /// kind of length. The type of the length values is determined by the
162 162
  /// \ref concepts::ReadMap::Value "Value" type of the length map.
163 163
  ///
164 164
  /// There is also a \ref bellmanFord() "function-type interface" for the
165 165
  /// Bellman-Ford algorithm, which is convenient in the simplier cases and
166 166
  /// it can be used easier.
167 167
  ///
168 168
  /// \tparam GR The type of the digraph the algorithm runs on.
169 169
  /// The default type is \ref ListDigraph.
170 170
  /// \tparam LEN A \ref concepts::ReadMap "readable" arc map that specifies
171 171
  /// the lengths of the arcs. The default map type is
172 172
  /// \ref concepts::Digraph::ArcMap "GR::ArcMap<int>".
173 173
#ifdef DOXYGEN
174 174
  template <typename GR, typename LEN, typename TR>
175 175
#else
176 176
  template <typename GR=ListDigraph,
177 177
            typename LEN=typename GR::template ArcMap<int>,
178 178
            typename TR=BellmanFordDefaultTraits<GR,LEN> >
179 179
#endif
180 180
  class BellmanFord {
181 181
  public:
182 182

	
183 183
    ///The type of the underlying digraph.
184 184
    typedef typename TR::Digraph Digraph;
185 185
    
186 186
    /// \brief The type of the arc lengths.
187 187
    typedef typename TR::LengthMap::Value Value;
188 188
    /// \brief The type of the map that stores the arc lengths.
189 189
    typedef typename TR::LengthMap LengthMap;
190 190
    /// \brief The type of the map that stores the last
191 191
    /// arcs of the shortest paths.
192 192
    typedef typename TR::PredMap PredMap;
193 193
    /// \brief The type of the map that stores the distances of the nodes.
194 194
    typedef typename TR::DistMap DistMap;
195 195
    /// The type of the paths.
196 196
    typedef PredMapPath<Digraph, PredMap> Path;
197 197
    ///\brief The \ref BellmanFordDefaultOperationTraits
198 198
    /// "operation traits class" of the algorithm.
199 199
    typedef typename TR::OperationTraits OperationTraits;
200 200

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

	
204 204
  private:
205 205

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

	
211 211
    // Pointer to the underlying digraph.
212 212
    const Digraph *_gr;
213 213
    // Pointer to the length map
214 214
    const LengthMap *_length;
215 215
    // Pointer to the map of predecessors arcs.
216 216
    PredMap *_pred;
217 217
    // Indicates if _pred is locally allocated (true) or not.
218 218
    bool _local_pred;
219 219
    // Pointer to the map of distances.
220 220
    DistMap *_dist;
221 221
    // Indicates if _dist is locally allocated (true) or not.
222 222
    bool _local_dist;
223 223

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

	
227 227
    std::vector<Node> _process;
228 228

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

	
246 246
    /// \name Named Template Parameters
247 247

	
248 248
    ///@{
249 249

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

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

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

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

	
312 312
  protected:
313 313
    
314 314
    BellmanFord() {}
315 315

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

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

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

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

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

	
388 388
    ///@{
389 389

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	
933 933
    typedef typename TR::Digraph Digraph;
934 934

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

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

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

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

	
962 962
    ~BellmanFordWizard() {}
963 963

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

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

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

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

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

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

	
1097 1097
} //END OF NAMESPACE LEMON
1098 1098

	
1099 1099
#endif
1100 1100

	
Show white space 768 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_BFS_H
20 20
#define LEMON_BFS_H
21 21

	
22 22
///\ingroup search
23 23
///\file
24 24
///\brief BFS algorithm.
25 25

	
26 26
#include <lemon/list_graph.h>
27 27
#include <lemon/bits/path_dump.h>
28 28
#include <lemon/core.h>
29 29
#include <lemon/error.h>
30 30
#include <lemon/maps.h>
31 31
#include <lemon/path.h>
32 32

	
33 33
namespace lemon {
34 34

	
35 35
  ///Default traits class of Bfs class.
36 36

	
37 37
  ///Default traits class of Bfs class.
38 38
  ///\tparam GR Digraph type.
39 39
  template<class GR>
40 40
  struct BfsDefaultTraits
41 41
  {
42 42
    ///The type of the digraph the algorithm runs on.
43 43
    typedef GR Digraph;
44 44

	
45 45
    ///\brief The type of the map that stores the predecessor
46 46
    ///arcs of the shortest paths.
47 47
    ///
48 48
    ///The type of the map that stores the predecessor
49 49
    ///arcs of the shortest paths.
50 50
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
51 51
    typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
52 52
    ///Instantiates a \c PredMap.
53 53

	
54 54
    ///This function instantiates a \ref PredMap.
55 55
    ///\param g is the digraph, to which we would like to define the
56 56
    ///\ref PredMap.
57 57
    static PredMap *createPredMap(const Digraph &g)
58 58
    {
59 59
      return new PredMap(g);
60 60
    }
61 61

	
62 62
    ///The type of the map that indicates which nodes are processed.
63 63

	
64 64
    ///The type of the map that indicates which nodes are processed.
65 65
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
66
    ///By default it is a NullMap.
66
    ///By default, it is a NullMap.
67 67
    typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
68 68
    ///Instantiates a \c ProcessedMap.
69 69

	
70 70
    ///This function instantiates a \ref ProcessedMap.
71 71
    ///\param g is the digraph, to which
72 72
    ///we would like to define the \ref ProcessedMap
73 73
#ifdef DOXYGEN
74 74
    static ProcessedMap *createProcessedMap(const Digraph &g)
75 75
#else
76 76
    static ProcessedMap *createProcessedMap(const Digraph &)
77 77
#endif
78 78
    {
79 79
      return new ProcessedMap();
80 80
    }
81 81

	
82 82
    ///The type of the map that indicates which nodes are reached.
83 83

	
84 84
    ///The type of the map that indicates which nodes are reached.
85 85
    ///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
86 86
    typedef typename Digraph::template NodeMap<bool> ReachedMap;
87 87
    ///Instantiates a \c ReachedMap.
88 88

	
89 89
    ///This function instantiates a \ref ReachedMap.
90 90
    ///\param g is the digraph, to which
91 91
    ///we would like to define the \ref ReachedMap.
92 92
    static ReachedMap *createReachedMap(const Digraph &g)
93 93
    {
94 94
      return new ReachedMap(g);
95 95
    }
96 96

	
97 97
    ///The type of the map that stores the distances of the nodes.
98 98

	
99 99
    ///The type of the map that stores the distances of the nodes.
100 100
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
101 101
    typedef typename Digraph::template NodeMap<int> DistMap;
102 102
    ///Instantiates a \c DistMap.
103 103

	
104 104
    ///This function instantiates a \ref DistMap.
105 105
    ///\param g is the digraph, to which we would like to define the
106 106
    ///\ref DistMap.
107 107
    static DistMap *createDistMap(const Digraph &g)
108 108
    {
109 109
      return new DistMap(g);
110 110
    }
111 111
  };
112 112

	
113 113
  ///%BFS algorithm class.
114 114

	
115 115
  ///\ingroup search
116 116
  ///This class provides an efficient implementation of the %BFS algorithm.
117 117
  ///
118 118
  ///There is also a \ref bfs() "function-type interface" for the BFS
119 119
  ///algorithm, which is convenient in the simplier cases and it can be
120 120
  ///used easier.
121 121
  ///
122 122
  ///\tparam GR The type of the digraph the algorithm runs on.
123 123
  ///The default type is \ref ListDigraph.
124 124
#ifdef DOXYGEN
125 125
  template <typename GR,
126 126
            typename TR>
127 127
#else
128 128
  template <typename GR=ListDigraph,
129 129
            typename TR=BfsDefaultTraits<GR> >
130 130
#endif
131 131
  class Bfs {
132 132
  public:
133 133

	
134 134
    ///The type of the digraph the algorithm runs on.
135 135
    typedef typename TR::Digraph Digraph;
136 136

	
137 137
    ///\brief The type of the map that stores the predecessor arcs of the
138 138
    ///shortest paths.
139 139
    typedef typename TR::PredMap PredMap;
140 140
    ///The type of the map that stores the distances of the nodes.
141 141
    typedef typename TR::DistMap DistMap;
142 142
    ///The type of the map that indicates which nodes are reached.
143 143
    typedef typename TR::ReachedMap ReachedMap;
144 144
    ///The type of the map that indicates which nodes are processed.
145 145
    typedef typename TR::ProcessedMap ProcessedMap;
146 146
    ///The type of the paths.
147 147
    typedef PredMapPath<Digraph, PredMap> Path;
148 148

	
149 149
    ///The \ref BfsDefaultTraits "traits class" of the algorithm.
150 150
    typedef TR Traits;
151 151

	
152 152
  private:
153 153

	
154 154
    typedef typename Digraph::Node Node;
155 155
    typedef typename Digraph::NodeIt NodeIt;
156 156
    typedef typename Digraph::Arc Arc;
157 157
    typedef typename Digraph::OutArcIt OutArcIt;
158 158

	
159 159
    //Pointer to the underlying digraph.
160 160
    const Digraph *G;
161 161
    //Pointer to the map of predecessor arcs.
162 162
    PredMap *_pred;
163 163
    //Indicates if _pred is locally allocated (true) or not.
164 164
    bool local_pred;
165 165
    //Pointer to the map of distances.
166 166
    DistMap *_dist;
167 167
    //Indicates if _dist is locally allocated (true) or not.
168 168
    bool local_dist;
169 169
    //Pointer to the map of reached status of the nodes.
170 170
    ReachedMap *_reached;
171 171
    //Indicates if _reached is locally allocated (true) or not.
172 172
    bool local_reached;
173 173
    //Pointer to the map of processed status of the nodes.
174 174
    ProcessedMap *_processed;
175 175
    //Indicates if _processed is locally allocated (true) or not.
176 176
    bool local_processed;
177 177

	
178 178
    std::vector<typename Digraph::Node> _queue;
179 179
    int _queue_head,_queue_tail,_queue_next_dist;
180 180
    int _curr_dist;
181 181

	
182 182
    //Creates the maps if necessary.
183 183
    void create_maps()
184 184
    {
185 185
      if(!_pred) {
186 186
        local_pred = true;
187 187
        _pred = Traits::createPredMap(*G);
188 188
      }
189 189
      if(!_dist) {
190 190
        local_dist = true;
191 191
        _dist = Traits::createDistMap(*G);
192 192
      }
193 193
      if(!_reached) {
194 194
        local_reached = true;
195 195
        _reached = Traits::createReachedMap(*G);
196 196
      }
197 197
      if(!_processed) {
198 198
        local_processed = true;
199 199
        _processed = Traits::createProcessedMap(*G);
200 200
      }
201 201
    }
202 202

	
203 203
  protected:
204 204

	
205 205
    Bfs() {}
206 206

	
207 207
  public:
208 208

	
209 209
    typedef Bfs Create;
210 210

	
211 211
    ///\name Named Template Parameters
212 212

	
213 213
    ///@{
214 214

	
215 215
    template <class T>
216 216
    struct SetPredMapTraits : public Traits {
217 217
      typedef T PredMap;
218 218
      static PredMap *createPredMap(const Digraph &)
219 219
      {
220 220
        LEMON_ASSERT(false, "PredMap is not initialized");
221 221
        return 0; // ignore warnings
222 222
      }
223 223
    };
224 224
    ///\brief \ref named-templ-param "Named parameter" for setting
225 225
    ///\c PredMap type.
226 226
    ///
227 227
    ///\ref named-templ-param "Named parameter" for setting
228 228
    ///\c PredMap type.
229 229
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
230 230
    template <class T>
231 231
    struct SetPredMap : public Bfs< Digraph, SetPredMapTraits<T> > {
232 232
      typedef Bfs< Digraph, SetPredMapTraits<T> > Create;
233 233
    };
234 234

	
235 235
    template <class T>
236 236
    struct SetDistMapTraits : public Traits {
237 237
      typedef T DistMap;
238 238
      static DistMap *createDistMap(const Digraph &)
239 239
      {
240 240
        LEMON_ASSERT(false, "DistMap is not initialized");
241 241
        return 0; // ignore warnings
242 242
      }
243 243
    };
244 244
    ///\brief \ref named-templ-param "Named parameter" for setting
245 245
    ///\c DistMap type.
246 246
    ///
247 247
    ///\ref named-templ-param "Named parameter" for setting
248 248
    ///\c DistMap type.
249 249
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
250 250
    template <class T>
251 251
    struct SetDistMap : public Bfs< Digraph, SetDistMapTraits<T> > {
252 252
      typedef Bfs< Digraph, SetDistMapTraits<T> > Create;
253 253
    };
254 254

	
255 255
    template <class T>
256 256
    struct SetReachedMapTraits : public Traits {
257 257
      typedef T ReachedMap;
258 258
      static ReachedMap *createReachedMap(const Digraph &)
259 259
      {
260 260
        LEMON_ASSERT(false, "ReachedMap is not initialized");
261 261
        return 0; // ignore warnings
262 262
      }
263 263
    };
264 264
    ///\brief \ref named-templ-param "Named parameter" for setting
265 265
    ///\c ReachedMap type.
266 266
    ///
267 267
    ///\ref named-templ-param "Named parameter" for setting
268 268
    ///\c ReachedMap type.
269 269
    ///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
270 270
    template <class T>
271 271
    struct SetReachedMap : public Bfs< Digraph, SetReachedMapTraits<T> > {
272 272
      typedef Bfs< Digraph, SetReachedMapTraits<T> > Create;
273 273
    };
274 274

	
275 275
    template <class T>
276 276
    struct SetProcessedMapTraits : public Traits {
277 277
      typedef T ProcessedMap;
278 278
      static ProcessedMap *createProcessedMap(const Digraph &)
279 279
      {
280 280
        LEMON_ASSERT(false, "ProcessedMap is not initialized");
281 281
        return 0; // ignore warnings
282 282
      }
283 283
    };
284 284
    ///\brief \ref named-templ-param "Named parameter" for setting
285 285
    ///\c ProcessedMap type.
286 286
    ///
287 287
    ///\ref named-templ-param "Named parameter" for setting
288 288
    ///\c ProcessedMap type.
289 289
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
290 290
    template <class T>
291 291
    struct SetProcessedMap : public Bfs< Digraph, SetProcessedMapTraits<T> > {
292 292
      typedef Bfs< Digraph, SetProcessedMapTraits<T> > Create;
293 293
    };
294 294

	
295 295
    struct SetStandardProcessedMapTraits : public Traits {
296 296
      typedef typename Digraph::template NodeMap<bool> ProcessedMap;
297 297
      static ProcessedMap *createProcessedMap(const Digraph &g)
298 298
      {
299 299
        return new ProcessedMap(g);
300 300
        return 0; // ignore warnings
301 301
      }
302 302
    };
303 303
    ///\brief \ref named-templ-param "Named parameter" for setting
304 304
    ///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
305 305
    ///
306 306
    ///\ref named-templ-param "Named parameter" for setting
307 307
    ///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
308 308
    ///If you don't set it explicitly, it will be automatically allocated.
309 309
    struct SetStandardProcessedMap :
310 310
      public Bfs< Digraph, SetStandardProcessedMapTraits > {
311 311
      typedef Bfs< Digraph, SetStandardProcessedMapTraits > Create;
312 312
    };
313 313

	
314 314
    ///@}
315 315

	
316 316
  public:
317 317

	
318 318
    ///Constructor.
319 319

	
320 320
    ///Constructor.
321 321
    ///\param g The digraph the algorithm runs on.
322 322
    Bfs(const Digraph &g) :
323 323
      G(&g),
324 324
      _pred(NULL), local_pred(false),
325 325
      _dist(NULL), local_dist(false),
326 326
      _reached(NULL), local_reached(false),
327 327
      _processed(NULL), local_processed(false)
328 328
    { }
329 329

	
330 330
    ///Destructor.
331 331
    ~Bfs()
332 332
    {
333 333
      if(local_pred) delete _pred;
334 334
      if(local_dist) delete _dist;
335 335
      if(local_reached) delete _reached;
336 336
      if(local_processed) delete _processed;
337 337
    }
338 338

	
339 339
    ///Sets the map that stores the predecessor arcs.
340 340

	
341 341
    ///Sets the map that stores the predecessor arcs.
342 342
    ///If you don't use this function before calling \ref run(Node) "run()"
343 343
    ///or \ref init(), an instance will be allocated automatically.
344 344
    ///The destructor deallocates this automatically allocated map,
345 345
    ///of course.
346 346
    ///\return <tt> (*this) </tt>
347 347
    Bfs &predMap(PredMap &m)
348 348
    {
349 349
      if(local_pred) {
350 350
        delete _pred;
351 351
        local_pred=false;
352 352
      }
353 353
      _pred = &m;
354 354
      return *this;
355 355
    }
356 356

	
357 357
    ///Sets the map that indicates which nodes are reached.
358 358

	
359 359
    ///Sets the map that indicates which nodes are reached.
360 360
    ///If you don't use this function before calling \ref run(Node) "run()"
361 361
    ///or \ref init(), an instance will be allocated automatically.
362 362
    ///The destructor deallocates this automatically allocated map,
363 363
    ///of course.
364 364
    ///\return <tt> (*this) </tt>
365 365
    Bfs &reachedMap(ReachedMap &m)
366 366
    {
367 367
      if(local_reached) {
368 368
        delete _reached;
369 369
        local_reached=false;
370 370
      }
371 371
      _reached = &m;
372 372
      return *this;
373 373
    }
374 374

	
375 375
    ///Sets the map that indicates which nodes are processed.
376 376

	
377 377
    ///Sets the map that indicates which nodes are processed.
378 378
    ///If you don't use this function before calling \ref run(Node) "run()"
379 379
    ///or \ref init(), an instance will be allocated automatically.
380 380
    ///The destructor deallocates this automatically allocated map,
381 381
    ///of course.
382 382
    ///\return <tt> (*this) </tt>
383 383
    Bfs &processedMap(ProcessedMap &m)
384 384
    {
385 385
      if(local_processed) {
386 386
        delete _processed;
387 387
        local_processed=false;
388 388
      }
389 389
      _processed = &m;
390 390
      return *this;
391 391
    }
392 392

	
393 393
    ///Sets the map that stores the distances of the nodes.
394 394

	
395 395
    ///Sets the map that stores the distances of the nodes calculated by
396 396
    ///the algorithm.
397 397
    ///If you don't use this function before calling \ref run(Node) "run()"
398 398
    ///or \ref init(), an instance will be allocated automatically.
399 399
    ///The destructor deallocates this automatically allocated map,
400 400
    ///of course.
401 401
    ///\return <tt> (*this) </tt>
402 402
    Bfs &distMap(DistMap &m)
403 403
    {
404 404
      if(local_dist) {
405 405
        delete _dist;
406 406
        local_dist=false;
407 407
      }
408 408
      _dist = &m;
409 409
      return *this;
410 410
    }
411 411

	
412 412
  public:
413 413

	
414 414
    ///\name Execution Control
415 415
    ///The simplest way to execute the BFS algorithm is to use one of the
416 416
    ///member functions called \ref run(Node) "run()".\n
417 417
    ///If you need better control on the execution, you have to call
418 418
    ///\ref init() first, then you can add several source nodes with
419 419
    ///\ref addSource(). Finally the actual path computation can be
420 420
    ///performed with one of the \ref start() functions.
421 421

	
422 422
    ///@{
423 423

	
424 424
    ///\brief Initializes the internal data structures.
425 425
    ///
426 426
    ///Initializes the internal data structures.
427 427
    void init()
428 428
    {
429 429
      create_maps();
430 430
      _queue.resize(countNodes(*G));
431 431
      _queue_head=_queue_tail=0;
432 432
      _curr_dist=1;
433 433
      for ( NodeIt u(*G) ; u!=INVALID ; ++u ) {
434 434
        _pred->set(u,INVALID);
435 435
        _reached->set(u,false);
436 436
        _processed->set(u,false);
437 437
      }
438 438
    }
439 439

	
440 440
    ///Adds a new source node.
441 441

	
442 442
    ///Adds a new source node to the set of nodes to be processed.
443 443
    ///
444 444
    void addSource(Node s)
445 445
    {
446 446
      if(!(*_reached)[s])
447 447
        {
448 448
          _reached->set(s,true);
449 449
          _pred->set(s,INVALID);
450 450
          _dist->set(s,0);
... ...
@@ -471,769 +471,769 @@
471 471
      Node m;
472 472
      for(OutArcIt e(*G,n);e!=INVALID;++e)
473 473
        if(!(*_reached)[m=G->target(e)]) {
474 474
          _queue[_queue_head++]=m;
475 475
          _reached->set(m,true);
476 476
          _pred->set(m,e);
477 477
          _dist->set(m,_curr_dist);
478 478
        }
479 479
      return n;
480 480
    }
481 481

	
482 482
    ///Processes the next node.
483 483

	
484 484
    ///Processes the next node and checks if the given target node
485 485
    ///is reached. If the target node is reachable from the processed
486 486
    ///node, then the \c reach parameter will be set to \c true.
487 487
    ///
488 488
    ///\param target The target node.
489 489
    ///\retval reach Indicates if the target node is reached.
490 490
    ///It should be initially \c false.
491 491
    ///
492 492
    ///\return The processed node.
493 493
    ///
494 494
    ///\pre The queue must not be empty.
495 495
    Node processNextNode(Node target, bool& reach)
496 496
    {
497 497
      if(_queue_tail==_queue_next_dist) {
498 498
        _curr_dist++;
499 499
        _queue_next_dist=_queue_head;
500 500
      }
501 501
      Node n=_queue[_queue_tail++];
502 502
      _processed->set(n,true);
503 503
      Node m;
504 504
      for(OutArcIt e(*G,n);e!=INVALID;++e)
505 505
        if(!(*_reached)[m=G->target(e)]) {
506 506
          _queue[_queue_head++]=m;
507 507
          _reached->set(m,true);
508 508
          _pred->set(m,e);
509 509
          _dist->set(m,_curr_dist);
510 510
          reach = reach || (target == m);
511 511
        }
512 512
      return n;
513 513
    }
514 514

	
515 515
    ///Processes the next node.
516 516

	
517 517
    ///Processes the next node and checks if at least one of reached
518 518
    ///nodes has \c true value in the \c nm node map. If one node
519 519
    ///with \c true value is reachable from the processed node, then the
520 520
    ///\c rnode parameter will be set to the first of such nodes.
521 521
    ///
522 522
    ///\param nm A \c bool (or convertible) node map that indicates the
523 523
    ///possible targets.
524 524
    ///\retval rnode The reached target node.
525 525
    ///It should be initially \c INVALID.
526 526
    ///
527 527
    ///\return The processed node.
528 528
    ///
529 529
    ///\pre The queue must not be empty.
530 530
    template<class NM>
531 531
    Node processNextNode(const NM& nm, Node& rnode)
532 532
    {
533 533
      if(_queue_tail==_queue_next_dist) {
534 534
        _curr_dist++;
535 535
        _queue_next_dist=_queue_head;
536 536
      }
537 537
      Node n=_queue[_queue_tail++];
538 538
      _processed->set(n,true);
539 539
      Node m;
540 540
      for(OutArcIt e(*G,n);e!=INVALID;++e)
541 541
        if(!(*_reached)[m=G->target(e)]) {
542 542
          _queue[_queue_head++]=m;
543 543
          _reached->set(m,true);
544 544
          _pred->set(m,e);
545 545
          _dist->set(m,_curr_dist);
546 546
          if (nm[m] && rnode == INVALID) rnode = m;
547 547
        }
548 548
      return n;
549 549
    }
550 550

	
551 551
    ///The next node to be processed.
552 552

	
553 553
    ///Returns the next node to be processed or \c INVALID if the queue
554 554
    ///is empty.
555 555
    Node nextNode() const
556 556
    {
557 557
      return _queue_tail<_queue_head?_queue[_queue_tail]:INVALID;
558 558
    }
559 559

	
560 560
    ///Returns \c false if there are nodes to be processed.
561 561

	
562 562
    ///Returns \c false if there are nodes to be processed
563 563
    ///in the queue.
564 564
    bool emptyQueue() const { return _queue_tail==_queue_head; }
565 565

	
566 566
    ///Returns the number of the nodes to be processed.
567 567

	
568 568
    ///Returns the number of the nodes to be processed
569 569
    ///in the queue.
570 570
    int queueSize() const { return _queue_head-_queue_tail; }
571 571

	
572 572
    ///Executes the algorithm.
573 573

	
574 574
    ///Executes the algorithm.
575 575
    ///
576 576
    ///This method runs the %BFS algorithm from the root node(s)
577 577
    ///in order to compute the shortest path to each node.
578 578
    ///
579 579
    ///The algorithm computes
580 580
    ///- the shortest path tree (forest),
581 581
    ///- the distance of each node from the root(s).
582 582
    ///
583 583
    ///\pre init() must be called and at least one root node should be
584 584
    ///added with addSource() before using this function.
585 585
    ///
586 586
    ///\note <tt>b.start()</tt> is just a shortcut of the following code.
587 587
    ///\code
588 588
    ///  while ( !b.emptyQueue() ) {
589 589
    ///    b.processNextNode();
590 590
    ///  }
591 591
    ///\endcode
592 592
    void start()
593 593
    {
594 594
      while ( !emptyQueue() ) processNextNode();
595 595
    }
596 596

	
597 597
    ///Executes the algorithm until the given target node is reached.
598 598

	
599 599
    ///Executes the algorithm until the given target node is reached.
600 600
    ///
601 601
    ///This method runs the %BFS algorithm from the root node(s)
602 602
    ///in order to compute the shortest path to \c t.
603 603
    ///
604 604
    ///The algorithm computes
605 605
    ///- the shortest path to \c t,
606 606
    ///- the distance of \c t from the root(s).
607 607
    ///
608 608
    ///\pre init() must be called and at least one root node should be
609 609
    ///added with addSource() before using this function.
610 610
    ///
611 611
    ///\note <tt>b.start(t)</tt> is just a shortcut of the following code.
612 612
    ///\code
613 613
    ///  bool reach = false;
614 614
    ///  while ( !b.emptyQueue() && !reach ) {
615 615
    ///    b.processNextNode(t, reach);
616 616
    ///  }
617 617
    ///\endcode
618 618
    void start(Node t)
619 619
    {
620 620
      bool reach = false;
621 621
      while ( !emptyQueue() && !reach ) processNextNode(t, reach);
622 622
    }
623 623

	
624 624
    ///Executes the algorithm until a condition is met.
625 625

	
626 626
    ///Executes the algorithm until a condition is met.
627 627
    ///
628 628
    ///This method runs the %BFS algorithm from the root node(s) in
629 629
    ///order to compute the shortest path to a node \c v with
630 630
    /// <tt>nm[v]</tt> true, if such a node can be found.
631 631
    ///
632 632
    ///\param nm A \c bool (or convertible) node map. The algorithm
633 633
    ///will stop when it reaches a node \c v with <tt>nm[v]</tt> true.
634 634
    ///
635 635
    ///\return The reached node \c v with <tt>nm[v]</tt> true or
636 636
    ///\c INVALID if no such node was found.
637 637
    ///
638 638
    ///\pre init() must be called and at least one root node should be
639 639
    ///added with addSource() before using this function.
640 640
    ///
641 641
    ///\note <tt>b.start(nm)</tt> is just a shortcut of the following code.
642 642
    ///\code
643 643
    ///  Node rnode = INVALID;
644 644
    ///  while ( !b.emptyQueue() && rnode == INVALID ) {
645 645
    ///    b.processNextNode(nm, rnode);
646 646
    ///  }
647 647
    ///  return rnode;
648 648
    ///\endcode
649 649
    template<class NodeBoolMap>
650 650
    Node start(const NodeBoolMap &nm)
651 651
    {
652 652
      Node rnode = INVALID;
653 653
      while ( !emptyQueue() && rnode == INVALID ) {
654 654
        processNextNode(nm, rnode);
655 655
      }
656 656
      return rnode;
657 657
    }
658 658

	
659 659
    ///Runs the algorithm from the given source node.
660 660

	
661 661
    ///This method runs the %BFS algorithm from node \c s
662 662
    ///in order to compute the shortest path to each node.
663 663
    ///
664 664
    ///The algorithm computes
665 665
    ///- the shortest path tree,
666 666
    ///- the distance of each node from the root.
667 667
    ///
668 668
    ///\note <tt>b.run(s)</tt> is just a shortcut of the following code.
669 669
    ///\code
670 670
    ///  b.init();
671 671
    ///  b.addSource(s);
672 672
    ///  b.start();
673 673
    ///\endcode
674 674
    void run(Node s) {
675 675
      init();
676 676
      addSource(s);
677 677
      start();
678 678
    }
679 679

	
680 680
    ///Finds the shortest path between \c s and \c t.
681 681

	
682 682
    ///This method runs the %BFS algorithm from node \c s
683 683
    ///in order to compute the shortest path to node \c t
684 684
    ///(it stops searching when \c t is processed).
685 685
    ///
686 686
    ///\return \c true if \c t is reachable form \c s.
687 687
    ///
688 688
    ///\note Apart from the return value, <tt>b.run(s,t)</tt> is just a
689 689
    ///shortcut of the following code.
690 690
    ///\code
691 691
    ///  b.init();
692 692
    ///  b.addSource(s);
693 693
    ///  b.start(t);
694 694
    ///\endcode
695 695
    bool run(Node s,Node t) {
696 696
      init();
697 697
      addSource(s);
698 698
      start(t);
699 699
      return reached(t);
700 700
    }
701 701

	
702 702
    ///Runs the algorithm to visit all nodes in the digraph.
703 703

	
704 704
    ///This method runs the %BFS algorithm in order to
705 705
    ///compute the shortest path to each node.
706 706
    ///
707 707
    ///The algorithm computes
708 708
    ///- the shortest path tree (forest),
709 709
    ///- the distance of each node from the root(s).
710 710
    ///
711 711
    ///\note <tt>b.run(s)</tt> is just a shortcut of the following code.
712 712
    ///\code
713 713
    ///  b.init();
714 714
    ///  for (NodeIt n(gr); n != INVALID; ++n) {
715 715
    ///    if (!b.reached(n)) {
716 716
    ///      b.addSource(n);
717 717
    ///      b.start();
718 718
    ///    }
719 719
    ///  }
720 720
    ///\endcode
721 721
    void run() {
722 722
      init();
723 723
      for (NodeIt n(*G); n != INVALID; ++n) {
724 724
        if (!reached(n)) {
725 725
          addSource(n);
726 726
          start();
727 727
        }
728 728
      }
729 729
    }
730 730

	
731 731
    ///@}
732 732

	
733 733
    ///\name Query Functions
734 734
    ///The results of the BFS algorithm can be obtained using these
735 735
    ///functions.\n
736 736
    ///Either \ref run(Node) "run()" or \ref start() should be called
737 737
    ///before using them.
738 738

	
739 739
    ///@{
740 740

	
741 741
    ///The shortest path to the given node.
742 742

	
743 743
    ///Returns the shortest path to the given node from the root(s).
744 744
    ///
745 745
    ///\warning \c t should be reached from the root(s).
746 746
    ///
747 747
    ///\pre Either \ref run(Node) "run()" or \ref init()
748 748
    ///must be called before using this function.
749 749
    Path path(Node t) const { return Path(*G, *_pred, t); }
750 750

	
751 751
    ///The distance of the given node from the root(s).
752 752

	
753 753
    ///Returns the distance of the given node from the root(s).
754 754
    ///
755 755
    ///\warning If node \c v is not reached from the root(s), then
756 756
    ///the return value of this function is undefined.
757 757
    ///
758 758
    ///\pre Either \ref run(Node) "run()" or \ref init()
759 759
    ///must be called before using this function.
760 760
    int dist(Node v) const { return (*_dist)[v]; }
761 761

	
762 762
    ///\brief Returns the 'previous arc' of the shortest path tree for
763 763
    ///the given node.
764 764
    ///
765 765
    ///This function returns the 'previous arc' of the shortest path
766 766
    ///tree for the node \c v, i.e. it returns the last arc of a
767 767
    ///shortest path from a root to \c v. It is \c INVALID if \c v
768 768
    ///is not reached from the root(s) or if \c v is a root.
769 769
    ///
770 770
    ///The shortest path tree used here is equal to the shortest path
771 771
    ///tree used in \ref predNode() and \ref predMap().
772 772
    ///
773 773
    ///\pre Either \ref run(Node) "run()" or \ref init()
774 774
    ///must be called before using this function.
775 775
    Arc predArc(Node v) const { return (*_pred)[v];}
776 776

	
777 777
    ///\brief Returns the 'previous node' of the shortest path tree for
778 778
    ///the given node.
779 779
    ///
780 780
    ///This function returns the 'previous node' of the shortest path
781 781
    ///tree for the node \c v, i.e. it returns the last but one node
782 782
    ///of a shortest path from a root to \c v. It is \c INVALID
783 783
    ///if \c v is not reached from the root(s) or if \c v is a root.
784 784
    ///
785 785
    ///The shortest path tree used here is equal to the shortest path
786 786
    ///tree used in \ref predArc() and \ref predMap().
787 787
    ///
788 788
    ///\pre Either \ref run(Node) "run()" or \ref init()
789 789
    ///must be called before using this function.
790 790
    Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
791 791
                                  G->source((*_pred)[v]); }
792 792

	
793 793
    ///\brief Returns a const reference to the node map that stores the
794 794
    /// distances of the nodes.
795 795
    ///
796 796
    ///Returns a const reference to the node map that stores the distances
797 797
    ///of the nodes calculated by the algorithm.
798 798
    ///
799 799
    ///\pre Either \ref run(Node) "run()" or \ref init()
800 800
    ///must be called before using this function.
801 801
    const DistMap &distMap() const { return *_dist;}
802 802

	
803 803
    ///\brief Returns a const reference to the node map that stores the
804 804
    ///predecessor arcs.
805 805
    ///
806 806
    ///Returns a const reference to the node map that stores the predecessor
807 807
    ///arcs, which form the shortest path tree (forest).
808 808
    ///
809 809
    ///\pre Either \ref run(Node) "run()" or \ref init()
810 810
    ///must be called before using this function.
811 811
    const PredMap &predMap() const { return *_pred;}
812 812

	
813 813
    ///Checks if the given node is reached from the root(s).
814 814

	
815 815
    ///Returns \c true if \c v is reached from the root(s).
816 816
    ///
817 817
    ///\pre Either \ref run(Node) "run()" or \ref init()
818 818
    ///must be called before using this function.
819 819
    bool reached(Node v) const { return (*_reached)[v]; }
820 820

	
821 821
    ///@}
822 822
  };
823 823

	
824 824
  ///Default traits class of bfs() function.
825 825

	
826 826
  ///Default traits class of bfs() function.
827 827
  ///\tparam GR Digraph type.
828 828
  template<class GR>
829 829
  struct BfsWizardDefaultTraits
830 830
  {
831 831
    ///The type of the digraph the algorithm runs on.
832 832
    typedef GR Digraph;
833 833

	
834 834
    ///\brief The type of the map that stores the predecessor
835 835
    ///arcs of the shortest paths.
836 836
    ///
837 837
    ///The type of the map that stores the predecessor
838 838
    ///arcs of the shortest paths.
839 839
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
840 840
    typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
841 841
    ///Instantiates a PredMap.
842 842

	
843 843
    ///This function instantiates a PredMap.
844 844
    ///\param g is the digraph, to which we would like to define the
845 845
    ///PredMap.
846 846
    static PredMap *createPredMap(const Digraph &g)
847 847
    {
848 848
      return new PredMap(g);
849 849
    }
850 850

	
851 851
    ///The type of the map that indicates which nodes are processed.
852 852

	
853 853
    ///The type of the map that indicates which nodes are processed.
854 854
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
855
    ///By default it is a NullMap.
855
    ///By default, it is a NullMap.
856 856
    typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
857 857
    ///Instantiates a ProcessedMap.
858 858

	
859 859
    ///This function instantiates a ProcessedMap.
860 860
    ///\param g is the digraph, to which
861 861
    ///we would like to define the ProcessedMap.
862 862
#ifdef DOXYGEN
863 863
    static ProcessedMap *createProcessedMap(const Digraph &g)
864 864
#else
865 865
    static ProcessedMap *createProcessedMap(const Digraph &)
866 866
#endif
867 867
    {
868 868
      return new ProcessedMap();
869 869
    }
870 870

	
871 871
    ///The type of the map that indicates which nodes are reached.
872 872

	
873 873
    ///The type of the map that indicates which nodes are reached.
874 874
    ///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
875 875
    typedef typename Digraph::template NodeMap<bool> ReachedMap;
876 876
    ///Instantiates a ReachedMap.
877 877

	
878 878
    ///This function instantiates a ReachedMap.
879 879
    ///\param g is the digraph, to which
880 880
    ///we would like to define the ReachedMap.
881 881
    static ReachedMap *createReachedMap(const Digraph &g)
882 882
    {
883 883
      return new ReachedMap(g);
884 884
    }
885 885

	
886 886
    ///The type of the map that stores the distances of the nodes.
887 887

	
888 888
    ///The type of the map that stores the distances of the nodes.
889 889
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
890 890
    typedef typename Digraph::template NodeMap<int> DistMap;
891 891
    ///Instantiates a DistMap.
892 892

	
893 893
    ///This function instantiates a DistMap.
894 894
    ///\param g is the digraph, to which we would like to define
895 895
    ///the DistMap
896 896
    static DistMap *createDistMap(const Digraph &g)
897 897
    {
898 898
      return new DistMap(g);
899 899
    }
900 900

	
901 901
    ///The type of the shortest paths.
902 902

	
903 903
    ///The type of the shortest paths.
904 904
    ///It must conform to the \ref concepts::Path "Path" concept.
905 905
    typedef lemon::Path<Digraph> Path;
906 906
  };
907 907

	
908 908
  /// Default traits class used by BfsWizard
909 909

	
910 910
  /// Default traits class used by BfsWizard.
911 911
  /// \tparam GR The type of the digraph.
912 912
  template<class GR>
913 913
  class BfsWizardBase : public BfsWizardDefaultTraits<GR>
914 914
  {
915 915

	
916 916
    typedef BfsWizardDefaultTraits<GR> Base;
917 917
  protected:
918 918
    //The type of the nodes in the digraph.
919 919
    typedef typename Base::Digraph::Node Node;
920 920

	
921 921
    //Pointer to the digraph the algorithm runs on.
922 922
    void *_g;
923 923
    //Pointer to the map of reached nodes.
924 924
    void *_reached;
925 925
    //Pointer to the map of processed nodes.
926 926
    void *_processed;
927 927
    //Pointer to the map of predecessors arcs.
928 928
    void *_pred;
929 929
    //Pointer to the map of distances.
930 930
    void *_dist;
931 931
    //Pointer to the shortest path to the target node.
932 932
    void *_path;
933 933
    //Pointer to the distance of the target node.
934 934
    int *_di;
935 935

	
936 936
    public:
937 937
    /// Constructor.
938 938

	
939 939
    /// This constructor does not require parameters, it initiates
940 940
    /// all of the attributes to \c 0.
941 941
    BfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0),
942 942
                      _dist(0), _path(0), _di(0) {}
943 943

	
944 944
    /// Constructor.
945 945

	
946 946
    /// This constructor requires one parameter,
947 947
    /// others are initiated to \c 0.
948 948
    /// \param g The digraph the algorithm runs on.
949 949
    BfsWizardBase(const GR &g) :
950 950
      _g(reinterpret_cast<void*>(const_cast<GR*>(&g))),
951 951
      _reached(0), _processed(0), _pred(0), _dist(0),  _path(0), _di(0) {}
952 952

	
953 953
  };
954 954

	
955 955
  /// Auxiliary class for the function-type interface of BFS algorithm.
956 956

	
957 957
  /// This auxiliary class is created to implement the
958 958
  /// \ref bfs() "function-type interface" of \ref Bfs algorithm.
959 959
  /// It does not have own \ref run(Node) "run()" method, it uses the
960 960
  /// functions and features of the plain \ref Bfs.
961 961
  ///
962 962
  /// This class should only be used through the \ref bfs() function,
963 963
  /// which makes it easier to use the algorithm.
964 964
  template<class TR>
965 965
  class BfsWizard : public TR
966 966
  {
967 967
    typedef TR Base;
968 968

	
969 969
    typedef typename TR::Digraph Digraph;
970 970

	
971 971
    typedef typename Digraph::Node Node;
972 972
    typedef typename Digraph::NodeIt NodeIt;
973 973
    typedef typename Digraph::Arc Arc;
974 974
    typedef typename Digraph::OutArcIt OutArcIt;
975 975

	
976 976
    typedef typename TR::PredMap PredMap;
977 977
    typedef typename TR::DistMap DistMap;
978 978
    typedef typename TR::ReachedMap ReachedMap;
979 979
    typedef typename TR::ProcessedMap ProcessedMap;
980 980
    typedef typename TR::Path Path;
981 981

	
982 982
  public:
983 983

	
984 984
    /// Constructor.
985 985
    BfsWizard() : TR() {}
986 986

	
987 987
    /// Constructor that requires parameters.
988 988

	
989 989
    /// Constructor that requires parameters.
990 990
    /// These parameters will be the default values for the traits class.
991 991
    /// \param g The digraph the algorithm runs on.
992 992
    BfsWizard(const Digraph &g) :
993 993
      TR(g) {}
994 994

	
995 995
    ///Copy constructor
996 996
    BfsWizard(const TR &b) : TR(b) {}
997 997

	
998 998
    ~BfsWizard() {}
999 999

	
1000 1000
    ///Runs BFS algorithm from the given source node.
1001 1001

	
1002 1002
    ///This method runs BFS algorithm from node \c s
1003 1003
    ///in order to compute the shortest path to each node.
1004 1004
    void run(Node s)
1005 1005
    {
1006 1006
      Bfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g));
1007 1007
      if (Base::_pred)
1008 1008
        alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
1009 1009
      if (Base::_dist)
1010 1010
        alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
1011 1011
      if (Base::_reached)
1012 1012
        alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached));
1013 1013
      if (Base::_processed)
1014 1014
        alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
1015 1015
      if (s!=INVALID)
1016 1016
        alg.run(s);
1017 1017
      else
1018 1018
        alg.run();
1019 1019
    }
1020 1020

	
1021 1021
    ///Finds the shortest path between \c s and \c t.
1022 1022

	
1023 1023
    ///This method runs BFS algorithm from node \c s
1024 1024
    ///in order to compute the shortest path to node \c t
1025 1025
    ///(it stops searching when \c t is processed).
1026 1026
    ///
1027 1027
    ///\return \c true if \c t is reachable form \c s.
1028 1028
    bool run(Node s, Node t)
1029 1029
    {
1030 1030
      Bfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g));
1031 1031
      if (Base::_pred)
1032 1032
        alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
1033 1033
      if (Base::_dist)
1034 1034
        alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
1035 1035
      if (Base::_reached)
1036 1036
        alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached));
1037 1037
      if (Base::_processed)
1038 1038
        alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
1039 1039
      alg.run(s,t);
1040 1040
      if (Base::_path)
1041 1041
        *reinterpret_cast<Path*>(Base::_path) = alg.path(t);
1042 1042
      if (Base::_di)
1043 1043
        *Base::_di = alg.dist(t);
1044 1044
      return alg.reached(t);
1045 1045
    }
1046 1046

	
1047 1047
    ///Runs BFS algorithm to visit all nodes in the digraph.
1048 1048

	
1049 1049
    ///This method runs BFS algorithm in order to compute
1050 1050
    ///the shortest path to each node.
1051 1051
    void run()
1052 1052
    {
1053 1053
      run(INVALID);
1054 1054
    }
1055 1055

	
1056 1056
    template<class T>
1057 1057
    struct SetPredMapBase : public Base {
1058 1058
      typedef T PredMap;
1059 1059
      static PredMap *createPredMap(const Digraph &) { return 0; };
1060 1060
      SetPredMapBase(const TR &b) : TR(b) {}
1061 1061
    };
1062 1062

	
1063 1063
    ///\brief \ref named-templ-param "Named parameter" for setting
1064 1064
    ///the predecessor map.
1065 1065
    ///
1066 1066
    ///\ref named-templ-param "Named parameter" function for setting
1067 1067
    ///the map that stores the predecessor arcs of the nodes.
1068 1068
    template<class T>
1069 1069
    BfsWizard<SetPredMapBase<T> > predMap(const T &t)
1070 1070
    {
1071 1071
      Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
1072 1072
      return BfsWizard<SetPredMapBase<T> >(*this);
1073 1073
    }
1074 1074

	
1075 1075
    template<class T>
1076 1076
    struct SetReachedMapBase : public Base {
1077 1077
      typedef T ReachedMap;
1078 1078
      static ReachedMap *createReachedMap(const Digraph &) { return 0; };
1079 1079
      SetReachedMapBase(const TR &b) : TR(b) {}
1080 1080
    };
1081 1081

	
1082 1082
    ///\brief \ref named-templ-param "Named parameter" for setting
1083 1083
    ///the reached map.
1084 1084
    ///
1085 1085
    ///\ref named-templ-param "Named parameter" function for setting
1086 1086
    ///the map that indicates which nodes are reached.
1087 1087
    template<class T>
1088 1088
    BfsWizard<SetReachedMapBase<T> > reachedMap(const T &t)
1089 1089
    {
1090 1090
      Base::_reached=reinterpret_cast<void*>(const_cast<T*>(&t));
1091 1091
      return BfsWizard<SetReachedMapBase<T> >(*this);
1092 1092
    }
1093 1093

	
1094 1094
    template<class T>
1095 1095
    struct SetDistMapBase : public Base {
1096 1096
      typedef T DistMap;
1097 1097
      static DistMap *createDistMap(const Digraph &) { return 0; };
1098 1098
      SetDistMapBase(const TR &b) : TR(b) {}
1099 1099
    };
1100 1100

	
1101 1101
    ///\brief \ref named-templ-param "Named parameter" for setting
1102 1102
    ///the distance map.
1103 1103
    ///
1104 1104
    ///\ref named-templ-param "Named parameter" function for setting
1105 1105
    ///the map that stores the distances of the nodes calculated
1106 1106
    ///by the algorithm.
1107 1107
    template<class T>
1108 1108
    BfsWizard<SetDistMapBase<T> > distMap(const T &t)
1109 1109
    {
1110 1110
      Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t));
1111 1111
      return BfsWizard<SetDistMapBase<T> >(*this);
1112 1112
    }
1113 1113

	
1114 1114
    template<class T>
1115 1115
    struct SetProcessedMapBase : public Base {
1116 1116
      typedef T ProcessedMap;
1117 1117
      static ProcessedMap *createProcessedMap(const Digraph &) { return 0; };
1118 1118
      SetProcessedMapBase(const TR &b) : TR(b) {}
1119 1119
    };
1120 1120

	
1121 1121
    ///\brief \ref named-func-param "Named parameter" for setting
1122 1122
    ///the processed map.
1123 1123
    ///
1124 1124
    ///\ref named-templ-param "Named parameter" function for setting
1125 1125
    ///the map that indicates which nodes are processed.
1126 1126
    template<class T>
1127 1127
    BfsWizard<SetProcessedMapBase<T> > processedMap(const T &t)
1128 1128
    {
1129 1129
      Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t));
1130 1130
      return BfsWizard<SetProcessedMapBase<T> >(*this);
1131 1131
    }
1132 1132

	
1133 1133
    template<class T>
1134 1134
    struct SetPathBase : public Base {
1135 1135
      typedef T Path;
1136 1136
      SetPathBase(const TR &b) : TR(b) {}
1137 1137
    };
1138 1138
    ///\brief \ref named-func-param "Named parameter"
1139 1139
    ///for getting the shortest path to the target node.
1140 1140
    ///
1141 1141
    ///\ref named-func-param "Named parameter"
1142 1142
    ///for getting the shortest path to the target node.
1143 1143
    template<class T>
1144 1144
    BfsWizard<SetPathBase<T> > path(const T &t)
1145 1145
    {
1146 1146
      Base::_path=reinterpret_cast<void*>(const_cast<T*>(&t));
1147 1147
      return BfsWizard<SetPathBase<T> >(*this);
1148 1148
    }
1149 1149

	
1150 1150
    ///\brief \ref named-func-param "Named parameter"
1151 1151
    ///for getting the distance of the target node.
1152 1152
    ///
1153 1153
    ///\ref named-func-param "Named parameter"
1154 1154
    ///for getting the distance of the target node.
1155 1155
    BfsWizard dist(const int &d)
1156 1156
    {
1157 1157
      Base::_di=const_cast<int*>(&d);
1158 1158
      return *this;
1159 1159
    }
1160 1160

	
1161 1161
  };
1162 1162

	
1163 1163
  ///Function-type interface for BFS algorithm.
1164 1164

	
1165 1165
  /// \ingroup search
1166 1166
  ///Function-type interface for BFS algorithm.
1167 1167
  ///
1168 1168
  ///This function also has several \ref named-func-param "named parameters",
1169 1169
  ///they are declared as the members of class \ref BfsWizard.
1170 1170
  ///The following examples show how to use these parameters.
1171 1171
  ///\code
1172 1172
  ///  // Compute shortest path from node s to each node
1173 1173
  ///  bfs(g).predMap(preds).distMap(dists).run(s);
1174 1174
  ///
1175 1175
  ///  // Compute shortest path from s to t
1176 1176
  ///  bool reached = bfs(g).path(p).dist(d).run(s,t);
1177 1177
  ///\endcode
1178 1178
  ///\warning Don't forget to put the \ref BfsWizard::run(Node) "run()"
1179 1179
  ///to the end of the parameter list.
1180 1180
  ///\sa BfsWizard
1181 1181
  ///\sa Bfs
1182 1182
  template<class GR>
1183 1183
  BfsWizard<BfsWizardBase<GR> >
1184 1184
  bfs(const GR &digraph)
1185 1185
  {
1186 1186
    return BfsWizard<BfsWizardBase<GR> >(digraph);
1187 1187
  }
1188 1188

	
1189 1189
#ifdef DOXYGEN
1190 1190
  /// \brief Visitor class for BFS.
1191 1191
  ///
1192 1192
  /// This class defines the interface of the BfsVisit events, and
1193 1193
  /// it could be the base of a real visitor class.
1194 1194
  template <typename GR>
1195 1195
  struct BfsVisitor {
1196 1196
    typedef GR Digraph;
1197 1197
    typedef typename Digraph::Arc Arc;
1198 1198
    typedef typename Digraph::Node Node;
1199 1199
    /// \brief Called for the source node(s) of the BFS.
1200 1200
    ///
1201 1201
    /// This function is called for the source node(s) of the BFS.
1202 1202
    void start(const Node& node) {}
1203 1203
    /// \brief Called when a node is reached first time.
1204 1204
    ///
1205 1205
    /// This function is called when a node is reached first time.
1206 1206
    void reach(const Node& node) {}
1207 1207
    /// \brief Called when a node is processed.
1208 1208
    ///
1209 1209
    /// This function is called when a node is processed.
1210 1210
    void process(const Node& node) {}
1211 1211
    /// \brief Called when an arc reaches a new node.
1212 1212
    ///
1213 1213
    /// This function is called when the BFS finds an arc whose target node
1214 1214
    /// is not reached yet.
1215 1215
    void discover(const Arc& arc) {}
1216 1216
    /// \brief Called when an arc is examined but its target node is
1217 1217
    /// already discovered.
1218 1218
    ///
1219 1219
    /// This function is called when an arc is examined but its target node is
1220 1220
    /// already discovered.
1221 1221
    void examine(const Arc& arc) {}
1222 1222
  };
1223 1223
#else
1224 1224
  template <typename GR>
1225 1225
  struct BfsVisitor {
1226 1226
    typedef GR Digraph;
1227 1227
    typedef typename Digraph::Arc Arc;
1228 1228
    typedef typename Digraph::Node Node;
1229 1229
    void start(const Node&) {}
1230 1230
    void reach(const Node&) {}
1231 1231
    void process(const Node&) {}
1232 1232
    void discover(const Arc&) {}
1233 1233
    void examine(const Arc&) {}
1234 1234

	
1235 1235
    template <typename _Visitor>
1236 1236
    struct Constraints {
1237 1237
      void constraints() {
1238 1238
        Arc arc;
1239 1239
        Node node;
Show white space 768 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_CIRCULATION_H
20 20
#define LEMON_CIRCULATION_H
21 21

	
22 22
#include <lemon/tolerance.h>
23 23
#include <lemon/elevator.h>
24 24
#include <limits>
25 25

	
26 26
///\ingroup max_flow
27 27
///\file
28 28
///\brief Push-relabel algorithm for finding a feasible circulation.
29 29
///
30 30
namespace lemon {
31 31

	
32 32
  /// \brief Default traits class of Circulation class.
33 33
  ///
34 34
  /// Default traits class of Circulation class.
35 35
  ///
36 36
  /// \tparam GR Type of the digraph the algorithm runs on.
37 37
  /// \tparam LM The type of the lower bound map.
38 38
  /// \tparam UM The type of the upper bound (capacity) map.
39 39
  /// \tparam SM The type of the supply map.
40 40
  template <typename GR, typename LM,
41 41
            typename UM, typename SM>
42 42
  struct CirculationDefaultTraits {
43 43

	
44 44
    /// \brief The type of the digraph the algorithm runs on.
45 45
    typedef GR Digraph;
46 46

	
47 47
    /// \brief The type of the lower bound map.
48 48
    ///
49 49
    /// The type of the map that stores the lower bounds on the arcs.
50 50
    /// It must conform to the \ref concepts::ReadMap "ReadMap" concept.
51 51
    typedef LM LowerMap;
52 52

	
53 53
    /// \brief The type of the upper bound (capacity) map.
54 54
    ///
55 55
    /// The type of the map that stores the upper bounds (capacities)
56 56
    /// on the arcs.
57 57
    /// It must conform to the \ref concepts::ReadMap "ReadMap" concept.
58 58
    typedef UM UpperMap;
59 59

	
60 60
    /// \brief The type of supply map.
61 61
    ///
62 62
    /// The type of the map that stores the signed supply values of the 
63 63
    /// nodes. 
64 64
    /// It must conform to the \ref concepts::ReadMap "ReadMap" concept.
65 65
    typedef SM SupplyMap;
66 66

	
67 67
    /// \brief The type of the flow and supply values.
68 68
    typedef typename SupplyMap::Value Value;
69 69

	
70 70
    /// \brief The type of the map that stores the flow values.
71 71
    ///
72 72
    /// The type of the map that stores the flow values.
73 73
    /// It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap"
74 74
    /// concept.
75 75
#ifdef DOXYGEN
76 76
    typedef GR::ArcMap<Value> FlowMap;
77 77
#else
78 78
    typedef typename Digraph::template ArcMap<Value> FlowMap;
79 79
#endif
80 80

	
81 81
    /// \brief Instantiates a FlowMap.
82 82
    ///
83 83
    /// This function instantiates a \ref FlowMap.
84 84
    /// \param digraph The digraph for which we would like to define
85 85
    /// the flow map.
86 86
    static FlowMap* createFlowMap(const Digraph& digraph) {
87 87
      return new FlowMap(digraph);
88 88
    }
89 89

	
90 90
    /// \brief The elevator type used by the algorithm.
91 91
    ///
92 92
    /// The elevator type used by the algorithm.
93 93
    ///
94 94
    /// \sa Elevator, LinkedElevator
95 95
#ifdef DOXYGEN
96 96
    typedef lemon::Elevator<GR, GR::Node> Elevator;
97 97
#else
98 98
    typedef lemon::Elevator<Digraph, typename Digraph::Node> Elevator;
99 99
#endif
100 100

	
101 101
    /// \brief Instantiates an Elevator.
102 102
    ///
103 103
    /// This function instantiates an \ref Elevator.
104 104
    /// \param digraph The digraph for which we would like to define
105 105
    /// the elevator.
106 106
    /// \param max_level The maximum level of the elevator.
107 107
    static Elevator* createElevator(const Digraph& digraph, int max_level) {
108 108
      return new Elevator(digraph, max_level);
109 109
    }
110 110

	
111 111
    /// \brief The tolerance used by the algorithm
112 112
    ///
113 113
    /// The tolerance used by the algorithm to handle inexact computation.
114 114
    typedef lemon::Tolerance<Value> Tolerance;
115 115

	
116 116
  };
117 117

	
118 118
  /**
119 119
     \brief Push-relabel algorithm for the network circulation problem.
120 120

	
121 121
     \ingroup max_flow
122 122
     This class implements a push-relabel algorithm for the \e network
123 123
     \e circulation problem.
124 124
     It is to find a feasible circulation when lower and upper bounds
125 125
     are given for the flow values on the arcs and lower bounds are
126 126
     given for the difference between the outgoing and incoming flow
127 127
     at the nodes.
128 128

	
129 129
     The exact formulation of this problem is the following.
130 130
     Let \f$G=(V,A)\f$ be a digraph, \f$lower: A\rightarrow\mathbf{R}\f$
131 131
     \f$upper: A\rightarrow\mathbf{R}\cup\{\infty\}\f$ denote the lower and
132 132
     upper bounds on the arcs, for which \f$lower(uv) \leq upper(uv)\f$
133 133
     holds for all \f$uv\in A\f$, and \f$sup: V\rightarrow\mathbf{R}\f$
134 134
     denotes the signed supply values of the nodes.
135 135
     If \f$sup(u)>0\f$, then \f$u\f$ is a supply node with \f$sup(u)\f$
136 136
     supply, if \f$sup(u)<0\f$, then \f$u\f$ is a demand node with
137 137
     \f$-sup(u)\f$ demand.
138 138
     A feasible circulation is an \f$f: A\rightarrow\mathbf{R}\f$
139 139
     solution of the following problem.
140 140

	
141 141
     \f[ \sum_{uv\in A} f(uv) - \sum_{vu\in A} f(vu)
142 142
     \geq sup(u) \quad \forall u\in V, \f]
143 143
     \f[ lower(uv) \leq f(uv) \leq upper(uv) \quad \forall uv\in A. \f]
144 144
     
145 145
     The sum of the supply values, i.e. \f$\sum_{u\in V} sup(u)\f$ must be
146 146
     zero or negative in order to have a feasible solution (since the sum
147 147
     of the expressions on the left-hand side of the inequalities is zero).
148 148
     It means that the total demand must be greater or equal to the total
149 149
     supply and all the supplies have to be carried out from the supply nodes,
150 150
     but there could be demands that are not satisfied.
151 151
     If \f$\sum_{u\in V} sup(u)\f$ is zero, then all the supply/demand
152 152
     constraints have to be satisfied with equality, i.e. all demands
153 153
     have to be satisfied and all supplies have to be used.
154 154
     
155 155
     If you need the opposite inequalities in the supply/demand constraints
156 156
     (i.e. the total demand is less than the total supply and all the demands
157 157
     have to be satisfied while there could be supplies that are not used),
158 158
     then you could easily transform the problem to the above form by reversing
159 159
     the direction of the arcs and taking the negative of the supply values
160 160
     (e.g. using \ref ReverseDigraph and \ref NegMap adaptors).
161 161

	
162 162
     This algorithm either calculates a feasible circulation, or provides
163 163
     a \ref barrier() "barrier", which prooves that a feasible soultion
164 164
     cannot exist.
165 165

	
166 166
     Note that this algorithm also provides a feasible solution for the
167 167
     \ref min_cost_flow "minimum cost flow problem".
168 168

	
169 169
     \tparam GR The type of the digraph the algorithm runs on.
170 170
     \tparam LM The type of the lower bound map. The default
171 171
     map type is \ref concepts::Digraph::ArcMap "GR::ArcMap<int>".
172 172
     \tparam UM The type of the upper bound (capacity) map.
173 173
     The default map type is \c LM.
174 174
     \tparam SM The type of the supply map. The default map type is
175 175
     \ref concepts::Digraph::NodeMap "GR::NodeMap<UM::Value>".
176 176
  */
177 177
#ifdef DOXYGEN
178 178
template< typename GR,
179 179
          typename LM,
180 180
          typename UM,
181 181
          typename SM,
182 182
          typename TR >
183 183
#else
184 184
template< typename GR,
185 185
          typename LM = typename GR::template ArcMap<int>,
186 186
          typename UM = LM,
187 187
          typename SM = typename GR::template NodeMap<typename UM::Value>,
188 188
          typename TR = CirculationDefaultTraits<GR, LM, UM, SM> >
189 189
#endif
190 190
  class Circulation {
191 191
  public:
192 192

	
193 193
    ///The \ref CirculationDefaultTraits "traits class" of the algorithm.
194 194
    typedef TR Traits;
195 195
    ///The type of the digraph the algorithm runs on.
196 196
    typedef typename Traits::Digraph Digraph;
197 197
    ///The type of the flow and supply values.
198 198
    typedef typename Traits::Value Value;
199 199

	
200 200
    ///The type of the lower bound map.
201 201
    typedef typename Traits::LowerMap LowerMap;
202 202
    ///The type of the upper bound (capacity) map.
203 203
    typedef typename Traits::UpperMap UpperMap;
204 204
    ///The type of the supply map.
205 205
    typedef typename Traits::SupplyMap SupplyMap;
206 206
    ///The type of the flow map.
207 207
    typedef typename Traits::FlowMap FlowMap;
208 208

	
209 209
    ///The type of the elevator.
210 210
    typedef typename Traits::Elevator Elevator;
211 211
    ///The type of the tolerance.
212 212
    typedef typename Traits::Tolerance Tolerance;
213 213

	
214 214
  private:
215 215

	
216 216
    TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
217 217

	
218 218
    const Digraph &_g;
219 219
    int _node_num;
220 220

	
221 221
    const LowerMap *_lo;
222 222
    const UpperMap *_up;
223 223
    const SupplyMap *_supply;
224 224

	
225 225
    FlowMap *_flow;
226 226
    bool _local_flow;
227 227

	
228 228
    Elevator* _level;
229 229
    bool _local_level;
230 230

	
231 231
    typedef typename Digraph::template NodeMap<Value> ExcessMap;
232 232
    ExcessMap* _excess;
233 233

	
234 234
    Tolerance _tol;
235 235
    int _el;
236 236

	
237 237
  public:
238 238

	
239 239
    typedef Circulation Create;
240 240

	
241 241
    ///\name Named Template Parameters
242 242

	
243 243
    ///@{
244 244

	
245 245
    template <typename T>
246 246
    struct SetFlowMapTraits : public Traits {
247 247
      typedef T FlowMap;
248 248
      static FlowMap *createFlowMap(const Digraph&) {
249 249
        LEMON_ASSERT(false, "FlowMap is not initialized");
250 250
        return 0; // ignore warnings
251 251
      }
252 252
    };
253 253

	
254 254
    /// \brief \ref named-templ-param "Named parameter" for setting
255 255
    /// FlowMap type
256 256
    ///
257 257
    /// \ref named-templ-param "Named parameter" for setting FlowMap
258 258
    /// type.
259 259
    template <typename T>
260 260
    struct SetFlowMap
261 261
      : public Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
262 262
                           SetFlowMapTraits<T> > {
263 263
      typedef Circulation<Digraph, LowerMap, UpperMap, SupplyMap,
264 264
                          SetFlowMapTraits<T> > Create;
265 265
    };
266 266

	
267 267
    template <typename T>
268 268
    struct SetElevatorTraits : public Traits {
269 269
      typedef T Elevator;
270 270
      static Elevator *createElevator(const Digraph&, int) {
271 271
        LEMON_ASSERT(false, "Elevator is not initialized");
272 272
        return 0; // ignore warnings
273 273
      }
274 274
    };
275 275

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

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

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

	
321 321
    /// @}
322 322

	
323 323
  protected:
324 324

	
325 325
    Circulation() {}
326 326

	
327 327
  public:
328 328

	
329 329
    /// Constructor.
330 330

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

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

	
349 349

	
350 350
  private:
351 351

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

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

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

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

	
387 387
  public:
388 388

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

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

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

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

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

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

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

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

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

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

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

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

	
483 483
    ///@{
484 484

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

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

	
494 494
      createStructures();
495 495

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

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

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

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

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

	
526 526
      createStructures();
527 527

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

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

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

	
558 558
    ///Executes the algorithm
559 559

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

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

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

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

	
646 646
    /// Runs the algorithm.
647 647

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

	
663 663
    /// @}
664 664

	
665 665
    /// \name Query Functions
666 666
    /// The results of the circulation algorithm can be obtained using
667 667
    /// these functions.\n
668 668
    /// Either \ref run() or \ref start() should be called before
669 669
    /// using them.
670 670

	
671 671
    ///@{
672 672

	
673 673
    /// \brief Returns the flow value on the given arc.
674 674
    ///
675 675
    /// Returns the flow value on the given arc.
676 676
    ///
677 677
    /// \pre Either \ref run() or \ref init() must be called before
678 678
    /// using this function.
679 679
    Value flow(const Arc& arc) const {
680 680
      return (*_flow)[arc];
681 681
    }
682 682

	
683 683
    /// \brief Returns a const reference to the flow map.
684 684
    ///
685 685
    /// Returns a const reference to the arc map storing the found flow.
686 686
    ///
687 687
    /// \pre Either \ref run() or \ref init() must be called before
688 688
    /// using this function.
689 689
    const FlowMap& flowMap() const {
690 690
      return *_flow;
691 691
    }
692 692

	
693 693
    /**
Show white space 768 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_CONCEPTS_DIGRAPH_H
20 20
#define LEMON_CONCEPTS_DIGRAPH_H
21 21

	
22 22
///\ingroup graph_concepts
23 23
///\file
24 24
///\brief The concept of directed graphs.
25 25

	
26 26
#include <lemon/core.h>
27 27
#include <lemon/concepts/maps.h>
28 28
#include <lemon/concept_check.h>
29 29
#include <lemon/concepts/graph_components.h>
30 30

	
31 31
namespace lemon {
32 32
  namespace concepts {
33 33

	
34 34
    /// \ingroup graph_concepts
35 35
    ///
36 36
    /// \brief Class describing the concept of directed graphs.
37 37
    ///
38 38
    /// This class describes the common interface of all directed
39 39
    /// graphs (digraphs).
40 40
    ///
41 41
    /// Like all concept classes, it only provides an interface
42 42
    /// without any sensible implementation. So any general algorithm for
43 43
    /// directed graphs should compile with this class, but it will not
44 44
    /// run properly, of course.
45 45
    /// An actual digraph implementation like \ref ListDigraph or
46 46
    /// \ref SmartDigraph may have additional functionality.
47 47
    ///
48 48
    /// \sa Graph
49 49
    class Digraph {
50 50
    private:
51 51
      /// Diraphs are \e not copy constructible. Use DigraphCopy instead.
52 52
      Digraph(const Digraph &) {}
53 53
      /// \brief Assignment of a digraph to another one is \e not allowed.
54 54
      /// Use DigraphCopy instead.
55 55
      void operator=(const Digraph &) {}
56 56

	
57 57
    public:
58 58
      /// Default constructor.
59 59
      Digraph() { }
60 60

	
61 61
      /// The node type of the digraph
62 62

	
63 63
      /// This class identifies a node of the digraph. It also serves
64 64
      /// as a base class of the node iterators,
65 65
      /// thus they convert to this type.
66 66
      class Node {
67 67
      public:
68 68
        /// Default constructor
69 69

	
70 70
        /// Default constructor.
71 71
        /// \warning It sets the object to an undefined value.
72 72
        Node() { }
73 73
        /// Copy constructor.
74 74

	
75 75
        /// Copy constructor.
76 76
        ///
77 77
        Node(const Node&) { }
78 78

	
79 79
        /// %Invalid constructor \& conversion.
80 80

	
81 81
        /// Initializes the object to be invalid.
82 82
        /// \sa Invalid for more details.
83 83
        Node(Invalid) { }
84 84
        /// Equality operator
85 85

	
86 86
        /// Equality operator.
87 87
        ///
88 88
        /// Two iterators are equal if and only if they point to the
89 89
        /// same object or both are \c INVALID.
90 90
        bool operator==(Node) const { return true; }
91 91

	
92 92
        /// Inequality operator
93 93

	
94 94
        /// Inequality operator.
95 95
        bool operator!=(Node) const { return true; }
96 96

	
97 97
        /// Artificial ordering operator.
98 98

	
99 99
        /// Artificial ordering operator.
100 100
        ///
101 101
        /// \note This operator only has to define some strict ordering of
102 102
        /// the nodes; this order has nothing to do with the iteration
103 103
        /// ordering of the nodes.
104 104
        bool operator<(Node) const { return false; }
105 105
      };
106 106

	
107 107
      /// Iterator class for the nodes.
108 108

	
109 109
      /// This iterator goes through each node of the digraph.
110
      /// Its usage is quite simple, for example you can count the number
110
      /// Its usage is quite simple, for example, you can count the number
111 111
      /// of nodes in a digraph \c g of type \c %Digraph like this:
112 112
      ///\code
113 113
      /// int count=0;
114 114
      /// for (Digraph::NodeIt n(g); n!=INVALID; ++n) ++count;
115 115
      ///\endcode
116 116
      class NodeIt : public Node {
117 117
      public:
118 118
        /// Default constructor
119 119

	
120 120
        /// Default constructor.
121 121
        /// \warning It sets the iterator to an undefined value.
122 122
        NodeIt() { }
123 123
        /// Copy constructor.
124 124

	
125 125
        /// Copy constructor.
126 126
        ///
127 127
        NodeIt(const NodeIt& n) : Node(n) { }
128 128
        /// %Invalid constructor \& conversion.
129 129

	
130 130
        /// Initializes the iterator to be invalid.
131 131
        /// \sa Invalid for more details.
132 132
        NodeIt(Invalid) { }
133 133
        /// Sets the iterator to the first node.
134 134

	
135 135
        /// Sets the iterator to the first node of the given digraph.
136 136
        ///
137 137
        explicit NodeIt(const Digraph&) { }
138 138
        /// Sets the iterator to the given node.
139 139

	
140 140
        /// Sets the iterator to the given node of the given digraph.
141 141
        ///
142 142
        NodeIt(const Digraph&, const Node&) { }
143 143
        /// Next node.
144 144

	
145 145
        /// Assign the iterator to the next node.
146 146
        ///
147 147
        NodeIt& operator++() { return *this; }
148 148
      };
149 149

	
150 150

	
151 151
      /// The arc type of the digraph
152 152

	
153 153
      /// This class identifies an arc of the digraph. It also serves
154 154
      /// as a base class of the arc iterators,
155 155
      /// thus they will convert to this type.
156 156
      class Arc {
157 157
      public:
158 158
        /// Default constructor
159 159

	
160 160
        /// Default constructor.
161 161
        /// \warning It sets the object to an undefined value.
162 162
        Arc() { }
163 163
        /// Copy constructor.
164 164

	
165 165
        /// Copy constructor.
166 166
        ///
167 167
        Arc(const Arc&) { }
168 168
        /// %Invalid constructor \& conversion.
169 169

	
170 170
        /// Initializes the object to be invalid.
171 171
        /// \sa Invalid for more details.
172 172
        Arc(Invalid) { }
173 173
        /// Equality operator
174 174

	
175 175
        /// Equality operator.
176 176
        ///
177 177
        /// Two iterators are equal if and only if they point to the
178 178
        /// same object or both are \c INVALID.
179 179
        bool operator==(Arc) const { return true; }
180 180
        /// Inequality operator
181 181

	
182 182
        /// Inequality operator.
183 183
        bool operator!=(Arc) const { return true; }
184 184

	
185 185
        /// Artificial ordering operator.
186 186

	
187 187
        /// Artificial ordering operator.
188 188
        ///
189 189
        /// \note This operator only has to define some strict ordering of
190 190
        /// the arcs; this order has nothing to do with the iteration
191 191
        /// ordering of the arcs.
192 192
        bool operator<(Arc) const { return false; }
193 193
      };
194 194

	
195 195
      /// Iterator class for the outgoing arcs of a node.
196 196

	
197 197
      /// This iterator goes trough the \e outgoing arcs of a certain node
198 198
      /// of a digraph.
199
      /// Its usage is quite simple, for example you can count the number
199
      /// Its usage is quite simple, for example, you can count the number
200 200
      /// of outgoing arcs of a node \c n
201 201
      /// in a digraph \c g of type \c %Digraph as follows.
202 202
      ///\code
203 203
      /// int count=0;
204 204
      /// for (Digraph::OutArcIt a(g, n); a!=INVALID; ++a) ++count;
205 205
      ///\endcode
206 206
      class OutArcIt : public Arc {
207 207
      public:
208 208
        /// Default constructor
209 209

	
210 210
        /// Default constructor.
211 211
        /// \warning It sets the iterator to an undefined value.
212 212
        OutArcIt() { }
213 213
        /// Copy constructor.
214 214

	
215 215
        /// Copy constructor.
216 216
        ///
217 217
        OutArcIt(const OutArcIt& e) : Arc(e) { }
218 218
        /// %Invalid constructor \& conversion.
219 219

	
220 220
        /// Initializes the iterator to be invalid.
221 221
        /// \sa Invalid for more details.
222 222
        OutArcIt(Invalid) { }
223 223
        /// Sets the iterator to the first outgoing arc.
224 224

	
225 225
        /// Sets the iterator to the first outgoing arc of the given node.
226 226
        ///
227 227
        OutArcIt(const Digraph&, const Node&) { }
228 228
        /// Sets the iterator to the given arc.
229 229

	
230 230
        /// Sets the iterator to the given arc of the given digraph.
231 231
        ///
232 232
        OutArcIt(const Digraph&, const Arc&) { }
233 233
        /// Next outgoing arc
234 234

	
235 235
        /// Assign the iterator to the next
236 236
        /// outgoing arc of the corresponding node.
237 237
        OutArcIt& operator++() { return *this; }
238 238
      };
239 239

	
240 240
      /// Iterator class for the incoming arcs of a node.
241 241

	
242 242
      /// This iterator goes trough the \e incoming arcs of a certain node
243 243
      /// of a digraph.
244
      /// Its usage is quite simple, for example you can count the number
244
      /// Its usage is quite simple, for example, you can count the number
245 245
      /// of incoming arcs of a node \c n
246 246
      /// in a digraph \c g of type \c %Digraph as follows.
247 247
      ///\code
248 248
      /// int count=0;
249 249
      /// for(Digraph::InArcIt a(g, n); a!=INVALID; ++a) ++count;
250 250
      ///\endcode
251 251
      class InArcIt : public Arc {
252 252
      public:
253 253
        /// Default constructor
254 254

	
255 255
        /// Default constructor.
256 256
        /// \warning It sets the iterator to an undefined value.
257 257
        InArcIt() { }
258 258
        /// Copy constructor.
259 259

	
260 260
        /// Copy constructor.
261 261
        ///
262 262
        InArcIt(const InArcIt& e) : Arc(e) { }
263 263
        /// %Invalid constructor \& conversion.
264 264

	
265 265
        /// Initializes the iterator to be invalid.
266 266
        /// \sa Invalid for more details.
267 267
        InArcIt(Invalid) { }
268 268
        /// Sets the iterator to the first incoming arc.
269 269

	
270 270
        /// Sets the iterator to the first incoming arc of the given node.
271 271
        ///
272 272
        InArcIt(const Digraph&, const Node&) { }
273 273
        /// Sets the iterator to the given arc.
274 274

	
275 275
        /// Sets the iterator to the given arc of the given digraph.
276 276
        ///
277 277
        InArcIt(const Digraph&, const Arc&) { }
278 278
        /// Next incoming arc
279 279

	
280 280
        /// Assign the iterator to the next
281 281
        /// incoming arc of the corresponding node.
282 282
        InArcIt& operator++() { return *this; }
283 283
      };
284 284

	
285 285
      /// Iterator class for the arcs.
286 286

	
287 287
      /// This iterator goes through each arc of the digraph.
288
      /// Its usage is quite simple, for example you can count the number
288
      /// Its usage is quite simple, for example, you can count the number
289 289
      /// of arcs in a digraph \c g of type \c %Digraph as follows:
290 290
      ///\code
291 291
      /// int count=0;
292 292
      /// for(Digraph::ArcIt a(g); a!=INVALID; ++a) ++count;
293 293
      ///\endcode
294 294
      class ArcIt : public Arc {
295 295
      public:
296 296
        /// Default constructor
297 297

	
298 298
        /// Default constructor.
299 299
        /// \warning It sets the iterator to an undefined value.
300 300
        ArcIt() { }
301 301
        /// Copy constructor.
302 302

	
303 303
        /// Copy constructor.
304 304
        ///
305 305
        ArcIt(const ArcIt& e) : Arc(e) { }
306 306
        /// %Invalid constructor \& conversion.
307 307

	
308 308
        /// Initializes the iterator to be invalid.
309 309
        /// \sa Invalid for more details.
310 310
        ArcIt(Invalid) { }
311 311
        /// Sets the iterator to the first arc.
312 312

	
313 313
        /// Sets the iterator to the first arc of the given digraph.
314 314
        ///
315 315
        explicit ArcIt(const Digraph& g) { ignore_unused_variable_warning(g); }
316 316
        /// Sets the iterator to the given arc.
317 317

	
318 318
        /// Sets the iterator to the given arc of the given digraph.
319 319
        ///
320 320
        ArcIt(const Digraph&, const Arc&) { }
321 321
        /// Next arc
322 322

	
323 323
        /// Assign the iterator to the next arc.
324 324
        ///
325 325
        ArcIt& operator++() { return *this; }
326 326
      };
327 327

	
328 328
      /// \brief The source node of the arc.
329 329
      ///
330 330
      /// Returns the source node of the given arc.
331 331
      Node source(Arc) const { return INVALID; }
332 332

	
333 333
      /// \brief The target node of the arc.
334 334
      ///
335 335
      /// Returns the target node of the given arc.
336 336
      Node target(Arc) const { return INVALID; }
337 337

	
338 338
      /// \brief The ID of the node.
339 339
      ///
340 340
      /// Returns the ID of the given node.
341 341
      int id(Node) const { return -1; }
342 342

	
343 343
      /// \brief The ID of the arc.
344 344
      ///
345 345
      /// Returns the ID of the given arc.
346 346
      int id(Arc) const { return -1; }
347 347

	
348 348
      /// \brief The node with the given ID.
349 349
      ///
350 350
      /// Returns the node with the given ID.
351 351
      /// \pre The argument should be a valid node ID in the digraph.
352 352
      Node nodeFromId(int) const { return INVALID; }
353 353

	
354 354
      /// \brief The arc with the given ID.
355 355
      ///
356 356
      /// Returns the arc with the given ID.
357 357
      /// \pre The argument should be a valid arc ID in the digraph.
358 358
      Arc arcFromId(int) const { return INVALID; }
359 359

	
360 360
      /// \brief An upper bound on the node IDs.
361 361
      ///
362 362
      /// Returns an upper bound on the node IDs.
363 363
      int maxNodeId() const { return -1; }
364 364

	
365 365
      /// \brief An upper bound on the arc IDs.
366 366
      ///
367 367
      /// Returns an upper bound on the arc IDs.
368 368
      int maxArcId() const { return -1; }
369 369

	
370 370
      void first(Node&) const {}
371 371
      void next(Node&) const {}
372 372

	
373 373
      void first(Arc&) const {}
374 374
      void next(Arc&) const {}
375 375

	
376 376

	
377 377
      void firstIn(Arc&, const Node&) const {}
378 378
      void nextIn(Arc&) const {}
379 379

	
380 380
      void firstOut(Arc&, const Node&) const {}
381 381
      void nextOut(Arc&) const {}
382 382

	
383 383
      // The second parameter is dummy.
384 384
      Node fromId(int, Node) const { return INVALID; }
385 385
      // The second parameter is dummy.
386 386
      Arc fromId(int, Arc) const { return INVALID; }
387 387

	
388 388
      // Dummy parameter.
389 389
      int maxId(Node) const { return -1; }
390 390
      // Dummy parameter.
391 391
      int maxId(Arc) const { return -1; }
392 392

	
393 393
      /// \brief The opposite node on the arc.
394 394
      ///
395 395
      /// Returns the opposite node on the given arc.
396 396
      Node oppositeNode(Node, Arc) const { return INVALID; }
397 397

	
398 398
      /// \brief The base node of the iterator.
399 399
      ///
400 400
      /// Returns the base node of the given outgoing arc iterator
401 401
      /// (i.e. the source node of the corresponding arc).
402 402
      Node baseNode(OutArcIt) const { return INVALID; }
403 403

	
404 404
      /// \brief The running node of the iterator.
405 405
      ///
406 406
      /// Returns the running node of the given outgoing arc iterator
407 407
      /// (i.e. the target node of the corresponding arc).
408 408
      Node runningNode(OutArcIt) const { return INVALID; }
409 409

	
410 410
      /// \brief The base node of the iterator.
411 411
      ///
412 412
      /// Returns the base node of the given incomming arc iterator
413 413
      /// (i.e. the target node of the corresponding arc).
414 414
      Node baseNode(InArcIt) const { return INVALID; }
415 415

	
416 416
      /// \brief The running node of the iterator.
417 417
      ///
418 418
      /// Returns the running node of the given incomming arc iterator
419 419
      /// (i.e. the source node of the corresponding arc).
420 420
      Node runningNode(InArcIt) const { return INVALID; }
421 421

	
422 422
      /// \brief Standard graph map type for the nodes.
423 423
      ///
424 424
      /// Standard graph map type for the nodes.
425 425
      /// It conforms to the ReferenceMap concept.
426 426
      template<class T>
427 427
      class NodeMap : public ReferenceMap<Node, T, T&, const T&> {
428 428
      public:
429 429

	
430 430
        /// Constructor
431 431
        explicit NodeMap(const Digraph&) { }
432 432
        /// Constructor with given initial value
433 433
        NodeMap(const Digraph&, T) { }
434 434

	
435 435
      private:
436 436
        ///Copy constructor
437 437
        NodeMap(const NodeMap& nm) : 
438 438
          ReferenceMap<Node, T, T&, const T&>(nm) { }
439 439
        ///Assignment operator
440 440
        template <typename CMap>
441 441
        NodeMap& operator=(const CMap&) {
442 442
          checkConcept<ReadMap<Node, T>, CMap>();
443 443
          return *this;
444 444
        }
445 445
      };
446 446

	
447 447
      /// \brief Standard graph map type for the arcs.
448 448
      ///
449 449
      /// Standard graph map type for the arcs.
450 450
      /// It conforms to the ReferenceMap concept.
451 451
      template<class T>
452 452
      class ArcMap : public ReferenceMap<Arc, T, T&, const T&> {
453 453
      public:
454 454

	
455 455
        /// Constructor
456 456
        explicit ArcMap(const Digraph&) { }
457 457
        /// Constructor with given initial value
458 458
        ArcMap(const Digraph&, T) { }
459 459

	
460 460
      private:
461 461
        ///Copy constructor
462 462
        ArcMap(const ArcMap& em) :
463 463
          ReferenceMap<Arc, T, T&, const T&>(em) { }
464 464
        ///Assignment operator
465 465
        template <typename CMap>
466 466
        ArcMap& operator=(const CMap&) {
467 467
          checkConcept<ReadMap<Arc, T>, CMap>();
468 468
          return *this;
469 469
        }
470 470
      };
471 471

	
472 472
      template <typename _Digraph>
473 473
      struct Constraints {
474 474
        void constraints() {
475 475
          checkConcept<BaseDigraphComponent, _Digraph>();
476 476
          checkConcept<IterableDigraphComponent<>, _Digraph>();
477 477
          checkConcept<IDableDigraphComponent<>, _Digraph>();
478 478
          checkConcept<MappableDigraphComponent<>, _Digraph>();
479 479
        }
480 480
      };
481 481

	
482 482
    };
483 483

	
484 484
  } //namespace concepts
485 485
} //namespace lemon
486 486

	
487 487

	
488 488

	
489 489
#endif
Show white space 768 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
///\ingroup graph_concepts
20 20
///\file
21 21
///\brief The concept of undirected graphs.
22 22

	
23 23
#ifndef LEMON_CONCEPTS_GRAPH_H
24 24
#define LEMON_CONCEPTS_GRAPH_H
25 25

	
26 26
#include <lemon/concepts/graph_components.h>
27 27
#include <lemon/concepts/maps.h>
28 28
#include <lemon/concept_check.h>
29 29
#include <lemon/core.h>
30 30

	
31 31
namespace lemon {
32 32
  namespace concepts {
33 33

	
34 34
    /// \ingroup graph_concepts
35 35
    ///
36 36
    /// \brief Class describing the concept of undirected graphs.
37 37
    ///
38 38
    /// This class describes the common interface of all undirected
39 39
    /// graphs.
40 40
    ///
41 41
    /// Like all concept classes, it only provides an interface
42 42
    /// without any sensible implementation. So any general algorithm for
43 43
    /// undirected graphs should compile with this class, but it will not
44 44
    /// run properly, of course.
45 45
    /// An actual graph implementation like \ref ListGraph or
46 46
    /// \ref SmartGraph may have additional functionality.    
47 47
    ///
48 48
    /// The undirected graphs also fulfill the concept of \ref Digraph
49 49
    /// "directed graphs", since each edge can also be regarded as two
50 50
    /// oppositely directed arcs.
51 51
    /// Undirected graphs provide an Edge type for the undirected edges and
52 52
    /// an Arc type for the directed arcs. The Arc type is convertible to
53 53
    /// Edge or inherited from it, i.e. the corresponding edge can be
54 54
    /// obtained from an arc.
55 55
    /// EdgeIt and EdgeMap classes can be used for the edges, while ArcIt
56 56
    /// and ArcMap classes can be used for the arcs (just like in digraphs).
57 57
    /// Both InArcIt and OutArcIt iterates on the same edges but with
58 58
    /// opposite direction. IncEdgeIt also iterates on the same edges
59 59
    /// as OutArcIt and InArcIt, but it is not convertible to Arc,
60 60
    /// only to Edge.
61 61
    ///
62 62
    /// In LEMON, each undirected edge has an inherent orientation.
63 63
    /// Thus it can defined if an arc is forward or backward oriented in
64 64
    /// an undirected graph with respect to this default oriantation of
65 65
    /// the represented edge.
66 66
    /// With the direction() and direct() functions the direction
67 67
    /// of an arc can be obtained and set, respectively.
68 68
    ///
69 69
    /// Only nodes and edges can be added to or removed from an undirected
70 70
    /// graph and the corresponding arcs are added or removed automatically.
71 71
    ///
72 72
    /// \sa Digraph
73 73
    class Graph {
74 74
    private:
75 75
      /// Graphs are \e not copy constructible. Use DigraphCopy instead.
76 76
      Graph(const Graph&) {}
77 77
      /// \brief Assignment of a graph to another one is \e not allowed.
78 78
      /// Use DigraphCopy instead.
79 79
      void operator=(const Graph&) {}
80 80

	
81 81
    public:
82 82
      /// Default constructor.
83 83
      Graph() {}
84 84

	
85 85
      /// \brief Undirected graphs should be tagged with \c UndirectedTag.
86 86
      ///
87 87
      /// Undirected graphs should be tagged with \c UndirectedTag.
88 88
      /// 
89 89
      /// This tag helps the \c enable_if technics to make compile time
90 90
      /// specializations for undirected graphs.
91 91
      typedef True UndirectedTag;
92 92

	
93 93
      /// The node type of the graph
94 94

	
95 95
      /// This class identifies a node of the graph. It also serves
96 96
      /// as a base class of the node iterators,
97 97
      /// thus they convert to this type.
98 98
      class Node {
99 99
      public:
100 100
        /// Default constructor
101 101

	
102 102
        /// Default constructor.
103 103
        /// \warning It sets the object to an undefined value.
104 104
        Node() { }
105 105
        /// Copy constructor.
106 106

	
107 107
        /// Copy constructor.
108 108
        ///
109 109
        Node(const Node&) { }
110 110

	
111 111
        /// %Invalid constructor \& conversion.
112 112

	
113 113
        /// Initializes the object to be invalid.
114 114
        /// \sa Invalid for more details.
115 115
        Node(Invalid) { }
116 116
        /// Equality operator
117 117

	
118 118
        /// Equality operator.
119 119
        ///
120 120
        /// Two iterators are equal if and only if they point to the
121 121
        /// same object or both are \c INVALID.
122 122
        bool operator==(Node) const { return true; }
123 123

	
124 124
        /// Inequality operator
125 125

	
126 126
        /// Inequality operator.
127 127
        bool operator!=(Node) const { return true; }
128 128

	
129 129
        /// Artificial ordering operator.
130 130

	
131 131
        /// Artificial ordering operator.
132 132
        ///
133 133
        /// \note This operator only has to define some strict ordering of
134 134
        /// the items; this order has nothing to do with the iteration
135 135
        /// ordering of the items.
136 136
        bool operator<(Node) const { return false; }
137 137

	
138 138
      };
139 139

	
140 140
      /// Iterator class for the nodes.
141 141

	
142 142
      /// This iterator goes through each node of the graph.
143
      /// Its usage is quite simple, for example you can count the number
143
      /// Its usage is quite simple, for example, you can count the number
144 144
      /// of nodes in a graph \c g of type \c %Graph like this:
145 145
      ///\code
146 146
      /// int count=0;
147 147
      /// for (Graph::NodeIt n(g); n!=INVALID; ++n) ++count;
148 148
      ///\endcode
149 149
      class NodeIt : public Node {
150 150
      public:
151 151
        /// Default constructor
152 152

	
153 153
        /// Default constructor.
154 154
        /// \warning It sets the iterator to an undefined value.
155 155
        NodeIt() { }
156 156
        /// Copy constructor.
157 157

	
158 158
        /// Copy constructor.
159 159
        ///
160 160
        NodeIt(const NodeIt& n) : Node(n) { }
161 161
        /// %Invalid constructor \& conversion.
162 162

	
163 163
        /// Initializes the iterator to be invalid.
164 164
        /// \sa Invalid for more details.
165 165
        NodeIt(Invalid) { }
166 166
        /// Sets the iterator to the first node.
167 167

	
168 168
        /// Sets the iterator to the first node of the given digraph.
169 169
        ///
170 170
        explicit NodeIt(const Graph&) { }
171 171
        /// Sets the iterator to the given node.
172 172

	
173 173
        /// Sets the iterator to the given node of the given digraph.
174 174
        ///
175 175
        NodeIt(const Graph&, const Node&) { }
176 176
        /// Next node.
177 177

	
178 178
        /// Assign the iterator to the next node.
179 179
        ///
180 180
        NodeIt& operator++() { return *this; }
181 181
      };
182 182

	
183 183

	
184 184
      /// The edge type of the graph
185 185

	
186 186
      /// This class identifies an edge of the graph. It also serves
187 187
      /// as a base class of the edge iterators,
188 188
      /// thus they will convert to this type.
189 189
      class Edge {
190 190
      public:
191 191
        /// Default constructor
192 192

	
193 193
        /// Default constructor.
194 194
        /// \warning It sets the object to an undefined value.
195 195
        Edge() { }
196 196
        /// Copy constructor.
197 197

	
198 198
        /// Copy constructor.
199 199
        ///
200 200
        Edge(const Edge&) { }
201 201
        /// %Invalid constructor \& conversion.
202 202

	
203 203
        /// Initializes the object to be invalid.
204 204
        /// \sa Invalid for more details.
205 205
        Edge(Invalid) { }
206 206
        /// Equality operator
207 207

	
208 208
        /// Equality operator.
209 209
        ///
210 210
        /// Two iterators are equal if and only if they point to the
211 211
        /// same object or both are \c INVALID.
212 212
        bool operator==(Edge) const { return true; }
213 213
        /// Inequality operator
214 214

	
215 215
        /// Inequality operator.
216 216
        bool operator!=(Edge) const { return true; }
217 217

	
218 218
        /// Artificial ordering operator.
219 219

	
220 220
        /// Artificial ordering operator.
221 221
        ///
222 222
        /// \note This operator only has to define some strict ordering of
223 223
        /// the edges; this order has nothing to do with the iteration
224 224
        /// ordering of the edges.
225 225
        bool operator<(Edge) const { return false; }
226 226
      };
227 227

	
228 228
      /// Iterator class for the edges.
229 229

	
230 230
      /// This iterator goes through each edge of the graph.
231
      /// Its usage is quite simple, for example you can count the number
231
      /// Its usage is quite simple, for example, you can count the number
232 232
      /// of edges in a graph \c g of type \c %Graph as follows:
233 233
      ///\code
234 234
      /// int count=0;
235 235
      /// for(Graph::EdgeIt e(g); e!=INVALID; ++e) ++count;
236 236
      ///\endcode
237 237
      class EdgeIt : public Edge {
238 238
      public:
239 239
        /// Default constructor
240 240

	
241 241
        /// Default constructor.
242 242
        /// \warning It sets the iterator to an undefined value.
243 243
        EdgeIt() { }
244 244
        /// Copy constructor.
245 245

	
246 246
        /// Copy constructor.
247 247
        ///
248 248
        EdgeIt(const EdgeIt& e) : Edge(e) { }
249 249
        /// %Invalid constructor \& conversion.
250 250

	
251 251
        /// Initializes the iterator to be invalid.
252 252
        /// \sa Invalid for more details.
253 253
        EdgeIt(Invalid) { }
254 254
        /// Sets the iterator to the first edge.
255 255

	
256 256
        /// Sets the iterator to the first edge of the given graph.
257 257
        ///
258 258
        explicit EdgeIt(const Graph&) { }
259 259
        /// Sets the iterator to the given edge.
260 260

	
261 261
        /// Sets the iterator to the given edge of the given graph.
262 262
        ///
263 263
        EdgeIt(const Graph&, const Edge&) { }
264 264
        /// Next edge
265 265

	
266 266
        /// Assign the iterator to the next edge.
267 267
        ///
268 268
        EdgeIt& operator++() { return *this; }
269 269
      };
270 270

	
271 271
      /// Iterator class for the incident edges of a node.
272 272

	
273 273
      /// This iterator goes trough the incident undirected edges
274 274
      /// of a certain node of a graph.
275
      /// Its usage is quite simple, for example you can compute the
275
      /// Its usage is quite simple, for example, you can compute the
276 276
      /// degree (i.e. the number of incident edges) of a node \c n
277 277
      /// in a graph \c g of type \c %Graph as follows.
278 278
      ///
279 279
      ///\code
280 280
      /// int count=0;
281 281
      /// for(Graph::IncEdgeIt e(g, n); e!=INVALID; ++e) ++count;
282 282
      ///\endcode
283 283
      ///
284 284
      /// \warning Loop edges will be iterated twice.
285 285
      class IncEdgeIt : public Edge {
286 286
      public:
287 287
        /// Default constructor
288 288

	
289 289
        /// Default constructor.
290 290
        /// \warning It sets the iterator to an undefined value.
291 291
        IncEdgeIt() { }
292 292
        /// Copy constructor.
293 293

	
294 294
        /// Copy constructor.
295 295
        ///
296 296
        IncEdgeIt(const IncEdgeIt& e) : Edge(e) { }
297 297
        /// %Invalid constructor \& conversion.
298 298

	
299 299
        /// Initializes the iterator to be invalid.
300 300
        /// \sa Invalid for more details.
301 301
        IncEdgeIt(Invalid) { }
302 302
        /// Sets the iterator to the first incident edge.
303 303

	
304 304
        /// Sets the iterator to the first incident edge of the given node.
305 305
        ///
306 306
        IncEdgeIt(const Graph&, const Node&) { }
307 307
        /// Sets the iterator to the given edge.
308 308

	
309 309
        /// Sets the iterator to the given edge of the given graph.
310 310
        ///
311 311
        IncEdgeIt(const Graph&, const Edge&) { }
312 312
        /// Next incident edge
313 313

	
314 314
        /// Assign the iterator to the next incident edge
315 315
        /// of the corresponding node.
316 316
        IncEdgeIt& operator++() { return *this; }
317 317
      };
318 318

	
319 319
      /// The arc type of the graph
320 320

	
321 321
      /// This class identifies a directed arc of the graph. It also serves
322 322
      /// as a base class of the arc iterators,
323 323
      /// thus they will convert to this type.
324 324
      class Arc {
325 325
      public:
326 326
        /// Default constructor
327 327

	
328 328
        /// Default constructor.
329 329
        /// \warning It sets the object to an undefined value.
330 330
        Arc() { }
331 331
        /// Copy constructor.
332 332

	
333 333
        /// Copy constructor.
334 334
        ///
335 335
        Arc(const Arc&) { }
336 336
        /// %Invalid constructor \& conversion.
337 337

	
338 338
        /// Initializes the object to be invalid.
339 339
        /// \sa Invalid for more details.
340 340
        Arc(Invalid) { }
341 341
        /// Equality operator
342 342

	
343 343
        /// Equality operator.
344 344
        ///
345 345
        /// Two iterators are equal if and only if they point to the
346 346
        /// same object or both are \c INVALID.
347 347
        bool operator==(Arc) const { return true; }
348 348
        /// Inequality operator
349 349

	
350 350
        /// Inequality operator.
351 351
        bool operator!=(Arc) const { return true; }
352 352

	
353 353
        /// Artificial ordering operator.
354 354

	
355 355
        /// Artificial ordering operator.
356 356
        ///
357 357
        /// \note This operator only has to define some strict ordering of
358 358
        /// the arcs; this order has nothing to do with the iteration
359 359
        /// ordering of the arcs.
360 360
        bool operator<(Arc) const { return false; }
361 361

	
362 362
        /// Converison to \c Edge
363 363
        
364 364
        /// Converison to \c Edge.
365 365
        ///
366 366
        operator Edge() const { return Edge(); }
367 367
      };
368 368

	
369 369
      /// Iterator class for the arcs.
370 370

	
371 371
      /// This iterator goes through each directed arc of the graph.
372
      /// Its usage is quite simple, for example you can count the number
372
      /// Its usage is quite simple, for example, you can count the number
373 373
      /// of arcs in a graph \c g of type \c %Graph as follows:
374 374
      ///\code
375 375
      /// int count=0;
376 376
      /// for(Graph::ArcIt a(g); a!=INVALID; ++a) ++count;
377 377
      ///\endcode
378 378
      class ArcIt : public Arc {
379 379
      public:
380 380
        /// Default constructor
381 381

	
382 382
        /// Default constructor.
383 383
        /// \warning It sets the iterator to an undefined value.
384 384
        ArcIt() { }
385 385
        /// Copy constructor.
386 386

	
387 387
        /// Copy constructor.
388 388
        ///
389 389
        ArcIt(const ArcIt& e) : Arc(e) { }
390 390
        /// %Invalid constructor \& conversion.
391 391

	
392 392
        /// Initializes the iterator to be invalid.
393 393
        /// \sa Invalid for more details.
394 394
        ArcIt(Invalid) { }
395 395
        /// Sets the iterator to the first arc.
396 396

	
397 397
        /// Sets the iterator to the first arc of the given graph.
398 398
        ///
399 399
        explicit ArcIt(const Graph &g) { ignore_unused_variable_warning(g); }
400 400
        /// Sets the iterator to the given arc.
401 401

	
402 402
        /// Sets the iterator to the given arc of the given graph.
403 403
        ///
404 404
        ArcIt(const Graph&, const Arc&) { }
405 405
        /// Next arc
406 406

	
407 407
        /// Assign the iterator to the next arc.
408 408
        ///
409 409
        ArcIt& operator++() { return *this; }
410 410
      };
411 411

	
412 412
      /// Iterator class for the outgoing arcs of a node.
413 413

	
414 414
      /// This iterator goes trough the \e outgoing directed arcs of a
415 415
      /// certain node of a graph.
416
      /// Its usage is quite simple, for example you can count the number
416
      /// Its usage is quite simple, for example, you can count the number
417 417
      /// of outgoing arcs of a node \c n
418 418
      /// in a graph \c g of type \c %Graph as follows.
419 419
      ///\code
420 420
      /// int count=0;
421 421
      /// for (Digraph::OutArcIt a(g, n); a!=INVALID; ++a) ++count;
422 422
      ///\endcode
423 423
      class OutArcIt : public Arc {
424 424
      public:
425 425
        /// Default constructor
426 426

	
427 427
        /// Default constructor.
428 428
        /// \warning It sets the iterator to an undefined value.
429 429
        OutArcIt() { }
430 430
        /// Copy constructor.
431 431

	
432 432
        /// Copy constructor.
433 433
        ///
434 434
        OutArcIt(const OutArcIt& e) : Arc(e) { }
435 435
        /// %Invalid constructor \& conversion.
436 436

	
437 437
        /// Initializes the iterator to be invalid.
438 438
        /// \sa Invalid for more details.
439 439
        OutArcIt(Invalid) { }
440 440
        /// Sets the iterator to the first outgoing arc.
441 441

	
442 442
        /// Sets the iterator to the first outgoing arc of the given node.
443 443
        ///
444 444
        OutArcIt(const Graph& n, const Node& g) {
445 445
          ignore_unused_variable_warning(n);
446 446
          ignore_unused_variable_warning(g);
447 447
        }
448 448
        /// Sets the iterator to the given arc.
449 449

	
450 450
        /// Sets the iterator to the given arc of the given graph.
451 451
        ///
452 452
        OutArcIt(const Graph&, const Arc&) { }
453 453
        /// Next outgoing arc
454 454

	
455 455
        /// Assign the iterator to the next
456 456
        /// outgoing arc of the corresponding node.
457 457
        OutArcIt& operator++() { return *this; }
458 458
      };
459 459

	
460 460
      /// Iterator class for the incoming arcs of a node.
461 461

	
462 462
      /// This iterator goes trough the \e incoming directed arcs of a
463 463
      /// certain node of a graph.
464
      /// Its usage is quite simple, for example you can count the number
464
      /// Its usage is quite simple, for example, you can count the number
465 465
      /// of incoming arcs of a node \c n
466 466
      /// in a graph \c g of type \c %Graph as follows.
467 467
      ///\code
468 468
      /// int count=0;
469 469
      /// for (Digraph::InArcIt a(g, n); a!=INVALID; ++a) ++count;
470 470
      ///\endcode
471 471
      class InArcIt : public Arc {
472 472
      public:
473 473
        /// Default constructor
474 474

	
475 475
        /// Default constructor.
476 476
        /// \warning It sets the iterator to an undefined value.
477 477
        InArcIt() { }
478 478
        /// Copy constructor.
479 479

	
480 480
        /// Copy constructor.
481 481
        ///
482 482
        InArcIt(const InArcIt& e) : Arc(e) { }
483 483
        /// %Invalid constructor \& conversion.
484 484

	
485 485
        /// Initializes the iterator to be invalid.
486 486
        /// \sa Invalid for more details.
487 487
        InArcIt(Invalid) { }
488 488
        /// Sets the iterator to the first incoming arc.
489 489

	
490 490
        /// Sets the iterator to the first incoming arc of the given node.
491 491
        ///
492 492
        InArcIt(const Graph& g, const Node& n) {
493 493
          ignore_unused_variable_warning(n);
494 494
          ignore_unused_variable_warning(g);
495 495
        }
496 496
        /// Sets the iterator to the given arc.
497 497

	
498 498
        /// Sets the iterator to the given arc of the given graph.
499 499
        ///
500 500
        InArcIt(const Graph&, const Arc&) { }
501 501
        /// Next incoming arc
502 502

	
503 503
        /// Assign the iterator to the next
504 504
        /// incoming arc of the corresponding node.
505 505
        InArcIt& operator++() { return *this; }
506 506
      };
507 507

	
508 508
      /// \brief Standard graph map type for the nodes.
509 509
      ///
510 510
      /// Standard graph map type for the nodes.
511 511
      /// It conforms to the ReferenceMap concept.
512 512
      template<class T>
513 513
      class NodeMap : public ReferenceMap<Node, T, T&, const T&>
514 514
      {
515 515
      public:
516 516

	
517 517
        /// Constructor
518 518
        explicit NodeMap(const Graph&) { }
519 519
        /// Constructor with given initial value
520 520
        NodeMap(const Graph&, T) { }
521 521

	
522 522
      private:
523 523
        ///Copy constructor
524 524
        NodeMap(const NodeMap& nm) :
525 525
          ReferenceMap<Node, T, T&, const T&>(nm) { }
526 526
        ///Assignment operator
527 527
        template <typename CMap>
528 528
        NodeMap& operator=(const CMap&) {
529 529
          checkConcept<ReadMap<Node, T>, CMap>();
530 530
          return *this;
531 531
        }
532 532
      };
533 533

	
534 534
      /// \brief Standard graph map type for the arcs.
535 535
      ///
536 536
      /// Standard graph map type for the arcs.
537 537
      /// It conforms to the ReferenceMap concept.
538 538
      template<class T>
539 539
      class ArcMap : public ReferenceMap<Arc, T, T&, const T&>
540 540
      {
541 541
      public:
542 542

	
543 543
        /// Constructor
544 544
        explicit ArcMap(const Graph&) { }
545 545
        /// Constructor with given initial value
546 546
        ArcMap(const Graph&, T) { }
547 547

	
548 548
      private:
549 549
        ///Copy constructor
550 550
        ArcMap(const ArcMap& em) :
551 551
          ReferenceMap<Arc, T, T&, const T&>(em) { }
552 552
        ///Assignment operator
553 553
        template <typename CMap>
554 554
        ArcMap& operator=(const CMap&) {
555 555
          checkConcept<ReadMap<Arc, T>, CMap>();
556 556
          return *this;
557 557
        }
558 558
      };
559 559

	
560 560
      /// \brief Standard graph map type for the edges.
561 561
      ///
562 562
      /// Standard graph map type for the edges.
563 563
      /// It conforms to the ReferenceMap concept.
564 564
      template<class T>
565 565
      class EdgeMap : public ReferenceMap<Edge, T, T&, const T&>
566 566
      {
567 567
      public:
568 568

	
569 569
        /// Constructor
570 570
        explicit EdgeMap(const Graph&) { }
571 571
        /// Constructor with given initial value
572 572
        EdgeMap(const Graph&, T) { }
573 573

	
574 574
      private:
575 575
        ///Copy constructor
576 576
        EdgeMap(const EdgeMap& em) :
577 577
          ReferenceMap<Edge, T, T&, const T&>(em) {}
578 578
        ///Assignment operator
579 579
        template <typename CMap>
580 580
        EdgeMap& operator=(const CMap&) {
581 581
          checkConcept<ReadMap<Edge, T>, CMap>();
582 582
          return *this;
583 583
        }
584 584
      };
585 585

	
586 586
      /// \brief The first node of the edge.
587 587
      ///
588 588
      /// Returns the first node of the given edge.
589 589
      ///
590
      /// Edges don't have source and target nodes, however methods
590
      /// Edges don't have source and target nodes, however, methods
591 591
      /// u() and v() are used to query the two end-nodes of an edge.
592 592
      /// The orientation of an edge that arises this way is called
593 593
      /// the inherent direction, it is used to define the default
594 594
      /// direction for the corresponding arcs.
595 595
      /// \sa v()
596 596
      /// \sa direction()
597 597
      Node u(Edge) const { return INVALID; }
598 598

	
599 599
      /// \brief The second node of the edge.
600 600
      ///
601 601
      /// Returns the second node of the given edge.
602 602
      ///
603
      /// Edges don't have source and target nodes, however methods
603
      /// Edges don't have source and target nodes, however, methods
604 604
      /// u() and v() are used to query the two end-nodes of an edge.
605 605
      /// The orientation of an edge that arises this way is called
606 606
      /// the inherent direction, it is used to define the default
607 607
      /// direction for the corresponding arcs.
608 608
      /// \sa u()
609 609
      /// \sa direction()
610 610
      Node v(Edge) const { return INVALID; }
611 611

	
612 612
      /// \brief The source node of the arc.
613 613
      ///
614 614
      /// Returns the source node of the given arc.
615 615
      Node source(Arc) const { return INVALID; }
616 616

	
617 617
      /// \brief The target node of the arc.
618 618
      ///
619 619
      /// Returns the target node of the given arc.
620 620
      Node target(Arc) const { return INVALID; }
621 621

	
622 622
      /// \brief The ID of the node.
623 623
      ///
624 624
      /// Returns the ID of the given node.
625 625
      int id(Node) const { return -1; }
626 626

	
627 627
      /// \brief The ID of the edge.
628 628
      ///
629 629
      /// Returns the ID of the given edge.
630 630
      int id(Edge) const { return -1; }
631 631

	
632 632
      /// \brief The ID of the arc.
633 633
      ///
634 634
      /// Returns the ID of the given arc.
635 635
      int id(Arc) const { return -1; }
636 636

	
637 637
      /// \brief The node with the given ID.
638 638
      ///
639 639
      /// Returns the node with the given ID.
640 640
      /// \pre The argument should be a valid node ID in the graph.
641 641
      Node nodeFromId(int) const { return INVALID; }
642 642

	
643 643
      /// \brief The edge with the given ID.
644 644
      ///
645 645
      /// Returns the edge with the given ID.
646 646
      /// \pre The argument should be a valid edge ID in the graph.
647 647
      Edge edgeFromId(int) const { return INVALID; }
648 648

	
649 649
      /// \brief The arc with the given ID.
650 650
      ///
651 651
      /// Returns the arc with the given ID.
652 652
      /// \pre The argument should be a valid arc ID in the graph.
653 653
      Arc arcFromId(int) const { return INVALID; }
654 654

	
655 655
      /// \brief An upper bound on the node IDs.
656 656
      ///
657 657
      /// Returns an upper bound on the node IDs.
658 658
      int maxNodeId() const { return -1; }
659 659

	
660 660
      /// \brief An upper bound on the edge IDs.
661 661
      ///
662 662
      /// Returns an upper bound on the edge IDs.
663 663
      int maxEdgeId() const { return -1; }
664 664

	
665 665
      /// \brief An upper bound on the arc IDs.
666 666
      ///
667 667
      /// Returns an upper bound on the arc IDs.
668 668
      int maxArcId() const { return -1; }
669 669

	
670 670
      /// \brief The direction of the arc.
671 671
      ///
672 672
      /// Returns \c true if the direction of the given arc is the same as
673 673
      /// the inherent orientation of the represented edge.
674 674
      bool direction(Arc) const { return true; }
675 675

	
676 676
      /// \brief Direct the edge.
677 677
      ///
678 678
      /// Direct the given edge. The returned arc
679 679
      /// represents the given edge and its direction comes
680 680
      /// from the bool parameter. If it is \c true, then the direction
681 681
      /// of the arc is the same as the inherent orientation of the edge.
682 682
      Arc direct(Edge, bool) const {
683 683
        return INVALID;
684 684
      }
685 685

	
686 686
      /// \brief Direct the edge.
687 687
      ///
688 688
      /// Direct the given edge. The returned arc represents the given
689 689
      /// edge and its source node is the given node.
690 690
      Arc direct(Edge, Node) const {
691 691
        return INVALID;
692 692
      }
693 693

	
694 694
      /// \brief The oppositely directed arc.
695 695
      ///
696 696
      /// Returns the oppositely directed arc representing the same edge.
697 697
      Arc oppositeArc(Arc) const { return INVALID; }
698 698

	
699 699
      /// \brief The opposite node on the edge.
700 700
      ///
701 701
      /// Returns the opposite node on the given edge.
702 702
      Node oppositeNode(Node, Edge) const { return INVALID; }
703 703

	
704 704
      void first(Node&) const {}
705 705
      void next(Node&) const {}
706 706

	
707 707
      void first(Edge&) const {}
708 708
      void next(Edge&) const {}
709 709

	
710 710
      void first(Arc&) const {}
711 711
      void next(Arc&) const {}
712 712

	
713 713
      void firstOut(Arc&, Node) const {}
714 714
      void nextOut(Arc&) const {}
715 715

	
716 716
      void firstIn(Arc&, Node) const {}
717 717
      void nextIn(Arc&) const {}
718 718

	
719 719
      void firstInc(Edge &, bool &, const Node &) const {}
720 720
      void nextInc(Edge &, bool &) const {}
721 721

	
722 722
      // The second parameter is dummy.
723 723
      Node fromId(int, Node) const { return INVALID; }
724 724
      // The second parameter is dummy.
725 725
      Edge fromId(int, Edge) const { return INVALID; }
726 726
      // The second parameter is dummy.
727 727
      Arc fromId(int, Arc) const { return INVALID; }
728 728

	
729 729
      // Dummy parameter.
730 730
      int maxId(Node) const { return -1; }
731 731
      // Dummy parameter.
732 732
      int maxId(Edge) const { return -1; }
733 733
      // Dummy parameter.
734 734
      int maxId(Arc) const { return -1; }
735 735

	
736 736
      /// \brief The base node of the iterator.
737 737
      ///
738 738
      /// Returns the base node of the given incident edge iterator.
739 739
      Node baseNode(IncEdgeIt) const { return INVALID; }
740 740

	
741 741
      /// \brief The running node of the iterator.
742 742
      ///
743 743
      /// Returns the running node of the given incident edge iterator.
744 744
      Node runningNode(IncEdgeIt) const { return INVALID; }
745 745

	
746 746
      /// \brief The base node of the iterator.
747 747
      ///
748 748
      /// Returns the base node of the given outgoing arc iterator
749 749
      /// (i.e. the source node of the corresponding arc).
750 750
      Node baseNode(OutArcIt) const { return INVALID; }
751 751

	
752 752
      /// \brief The running node of the iterator.
753 753
      ///
754 754
      /// Returns the running node of the given outgoing arc iterator
755 755
      /// (i.e. the target node of the corresponding arc).
756 756
      Node runningNode(OutArcIt) const { return INVALID; }
757 757

	
758 758
      /// \brief The base node of the iterator.
759 759
      ///
760 760
      /// Returns the base node of the given incomming arc iterator
761 761
      /// (i.e. the target node of the corresponding arc).
762 762
      Node baseNode(InArcIt) const { return INVALID; }
763 763

	
764 764
      /// \brief The running node of the iterator.
765 765
      ///
766 766
      /// Returns the running node of the given incomming arc iterator
767 767
      /// (i.e. the source node of the corresponding arc).
768 768
      Node runningNode(InArcIt) const { return INVALID; }
769 769

	
770 770
      template <typename _Graph>
771 771
      struct Constraints {
772 772
        void constraints() {
773 773
          checkConcept<BaseGraphComponent, _Graph>();
774 774
          checkConcept<IterableGraphComponent<>, _Graph>();
775 775
          checkConcept<IDableGraphComponent<>, _Graph>();
776 776
          checkConcept<MappableGraphComponent<>, _Graph>();
777 777
        }
778 778
      };
779 779

	
780 780
    };
781 781

	
782 782
  }
783 783

	
784 784
}
785 785

	
786 786
#endif
Show white space 768 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
///\ingroup graph_concepts
20 20
///\file
21
///\brief The concept of graph components.
21
///\brief The concepts of graph components.
22 22

	
23 23
#ifndef LEMON_CONCEPTS_GRAPH_COMPONENTS_H
24 24
#define LEMON_CONCEPTS_GRAPH_COMPONENTS_H
25 25

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

	
29 29
#include <lemon/bits/alteration_notifier.h>
30 30

	
31 31
namespace lemon {
32 32
  namespace concepts {
33 33

	
34 34
    /// \brief Concept class for \c Node, \c Arc and \c Edge types.
35 35
    ///
36 36
    /// This class describes the concept of \c Node, \c Arc and \c Edge
37 37
    /// subtypes of digraph and graph types.
38 38
    ///
39 39
    /// \note This class is a template class so that we can use it to
40 40
    /// create graph skeleton classes. The reason for this is that \c Node
41 41
    /// and \c Arc (or \c Edge) types should \e not derive from the same 
42 42
    /// base class. For \c Node you should instantiate it with character
43 43
    /// \c 'n', for \c Arc with \c 'a' and for \c Edge with \c 'e'.
44 44
#ifndef DOXYGEN
45 45
    template <char sel = '0'>
46 46
#endif
47 47
    class GraphItem {
48 48
    public:
49 49
      /// \brief Default constructor.
50 50
      ///
51 51
      /// Default constructor.
52 52
      /// \warning The default constructor is not required to set
53 53
      /// the item to some well-defined value. So you should consider it
54 54
      /// as uninitialized.
55 55
      GraphItem() {}
56 56

	
57 57
      /// \brief Copy constructor.
58 58
      ///
59 59
      /// Copy constructor.
60 60
      GraphItem(const GraphItem &) {}
61 61

	
62 62
      /// \brief Constructor for conversion from \c INVALID.
63 63
      ///
64 64
      /// Constructor for conversion from \c INVALID.
65 65
      /// It initializes the item to be invalid.
66 66
      /// \sa Invalid for more details.
67 67
      GraphItem(Invalid) {}
68 68

	
69 69
      /// \brief Assignment operator.
70 70
      ///
71 71
      /// Assignment operator for the item.
72 72
      GraphItem& operator=(const GraphItem&) { return *this; }
73 73

	
74 74
      /// \brief Assignment operator for INVALID.
75 75
      ///
76 76
      /// This operator makes the item invalid.
77 77
      GraphItem& operator=(Invalid) { return *this; }
78 78

	
79 79
      /// \brief Equality operator.
80 80
      ///
81 81
      /// Equality operator.
82 82
      bool operator==(const GraphItem&) const { return false; }
83 83

	
84 84
      /// \brief Inequality operator.
85 85
      ///
86 86
      /// Inequality operator.
87 87
      bool operator!=(const GraphItem&) const { return false; }
88 88

	
89 89
      /// \brief Ordering operator.
90 90
      ///
91 91
      /// This operator defines an ordering of the items.
92 92
      /// It makes possible to use graph item types as key types in 
93 93
      /// associative containers (e.g. \c std::map).
94 94
      ///
95 95
      /// \note This operator only has to define some strict ordering of
96 96
      /// the items; this order has nothing to do with the iteration
97 97
      /// ordering of the items.
98 98
      bool operator<(const GraphItem&) const { return false; }
99 99

	
100 100
      template<typename _GraphItem>
101 101
      struct Constraints {
102 102
        void constraints() {
103 103
          _GraphItem i1;
104 104
          i1=INVALID;
105 105
          _GraphItem i2 = i1;
106 106
          _GraphItem i3 = INVALID;
107 107

	
108 108
          i1 = i2 = i3;
109 109

	
110 110
          bool b;
111 111
          b = (ia == ib) && (ia != ib);
112 112
          b = (ia == INVALID) && (ib != INVALID);
113 113
          b = (ia < ib);
114 114
        }
115 115

	
116 116
        const _GraphItem &ia;
117 117
        const _GraphItem &ib;
118 118
      };
119 119
    };
120 120

	
121 121
    /// \brief Base skeleton class for directed graphs.
122 122
    ///
123 123
    /// This class describes the base interface of directed graph types.
124 124
    /// All digraph %concepts have to conform to this class.
125 125
    /// It just provides types for nodes and arcs and functions 
126 126
    /// to get the source and the target nodes of arcs.
127 127
    class BaseDigraphComponent {
128 128
    public:
129 129

	
130 130
      typedef BaseDigraphComponent Digraph;
131 131

	
132 132
      /// \brief Node class of the digraph.
133 133
      ///
134 134
      /// This class represents the nodes of the digraph.
135 135
      typedef GraphItem<'n'> Node;
136 136

	
137 137
      /// \brief Arc class of the digraph.
138 138
      ///
139 139
      /// This class represents the arcs of the digraph.
140 140
      typedef GraphItem<'a'> Arc;
141 141

	
142 142
      /// \brief Return the source node of an arc.
143 143
      ///
144 144
      /// This function returns the source node of an arc.
145 145
      Node source(const Arc&) const { return INVALID; }
146 146

	
147 147
      /// \brief Return the target node of an arc.
148 148
      ///
149 149
      /// This function returns the target node of an arc.
150 150
      Node target(const Arc&) const { return INVALID; }
151 151

	
152 152
      /// \brief Return the opposite node on the given arc.
153 153
      ///
154 154
      /// This function returns the opposite node on the given arc.
155 155
      Node oppositeNode(const Node&, const Arc&) const {
156 156
        return INVALID;
157 157
      }
158 158

	
159 159
      template <typename _Digraph>
160 160
      struct Constraints {
161 161
        typedef typename _Digraph::Node Node;
162 162
        typedef typename _Digraph::Arc Arc;
163 163

	
164 164
        void constraints() {
165 165
          checkConcept<GraphItem<'n'>, Node>();
166 166
          checkConcept<GraphItem<'a'>, Arc>();
167 167
          {
168 168
            Node n;
169 169
            Arc e(INVALID);
170 170
            n = digraph.source(e);
171 171
            n = digraph.target(e);
172 172
            n = digraph.oppositeNode(n, e);
173 173
          }
174 174
        }
175 175

	
176 176
        const _Digraph& digraph;
177 177
      };
178 178
    };
179 179

	
180 180
    /// \brief Base skeleton class for undirected graphs.
181 181
    ///
182 182
    /// This class describes the base interface of undirected graph types.
183 183
    /// All graph %concepts have to conform to this class.
184 184
    /// It extends the interface of \ref BaseDigraphComponent with an
185 185
    /// \c Edge type and functions to get the end nodes of edges,
186 186
    /// to convert from arcs to edges and to get both direction of edges.
187 187
    class BaseGraphComponent : public BaseDigraphComponent {
188 188
    public:
189 189

	
190 190
      typedef BaseGraphComponent Graph;
191 191

	
192 192
      typedef BaseDigraphComponent::Node Node;
193 193
      typedef BaseDigraphComponent::Arc Arc;
194 194

	
195 195
      /// \brief Undirected edge class of the graph.
196 196
      ///
197 197
      /// This class represents the undirected edges of the graph.
198 198
      /// Undirected graphs can be used as directed graphs, each edge is
199 199
      /// represented by two opposite directed arcs.
200 200
      class Edge : public GraphItem<'e'> {
201 201
        typedef GraphItem<'e'> Parent;
202 202

	
203 203
      public:
204 204
        /// \brief Default constructor.
205 205
        ///
206 206
        /// Default constructor.
207 207
        /// \warning The default constructor is not required to set
208 208
        /// the item to some well-defined value. So you should consider it
209 209
        /// as uninitialized.
210 210
        Edge() {}
211 211

	
212 212
        /// \brief Copy constructor.
213 213
        ///
214 214
        /// Copy constructor.
215 215
        Edge(const Edge &) : Parent() {}
216 216

	
217 217
        /// \brief Constructor for conversion from \c INVALID.
218 218
        ///
219 219
        /// Constructor for conversion from \c INVALID.
220 220
        /// It initializes the item to be invalid.
221 221
        /// \sa Invalid for more details.
222 222
        Edge(Invalid) {}
223 223

	
224 224
        /// \brief Constructor for conversion from an arc.
225 225
        ///
226 226
        /// Constructor for conversion from an arc.
227 227
        /// Besides the core graph item functionality each arc should
228 228
        /// be convertible to the represented edge.
229 229
        Edge(const Arc&) {}
230 230
     };
231 231

	
232 232
      /// \brief Return one end node of an edge.
233 233
      ///
234 234
      /// This function returns one end node of an edge.
235 235
      Node u(const Edge&) const { return INVALID; }
236 236

	
237 237
      /// \brief Return the other end node of an edge.
238 238
      ///
239 239
      /// This function returns the other end node of an edge.
240 240
      Node v(const Edge&) const { return INVALID; }
241 241

	
242 242
      /// \brief Return a directed arc related to an edge.
243 243
      ///
244 244
      /// This function returns a directed arc from its direction and the
245 245
      /// represented edge.
246 246
      Arc direct(const Edge&, bool) const { return INVALID; }
247 247

	
248 248
      /// \brief Return a directed arc related to an edge.
249 249
      ///
250 250
      /// This function returns a directed arc from its source node and the
251 251
      /// represented edge.
252 252
      Arc direct(const Edge&, const Node&) const { return INVALID; }
253 253

	
254 254
      /// \brief Return the direction of the arc.
255 255
      ///
256 256
      /// Returns the direction of the arc. Each arc represents an
257 257
      /// edge with a direction. It gives back the
258 258
      /// direction.
259 259
      bool direction(const Arc&) const { return true; }
260 260

	
261 261
      /// \brief Return the opposite arc.
262 262
      ///
263 263
      /// This function returns the opposite arc, i.e. the arc representing
264 264
      /// the same edge and has opposite direction.
265 265
      Arc oppositeArc(const Arc&) const { return INVALID; }
266 266

	
267 267
      template <typename _Graph>
268 268
      struct Constraints {
269 269
        typedef typename _Graph::Node Node;
270 270
        typedef typename _Graph::Arc Arc;
271 271
        typedef typename _Graph::Edge Edge;
272 272

	
273 273
        void constraints() {
274 274
          checkConcept<BaseDigraphComponent, _Graph>();
275 275
          checkConcept<GraphItem<'e'>, Edge>();
276 276
          {
277 277
            Node n;
278 278
            Edge ue(INVALID);
279 279
            Arc e;
280 280
            n = graph.u(ue);
281 281
            n = graph.v(ue);
282 282
            e = graph.direct(ue, true);
283 283
            e = graph.direct(ue, false);
284 284
            e = graph.direct(ue, n);
285 285
            e = graph.oppositeArc(e);
286 286
            ue = e;
287 287
            bool d = graph.direction(e);
288 288
            ignore_unused_variable_warning(d);
289 289
          }
290 290
        }
291 291

	
292 292
        const _Graph& graph;
293 293
      };
294 294

	
295 295
    };
296 296

	
297 297
    /// \brief Skeleton class for \e idable directed graphs.
298 298
    ///
299 299
    /// This class describes the interface of \e idable directed graphs.
300 300
    /// It extends \ref BaseDigraphComponent with the core ID functions.
301 301
    /// The ids of the items must be unique and immutable.
302 302
    /// This concept is part of the Digraph concept.
303 303
    template <typename BAS = BaseDigraphComponent>
304 304
    class IDableDigraphComponent : public BAS {
305 305
    public:
306 306

	
307 307
      typedef BAS Base;
308 308
      typedef typename Base::Node Node;
309 309
      typedef typename Base::Arc Arc;
310 310

	
311 311
      /// \brief Return a unique integer id for the given node.
312 312
      ///
313 313
      /// This function returns a unique integer id for the given node.
314 314
      int id(const Node&) const { return -1; }
315 315

	
316 316
      /// \brief Return the node by its unique id.
317 317
      ///
318 318
      /// This function returns the node by its unique id.
319 319
      /// If the digraph does not contain a node with the given id,
320 320
      /// then the result of the function is undefined.
321 321
      Node nodeFromId(int) const { return INVALID; }
322 322

	
323 323
      /// \brief Return a unique integer id for the given arc.
324 324
      ///
325 325
      /// This function returns a unique integer id for the given arc.
326 326
      int id(const Arc&) const { return -1; }
327 327

	
328 328
      /// \brief Return the arc by its unique id.
329 329
      ///
330 330
      /// This function returns the arc by its unique id.
331 331
      /// If the digraph does not contain an arc with the given id,
332 332
      /// then the result of the function is undefined.
333 333
      Arc arcFromId(int) const { return INVALID; }
334 334

	
335 335
      /// \brief Return an integer greater or equal to the maximum
336 336
      /// node id.
337 337
      ///
338 338
      /// This function returns an integer greater or equal to the
339 339
      /// maximum node id.
340 340
      int maxNodeId() const { return -1; }
341 341

	
342 342
      /// \brief Return an integer greater or equal to the maximum
343 343
      /// arc id.
344 344
      ///
345 345
      /// This function returns an integer greater or equal to the
346 346
      /// maximum arc id.
347 347
      int maxArcId() const { return -1; }
348 348

	
349 349
      template <typename _Digraph>
350 350
      struct Constraints {
351 351

	
352 352
        void constraints() {
353 353
          checkConcept<Base, _Digraph >();
354 354
          typename _Digraph::Node node;
355 355
          node=INVALID;
356 356
          int nid = digraph.id(node);
357 357
          nid = digraph.id(node);
358 358
          node = digraph.nodeFromId(nid);
359 359
          typename _Digraph::Arc arc;
360 360
          arc=INVALID;
361 361
          int eid = digraph.id(arc);
362 362
          eid = digraph.id(arc);
363 363
          arc = digraph.arcFromId(eid);
364 364

	
365 365
          nid = digraph.maxNodeId();
366 366
          ignore_unused_variable_warning(nid);
367 367
          eid = digraph.maxArcId();
368 368
          ignore_unused_variable_warning(eid);
369 369
        }
370 370

	
371 371
        const _Digraph& digraph;
372 372
      };
373 373
    };
374 374

	
375 375
    /// \brief Skeleton class for \e idable undirected graphs.
376 376
    ///
377 377
    /// This class describes the interface of \e idable undirected
378 378
    /// graphs. It extends \ref IDableDigraphComponent with the core ID
379 379
    /// functions of undirected graphs.
380 380
    /// The ids of the items must be unique and immutable.
381 381
    /// This concept is part of the Graph concept.
382 382
    template <typename BAS = BaseGraphComponent>
383 383
    class IDableGraphComponent : public IDableDigraphComponent<BAS> {
384 384
    public:
385 385

	
386 386
      typedef BAS Base;
387 387
      typedef typename Base::Edge Edge;
388 388

	
389 389
      using IDableDigraphComponent<Base>::id;
390 390

	
391 391
      /// \brief Return a unique integer id for the given edge.
392 392
      ///
393 393
      /// This function returns a unique integer id for the given edge.
394 394
      int id(const Edge&) const { return -1; }
395 395

	
396 396
      /// \brief Return the edge by its unique id.
397 397
      ///
398 398
      /// This function returns the edge by its unique id.
399 399
      /// If the graph does not contain an edge with the given id,
400 400
      /// then the result of the function is undefined.
401 401
      Edge edgeFromId(int) const { return INVALID; }
402 402

	
403 403
      /// \brief Return an integer greater or equal to the maximum
404 404
      /// edge id.
405 405
      ///
Show white space 768 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_COUNTER_H
20 20
#define LEMON_COUNTER_H
21 21

	
22 22
#include <string>
23 23
#include <iostream>
24 24

	
25 25
///\ingroup timecount
26 26
///\file
27 27
///\brief Tools for counting steps and events
28 28

	
29 29
namespace lemon
30 30
{
31 31

	
32 32
  template<class P> class _NoSubCounter;
33 33

	
34 34
  template<class P>
35 35
  class _SubCounter
36 36
  {
37 37
    P &_parent;
38 38
    std::string _title;
39 39
    std::ostream &_os;
40 40
    int count;
41 41
  public:
42 42

	
43 43
    typedef _SubCounter<_SubCounter<P> > SubCounter;
44 44
    typedef _NoSubCounter<_SubCounter<P> > NoSubCounter;
45 45

	
46 46
    _SubCounter(P &parent)
47 47
      : _parent(parent), _title(), _os(std::cerr), count(0) {}
48 48
    _SubCounter(P &parent,std::string title,std::ostream &os=std::cerr)
49 49
      : _parent(parent), _title(title), _os(os), count(0) {}
50 50
    _SubCounter(P &parent,const char *title,std::ostream &os=std::cerr)
51 51
      : _parent(parent), _title(title), _os(os), count(0) {}
52 52
    ~_SubCounter() {
53 53
      _os << _title << count <<std::endl;
54 54
      _parent+=count;
55 55
    }
56 56
    _SubCounter &operator++() { count++; return *this;}
57 57
    int operator++(int) { return count++; }
58 58
    _SubCounter &operator--() { count--; return *this;}
59 59
    int operator--(int) { return count--; }
60 60
    _SubCounter &operator+=(int c) { count+=c; return *this;}
61 61
    _SubCounter &operator-=(int c) { count-=c; return *this;}
62 62
    operator int() {return count;}
63 63
  };
64 64

	
65 65
  template<class P>
66 66
  class _NoSubCounter
67 67
  {
68 68
    P &_parent;
69 69
  public:
70 70
    typedef _NoSubCounter<_NoSubCounter<P> > SubCounter;
71 71
    typedef _NoSubCounter<_NoSubCounter<P> > NoSubCounter;
72 72

	
73 73
    _NoSubCounter(P &parent) :_parent(parent) {}
74 74
    _NoSubCounter(P &parent,std::string,std::ostream &)
75 75
      :_parent(parent) {}
76 76
    _NoSubCounter(P &parent,std::string)
77 77
      :_parent(parent) {}
78 78
    _NoSubCounter(P &parent,const char *,std::ostream &)
79 79
      :_parent(parent) {}
80 80
    _NoSubCounter(P &parent,const char *)
81 81
      :_parent(parent) {}
82 82
    ~_NoSubCounter() {}
83 83
    _NoSubCounter &operator++() { ++_parent; return *this;}
84 84
    int operator++(int) { _parent++; return 0;}
85 85
    _NoSubCounter &operator--() { --_parent; return *this;}
86 86
    int operator--(int) { _parent--; return 0;}
87 87
    _NoSubCounter &operator+=(int c) { _parent+=c; return *this;}
88 88
    _NoSubCounter &operator-=(int c) { _parent-=c; return *this;}
89 89
    operator int() {return 0;}
90 90
  };
91 91

	
92 92

	
93 93
  /// \addtogroup timecount
94 94
  /// @{
95 95

	
96 96
  /// A counter class
97 97

	
98 98
  /// This class makes it easier to count certain events (e.g. for debug
99 99
  /// reasons).
100 100
  /// You can increment or decrement the counter using \c operator++,
101 101
  /// \c operator--, \c operator+= and \c operator-=. You can also
102 102
  /// define subcounters for the different phases of the algorithm or
103 103
  /// for different types of operations.
104 104
  /// A report containing the given title and the value of the counter
105 105
  /// is automatically printed on destruction.
106 106
  ///
107 107
  /// The following example shows the usage of counters and subcounters.
108 108
  /// \code
109 109
  /// // Bubble sort
110 110
  /// std::vector<T> v;
111 111
  /// ...
112 112
  /// Counter op("Operations: ");
113 113
  /// Counter::SubCounter as(op, "Assignments: ");
114 114
  /// Counter::SubCounter co(op, "Comparisons: ");
115 115
  /// for (int i = v.size()-1; i > 0; --i) {
116 116
  ///   for (int j = 0; j < i; ++j) {
117 117
  ///     if (v[j] > v[j+1]) {
118 118
  ///       T tmp = v[j];
119 119
  ///       v[j] = v[j+1];
120 120
  ///       v[j+1] = tmp;
121 121
  ///       as += 3;          // three assignments
122 122
  ///     }
123 123
  ///     ++co;               // one comparison
124 124
  ///   }
125 125
  /// }
126 126
  /// \endcode
127 127
  ///
128 128
  /// This code prints out something like that:
129 129
  /// \code
130 130
  /// Comparisons: 45
131 131
  /// Assignments: 57
132 132
  /// Operations: 102
133 133
  /// \endcode
134 134
  ///
135 135
  /// \sa NoCounter
136 136
  class Counter
137 137
  {
138 138
    std::string _title;
139 139
    std::ostream &_os;
140 140
    int count;
141 141
  public:
142 142

	
143 143
    /// SubCounter class
144 144

	
145 145
    /// This class can be used to setup subcounters for a \ref Counter
146 146
    /// to have finer reports. A subcounter provides exactly the same
147 147
    /// operations as the main \ref Counter, but it also increments and
148 148
    /// decrements the value of its parent.
149 149
    /// Subcounters can also have subcounters.
150 150
    ///
151 151
    /// The parent counter must be given as the first parameter of the
152 152
    /// constructor. Apart from that a title and an \c ostream object
153 153
    /// can also be given just like for the main \ref Counter.
154 154
    ///
155 155
    /// A report containing the given title and the value of the
156 156
    /// subcounter is automatically printed on destruction. If you
157 157
    /// would like to turn off this report, use \ref NoSubCounter
158 158
    /// instead.
159 159
    ///
160 160
    /// \sa NoSubCounter
161 161
    typedef _SubCounter<Counter> SubCounter;
162 162

	
163 163
    /// SubCounter class without printing report on destruction
164 164

	
165 165
    /// This class can be used to setup subcounters for a \ref Counter.
166 166
    /// It is the same as \ref SubCounter but it does not print report
167 167
    /// on destruction. (It modifies the value of its parent, so 'No'
168 168
    /// only means 'do not print'.)
169 169
    ///
170 170
    /// Replacing \ref SubCounter "SubCounter"s with \ref NoSubCounter
171 171
    /// "NoSubCounter"s makes it possible to turn off reporting
172 172
    /// subcounter values without actually removing the definitions
173 173
    /// and the increment or decrement operators.
174 174
    ///
175 175
    /// \sa SubCounter
176 176
    typedef _NoSubCounter<Counter> NoSubCounter;
177 177

	
178 178
    /// Constructor.
179 179
    Counter() : _title(), _os(std::cerr), count(0) {}
180 180
    /// Constructor.
181 181
    Counter(std::string title,std::ostream &os=std::cerr)
182 182
      : _title(title), _os(os), count(0) {}
183 183
    /// Constructor.
184 184
    Counter(const char *title,std::ostream &os=std::cerr)
185 185
      : _title(title), _os(os), count(0) {}
186 186
    /// Destructor. Prints the given title and the value of the counter.
187 187
    ~Counter() {
188 188
      _os << _title << count <<std::endl;
189 189
    }
190 190
    ///\e
191 191
    Counter &operator++() { count++; return *this;}
192 192
    ///\e
193 193
    int operator++(int) { return count++;}
194 194
    ///\e
195 195
    Counter &operator--() { count--; return *this;}
196 196
    ///\e
197 197
    int operator--(int) { return count--;}
198 198
    ///\e
199 199
    Counter &operator+=(int c) { count+=c; return *this;}
200 200
    ///\e
201 201
    Counter &operator-=(int c) { count-=c; return *this;}
202 202
    /// Resets the counter to the given value.
203 203

	
204 204
    /// Resets the counter to the given value.
205 205
    /// \note This function does not reset the values of
206 206
    /// \ref SubCounter "SubCounter"s but it resets \ref NoSubCounter
207 207
    /// "NoSubCounter"s along with the main counter.
208 208
    void reset(int c=0) {count=c;}
209 209
    /// Returns the value of the counter.
210 210
    operator int() {return count;}
211 211
  };
212 212

	
213 213
  /// 'Do nothing' version of Counter.
214 214

	
215
  /// This class can be used in the same way as \ref Counter however it
215
  /// This class can be used in the same way as \ref Counter, but it
216 216
  /// does not count at all and does not print report on destruction.
217 217
  ///
218 218
  /// Replacing a \ref Counter with a \ref NoCounter makes it possible
219 219
  /// to turn off all counting and reporting (SubCounters should also
220 220
  /// be replaced with NoSubCounters), so it does not affect the
221 221
  /// efficiency of the program at all.
222 222
  ///
223 223
  /// \sa Counter
224 224
  class NoCounter
225 225
  {
226 226
  public:
227 227
    typedef _NoSubCounter<NoCounter> SubCounter;
228 228
    typedef _NoSubCounter<NoCounter> NoSubCounter;
229 229

	
230 230
    NoCounter() {}
231 231
    NoCounter(std::string,std::ostream &) {}
232 232
    NoCounter(const char *,std::ostream &) {}
233 233
    NoCounter(std::string) {}
234 234
    NoCounter(const char *) {}
235 235
    NoCounter &operator++() { return *this; }
236 236
    int operator++(int) { return 0; }
237 237
    NoCounter &operator--() { return *this; }
238 238
    int operator--(int) { return 0; }
239 239
    NoCounter &operator+=(int) { return *this;}
240 240
    NoCounter &operator-=(int) { return *this;}
241 241
    void reset(int) {}
242 242
    void reset() {}
243 243
    operator int() {return 0;}
244 244
  };
245 245

	
246 246
  ///@}
247 247
}
248 248

	
249 249
#endif
Show white space 768 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_DFS_H
20 20
#define LEMON_DFS_H
21 21

	
22 22
///\ingroup search
23 23
///\file
24 24
///\brief DFS algorithm.
25 25

	
26 26
#include <lemon/list_graph.h>
27 27
#include <lemon/bits/path_dump.h>
28 28
#include <lemon/core.h>
29 29
#include <lemon/error.h>
30 30
#include <lemon/maps.h>
31 31
#include <lemon/path.h>
32 32

	
33 33
namespace lemon {
34 34

	
35 35
  ///Default traits class of Dfs class.
36 36

	
37 37
  ///Default traits class of Dfs class.
38 38
  ///\tparam GR Digraph type.
39 39
  template<class GR>
40 40
  struct DfsDefaultTraits
41 41
  {
42 42
    ///The type of the digraph the algorithm runs on.
43 43
    typedef GR Digraph;
44 44

	
45 45
    ///\brief The type of the map that stores the predecessor
46 46
    ///arcs of the %DFS paths.
47 47
    ///
48 48
    ///The type of the map that stores the predecessor
49 49
    ///arcs of the %DFS paths.
50 50
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
51 51
    typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
52 52
    ///Instantiates a \c PredMap.
53 53

	
54 54
    ///This function instantiates a \ref PredMap.
55 55
    ///\param g is the digraph, to which we would like to define the
56 56
    ///\ref PredMap.
57 57
    static PredMap *createPredMap(const Digraph &g)
58 58
    {
59 59
      return new PredMap(g);
60 60
    }
61 61

	
62 62
    ///The type of the map that indicates which nodes are processed.
63 63

	
64 64
    ///The type of the map that indicates which nodes are processed.
65 65
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
66
    ///By default it is a NullMap.
66
    ///By default, it is a NullMap.
67 67
    typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
68 68
    ///Instantiates a \c ProcessedMap.
69 69

	
70 70
    ///This function instantiates a \ref ProcessedMap.
71 71
    ///\param g is the digraph, to which
72 72
    ///we would like to define the \ref ProcessedMap.
73 73
#ifdef DOXYGEN
74 74
    static ProcessedMap *createProcessedMap(const Digraph &g)
75 75
#else
76 76
    static ProcessedMap *createProcessedMap(const Digraph &)
77 77
#endif
78 78
    {
79 79
      return new ProcessedMap();
80 80
    }
81 81

	
82 82
    ///The type of the map that indicates which nodes are reached.
83 83

	
84 84
    ///The type of the map that indicates which nodes are reached.
85 85
    ///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
86 86
    typedef typename Digraph::template NodeMap<bool> ReachedMap;
87 87
    ///Instantiates a \c ReachedMap.
88 88

	
89 89
    ///This function instantiates a \ref ReachedMap.
90 90
    ///\param g is the digraph, to which
91 91
    ///we would like to define the \ref ReachedMap.
92 92
    static ReachedMap *createReachedMap(const Digraph &g)
93 93
    {
94 94
      return new ReachedMap(g);
95 95
    }
96 96

	
97 97
    ///The type of the map that stores the distances of the nodes.
98 98

	
99 99
    ///The type of the map that stores the distances of the nodes.
100 100
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
101 101
    typedef typename Digraph::template NodeMap<int> DistMap;
102 102
    ///Instantiates a \c DistMap.
103 103

	
104 104
    ///This function instantiates a \ref DistMap.
105 105
    ///\param g is the digraph, to which we would like to define the
106 106
    ///\ref DistMap.
107 107
    static DistMap *createDistMap(const Digraph &g)
108 108
    {
109 109
      return new DistMap(g);
110 110
    }
111 111
  };
112 112

	
113 113
  ///%DFS algorithm class.
114 114

	
115 115
  ///\ingroup search
116 116
  ///This class provides an efficient implementation of the %DFS algorithm.
117 117
  ///
118 118
  ///There is also a \ref dfs() "function-type interface" for the DFS
119 119
  ///algorithm, which is convenient in the simplier cases and it can be
120 120
  ///used easier.
121 121
  ///
122 122
  ///\tparam GR The type of the digraph the algorithm runs on.
123 123
  ///The default type is \ref ListDigraph.
124 124
#ifdef DOXYGEN
125 125
  template <typename GR,
126 126
            typename TR>
127 127
#else
128 128
  template <typename GR=ListDigraph,
129 129
            typename TR=DfsDefaultTraits<GR> >
130 130
#endif
131 131
  class Dfs {
132 132
  public:
133 133

	
134 134
    ///The type of the digraph the algorithm runs on.
135 135
    typedef typename TR::Digraph Digraph;
136 136

	
137 137
    ///\brief The type of the map that stores the predecessor arcs of the
138 138
    ///DFS paths.
139 139
    typedef typename TR::PredMap PredMap;
140 140
    ///The type of the map that stores the distances of the nodes.
141 141
    typedef typename TR::DistMap DistMap;
142 142
    ///The type of the map that indicates which nodes are reached.
143 143
    typedef typename TR::ReachedMap ReachedMap;
144 144
    ///The type of the map that indicates which nodes are processed.
145 145
    typedef typename TR::ProcessedMap ProcessedMap;
146 146
    ///The type of the paths.
147 147
    typedef PredMapPath<Digraph, PredMap> Path;
148 148

	
149 149
    ///The \ref DfsDefaultTraits "traits class" of the algorithm.
150 150
    typedef TR Traits;
151 151

	
152 152
  private:
153 153

	
154 154
    typedef typename Digraph::Node Node;
155 155
    typedef typename Digraph::NodeIt NodeIt;
156 156
    typedef typename Digraph::Arc Arc;
157 157
    typedef typename Digraph::OutArcIt OutArcIt;
158 158

	
159 159
    //Pointer to the underlying digraph.
160 160
    const Digraph *G;
161 161
    //Pointer to the map of predecessor arcs.
162 162
    PredMap *_pred;
163 163
    //Indicates if _pred is locally allocated (true) or not.
164 164
    bool local_pred;
165 165
    //Pointer to the map of distances.
166 166
    DistMap *_dist;
167 167
    //Indicates if _dist is locally allocated (true) or not.
168 168
    bool local_dist;
169 169
    //Pointer to the map of reached status of the nodes.
170 170
    ReachedMap *_reached;
171 171
    //Indicates if _reached is locally allocated (true) or not.
172 172
    bool local_reached;
173 173
    //Pointer to the map of processed status of the nodes.
174 174
    ProcessedMap *_processed;
175 175
    //Indicates if _processed is locally allocated (true) or not.
176 176
    bool local_processed;
177 177

	
178 178
    std::vector<typename Digraph::OutArcIt> _stack;
179 179
    int _stack_head;
180 180

	
181 181
    //Creates the maps if necessary.
182 182
    void create_maps()
183 183
    {
184 184
      if(!_pred) {
185 185
        local_pred = true;
186 186
        _pred = Traits::createPredMap(*G);
187 187
      }
188 188
      if(!_dist) {
189 189
        local_dist = true;
190 190
        _dist = Traits::createDistMap(*G);
191 191
      }
192 192
      if(!_reached) {
193 193
        local_reached = true;
194 194
        _reached = Traits::createReachedMap(*G);
195 195
      }
196 196
      if(!_processed) {
197 197
        local_processed = true;
198 198
        _processed = Traits::createProcessedMap(*G);
199 199
      }
200 200
    }
201 201

	
202 202
  protected:
203 203

	
204 204
    Dfs() {}
205 205

	
206 206
  public:
207 207

	
208 208
    typedef Dfs Create;
209 209

	
210 210
    ///\name Named Template Parameters
211 211

	
212 212
    ///@{
213 213

	
214 214
    template <class T>
215 215
    struct SetPredMapTraits : public Traits {
216 216
      typedef T PredMap;
217 217
      static PredMap *createPredMap(const Digraph &)
218 218
      {
219 219
        LEMON_ASSERT(false, "PredMap is not initialized");
220 220
        return 0; // ignore warnings
221 221
      }
222 222
    };
223 223
    ///\brief \ref named-templ-param "Named parameter" for setting
224 224
    ///\c PredMap type.
225 225
    ///
226 226
    ///\ref named-templ-param "Named parameter" for setting
227 227
    ///\c PredMap type.
228 228
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
229 229
    template <class T>
230 230
    struct SetPredMap : public Dfs<Digraph, SetPredMapTraits<T> > {
231 231
      typedef Dfs<Digraph, SetPredMapTraits<T> > Create;
232 232
    };
233 233

	
234 234
    template <class T>
235 235
    struct SetDistMapTraits : public Traits {
236 236
      typedef T DistMap;
237 237
      static DistMap *createDistMap(const Digraph &)
238 238
      {
239 239
        LEMON_ASSERT(false, "DistMap is not initialized");
240 240
        return 0; // ignore warnings
241 241
      }
242 242
    };
243 243
    ///\brief \ref named-templ-param "Named parameter" for setting
244 244
    ///\c DistMap type.
245 245
    ///
246 246
    ///\ref named-templ-param "Named parameter" for setting
247 247
    ///\c DistMap type.
248 248
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
249 249
    template <class T>
250 250
    struct SetDistMap : public Dfs< Digraph, SetDistMapTraits<T> > {
251 251
      typedef Dfs<Digraph, SetDistMapTraits<T> > Create;
252 252
    };
253 253

	
254 254
    template <class T>
255 255
    struct SetReachedMapTraits : public Traits {
256 256
      typedef T ReachedMap;
257 257
      static ReachedMap *createReachedMap(const Digraph &)
258 258
      {
259 259
        LEMON_ASSERT(false, "ReachedMap is not initialized");
260 260
        return 0; // ignore warnings
261 261
      }
262 262
    };
263 263
    ///\brief \ref named-templ-param "Named parameter" for setting
264 264
    ///\c ReachedMap type.
265 265
    ///
266 266
    ///\ref named-templ-param "Named parameter" for setting
267 267
    ///\c ReachedMap type.
268 268
    ///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
269 269
    template <class T>
270 270
    struct SetReachedMap : public Dfs< Digraph, SetReachedMapTraits<T> > {
271 271
      typedef Dfs< Digraph, SetReachedMapTraits<T> > Create;
272 272
    };
273 273

	
274 274
    template <class T>
275 275
    struct SetProcessedMapTraits : public Traits {
276 276
      typedef T ProcessedMap;
277 277
      static ProcessedMap *createProcessedMap(const Digraph &)
278 278
      {
279 279
        LEMON_ASSERT(false, "ProcessedMap is not initialized");
280 280
        return 0; // ignore warnings
281 281
      }
282 282
    };
283 283
    ///\brief \ref named-templ-param "Named parameter" for setting
284 284
    ///\c ProcessedMap type.
285 285
    ///
286 286
    ///\ref named-templ-param "Named parameter" for setting
287 287
    ///\c ProcessedMap type.
288 288
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
289 289
    template <class T>
290 290
    struct SetProcessedMap : public Dfs< Digraph, SetProcessedMapTraits<T> > {
291 291
      typedef Dfs< Digraph, SetProcessedMapTraits<T> > Create;
292 292
    };
293 293

	
294 294
    struct SetStandardProcessedMapTraits : public Traits {
295 295
      typedef typename Digraph::template NodeMap<bool> ProcessedMap;
296 296
      static ProcessedMap *createProcessedMap(const Digraph &g)
297 297
      {
298 298
        return new ProcessedMap(g);
299 299
      }
300 300
    };
301 301
    ///\brief \ref named-templ-param "Named parameter" for setting
302 302
    ///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
303 303
    ///
304 304
    ///\ref named-templ-param "Named parameter" for setting
305 305
    ///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
306 306
    ///If you don't set it explicitly, it will be automatically allocated.
307 307
    struct SetStandardProcessedMap :
308 308
      public Dfs< Digraph, SetStandardProcessedMapTraits > {
309 309
      typedef Dfs< Digraph, SetStandardProcessedMapTraits > Create;
310 310
    };
311 311

	
312 312
    ///@}
313 313

	
314 314
  public:
315 315

	
316 316
    ///Constructor.
317 317

	
318 318
    ///Constructor.
319 319
    ///\param g The digraph the algorithm runs on.
320 320
    Dfs(const Digraph &g) :
321 321
      G(&g),
322 322
      _pred(NULL), local_pred(false),
323 323
      _dist(NULL), local_dist(false),
324 324
      _reached(NULL), local_reached(false),
325 325
      _processed(NULL), local_processed(false)
326 326
    { }
327 327

	
328 328
    ///Destructor.
329 329
    ~Dfs()
330 330
    {
331 331
      if(local_pred) delete _pred;
332 332
      if(local_dist) delete _dist;
333 333
      if(local_reached) delete _reached;
334 334
      if(local_processed) delete _processed;
335 335
    }
336 336

	
337 337
    ///Sets the map that stores the predecessor arcs.
338 338

	
339 339
    ///Sets the map that stores the predecessor arcs.
340 340
    ///If you don't use this function before calling \ref run(Node) "run()"
341 341
    ///or \ref init(), an instance will be allocated automatically.
342 342
    ///The destructor deallocates this automatically allocated map,
343 343
    ///of course.
344 344
    ///\return <tt> (*this) </tt>
345 345
    Dfs &predMap(PredMap &m)
346 346
    {
347 347
      if(local_pred) {
348 348
        delete _pred;
349 349
        local_pred=false;
350 350
      }
351 351
      _pred = &m;
352 352
      return *this;
353 353
    }
354 354

	
355 355
    ///Sets the map that indicates which nodes are reached.
356 356

	
357 357
    ///Sets the map that indicates which nodes are reached.
358 358
    ///If you don't use this function before calling \ref run(Node) "run()"
359 359
    ///or \ref init(), an instance will be allocated automatically.
360 360
    ///The destructor deallocates this automatically allocated map,
361 361
    ///of course.
362 362
    ///\return <tt> (*this) </tt>
363 363
    Dfs &reachedMap(ReachedMap &m)
364 364
    {
365 365
      if(local_reached) {
366 366
        delete _reached;
367 367
        local_reached=false;
368 368
      }
369 369
      _reached = &m;
370 370
      return *this;
371 371
    }
372 372

	
373 373
    ///Sets the map that indicates which nodes are processed.
374 374

	
375 375
    ///Sets the map that indicates which nodes are processed.
376 376
    ///If you don't use this function before calling \ref run(Node) "run()"
377 377
    ///or \ref init(), an instance will be allocated automatically.
378 378
    ///The destructor deallocates this automatically allocated map,
379 379
    ///of course.
380 380
    ///\return <tt> (*this) </tt>
381 381
    Dfs &processedMap(ProcessedMap &m)
382 382
    {
383 383
      if(local_processed) {
384 384
        delete _processed;
385 385
        local_processed=false;
386 386
      }
387 387
      _processed = &m;
388 388
      return *this;
389 389
    }
390 390

	
391 391
    ///Sets the map that stores the distances of the nodes.
392 392

	
393 393
    ///Sets the map that stores the distances of the nodes calculated by
394 394
    ///the algorithm.
395 395
    ///If you don't use this function before calling \ref run(Node) "run()"
396 396
    ///or \ref init(), an instance will be allocated automatically.
397 397
    ///The destructor deallocates this automatically allocated map,
398 398
    ///of course.
399 399
    ///\return <tt> (*this) </tt>
400 400
    Dfs &distMap(DistMap &m)
401 401
    {
402 402
      if(local_dist) {
403 403
        delete _dist;
404 404
        local_dist=false;
405 405
      }
406 406
      _dist = &m;
407 407
      return *this;
408 408
    }
409 409

	
410 410
  public:
411 411

	
412 412
    ///\name Execution Control
413 413
    ///The simplest way to execute the DFS algorithm is to use one of the
414 414
    ///member functions called \ref run(Node) "run()".\n
415 415
    ///If you need better control on the execution, you have to call
416 416
    ///\ref init() first, then you can add a source node with \ref addSource()
417 417
    ///and perform the actual computation with \ref start().
418 418
    ///This procedure can be repeated if there are nodes that have not
419 419
    ///been reached.
420 420

	
421 421
    ///@{
422 422

	
423 423
    ///\brief Initializes the internal data structures.
424 424
    ///
425 425
    ///Initializes the internal data structures.
426 426
    void init()
427 427
    {
428 428
      create_maps();
429 429
      _stack.resize(countNodes(*G));
430 430
      _stack_head=-1;
431 431
      for ( NodeIt u(*G) ; u!=INVALID ; ++u ) {
432 432
        _pred->set(u,INVALID);
433 433
        _reached->set(u,false);
434 434
        _processed->set(u,false);
435 435
      }
436 436
    }
437 437

	
438 438
    ///Adds a new source node.
439 439

	
440 440
    ///Adds a new source node to the set of nodes to be processed.
441 441
    ///
442 442
    ///\pre The stack must be empty. Otherwise the algorithm gives
443 443
    ///wrong results. (One of the outgoing arcs of all the source nodes
444 444
    ///except for the last one will not be visited and distances will
445 445
    ///also be wrong.)
446 446
    void addSource(Node s)
447 447
    {
448 448
      LEMON_DEBUG(emptyQueue(), "The stack is not empty.");
449 449
      if(!(*_reached)[s])
450 450
        {
451 451
          _reached->set(s,true);
452 452
          _pred->set(s,INVALID);
453 453
          OutArcIt e(*G,s);
454 454
          if(e!=INVALID) {
455 455
            _stack[++_stack_head]=e;
456 456
            _dist->set(s,_stack_head);
457 457
          }
458 458
          else {
459 459
            _processed->set(s,true);
460 460
            _dist->set(s,0);
461 461
          }
462 462
        }
463 463
    }
464 464

	
465 465
    ///Processes the next arc.
466 466

	
467 467
    ///Processes the next arc.
468 468
    ///
469 469
    ///\return The processed arc.
470 470
    ///
471 471
    ///\pre The stack must not be empty.
472 472
    Arc processNextArc()
473 473
    {
474 474
      Node m;
475 475
      Arc e=_stack[_stack_head];
476 476
      if(!(*_reached)[m=G->target(e)]) {
477 477
        _pred->set(m,e);
478 478
        _reached->set(m,true);
479 479
        ++_stack_head;
480 480
        _stack[_stack_head] = OutArcIt(*G, m);
481 481
        _dist->set(m,_stack_head);
482 482
      }
483 483
      else {
484 484
        m=G->source(e);
485 485
        ++_stack[_stack_head];
486 486
      }
487 487
      while(_stack_head>=0 && _stack[_stack_head]==INVALID) {
488 488
        _processed->set(m,true);
489 489
        --_stack_head;
490 490
        if(_stack_head>=0) {
491 491
          m=G->source(_stack[_stack_head]);
492 492
          ++_stack[_stack_head];
493 493
        }
494 494
      }
495 495
      return e;
496 496
    }
497 497

	
498 498
    ///Next arc to be processed.
499 499

	
500 500
    ///Next arc to be processed.
501 501
    ///
502 502
    ///\return The next arc to be processed or \c INVALID if the stack
503 503
    ///is empty.
504 504
    OutArcIt nextArc() const
505 505
    {
506 506
      return _stack_head>=0?_stack[_stack_head]:INVALID;
507 507
    }
508 508

	
509 509
    ///Returns \c false if there are nodes to be processed.
510 510

	
511 511
    ///Returns \c false if there are nodes to be processed
512 512
    ///in the queue (stack).
513 513
    bool emptyQueue() const { return _stack_head<0; }
514 514

	
515 515
    ///Returns the number of the nodes to be processed.
516 516

	
517 517
    ///Returns the number of the nodes to be processed
518 518
    ///in the queue (stack).
519 519
    int queueSize() const { return _stack_head+1; }
520 520

	
521 521
    ///Executes the algorithm.
522 522

	
523 523
    ///Executes the algorithm.
524 524
    ///
525 525
    ///This method runs the %DFS algorithm from the root node
526 526
    ///in order to compute the DFS path to each node.
527 527
    ///
528 528
    /// The algorithm computes
529 529
    ///- the %DFS tree,
530 530
    ///- the distance of each node from the root in the %DFS tree.
531 531
    ///
532 532
    ///\pre init() must be called and a root node should be
533 533
    ///added with addSource() before using this function.
534 534
    ///
535 535
    ///\note <tt>d.start()</tt> is just a shortcut of the following code.
536 536
    ///\code
537 537
    ///  while ( !d.emptyQueue() ) {
538 538
    ///    d.processNextArc();
539 539
    ///  }
540 540
    ///\endcode
541 541
    void start()
542 542
    {
543 543
      while ( !emptyQueue() ) processNextArc();
544 544
    }
545 545

	
546 546
    ///Executes the algorithm until the given target node is reached.
547 547

	
548 548
    ///Executes the algorithm until the given target node is reached.
549 549
    ///
550 550
    ///This method runs the %DFS algorithm from the root node
551 551
    ///in order to compute the DFS path to \c t.
552 552
    ///
553 553
    ///The algorithm computes
554 554
    ///- the %DFS path to \c t,
555 555
    ///- the distance of \c t from the root in the %DFS tree.
556 556
    ///
557 557
    ///\pre init() must be called and a root node should be
558 558
    ///added with addSource() before using this function.
559 559
    void start(Node t)
560 560
    {
561 561
      while ( !emptyQueue() && G->target(_stack[_stack_head])!=t )
562 562
        processNextArc();
563 563
    }
564 564

	
565 565
    ///Executes the algorithm until a condition is met.
566 566

	
567 567
    ///Executes the algorithm until a condition is met.
568 568
    ///
569 569
    ///This method runs the %DFS algorithm from the root node
570 570
    ///until an arc \c a with <tt>am[a]</tt> true is found.
571 571
    ///
572 572
    ///\param am A \c bool (or convertible) arc map. The algorithm
573 573
    ///will stop when it reaches an arc \c a with <tt>am[a]</tt> true.
574 574
    ///
575 575
    ///\return The reached arc \c a with <tt>am[a]</tt> true or
576 576
    ///\c INVALID if no such arc was found.
577 577
    ///
578 578
    ///\pre init() must be called and a root node should be
579 579
    ///added with addSource() before using this function.
580 580
    ///
581 581
    ///\warning Contrary to \ref Bfs and \ref Dijkstra, \c am is an arc map,
582 582
    ///not a node map.
583 583
    template<class ArcBoolMap>
584 584
    Arc start(const ArcBoolMap &am)
585 585
    {
586 586
      while ( !emptyQueue() && !am[_stack[_stack_head]] )
587 587
        processNextArc();
588 588
      return emptyQueue() ? INVALID : _stack[_stack_head];
589 589
    }
590 590

	
591 591
    ///Runs the algorithm from the given source node.
592 592

	
593 593
    ///This method runs the %DFS algorithm from node \c s
594 594
    ///in order to compute the DFS path to each node.
595 595
    ///
596 596
    ///The algorithm computes
597 597
    ///- the %DFS tree,
598 598
    ///- the distance of each node from the root in the %DFS tree.
599 599
    ///
600 600
    ///\note <tt>d.run(s)</tt> is just a shortcut of the following code.
601 601
    ///\code
602 602
    ///  d.init();
603 603
    ///  d.addSource(s);
604 604
    ///  d.start();
605 605
    ///\endcode
606 606
    void run(Node s) {
607 607
      init();
608 608
      addSource(s);
609 609
      start();
610 610
    }
611 611

	
612 612
    ///Finds the %DFS path between \c s and \c t.
613 613

	
614 614
    ///This method runs the %DFS algorithm from node \c s
615 615
    ///in order to compute the DFS path to node \c t
616 616
    ///(it stops searching when \c t is processed)
617 617
    ///
618 618
    ///\return \c true if \c t is reachable form \c s.
619 619
    ///
620 620
    ///\note Apart from the return value, <tt>d.run(s,t)</tt> is
621 621
    ///just a shortcut of the following code.
622 622
    ///\code
623 623
    ///  d.init();
624 624
    ///  d.addSource(s);
625 625
    ///  d.start(t);
626 626
    ///\endcode
627 627
    bool run(Node s,Node t) {
628 628
      init();
629 629
      addSource(s);
630 630
      start(t);
631 631
      return reached(t);
632 632
    }
633 633

	
634 634
    ///Runs the algorithm to visit all nodes in the digraph.
635 635

	
636 636
    ///This method runs the %DFS algorithm in order to compute the
637 637
    ///%DFS path to each node.
638 638
    ///
639 639
    ///The algorithm computes
640 640
    ///- the %DFS tree (forest),
641 641
    ///- the distance of each node from the root(s) in the %DFS tree.
642 642
    ///
643 643
    ///\note <tt>d.run()</tt> is just a shortcut of the following code.
644 644
    ///\code
645 645
    ///  d.init();
646 646
    ///  for (NodeIt n(digraph); n != INVALID; ++n) {
647 647
    ///    if (!d.reached(n)) {
648 648
    ///      d.addSource(n);
649 649
    ///      d.start();
650 650
    ///    }
651 651
    ///  }
652 652
    ///\endcode
653 653
    void run() {
654 654
      init();
655 655
      for (NodeIt it(*G); it != INVALID; ++it) {
656 656
        if (!reached(it)) {
657 657
          addSource(it);
658 658
          start();
659 659
        }
660 660
      }
661 661
    }
662 662

	
663 663
    ///@}
664 664

	
665 665
    ///\name Query Functions
666 666
    ///The results of the DFS algorithm can be obtained using these
667 667
    ///functions.\n
668 668
    ///Either \ref run(Node) "run()" or \ref start() should be called
669 669
    ///before using them.
670 670

	
671 671
    ///@{
672 672

	
673 673
    ///The DFS path to the given node.
674 674

	
675 675
    ///Returns the DFS path to the given node from the root(s).
676 676
    ///
677 677
    ///\warning \c t should be reached from the root(s).
678 678
    ///
679 679
    ///\pre Either \ref run(Node) "run()" or \ref init()
680 680
    ///must be called before using this function.
681 681
    Path path(Node t) const { return Path(*G, *_pred, t); }
682 682

	
683 683
    ///The distance of the given node from the root(s).
684 684

	
685 685
    ///Returns the distance of the given node from the root(s).
686 686
    ///
687 687
    ///\warning If node \c v is not reached from the root(s), then
688 688
    ///the return value of this function is undefined.
689 689
    ///
690 690
    ///\pre Either \ref run(Node) "run()" or \ref init()
691 691
    ///must be called before using this function.
692 692
    int dist(Node v) const { return (*_dist)[v]; }
693 693

	
694 694
    ///Returns the 'previous arc' of the %DFS tree for the given node.
695 695

	
696 696
    ///This function returns the 'previous arc' of the %DFS tree for the
697 697
    ///node \c v, i.e. it returns the last arc of a %DFS path from a
698 698
    ///root to \c v. It is \c INVALID if \c v is not reached from the
699 699
    ///root(s) or if \c v is a root.
700 700
    ///
701 701
    ///The %DFS tree used here is equal to the %DFS tree used in
702 702
    ///\ref predNode() and \ref predMap().
703 703
    ///
704 704
    ///\pre Either \ref run(Node) "run()" or \ref init()
705 705
    ///must be called before using this function.
706 706
    Arc predArc(Node v) const { return (*_pred)[v];}
707 707

	
708 708
    ///Returns the 'previous node' of the %DFS tree for the given node.
709 709

	
710 710
    ///This function returns the 'previous node' of the %DFS
711 711
    ///tree for the node \c v, i.e. it returns the last but one node
712 712
    ///of a %DFS path from a root to \c v. It is \c INVALID
713 713
    ///if \c v is not reached from the root(s) or if \c v is a root.
714 714
    ///
715 715
    ///The %DFS tree used here is equal to the %DFS tree used in
716 716
    ///\ref predArc() and \ref predMap().
717 717
    ///
718 718
    ///\pre Either \ref run(Node) "run()" or \ref init()
719 719
    ///must be called before using this function.
720 720
    Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
721 721
                                  G->source((*_pred)[v]); }
722 722

	
723 723
    ///\brief Returns a const reference to the node map that stores the
724 724
    ///distances of the nodes.
725 725
    ///
726 726
    ///Returns a const reference to the node map that stores the
727 727
    ///distances of the nodes calculated by the algorithm.
728 728
    ///
729 729
    ///\pre Either \ref run(Node) "run()" or \ref init()
730 730
    ///must be called before using this function.
731 731
    const DistMap &distMap() const { return *_dist;}
732 732

	
733 733
    ///\brief Returns a const reference to the node map that stores the
734 734
    ///predecessor arcs.
735 735
    ///
736 736
    ///Returns a const reference to the node map that stores the predecessor
737 737
    ///arcs, which form the DFS tree (forest).
738 738
    ///
739 739
    ///\pre Either \ref run(Node) "run()" or \ref init()
740 740
    ///must be called before using this function.
741 741
    const PredMap &predMap() const { return *_pred;}
742 742

	
743 743
    ///Checks if the given node. node is reached from the root(s).
744 744

	
745 745
    ///Returns \c true if \c v is reached from the root(s).
746 746
    ///
747 747
    ///\pre Either \ref run(Node) "run()" or \ref init()
748 748
    ///must be called before using this function.
749 749
    bool reached(Node v) const { return (*_reached)[v]; }
750 750

	
751 751
    ///@}
752 752
  };
753 753

	
754 754
  ///Default traits class of dfs() function.
755 755

	
756 756
  ///Default traits class of dfs() function.
757 757
  ///\tparam GR Digraph type.
758 758
  template<class GR>
759 759
  struct DfsWizardDefaultTraits
760 760
  {
761 761
    ///The type of the digraph the algorithm runs on.
762 762
    typedef GR Digraph;
763 763

	
764 764
    ///\brief The type of the map that stores the predecessor
765 765
    ///arcs of the %DFS paths.
766 766
    ///
767 767
    ///The type of the map that stores the predecessor
768 768
    ///arcs of the %DFS paths.
769 769
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
770 770
    typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
771 771
    ///Instantiates a PredMap.
772 772

	
773 773
    ///This function instantiates a PredMap.
774 774
    ///\param g is the digraph, to which we would like to define the
775 775
    ///PredMap.
776 776
    static PredMap *createPredMap(const Digraph &g)
777 777
    {
778 778
      return new PredMap(g);
779 779
    }
780 780

	
781 781
    ///The type of the map that indicates which nodes are processed.
782 782

	
783 783
    ///The type of the map that indicates which nodes are processed.
784 784
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
785
    ///By default it is a NullMap.
785
    ///By default, it is a NullMap.
786 786
    typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
787 787
    ///Instantiates a ProcessedMap.
788 788

	
789 789
    ///This function instantiates a ProcessedMap.
790 790
    ///\param g is the digraph, to which
791 791
    ///we would like to define the ProcessedMap.
792 792
#ifdef DOXYGEN
793 793
    static ProcessedMap *createProcessedMap(const Digraph &g)
794 794
#else
795 795
    static ProcessedMap *createProcessedMap(const Digraph &)
796 796
#endif
797 797
    {
798 798
      return new ProcessedMap();
799 799
    }
800 800

	
801 801
    ///The type of the map that indicates which nodes are reached.
802 802

	
803 803
    ///The type of the map that indicates which nodes are reached.
804 804
    ///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
805 805
    typedef typename Digraph::template NodeMap<bool> ReachedMap;
806 806
    ///Instantiates a ReachedMap.
807 807

	
808 808
    ///This function instantiates a ReachedMap.
809 809
    ///\param g is the digraph, to which
810 810
    ///we would like to define the ReachedMap.
811 811
    static ReachedMap *createReachedMap(const Digraph &g)
812 812
    {
813 813
      return new ReachedMap(g);
814 814
    }
815 815

	
816 816
    ///The type of the map that stores the distances of the nodes.
817 817

	
818 818
    ///The type of the map that stores the distances of the nodes.
819 819
    ///It must conform to the \ref concepts::WriteMap "WriteMap" concept.
820 820
    typedef typename Digraph::template NodeMap<int> DistMap;
821 821
    ///Instantiates a DistMap.
822 822

	
823 823
    ///This function instantiates a DistMap.
824 824
    ///\param g is the digraph, to which we would like to define
825 825
    ///the DistMap
826 826
    static DistMap *createDistMap(const Digraph &g)
827 827
    {
828 828
      return new DistMap(g);
829 829
    }
830 830

	
831 831
    ///The type of the DFS paths.
832 832

	
833 833
    ///The type of the DFS paths.
834 834
    ///It must conform to the \ref concepts::Path "Path" concept.
835 835
    typedef lemon::Path<Digraph> Path;
836 836
  };
837 837

	
838 838
  /// Default traits class used by DfsWizard
839 839

	
840 840
  /// Default traits class used by DfsWizard.
841 841
  /// \tparam GR The type of the digraph.
842 842
  template<class GR>
843 843
  class DfsWizardBase : public DfsWizardDefaultTraits<GR>
844 844
  {
845 845

	
846 846
    typedef DfsWizardDefaultTraits<GR> Base;
847 847
  protected:
848 848
    //The type of the nodes in the digraph.
849 849
    typedef typename Base::Digraph::Node Node;
850 850

	
851 851
    //Pointer to the digraph the algorithm runs on.
852 852
    void *_g;
853 853
    //Pointer to the map of reached nodes.
854 854
    void *_reached;
855 855
    //Pointer to the map of processed nodes.
856 856
    void *_processed;
857 857
    //Pointer to the map of predecessors arcs.
858 858
    void *_pred;
859 859
    //Pointer to the map of distances.
860 860
    void *_dist;
861 861
    //Pointer to the DFS path to the target node.
862 862
    void *_path;
863 863
    //Pointer to the distance of the target node.
864 864
    int *_di;
865 865

	
866 866
    public:
867 867
    /// Constructor.
868 868

	
869 869
    /// This constructor does not require parameters, it initiates
870 870
    /// all of the attributes to \c 0.
871 871
    DfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0),
872 872
                      _dist(0), _path(0), _di(0) {}
873 873

	
874 874
    /// Constructor.
875 875

	
876 876
    /// This constructor requires one parameter,
877 877
    /// others are initiated to \c 0.
878 878
    /// \param g The digraph the algorithm runs on.
879 879
    DfsWizardBase(const GR &g) :
880 880
      _g(reinterpret_cast<void*>(const_cast<GR*>(&g))),
881 881
      _reached(0), _processed(0), _pred(0), _dist(0),  _path(0), _di(0) {}
882 882

	
883 883
  };
884 884

	
885 885
  /// Auxiliary class for the function-type interface of DFS algorithm.
886 886

	
887 887
  /// This auxiliary class is created to implement the
888 888
  /// \ref dfs() "function-type interface" of \ref Dfs algorithm.
889 889
  /// It does not have own \ref run(Node) "run()" method, it uses the
890 890
  /// functions and features of the plain \ref Dfs.
891 891
  ///
892 892
  /// This class should only be used through the \ref dfs() function,
893 893
  /// which makes it easier to use the algorithm.
894 894
  template<class TR>
895 895
  class DfsWizard : public TR
896 896
  {
897 897
    typedef TR Base;
898 898

	
899 899
    typedef typename TR::Digraph Digraph;
900 900

	
901 901
    typedef typename Digraph::Node Node;
902 902
    typedef typename Digraph::NodeIt NodeIt;
903 903
    typedef typename Digraph::Arc Arc;
904 904
    typedef typename Digraph::OutArcIt OutArcIt;
905 905

	
906 906
    typedef typename TR::PredMap PredMap;
907 907
    typedef typename TR::DistMap DistMap;
908 908
    typedef typename TR::ReachedMap ReachedMap;
909 909
    typedef typename TR::ProcessedMap ProcessedMap;
910 910
    typedef typename TR::Path Path;
911 911

	
912 912
  public:
913 913

	
914 914
    /// Constructor.
915 915
    DfsWizard() : TR() {}
916 916

	
917 917
    /// Constructor that requires parameters.
918 918

	
919 919
    /// Constructor that requires parameters.
920 920
    /// These parameters will be the default values for the traits class.
921 921
    /// \param g The digraph the algorithm runs on.
922 922
    DfsWizard(const Digraph &g) :
923 923
      TR(g) {}
924 924

	
925 925
    ///Copy constructor
926 926
    DfsWizard(const TR &b) : TR(b) {}
927 927

	
928 928
    ~DfsWizard() {}
929 929

	
930 930
    ///Runs DFS algorithm from the given source node.
931 931

	
932 932
    ///This method runs DFS algorithm from node \c s
933 933
    ///in order to compute the DFS path to each node.
934 934
    void run(Node s)
935 935
    {
936 936
      Dfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g));
937 937
      if (Base::_pred)
938 938
        alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
939 939
      if (Base::_dist)
940 940
        alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
941 941
      if (Base::_reached)
942 942
        alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached));
943 943
      if (Base::_processed)
944 944
        alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
945 945
      if (s!=INVALID)
946 946
        alg.run(s);
947 947
      else
948 948
        alg.run();
949 949
    }
950 950

	
951 951
    ///Finds the DFS path between \c s and \c t.
952 952

	
953 953
    ///This method runs DFS algorithm from node \c s
954 954
    ///in order to compute the DFS path to node \c t
955 955
    ///(it stops searching when \c t is processed).
956 956
    ///
957 957
    ///\return \c true if \c t is reachable form \c s.
958 958
    bool run(Node s, Node t)
959 959
    {
960 960
      Dfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g));
961 961
      if (Base::_pred)
962 962
        alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
963 963
      if (Base::_dist)
964 964
        alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
965 965
      if (Base::_reached)
966 966
        alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached));
967 967
      if (Base::_processed)
968 968
        alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
969 969
      alg.run(s,t);
970 970
      if (Base::_path)
971 971
        *reinterpret_cast<Path*>(Base::_path) = alg.path(t);
972 972
      if (Base::_di)
973 973
        *Base::_di = alg.dist(t);
974 974
      return alg.reached(t);
975 975
      }
976 976

	
977 977
    ///Runs DFS algorithm to visit all nodes in the digraph.
978 978

	
979 979
    ///This method runs DFS algorithm in order to compute
980 980
    ///the DFS path to each node.
981 981
    void run()
982 982
    {
983 983
      run(INVALID);
984 984
    }
985 985

	
986 986
    template<class T>
987 987
    struct SetPredMapBase : public Base {
988 988
      typedef T PredMap;
989 989
      static PredMap *createPredMap(const Digraph &) { return 0; };
990 990
      SetPredMapBase(const TR &b) : TR(b) {}
991 991
    };
992 992

	
993 993
    ///\brief \ref named-templ-param "Named parameter" for setting
994 994
    ///the predecessor map.
995 995
    ///
996 996
    ///\ref named-templ-param "Named parameter" function for setting
997 997
    ///the map that stores the predecessor arcs of the nodes.
998 998
    template<class T>
999 999
    DfsWizard<SetPredMapBase<T> > predMap(const T &t)
1000 1000
    {
1001 1001
      Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
1002 1002
      return DfsWizard<SetPredMapBase<T> >(*this);
1003 1003
    }
1004 1004

	
1005 1005
    template<class T>
1006 1006
    struct SetReachedMapBase : public Base {
1007 1007
      typedef T ReachedMap;
1008 1008
      static ReachedMap *createReachedMap(const Digraph &) { return 0; };
1009 1009
      SetReachedMapBase(const TR &b) : TR(b) {}
1010 1010
    };
1011 1011

	
1012 1012
    ///\brief \ref named-templ-param "Named parameter" for setting
1013 1013
    ///the reached map.
1014 1014
    ///
1015 1015
    ///\ref named-templ-param "Named parameter" function for setting
1016 1016
    ///the map that indicates which nodes are reached.
1017 1017
    template<class T>
1018 1018
    DfsWizard<SetReachedMapBase<T> > reachedMap(const T &t)
1019 1019
    {
1020 1020
      Base::_reached=reinterpret_cast<void*>(const_cast<T*>(&t));
1021 1021
      return DfsWizard<SetReachedMapBase<T> >(*this);
1022 1022
    }
1023 1023

	
1024 1024
    template<class T>
1025 1025
    struct SetDistMapBase : public Base {
1026 1026
      typedef T DistMap;
1027 1027
      static DistMap *createDistMap(const Digraph &) { return 0; };
1028 1028
      SetDistMapBase(const TR &b) : TR(b) {}
1029 1029
    };
1030 1030

	
1031 1031
    ///\brief \ref named-templ-param "Named parameter" for setting
1032 1032
    ///the distance map.
1033 1033
    ///
1034 1034
    ///\ref named-templ-param "Named parameter" function for setting
1035 1035
    ///the map that stores the distances of the nodes calculated
1036 1036
    ///by the algorithm.
1037 1037
    template<class T>
1038 1038
    DfsWizard<SetDistMapBase<T> > distMap(const T &t)
1039 1039
    {
1040 1040
      Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t));
1041 1041
      return DfsWizard<SetDistMapBase<T> >(*this);
1042 1042
    }
1043 1043

	
1044 1044
    template<class T>
1045 1045
    struct SetProcessedMapBase : public Base {
1046 1046
      typedef T ProcessedMap;
1047 1047
      static ProcessedMap *createProcessedMap(const Digraph &) { return 0; };
1048 1048
      SetProcessedMapBase(const TR &b) : TR(b) {}
1049 1049
    };
1050 1050

	
1051 1051
    ///\brief \ref named-func-param "Named parameter" for setting
1052 1052
    ///the processed map.
1053 1053
    ///
1054 1054
    ///\ref named-templ-param "Named parameter" function for setting
1055 1055
    ///the map that indicates which nodes are processed.
1056 1056
    template<class T>
1057 1057
    DfsWizard<SetProcessedMapBase<T> > processedMap(const T &t)
1058 1058
    {
1059 1059
      Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t));
1060 1060
      return DfsWizard<SetProcessedMapBase<T> >(*this);
1061 1061
    }
1062 1062

	
1063 1063
    template<class T>
1064 1064
    struct SetPathBase : public Base {
1065 1065
      typedef T Path;
1066 1066
      SetPathBase(const TR &b) : TR(b) {}
1067 1067
    };
1068 1068
    ///\brief \ref named-func-param "Named parameter"
1069 1069
    ///for getting the DFS path to the target node.
1070 1070
    ///
1071 1071
    ///\ref named-func-param "Named parameter"
1072 1072
    ///for getting the DFS path to the target node.
1073 1073
    template<class T>
1074 1074
    DfsWizard<SetPathBase<T> > path(const T &t)
1075 1075
    {
1076 1076
      Base::_path=reinterpret_cast<void*>(const_cast<T*>(&t));
1077 1077
      return DfsWizard<SetPathBase<T> >(*this);
1078 1078
    }
1079 1079

	
1080 1080
    ///\brief \ref named-func-param "Named parameter"
1081 1081
    ///for getting the distance of the target node.
1082 1082
    ///
1083 1083
    ///\ref named-func-param "Named parameter"
1084 1084
    ///for getting the distance of the target node.
1085 1085
    DfsWizard dist(const int &d)
1086 1086
    {
1087 1087
      Base::_di=const_cast<int*>(&d);
1088 1088
      return *this;
1089 1089
    }
1090 1090

	
1091 1091
  };
1092 1092

	
1093 1093
  ///Function-type interface for DFS algorithm.
1094 1094

	
1095 1095
  ///\ingroup search
1096 1096
  ///Function-type interface for DFS algorithm.
1097 1097
  ///
1098 1098
  ///This function also has several \ref named-func-param "named parameters",
1099 1099
  ///they are declared as the members of class \ref DfsWizard.
1100 1100
  ///The following examples show how to use these parameters.
1101 1101
  ///\code
1102 1102
  ///  // Compute the DFS tree
1103 1103
  ///  dfs(g).predMap(preds).distMap(dists).run(s);
1104 1104
  ///
1105 1105
  ///  // Compute the DFS path from s to t
1106 1106
  ///  bool reached = dfs(g).path(p).dist(d).run(s,t);
1107 1107
  ///\endcode
1108 1108
  ///\warning Don't forget to put the \ref DfsWizard::run(Node) "run()"
1109 1109
  ///to the end of the parameter list.
1110 1110
  ///\sa DfsWizard
1111 1111
  ///\sa Dfs
1112 1112
  template<class GR>
1113 1113
  DfsWizard<DfsWizardBase<GR> >
1114 1114
  dfs(const GR &digraph)
1115 1115
  {
1116 1116
    return DfsWizard<DfsWizardBase<GR> >(digraph);
1117 1117
  }
1118 1118

	
1119 1119
#ifdef DOXYGEN
1120 1120
  /// \brief Visitor class for DFS.
1121 1121
  ///
1122 1122
  /// This class defines the interface of the DfsVisit events, and
1123 1123
  /// it could be the base of a real visitor class.
1124 1124
  template <typename GR>
1125 1125
  struct DfsVisitor {
1126 1126
    typedef GR Digraph;
1127 1127
    typedef typename Digraph::Arc Arc;
1128 1128
    typedef typename Digraph::Node Node;
1129 1129
    /// \brief Called for the source node of the DFS.
1130 1130
    ///
1131 1131
    /// This function is called for the source node of the DFS.
1132 1132
    void start(const Node& node) {}
1133 1133
    /// \brief Called when the source node is leaved.
1134 1134
    ///
1135 1135
    /// This function is called when the source node is leaved.
1136 1136
    void stop(const Node& node) {}
1137 1137
    /// \brief Called when a node is reached first time.
1138 1138
    ///
1139 1139
    /// This function is called when a node is reached first time.
1140 1140
    void reach(const Node& node) {}
1141 1141
    /// \brief Called when an arc reaches a new node.
1142 1142
    ///
1143 1143
    /// This function is called when the DFS finds an arc whose target node
1144 1144
    /// is not reached yet.
1145 1145
    void discover(const Arc& arc) {}
1146 1146
    /// \brief Called when an arc is examined but its target node is
1147 1147
    /// already discovered.
1148 1148
    ///
1149 1149
    /// This function is called when an arc is examined but its target node is
1150 1150
    /// already discovered.
1151 1151
    void examine(const Arc& arc) {}
1152 1152
    /// \brief Called when the DFS steps back from a node.
1153 1153
    ///
1154 1154
    /// This function is called when the DFS steps back from a node.
1155 1155
    void leave(const Node& node) {}
1156 1156
    /// \brief Called when the DFS steps back on an arc.
1157 1157
    ///
1158 1158
    /// This function is called when the DFS steps back on an arc.
1159 1159
    void backtrack(const Arc& arc) {}
1160 1160
  };
1161 1161
#else
1162 1162
  template <typename GR>
1163 1163
  struct DfsVisitor {
1164 1164
    typedef GR Digraph;
1165 1165
    typedef typename Digraph::Arc Arc;
1166 1166
    typedef typename Digraph::Node Node;
1167 1167
    void start(const Node&) {}
1168 1168
    void stop(const Node&) {}
1169 1169
    void reach(const Node&) {}

Changeset was too big and was cut off... Show full diff

0 comments (0 inline)