1 | 1 |
/* -*- C++ -*- |
2 | 2 |
* |
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* This file is a part of LEMON, a generic C++ optimization library |
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* |
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* Copyright (C) 2003-2008 |
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* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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* (Egervary Research Group on Combinatorial Optimization, EGRES). |
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* |
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* Permission to use, modify and distribute this software is granted |
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* provided that this copyright notice appears in all copies. For |
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* precise terms see the accompanying LICENSE file. |
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* |
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* This software is provided "AS IS" with no warranty of any kind, |
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* express or implied, and with no claim as to its suitability for any |
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* purpose. |
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* |
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*/ |
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|
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#ifndef LEMON_BFS_H |
20 | 20 |
#define LEMON_BFS_H |
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|
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///\ingroup search |
23 | 23 |
///\file |
24 | 24 |
///\brief Bfs algorithm. |
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|
26 | 26 |
#include <lemon/list_graph.h> |
27 | 27 |
#include <lemon/graph_utils.h> |
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#include <lemon/bits/path_dump.h> |
29 | 29 |
#include <lemon/bits/invalid.h> |
30 | 30 |
#include <lemon/error.h> |
31 | 31 |
#include <lemon/maps.h> |
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|
33 | 33 |
namespace lemon { |
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|
35 | 35 |
|
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|
37 | 37 |
///Default traits class of Bfs class. |
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|
39 | 39 |
///Default traits class of Bfs class. |
40 | 40 |
///\tparam GR Digraph type. |
41 | 41 |
template<class GR> |
42 | 42 |
struct BfsDefaultTraits |
43 | 43 |
{ |
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///The digraph type the algorithm runs on. |
45 | 45 |
typedef GR Digraph; |
46 | 46 |
///\brief The type of the map that stores the last |
47 | 47 |
///arcs of the shortest paths. |
48 | 48 |
/// |
49 | 49 |
///The type of the map that stores the last |
50 | 50 |
///arcs of the shortest paths. |
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///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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/// |
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typedef typename Digraph::template NodeMap<typename GR::Arc> PredMap; |
54 | 54 |
///Instantiates a PredMap. |
55 | 55 |
|
56 | 56 |
///This function instantiates a \ref PredMap. |
57 | 57 |
///\param G is the digraph, to which we would like to define the PredMap. |
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///\todo The digraph alone may be insufficient to initialize |
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static PredMap *createPredMap(const GR &G) |
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{ |
61 | 61 |
return new PredMap(G); |
62 | 62 |
} |
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///The type of the map that indicates which nodes are processed. |
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|
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///The type of the map that indicates which nodes are processed. |
66 | 66 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
67 | 67 |
///\todo named parameter to set this type, function to read and write. |
68 | 68 |
typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
69 | 69 |
///Instantiates a ProcessedMap. |
70 | 70 |
|
71 | 71 |
///This function instantiates a \ref ProcessedMap. |
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///\param g is the digraph, to which |
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///we would like to define the \ref ProcessedMap |
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#ifdef DOXYGEN |
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static ProcessedMap *createProcessedMap(const GR &g) |
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#else |
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static ProcessedMap *createProcessedMap(const GR &) |
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#endif |
79 | 79 |
{ |
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return new ProcessedMap(); |
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} |
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///The type of the map that indicates which nodes are reached. |
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|
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///The type of the map that indicates which nodes are reached. |
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///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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///\todo named parameter to set this type, function to read and write. |
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typedef typename Digraph::template NodeMap<bool> ReachedMap; |
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///Instantiates a ReachedMap. |
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|
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///This function instantiates a \ref ReachedMap. |
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///\param G is the digraph, to which |
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///we would like to define the \ref ReachedMap. |
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static ReachedMap *createReachedMap(const GR &G) |
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{ |
95 | 95 |
return new ReachedMap(G); |
96 | 96 |
} |
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///The type of the map that stores the dists of the nodes. |
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|
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///The type of the map that stores the dists of the nodes. |
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///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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/// |
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typedef typename Digraph::template NodeMap<int> DistMap; |
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///Instantiates a DistMap. |
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|
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///This function instantiates a \ref DistMap. |
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///\param G is the digraph, to which we would like to define the \ref DistMap |
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static DistMap *createDistMap(const GR &G) |
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{ |
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return new DistMap(G); |
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} |
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}; |
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|
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///%BFS algorithm class. |
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|
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///\ingroup search |
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///This class provides an efficient implementation of the %BFS algorithm. |
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/// |
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///\tparam GR The digraph type the algorithm runs on. The default value is |
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///\ref ListDigraph. The value of GR is not used directly by Bfs, it |
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///is only passed to \ref BfsDefaultTraits. |
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///\tparam TR Traits class to set various data types used by the algorithm. |
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///The default traits class is |
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///\ref BfsDefaultTraits "BfsDefaultTraits<GR>". |
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///See \ref BfsDefaultTraits for the documentation of |
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///a Bfs traits class. |
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|
127 | 127 |
#ifdef DOXYGEN |
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template <typename GR, |
129 | 129 |
typename TR> |
130 | 130 |
#else |
131 | 131 |
template <typename GR=ListDigraph, |
132 | 132 |
typename TR=BfsDefaultTraits<GR> > |
133 | 133 |
#endif |
134 | 134 |
class Bfs { |
135 | 135 |
public: |
136 | 136 |
/** |
137 | 137 |
* \brief \ref Exception for uninitialized parameters. |
138 | 138 |
* |
139 | 139 |
* This error represents problems in the initialization |
140 | 140 |
* of the parameters of the algorithms. |
141 | 141 |
*/ |
142 | 142 |
class UninitializedParameter : public lemon::UninitializedParameter { |
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public: |
144 | 144 |
virtual const char* what() const throw() { |
145 | 145 |
return "lemon::Bfs::UninitializedParameter"; |
146 | 146 |
} |
147 | 147 |
}; |
148 | 148 |
|
149 | 149 |
typedef TR Traits; |
150 | 150 |
///The type of the underlying digraph. |
151 | 151 |
typedef typename TR::Digraph Digraph; |
152 | 152 |
|
153 | 153 |
///\brief The type of the map that stores the last |
154 | 154 |
///arcs of the shortest paths. |
155 | 155 |
typedef typename TR::PredMap PredMap; |
156 | 156 |
///The type of the map indicating which nodes are reached. |
157 | 157 |
typedef typename TR::ReachedMap ReachedMap; |
158 | 158 |
///The type of the map indicating which nodes are processed. |
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typedef typename TR::ProcessedMap ProcessedMap; |
160 | 160 |
///The type of the map that stores the dists of the nodes. |
161 | 161 |
typedef typename TR::DistMap DistMap; |
162 | 162 |
private: |
163 | 163 |
|
164 | 164 |
typedef typename Digraph::Node Node; |
165 | 165 |
typedef typename Digraph::NodeIt NodeIt; |
166 | 166 |
typedef typename Digraph::Arc Arc; |
167 | 167 |
typedef typename Digraph::OutArcIt OutArcIt; |
168 | 168 |
|
169 | 169 |
/// Pointer to the underlying digraph. |
170 | 170 |
const Digraph *G; |
171 | 171 |
///Pointer to the map of predecessors arcs. |
172 | 172 |
PredMap *_pred; |
173 | 173 |
///Indicates if \ref _pred is locally allocated (\c true) or not. |
174 | 174 |
bool local_pred; |
175 | 175 |
///Pointer to the map of distances. |
176 | 176 |
DistMap *_dist; |
177 | 177 |
///Indicates if \ref _dist is locally allocated (\c true) or not. |
178 | 178 |
bool local_dist; |
179 | 179 |
///Pointer to the map of reached status of the nodes. |
180 | 180 |
ReachedMap *_reached; |
181 | 181 |
///Indicates if \ref _reached is locally allocated (\c true) or not. |
182 | 182 |
bool local_reached; |
183 | 183 |
///Pointer to the map of processed status of the nodes. |
184 | 184 |
ProcessedMap *_processed; |
185 | 185 |
///Indicates if \ref _processed is locally allocated (\c true) or not. |
186 | 186 |
bool local_processed; |
187 | 187 |
|
188 | 188 |
std::vector<typename Digraph::Node> _queue; |
189 | 189 |
int _queue_head,_queue_tail,_queue_next_dist; |
190 | 190 |
int _curr_dist; |
191 | 191 |
|
192 | 192 |
///Creates the maps if necessary. |
193 | 193 |
|
194 | 194 |
///\todo Better memory allocation (instead of new). |
195 | 195 |
void create_maps() |
196 | 196 |
{ |
197 | 197 |
if(!_pred) { |
198 | 198 |
local_pred = true; |
199 | 199 |
_pred = Traits::createPredMap(*G); |
200 | 200 |
} |
201 | 201 |
if(!_dist) { |
202 | 202 |
local_dist = true; |
203 | 203 |
_dist = Traits::createDistMap(*G); |
204 | 204 |
} |
205 | 205 |
if(!_reached) { |
206 | 206 |
local_reached = true; |
207 | 207 |
_reached = Traits::createReachedMap(*G); |
208 | 208 |
} |
209 | 209 |
if(!_processed) { |
210 | 210 |
local_processed = true; |
211 | 211 |
_processed = Traits::createProcessedMap(*G); |
212 | 212 |
} |
213 | 213 |
} |
214 | 214 |
|
215 | 215 |
protected: |
216 | 216 |
|
217 | 217 |
Bfs() {} |
218 | 218 |
|
219 | 219 |
public: |
220 | 220 |
|
221 | 221 |
typedef Bfs Create; |
222 | 222 |
|
223 | 223 |
///\name Named template parameters |
224 | 224 |
|
225 | 225 |
///@{ |
226 | 226 |
|
227 | 227 |
template <class T> |
228 | 228 |
struct DefPredMapTraits : public Traits { |
229 | 229 |
typedef T PredMap; |
230 | 230 |
static PredMap *createPredMap(const Digraph &) |
231 | 231 |
{ |
232 | 232 |
throw UninitializedParameter(); |
233 | 233 |
} |
234 | 234 |
}; |
235 | 235 |
///\brief \ref named-templ-param "Named parameter" for setting |
236 | 236 |
///PredMap type |
237 | 237 |
/// |
238 | 238 |
///\ref named-templ-param "Named parameter" for setting PredMap type |
239 | 239 |
/// |
240 | 240 |
template <class T> |
241 | 241 |
struct DefPredMap : public Bfs< Digraph, DefPredMapTraits<T> > { |
242 | 242 |
typedef Bfs< Digraph, DefPredMapTraits<T> > Create; |
243 | 243 |
}; |
244 | 244 |
|
245 | 245 |
template <class T> |
246 | 246 |
struct DefDistMapTraits : public Traits { |
247 | 247 |
typedef T DistMap; |
248 | 248 |
static DistMap *createDistMap(const Digraph &) |
249 | 249 |
{ |
250 | 250 |
throw UninitializedParameter(); |
251 | 251 |
} |
252 | 252 |
}; |
253 | 253 |
///\brief \ref named-templ-param "Named parameter" for setting |
254 | 254 |
///DistMap type |
255 | 255 |
/// |
256 | 256 |
///\ref named-templ-param "Named parameter" for setting DistMap type |
257 | 257 |
/// |
258 | 258 |
template <class T> |
259 | 259 |
struct DefDistMap : public Bfs< Digraph, DefDistMapTraits<T> > { |
260 | 260 |
typedef Bfs< Digraph, DefDistMapTraits<T> > Create; |
261 | 261 |
}; |
262 | 262 |
|
263 | 263 |
template <class T> |
264 | 264 |
struct DefReachedMapTraits : public Traits { |
265 | 265 |
typedef T ReachedMap; |
266 | 266 |
static ReachedMap *createReachedMap(const Digraph &) |
267 | 267 |
{ |
268 | 268 |
throw UninitializedParameter(); |
269 | 269 |
} |
270 | 270 |
}; |
271 | 271 |
///\brief \ref named-templ-param "Named parameter" for setting |
272 | 272 |
///ReachedMap type |
273 | 273 |
/// |
274 | 274 |
///\ref named-templ-param "Named parameter" for setting ReachedMap type |
275 | 275 |
/// |
276 | 276 |
template <class T> |
277 | 277 |
struct DefReachedMap : public Bfs< Digraph, DefReachedMapTraits<T> > { |
278 | 278 |
typedef Bfs< Digraph, DefReachedMapTraits<T> > Create; |
279 | 279 |
}; |
280 | 280 |
|
281 | 281 |
template <class T> |
282 | 282 |
struct DefProcessedMapTraits : public Traits { |
283 | 283 |
typedef T ProcessedMap; |
284 | 284 |
static ProcessedMap *createProcessedMap(const Digraph &) |
285 | 285 |
{ |
286 | 286 |
throw UninitializedParameter(); |
287 | 287 |
} |
288 | 288 |
}; |
289 | 289 |
///\brief \ref named-templ-param "Named parameter" for setting |
290 | 290 |
///ProcessedMap type |
291 | 291 |
/// |
292 | 292 |
///\ref named-templ-param "Named parameter" for setting ProcessedMap type |
293 | 293 |
/// |
294 | 294 |
template <class T> |
295 | 295 |
struct DefProcessedMap : public Bfs< Digraph, DefProcessedMapTraits<T> > { |
296 | 296 |
typedef Bfs< Digraph, DefProcessedMapTraits<T> > Create; |
297 | 297 |
}; |
298 | 298 |
|
299 | 299 |
struct DefDigraphProcessedMapTraits : public Traits { |
300 | 300 |
typedef typename Digraph::template NodeMap<bool> ProcessedMap; |
301 | 301 |
static ProcessedMap *createProcessedMap(const Digraph &G) |
302 | 302 |
{ |
303 | 303 |
return new ProcessedMap(G); |
304 | 304 |
} |
305 | 305 |
}; |
306 | 306 |
///\brief \ref named-templ-param "Named parameter" |
307 | 307 |
///for setting the ProcessedMap type to be Digraph::NodeMap<bool>. |
308 | 308 |
/// |
309 | 309 |
///\ref named-templ-param "Named parameter" |
310 | 310 |
///for setting the ProcessedMap type to be Digraph::NodeMap<bool>. |
311 | 311 |
///If you don't set it explicitly, it will be automatically allocated. |
312 | 312 |
template <class T> |
313 | 313 |
struct DefProcessedMapToBeDefaultMap : |
314 | 314 |
public Bfs< Digraph, DefDigraphProcessedMapTraits> { |
315 | 315 |
typedef Bfs< Digraph, DefDigraphProcessedMapTraits> Create; |
316 | 316 |
}; |
317 | 317 |
|
318 | 318 |
///@} |
319 | 319 |
|
320 | 320 |
public: |
321 | 321 |
|
322 | 322 |
///Constructor. |
323 | 323 |
|
324 | 324 |
///\param _G the digraph the algorithm will run on. |
325 | 325 |
/// |
326 | 326 |
Bfs(const Digraph& _G) : |
327 | 327 |
G(&_G), |
328 | 328 |
_pred(NULL), local_pred(false), |
329 | 329 |
_dist(NULL), local_dist(false), |
330 | 330 |
_reached(NULL), local_reached(false), |
331 | 331 |
_processed(NULL), local_processed(false) |
332 | 332 |
{ } |
333 | 333 |
|
334 | 334 |
///Destructor. |
335 | 335 |
~Bfs() |
336 | 336 |
{ |
337 | 337 |
if(local_pred) delete _pred; |
338 | 338 |
if(local_dist) delete _dist; |
339 | 339 |
if(local_reached) delete _reached; |
340 | 340 |
if(local_processed) delete _processed; |
341 | 341 |
} |
342 | 342 |
|
343 | 343 |
///Sets the map storing the predecessor arcs. |
344 | 344 |
|
345 | 345 |
///Sets the map storing the predecessor arcs. |
346 | 346 |
///If you don't use this function before calling \ref run(), |
347 | 347 |
///it will allocate one. The destructor deallocates this |
348 | 348 |
///automatically allocated map, of course. |
349 | 349 |
///\return <tt> (*this) </tt> |
350 | 350 |
Bfs &predMap(PredMap &m) |
351 | 351 |
{ |
352 | 352 |
if(local_pred) { |
353 | 353 |
delete _pred; |
354 | 354 |
local_pred=false; |
355 | 355 |
} |
356 | 356 |
_pred = &m; |
357 | 357 |
return *this; |
358 | 358 |
} |
359 | 359 |
|
360 | 360 |
///Sets the map indicating the reached nodes. |
361 | 361 |
|
362 | 362 |
///Sets the map indicating the reached nodes. |
363 | 363 |
///If you don't use this function before calling \ref run(), |
364 | 364 |
///it will allocate one. The destructor deallocates this |
365 | 365 |
///automatically allocated map, of course. |
366 | 366 |
///\return <tt> (*this) </tt> |
367 | 367 |
Bfs &reachedMap(ReachedMap &m) |
368 | 368 |
{ |
369 | 369 |
if(local_reached) { |
370 | 370 |
delete _reached; |
371 | 371 |
local_reached=false; |
372 | 372 |
} |
373 | 373 |
_reached = &m; |
374 | 374 |
return *this; |
375 | 375 |
} |
376 | 376 |
|
377 | 377 |
///Sets the map indicating the processed nodes. |
378 | 378 |
|
379 | 379 |
///Sets the map indicating the processed nodes. |
380 | 380 |
///If you don't use this function before calling \ref run(), |
381 | 381 |
///it will allocate one. The destructor deallocates this |
382 | 382 |
///automatically allocated map, of course. |
383 | 383 |
///\return <tt> (*this) </tt> |
384 | 384 |
Bfs &processedMap(ProcessedMap &m) |
385 | 385 |
{ |
386 | 386 |
if(local_processed) { |
387 | 387 |
delete _processed; |
388 | 388 |
local_processed=false; |
389 | 389 |
} |
390 | 390 |
_processed = &m; |
391 | 391 |
return *this; |
392 | 392 |
} |
393 | 393 |
|
394 | 394 |
///Sets the map storing the distances calculated by the algorithm. |
395 | 395 |
|
396 | 396 |
///Sets the map storing the distances calculated by the algorithm. |
397 | 397 |
///If you don't use this function before calling \ref run(), |
398 | 398 |
///it will allocate one. The destructor deallocates this |
399 | 399 |
///automatically allocated map, of course. |
400 | 400 |
///\return <tt> (*this) </tt> |
401 | 401 |
Bfs &distMap(DistMap &m) |
402 | 402 |
{ |
403 | 403 |
if(local_dist) { |
404 | 404 |
delete _dist; |
405 | 405 |
local_dist=false; |
406 | 406 |
} |
407 | 407 |
_dist = &m; |
408 | 408 |
return *this; |
409 | 409 |
} |
410 | 410 |
|
411 | 411 |
public: |
412 | 412 |
///\name Execution control |
413 | 413 |
///The simplest way to execute the algorithm is to use |
414 | 414 |
///one of the member functions called \c run(...). |
415 | 415 |
///\n |
416 | 416 |
///If you need more control on the execution, |
417 | 417 |
///first you must call \ref init(), then you can add several source nodes |
418 | 418 |
///with \ref addSource(). |
419 | 419 |
///Finally \ref start() will perform the actual path |
420 | 420 |
///computation. |
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 |
/// |
428 | 428 |
void init() |
429 | 429 |
{ |
430 | 430 |
create_maps(); |
431 | 431 |
_queue.resize(countNodes(*G)); |
432 | 432 |
_queue_head=_queue_tail=0; |
433 | 433 |
_curr_dist=1; |
434 | 434 |
for ( NodeIt u(*G) ; u!=INVALID ; ++u ) { |
435 | 435 |
_pred->set(u,INVALID); |
436 | 436 |
_reached->set(u,false); |
437 | 437 |
_processed->set(u,false); |
438 | 438 |
} |
439 | 439 |
} |
440 | 440 |
|
441 | 441 |
///Adds a new source node. |
442 | 442 |
|
443 | 443 |
///Adds a new source node to the set of nodes to be processed. |
444 | 444 |
/// |
445 | 445 |
void addSource(Node s) |
446 | 446 |
{ |
447 | 447 |
if(!(*_reached)[s]) |
448 | 448 |
{ |
449 | 449 |
_reached->set(s,true); |
450 | 450 |
_pred->set(s,INVALID); |
451 | 451 |
_dist->set(s,0); |
452 | 452 |
_queue[_queue_head++]=s; |
453 | 453 |
_queue_next_dist=_queue_head; |
454 | 454 |
} |
455 | 455 |
} |
456 | 456 |
|
457 | 457 |
///Processes the next node. |
458 | 458 |
|
459 | 459 |
///Processes the next node. |
460 | 460 |
/// |
461 | 461 |
///\return The processed node. |
462 | 462 |
/// |
463 | 463 |
///\warning The queue must not be empty! |
464 | 464 |
Node processNextNode() |
465 | 465 |
{ |
466 | 466 |
if(_queue_tail==_queue_next_dist) { |
467 | 467 |
_curr_dist++; |
468 | 468 |
_queue_next_dist=_queue_head; |
469 | 469 |
} |
470 | 470 |
Node n=_queue[_queue_tail++]; |
471 | 471 |
_processed->set(n,true); |
472 | 472 |
Node m; |
473 | 473 |
for(OutArcIt e(*G,n);e!=INVALID;++e) |
474 | 474 |
if(!(*_reached)[m=G->target(e)]) { |
475 | 475 |
_queue[_queue_head++]=m; |
476 | 476 |
_reached->set(m,true); |
477 | 477 |
_pred->set(m,e); |
478 | 478 |
_dist->set(m,_curr_dist); |
479 | 479 |
} |
480 | 480 |
return n; |
481 | 481 |
} |
482 | 482 |
|
483 | 483 |
///Processes the next node. |
484 | 484 |
|
485 | 485 |
///Processes the next node. And checks that the given target node |
486 | 486 |
///is reached. If the target node is reachable from the processed |
487 | 487 |
///node then the reached parameter will be set true. The reached |
488 | 488 |
///parameter should be initially false. |
489 | 489 |
/// |
490 | 490 |
///\param target The target node. |
491 | 491 |
///\retval reach Indicates that the target node is reached. |
492 | 492 |
///\return The processed node. |
493 | 493 |
/// |
494 | 494 |
///\warning 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 that at least one of |
518 | 518 |
///reached node has true value in the \c nm node map. If one node |
519 | 519 |
///with true value is reachable from the processed node then the |
520 | 520 |
///rnode parameter will be set to the first of such nodes. |
521 | 521 |
/// |
522 | 522 |
///\param nm The node map of possible targets. |
523 | 523 |
///\retval rnode The reached target node. |
524 | 524 |
///\return The processed node. |
525 | 525 |
/// |
526 | 526 |
///\warning The queue must not be empty! |
527 | 527 |
template<class NM> |
528 | 528 |
Node processNextNode(const NM& nm, Node& rnode) |
529 | 529 |
{ |
530 | 530 |
if(_queue_tail==_queue_next_dist) { |
531 | 531 |
_curr_dist++; |
532 | 532 |
_queue_next_dist=_queue_head; |
533 | 533 |
} |
534 | 534 |
Node n=_queue[_queue_tail++]; |
535 | 535 |
_processed->set(n,true); |
536 | 536 |
Node m; |
537 | 537 |
for(OutArcIt e(*G,n);e!=INVALID;++e) |
538 | 538 |
if(!(*_reached)[m=G->target(e)]) { |
539 | 539 |
_queue[_queue_head++]=m; |
540 | 540 |
_reached->set(m,true); |
541 | 541 |
_pred->set(m,e); |
542 | 542 |
_dist->set(m,_curr_dist); |
543 | 543 |
if (nm[m] && rnode == INVALID) rnode = m; |
544 | 544 |
} |
545 | 545 |
return n; |
546 | 546 |
} |
547 | 547 |
|
548 | 548 |
///Next node to be processed. |
549 | 549 |
|
550 | 550 |
///Next node to be processed. |
551 | 551 |
/// |
552 | 552 |
///\return The next node to be processed or INVALID if the queue is |
553 | 553 |
/// empty. |
554 | 554 |
Node nextNode() |
555 | 555 |
{ |
556 | 556 |
return _queue_tail<_queue_head?_queue[_queue_tail]:INVALID; |
557 | 557 |
} |
558 | 558 |
|
559 | 559 |
///\brief Returns \c false if there are nodes |
560 | 560 |
///to be processed in the queue |
561 | 561 |
/// |
562 | 562 |
///Returns \c false if there are nodes |
563 | 563 |
///to be processed in the queue |
564 | 564 |
bool emptyQueue() { return _queue_tail==_queue_head; } |
565 | 565 |
///Returns the number of the nodes to be processed. |
566 | 566 |
|
567 | 567 |
///Returns the number of the nodes to be processed in the queue. |
568 | 568 |
int queueSize() { return _queue_head-_queue_tail; } |
569 | 569 |
|
570 | 570 |
///Executes the algorithm. |
571 | 571 |
|
572 | 572 |
///Executes the algorithm. |
573 | 573 |
/// |
574 | 574 |
///\pre init() must be called and at least one node should be added |
575 | 575 |
///with addSource() before using this function. |
576 | 576 |
/// |
577 | 577 |
///This method runs the %BFS algorithm from the root node(s) |
578 | 578 |
///in order to |
579 | 579 |
///compute the |
580 | 580 |
///shortest path to each node. The algorithm computes |
581 | 581 |
///- The shortest path tree. |
582 | 582 |
///- The distance of each node from the root(s). |
583 | 583 |
void start() |
584 | 584 |
{ |
585 | 585 |
while ( !emptyQueue() ) processNextNode(); |
586 | 586 |
} |
587 | 587 |
|
588 | 588 |
///Executes the algorithm until \c dest is reached. |
589 | 589 |
|
590 | 590 |
///Executes the algorithm until \c dest is reached. |
591 | 591 |
/// |
592 | 592 |
///\pre init() must be called and at least one node should be added |
593 | 593 |
///with addSource() before using this function. |
594 | 594 |
/// |
595 | 595 |
///This method runs the %BFS algorithm from the root node(s) |
596 | 596 |
///in order to compute the shortest path to \c dest. |
597 | 597 |
///The algorithm computes |
598 | 598 |
///- The shortest path to \c dest. |
599 | 599 |
///- The distance of \c dest from the root(s). |
600 | 600 |
void start(Node dest) |
601 | 601 |
{ |
602 | 602 |
bool reach = false; |
603 | 603 |
while ( !emptyQueue() && !reach ) processNextNode(dest, reach); |
604 | 604 |
} |
605 | 605 |
|
606 | 606 |
///Executes the algorithm until a condition is met. |
607 | 607 |
|
608 | 608 |
///Executes the algorithm until a condition is met. |
609 | 609 |
/// |
610 | 610 |
///\pre init() must be called and at least one node should be added |
611 | 611 |
///with addSource() before using this function. |
612 | 612 |
/// |
613 | 613 |
///\param nm must be a bool (or convertible) node map. The |
614 | 614 |
///algorithm will stop when it reaches a node \c v with |
615 | 615 |
/// <tt>nm[v]</tt> true. |
616 | 616 |
/// |
617 | 617 |
///\return The reached node \c v with <tt>nm[v]</tt> true or |
618 | 618 |
///\c INVALID if no such node was found. |
619 | 619 |
template<class NM> |
620 | 620 |
Node start(const NM &nm) |
621 | 621 |
{ |
622 | 622 |
Node rnode = INVALID; |
623 | 623 |
while ( !emptyQueue() && rnode == INVALID ) { |
624 | 624 |
processNextNode(nm, rnode); |
625 | 625 |
} |
626 | 626 |
return rnode; |
627 | 627 |
} |
628 | 628 |
|
629 | 629 |
///Runs %BFS algorithm from node \c s. |
630 | 630 |
|
631 | 631 |
///This method runs the %BFS algorithm from a root node \c s |
632 | 632 |
///in order to |
633 | 633 |
///compute the |
634 | 634 |
///shortest path to each node. The algorithm computes |
635 | 635 |
///- The shortest path tree. |
636 | 636 |
///- The distance of each node from the root. |
637 | 637 |
/// |
638 | 638 |
///\note b.run(s) is just a shortcut of the following code. |
639 | 639 |
///\code |
640 | 640 |
/// b.init(); |
641 | 641 |
/// b.addSource(s); |
642 | 642 |
/// b.start(); |
643 | 643 |
///\endcode |
644 | 644 |
void run(Node s) { |
645 | 645 |
init(); |
646 | 646 |
addSource(s); |
647 | 647 |
start(); |
648 | 648 |
} |
649 | 649 |
|
650 | 650 |
///Finds the shortest path between \c s and \c t. |
651 | 651 |
|
652 | 652 |
///Finds the shortest path between \c s and \c t. |
653 | 653 |
/// |
654 | 654 |
///\return The length of the shortest s---t path if there exists one, |
655 | 655 |
///0 otherwise. |
656 | 656 |
///\note Apart from the return value, b.run(s) is |
657 | 657 |
///just a shortcut of the following code. |
658 | 658 |
///\code |
659 | 659 |
/// b.init(); |
660 | 660 |
/// b.addSource(s); |
661 | 661 |
/// b.start(t); |
662 | 662 |
///\endcode |
663 | 663 |
int run(Node s,Node t) { |
664 | 664 |
init(); |
665 | 665 |
addSource(s); |
666 | 666 |
start(t); |
667 | 667 |
return reached(t) ? _curr_dist : 0; |
668 | 668 |
} |
669 | 669 |
|
670 | 670 |
///@} |
671 | 671 |
|
672 | 672 |
///\name Query Functions |
673 | 673 |
///The result of the %BFS algorithm can be obtained using these |
674 | 674 |
///functions.\n |
675 | 675 |
///Before the use of these functions, |
676 | 676 |
///either run() or start() must be calleb. |
677 | 677 |
|
678 | 678 |
///@{ |
679 | 679 |
|
680 | 680 |
typedef PredMapPath<Digraph, PredMap> Path; |
681 | 681 |
|
682 | 682 |
///Gives back the shortest path. |
683 | 683 |
|
684 | 684 |
///Gives back the shortest path. |
685 | 685 |
///\pre The \c t should be reachable from the source. |
686 | 686 |
Path path(Node t) |
687 | 687 |
{ |
688 | 688 |
return Path(*G, *_pred, t); |
689 | 689 |
} |
690 | 690 |
|
691 | 691 |
///The distance of a node from the root(s). |
692 | 692 |
|
693 | 693 |
///Returns the distance of a node from the root(s). |
694 | 694 |
///\pre \ref run() must be called before using this function. |
695 | 695 |
///\warning If node \c v in unreachable from the root(s) the return value |
696 | 696 |
///of this function is undefined. |
697 | 697 |
int dist(Node v) const { return (*_dist)[v]; } |
698 | 698 |
|
699 | 699 |
///Returns the 'previous arc' of the shortest path tree. |
700 | 700 |
|
701 | 701 |
///For a node \c v it returns the 'previous arc' |
702 | 702 |
///of the shortest path tree, |
703 | 703 |
///i.e. it returns the last arc of a shortest path from the root(s) to \c |
704 | 704 |
///v. It is \ref INVALID |
705 | 705 |
///if \c v is unreachable from the root(s) or \c v is a root. The |
706 | 706 |
///shortest path tree used here is equal to the shortest path tree used in |
707 | 707 |
///\ref predNode(). |
708 | 708 |
///\pre Either \ref run() or \ref start() must be called before using |
709 | 709 |
///this function. |
710 | 710 |
Arc predArc(Node v) const { return (*_pred)[v];} |
711 | 711 |
|
712 | 712 |
///Returns the 'previous node' of the shortest path tree. |
713 | 713 |
|
714 | 714 |
///For a node \c v it returns the 'previous node' |
715 | 715 |
///of the shortest path tree, |
716 | 716 |
///i.e. it returns the last but one node from a shortest path from the |
717 | 717 |
///root(a) to \c /v. |
718 | 718 |
///It is INVALID if \c v is unreachable from the root(s) or |
719 | 719 |
///if \c v itself a root. |
720 | 720 |
///The shortest path tree used here is equal to the shortest path |
721 | 721 |
///tree used in \ref predArc(). |
722 | 722 |
///\pre Either \ref run() or \ref start() must be called before |
723 | 723 |
///using this function. |
724 | 724 |
Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID: |
725 | 725 |
G->source((*_pred)[v]); } |
726 | 726 |
|
727 | 727 |
///Returns a reference to the NodeMap of distances. |
728 | 728 |
|
729 | 729 |
///Returns a reference to the NodeMap of distances. |
730 | 730 |
///\pre Either \ref run() or \ref init() must |
731 | 731 |
///be called before using this function. |
732 | 732 |
const DistMap &distMap() const { return *_dist;} |
733 | 733 |
|
734 | 734 |
///Returns a reference to the shortest path tree map. |
735 | 735 |
|
736 | 736 |
///Returns a reference to the NodeMap of the arcs of the |
737 | 737 |
///shortest path tree. |
738 | 738 |
///\pre Either \ref run() or \ref init() |
739 | 739 |
///must be called before using this function. |
740 | 740 |
const PredMap &predMap() const { return *_pred;} |
741 | 741 |
|
742 | 742 |
///Checks if a node is reachable from the root. |
743 | 743 |
|
744 | 744 |
///Returns \c true if \c v is reachable from the root. |
745 | 745 |
///\warning The source nodes are indicated as unreached. |
746 | 746 |
///\pre Either \ref run() or \ref start() |
747 | 747 |
///must be called before using this function. |
748 | 748 |
/// |
749 | 749 |
bool reached(Node v) { return (*_reached)[v]; } |
750 | 750 |
|
751 | 751 |
///@} |
752 | 752 |
}; |
753 | 753 |
|
754 | 754 |
///Default traits class of Bfs function. |
755 | 755 |
|
756 | 756 |
///Default traits class of Bfs function. |
757 | 757 |
///\tparam GR Digraph type. |
758 | 758 |
template<class GR> |
759 | 759 |
struct BfsWizardDefaultTraits |
760 | 760 |
{ |
761 | 761 |
///The digraph type the algorithm runs on. |
762 | 762 |
typedef GR Digraph; |
763 | 763 |
///\brief The type of the map that stores the last |
764 | 764 |
///arcs of the shortest paths. |
765 | 765 |
/// |
766 | 766 |
///The type of the map that stores the last |
767 | 767 |
///arcs of the shortest paths. |
768 | 768 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
769 | 769 |
/// |
770 | 770 |
typedef NullMap<typename Digraph::Node,typename GR::Arc> PredMap; |
771 | 771 |
///Instantiates a PredMap. |
772 | 772 |
|
773 | 773 |
///This function instantiates a \ref PredMap. |
774 | 774 |
///\param g is the digraph, to which we would like to define the PredMap. |
775 | 775 |
///\todo The digraph alone may be insufficient to initialize |
776 | 776 |
#ifdef DOXYGEN |
777 | 777 |
static PredMap *createPredMap(const GR &g) |
778 | 778 |
#else |
779 | 779 |
static PredMap *createPredMap(const GR &) |
780 | 780 |
#endif |
781 | 781 |
{ |
782 | 782 |
return new PredMap(); |
783 | 783 |
} |
784 | 784 |
|
785 | 785 |
///The type of the map that indicates which nodes are processed. |
786 | 786 |
|
787 | 787 |
///The type of the map that indicates which nodes are processed. |
788 | 788 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
789 | 789 |
///\todo named parameter to set this type, function to read and write. |
790 | 790 |
typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
791 | 791 |
///Instantiates a ProcessedMap. |
792 | 792 |
|
793 | 793 |
///This function instantiates a \ref ProcessedMap. |
794 | 794 |
///\param g is the digraph, to which |
795 | 795 |
///we would like to define the \ref ProcessedMap |
796 | 796 |
#ifdef DOXYGEN |
797 | 797 |
static ProcessedMap *createProcessedMap(const GR &g) |
798 | 798 |
#else |
799 | 799 |
static ProcessedMap *createProcessedMap(const GR &) |
800 | 800 |
#endif |
801 | 801 |
{ |
802 | 802 |
return new ProcessedMap(); |
803 | 803 |
} |
804 | 804 |
///The type of the map that indicates which nodes are reached. |
805 | 805 |
|
806 | 806 |
///The type of the map that indicates which nodes are reached. |
807 | 807 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
808 | 808 |
///\todo named parameter to set this type, function to read and write. |
809 | 809 |
typedef typename Digraph::template NodeMap<bool> ReachedMap; |
810 | 810 |
///Instantiates a ReachedMap. |
811 | 811 |
|
812 | 812 |
///This function instantiates a \ref ReachedMap. |
813 | 813 |
///\param G is the digraph, to which |
814 | 814 |
///we would like to define the \ref ReachedMap. |
815 | 815 |
static ReachedMap *createReachedMap(const GR &G) |
816 | 816 |
{ |
817 | 817 |
return new ReachedMap(G); |
818 | 818 |
} |
819 | 819 |
///The type of the map that stores the dists of the nodes. |
820 | 820 |
|
821 | 821 |
///The type of the map that stores the dists of the nodes. |
822 | 822 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
823 | 823 |
/// |
824 | 824 |
typedef NullMap<typename Digraph::Node,int> DistMap; |
825 | 825 |
///Instantiates a DistMap. |
826 | 826 |
|
827 | 827 |
///This function instantiates a \ref DistMap. |
828 | 828 |
///\param g is the digraph, to which we would like to define the \ref DistMap |
829 | 829 |
#ifdef DOXYGEN |
830 | 830 |
static DistMap *createDistMap(const GR &g) |
831 | 831 |
#else |
832 | 832 |
static DistMap *createDistMap(const GR &) |
833 | 833 |
#endif |
834 | 834 |
{ |
835 | 835 |
return new DistMap(); |
836 | 836 |
} |
837 | 837 |
}; |
838 | 838 |
|
839 | 839 |
/// Default traits used by \ref BfsWizard |
840 | 840 |
|
841 | 841 |
/// To make it easier to use Bfs algorithm |
842 | 842 |
///we have created a wizard class. |
843 | 843 |
/// This \ref BfsWizard class needs default traits, |
844 | 844 |
///as well as the \ref Bfs class. |
845 | 845 |
/// The \ref BfsWizardBase is a class to be the default traits of the |
846 | 846 |
/// \ref BfsWizard class. |
847 | 847 |
template<class GR> |
848 | 848 |
class BfsWizardBase : public BfsWizardDefaultTraits<GR> |
849 | 849 |
{ |
850 | 850 |
|
851 | 851 |
typedef BfsWizardDefaultTraits<GR> Base; |
852 | 852 |
protected: |
853 | 853 |
/// Type of the nodes in the digraph. |
854 | 854 |
typedef typename Base::Digraph::Node Node; |
855 | 855 |
|
856 | 856 |
/// Pointer to the underlying digraph. |
857 | 857 |
void *_g; |
858 | 858 |
///Pointer to the map of reached nodes. |
859 | 859 |
void *_reached; |
860 | 860 |
///Pointer to the map of processed nodes. |
861 | 861 |
void *_processed; |
862 | 862 |
///Pointer to the map of predecessors arcs. |
863 | 863 |
void *_pred; |
864 | 864 |
///Pointer to the map of distances. |
865 | 865 |
void *_dist; |
866 | 866 |
///Pointer to the source node. |
867 | 867 |
Node _source; |
868 | 868 |
|
869 | 869 |
public: |
870 | 870 |
/// Constructor. |
871 | 871 |
|
872 | 872 |
/// This constructor does not require parameters, therefore it initiates |
873 | 873 |
/// all of the attributes to default values (0, INVALID). |
874 | 874 |
BfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0), |
875 | 875 |
_dist(0), _source(INVALID) {} |
876 | 876 |
|
877 | 877 |
/// Constructor. |
878 | 878 |
|
879 | 879 |
/// This constructor requires some parameters, |
880 | 880 |
/// listed in the parameters list. |
881 | 881 |
/// Others are initiated to 0. |
882 | 882 |
/// \param g is the initial value of \ref _g |
883 | 883 |
/// \param s is the initial value of \ref _source |
884 | 884 |
BfsWizardBase(const GR &g, Node s=INVALID) : |
885 | 885 |
_g(reinterpret_cast<void*>(const_cast<GR*>(&g))), |
886 | 886 |
_reached(0), _processed(0), _pred(0), _dist(0), _source(s) {} |
887 | 887 |
|
888 | 888 |
}; |
889 | 889 |
|
890 | 890 |
/// A class to make the usage of Bfs algorithm easier |
891 | 891 |
|
892 | 892 |
/// This class is created to make it easier to use Bfs algorithm. |
893 | 893 |
/// It uses the functions and features of the plain \ref Bfs, |
894 | 894 |
/// but it is much simpler to use it. |
895 | 895 |
/// |
896 | 896 |
/// Simplicity means that the way to change the types defined |
897 | 897 |
/// in the traits class is based on functions that returns the new class |
898 | 898 |
/// and not on templatable built-in classes. |
899 | 899 |
/// When using the plain \ref Bfs |
900 | 900 |
/// the new class with the modified type comes from |
901 | 901 |
/// the original class by using the :: |
902 | 902 |
/// operator. In the case of \ref BfsWizard only |
903 | 903 |
/// a function have to be called and it will |
904 | 904 |
/// return the needed class. |
905 | 905 |
/// |
906 | 906 |
/// It does not have own \ref run method. When its \ref run method is called |
907 | 907 |
/// it initiates a plain \ref Bfs class, and calls the \ref Bfs::run |
908 | 908 |
/// method of it. |
909 | 909 |
template<class TR> |
910 | 910 |
class BfsWizard : public TR |
911 | 911 |
{ |
912 | 912 |
typedef TR Base; |
913 | 913 |
|
914 | 914 |
///The type of the underlying digraph. |
915 | 915 |
typedef typename TR::Digraph Digraph; |
916 | 916 |
//\e |
917 | 917 |
typedef typename Digraph::Node Node; |
918 | 918 |
//\e |
919 | 919 |
typedef typename Digraph::NodeIt NodeIt; |
920 | 920 |
//\e |
921 | 921 |
typedef typename Digraph::Arc Arc; |
922 | 922 |
//\e |
923 | 923 |
typedef typename Digraph::OutArcIt OutArcIt; |
924 | 924 |
|
925 | 925 |
///\brief The type of the map that stores |
926 | 926 |
///the reached nodes |
927 | 927 |
typedef typename TR::ReachedMap ReachedMap; |
928 | 928 |
///\brief The type of the map that stores |
929 | 929 |
///the processed nodes |
930 | 930 |
typedef typename TR::ProcessedMap ProcessedMap; |
931 | 931 |
///\brief The type of the map that stores the last |
932 | 932 |
///arcs of the shortest paths. |
933 | 933 |
typedef typename TR::PredMap PredMap; |
934 | 934 |
///The type of the map that stores the dists of the nodes. |
935 | 935 |
typedef typename TR::DistMap DistMap; |
936 | 936 |
|
937 | 937 |
public: |
938 | 938 |
/// Constructor. |
939 | 939 |
BfsWizard() : TR() {} |
940 | 940 |
|
941 | 941 |
/// Constructor that requires parameters. |
942 | 942 |
|
943 | 943 |
/// Constructor that requires parameters. |
944 | 944 |
/// These parameters will be the default values for the traits class. |
945 | 945 |
BfsWizard(const Digraph &g, Node s=INVALID) : |
946 | 946 |
TR(g,s) {} |
947 | 947 |
|
948 | 948 |
///Copy constructor |
949 | 949 |
BfsWizard(const TR &b) : TR(b) {} |
950 | 950 |
|
951 | 951 |
~BfsWizard() {} |
952 | 952 |
|
953 | 953 |
///Runs Bfs algorithm from a given node. |
954 | 954 |
|
955 | 955 |
///Runs Bfs algorithm from a given node. |
956 | 956 |
///The node can be given by the \ref source function. |
957 | 957 |
void run() |
958 | 958 |
{ |
959 | 959 |
if(Base::_source==INVALID) throw UninitializedParameter(); |
960 | 960 |
Bfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g)); |
961 | 961 |
if(Base::_reached) |
962 | 962 |
alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached)); |
963 | 963 |
if(Base::_processed) |
964 | 964 |
alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed)); |
965 | 965 |
if(Base::_pred) |
966 | 966 |
alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred)); |
967 | 967 |
if(Base::_dist) |
968 | 968 |
alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist)); |
969 | 969 |
alg.run(Base::_source); |
970 | 970 |
} |
971 | 971 |
|
972 | 972 |
///Runs Bfs algorithm from the given node. |
973 | 973 |
|
974 | 974 |
///Runs Bfs algorithm from the given node. |
975 | 975 |
///\param s is the given source. |
976 | 976 |
void run(Node s) |
977 | 977 |
{ |
978 | 978 |
Base::_source=s; |
979 | 979 |
run(); |
980 | 980 |
} |
981 | 981 |
|
982 | 982 |
template<class T> |
983 | 983 |
struct DefPredMapBase : public Base { |
984 | 984 |
typedef T PredMap; |
985 | 985 |
static PredMap *createPredMap(const Digraph &) { return 0; }; |
986 | 986 |
DefPredMapBase(const TR &b) : TR(b) {} |
987 | 987 |
}; |
988 | 988 |
|
989 | 989 |
///\brief \ref named-templ-param "Named parameter" |
990 | 990 |
///function for setting PredMap |
991 | 991 |
/// |
992 | 992 |
/// \ref named-templ-param "Named parameter" |
993 | 993 |
///function for setting PredMap |
994 | 994 |
/// |
995 | 995 |
template<class T> |
996 | 996 |
BfsWizard<DefPredMapBase<T> > predMap(const T &t) |
997 | 997 |
{ |
998 | 998 |
Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t)); |
999 | 999 |
return BfsWizard<DefPredMapBase<T> >(*this); |
1000 | 1000 |
} |
1001 | 1001 |
|
1002 | 1002 |
|
1003 | 1003 |
template<class T> |
1004 | 1004 |
struct DefReachedMapBase : public Base { |
1005 | 1005 |
typedef T ReachedMap; |
1006 | 1006 |
static ReachedMap *createReachedMap(const Digraph &) { return 0; }; |
1007 | 1007 |
DefReachedMapBase(const TR &b) : TR(b) {} |
1008 | 1008 |
}; |
1009 | 1009 |
|
1010 | 1010 |
///\brief \ref named-templ-param "Named parameter" |
1011 | 1011 |
///function for setting ReachedMap |
1012 | 1012 |
/// |
1013 | 1013 |
/// \ref named-templ-param "Named parameter" |
1014 | 1014 |
///function for setting ReachedMap |
1015 | 1015 |
/// |
1016 | 1016 |
template<class T> |
1017 | 1017 |
BfsWizard<DefReachedMapBase<T> > reachedMap(const T &t) |
1018 | 1018 |
{ |
1019 |
Base:: |
|
1019 |
Base::_reached=reinterpret_cast<void*>(const_cast<T*>(&t)); |
|
1020 | 1020 |
return BfsWizard<DefReachedMapBase<T> >(*this); |
1021 | 1021 |
} |
1022 | 1022 |
|
1023 | 1023 |
|
1024 | 1024 |
template<class T> |
1025 | 1025 |
struct DefProcessedMapBase : public Base { |
1026 | 1026 |
typedef T ProcessedMap; |
1027 | 1027 |
static ProcessedMap *createProcessedMap(const Digraph &) { return 0; }; |
1028 | 1028 |
DefProcessedMapBase(const TR &b) : TR(b) {} |
1029 | 1029 |
}; |
1030 | 1030 |
|
1031 | 1031 |
///\brief \ref named-templ-param "Named parameter" |
1032 | 1032 |
///function for setting ProcessedMap |
1033 | 1033 |
/// |
1034 | 1034 |
/// \ref named-templ-param "Named parameter" |
1035 | 1035 |
///function for setting ProcessedMap |
1036 | 1036 |
/// |
1037 | 1037 |
template<class T> |
1038 | 1038 |
BfsWizard<DefProcessedMapBase<T> > processedMap(const T &t) |
1039 | 1039 |
{ |
1040 |
Base:: |
|
1040 |
Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t)); |
|
1041 | 1041 |
return BfsWizard<DefProcessedMapBase<T> >(*this); |
1042 | 1042 |
} |
1043 | 1043 |
|
1044 | 1044 |
|
1045 | 1045 |
template<class T> |
1046 | 1046 |
struct DefDistMapBase : public Base { |
1047 | 1047 |
typedef T DistMap; |
1048 | 1048 |
static DistMap *createDistMap(const Digraph &) { return 0; }; |
1049 | 1049 |
DefDistMapBase(const TR &b) : TR(b) {} |
1050 | 1050 |
}; |
1051 | 1051 |
|
1052 | 1052 |
///\brief \ref named-templ-param "Named parameter" |
1053 | 1053 |
///function for setting DistMap type |
1054 | 1054 |
/// |
1055 | 1055 |
/// \ref named-templ-param "Named parameter" |
1056 | 1056 |
///function for setting DistMap type |
1057 | 1057 |
/// |
1058 | 1058 |
template<class T> |
1059 | 1059 |
BfsWizard<DefDistMapBase<T> > distMap(const T &t) |
1060 | 1060 |
{ |
1061 | 1061 |
Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1062 | 1062 |
return BfsWizard<DefDistMapBase<T> >(*this); |
1063 | 1063 |
} |
1064 | 1064 |
|
1065 | 1065 |
/// Sets the source node, from which the Bfs algorithm runs. |
1066 | 1066 |
|
1067 | 1067 |
/// Sets the source node, from which the Bfs algorithm runs. |
1068 | 1068 |
/// \param s is the source node. |
1069 | 1069 |
BfsWizard<TR> &source(Node s) |
1070 | 1070 |
{ |
1071 | 1071 |
Base::_source=s; |
1072 | 1072 |
return *this; |
1073 | 1073 |
} |
1074 | 1074 |
|
1075 | 1075 |
}; |
1076 | 1076 |
|
1077 | 1077 |
///Function type interface for Bfs algorithm. |
1078 | 1078 |
|
1079 | 1079 |
/// \ingroup search |
1080 | 1080 |
///Function type interface for Bfs algorithm. |
1081 | 1081 |
/// |
1082 | 1082 |
///This function also has several |
1083 | 1083 |
///\ref named-templ-func-param "named parameters", |
1084 | 1084 |
///they are declared as the members of class \ref BfsWizard. |
1085 | 1085 |
///The following |
1086 | 1086 |
///example shows how to use these parameters. |
1087 | 1087 |
///\code |
1088 | 1088 |
/// bfs(g,source).predMap(preds).run(); |
1089 | 1089 |
///\endcode |
1090 | 1090 |
///\warning Don't forget to put the \ref BfsWizard::run() "run()" |
1091 | 1091 |
///to the end of the parameter list. |
1092 | 1092 |
///\sa BfsWizard |
1093 | 1093 |
///\sa Bfs |
1094 | 1094 |
template<class GR> |
1095 | 1095 |
BfsWizard<BfsWizardBase<GR> > |
1096 | 1096 |
bfs(const GR &g,typename GR::Node s=INVALID) |
1097 | 1097 |
{ |
1098 | 1098 |
return BfsWizard<BfsWizardBase<GR> >(g,s); |
1099 | 1099 |
} |
1100 | 1100 |
|
1101 | 1101 |
#ifdef DOXYGEN |
1102 | 1102 |
/// \brief Visitor class for bfs. |
1103 | 1103 |
/// |
1104 | 1104 |
/// This class defines the interface of the BfsVisit events, and |
1105 | 1105 |
/// it could be the base of a real Visitor class. |
1106 | 1106 |
template <typename _Digraph> |
1107 | 1107 |
struct BfsVisitor { |
1108 | 1108 |
typedef _Digraph Digraph; |
1109 | 1109 |
typedef typename Digraph::Arc Arc; |
1110 | 1110 |
typedef typename Digraph::Node Node; |
1111 | 1111 |
/// \brief Called when the arc reach a node. |
1112 | 1112 |
/// |
1113 | 1113 |
/// It is called when the bfs find an arc which target is not |
1114 | 1114 |
/// reached yet. |
1115 | 1115 |
void discover(const Arc& arc) {} |
1116 | 1116 |
/// \brief Called when the node reached first time. |
1117 | 1117 |
/// |
1118 | 1118 |
/// It is Called when the node reached first time. |
1119 | 1119 |
void reach(const Node& node) {} |
1120 | 1120 |
/// \brief Called when the arc examined but target of the arc |
1121 | 1121 |
/// already discovered. |
1122 | 1122 |
/// |
1123 | 1123 |
/// It called when the arc examined but the target of the arc |
1124 | 1124 |
/// already discovered. |
1125 | 1125 |
void examine(const Arc& arc) {} |
1126 | 1126 |
/// \brief Called for the source node of the bfs. |
1127 | 1127 |
/// |
1128 | 1128 |
/// It is called for the source node of the bfs. |
1129 | 1129 |
void start(const Node& node) {} |
1130 | 1130 |
/// \brief Called when the node processed. |
1131 | 1131 |
/// |
1132 | 1132 |
/// It is Called when the node processed. |
1133 | 1133 |
void process(const Node& node) {} |
1134 | 1134 |
}; |
1135 | 1135 |
#else |
1136 | 1136 |
template <typename _Digraph> |
1137 | 1137 |
struct BfsVisitor { |
1138 | 1138 |
typedef _Digraph Digraph; |
1139 | 1139 |
typedef typename Digraph::Arc Arc; |
1140 | 1140 |
typedef typename Digraph::Node Node; |
1141 | 1141 |
void discover(const Arc&) {} |
1142 | 1142 |
void reach(const Node&) {} |
1143 | 1143 |
void examine(const Arc&) {} |
1144 | 1144 |
void start(const Node&) {} |
1145 | 1145 |
void process(const Node&) {} |
1146 | 1146 |
|
1147 | 1147 |
template <typename _Visitor> |
1148 | 1148 |
struct Constraints { |
1149 | 1149 |
void constraints() { |
1150 | 1150 |
Arc arc; |
1151 | 1151 |
Node node; |
1152 | 1152 |
visitor.discover(arc); |
1153 | 1153 |
visitor.reach(node); |
1154 | 1154 |
visitor.examine(arc); |
1155 | 1155 |
visitor.start(node); |
1156 | 1156 |
visitor.process(node); |
1157 | 1157 |
} |
1158 | 1158 |
_Visitor& visitor; |
1159 | 1159 |
}; |
1160 | 1160 |
}; |
1161 | 1161 |
#endif |
1162 | 1162 |
|
1163 | 1163 |
/// \brief Default traits class of BfsVisit class. |
1164 | 1164 |
/// |
1165 | 1165 |
/// Default traits class of BfsVisit class. |
1166 | 1166 |
/// \tparam _Digraph Digraph type. |
1167 | 1167 |
template<class _Digraph> |
1168 | 1168 |
struct BfsVisitDefaultTraits { |
1169 | 1169 |
|
1170 | 1170 |
/// \brief The digraph type the algorithm runs on. |
1171 | 1171 |
typedef _Digraph Digraph; |
1172 | 1172 |
|
1173 | 1173 |
/// \brief The type of the map that indicates which nodes are reached. |
1174 | 1174 |
/// |
1175 | 1175 |
/// The type of the map that indicates which nodes are reached. |
1176 | 1176 |
/// It must meet the \ref concepts::WriteMap "WriteMap" concept. |
1177 | 1177 |
/// \todo named parameter to set this type, function to read and write. |
1178 | 1178 |
typedef typename Digraph::template NodeMap<bool> ReachedMap; |
1179 | 1179 |
|
1180 | 1180 |
/// \brief Instantiates a ReachedMap. |
1181 | 1181 |
/// |
1182 | 1182 |
/// This function instantiates a \ref ReachedMap. |
1183 | 1183 |
/// \param digraph is the digraph, to which |
1184 | 1184 |
/// we would like to define the \ref ReachedMap. |
1185 | 1185 |
static ReachedMap *createReachedMap(const Digraph &digraph) { |
1186 | 1186 |
return new ReachedMap(digraph); |
1187 | 1187 |
} |
1188 | 1188 |
|
1189 | 1189 |
}; |
1190 | 1190 |
|
1191 | 1191 |
/// \ingroup search |
1192 | 1192 |
/// |
1193 | 1193 |
/// \brief %BFS Visit algorithm class. |
1194 | 1194 |
/// |
1195 | 1195 |
/// This class provides an efficient implementation of the %BFS algorithm |
1196 | 1196 |
/// with visitor interface. |
1197 | 1197 |
/// |
1198 | 1198 |
/// The %BfsVisit class provides an alternative interface to the Bfs |
1199 | 1199 |
/// class. It works with callback mechanism, the BfsVisit object calls |
1200 | 1200 |
/// on every bfs event the \c Visitor class member functions. |
1201 | 1201 |
/// |
1202 | 1202 |
/// \tparam _Digraph The digraph type the algorithm runs on. The default value is |
1203 | 1203 |
/// \ref ListDigraph. The value of _Digraph is not used directly by Bfs, it |
1204 | 1204 |
/// is only passed to \ref BfsDefaultTraits. |
1205 | 1205 |
/// \tparam _Visitor The Visitor object for the algorithm. The |
1206 | 1206 |
/// \ref BfsVisitor "BfsVisitor<_Digraph>" is an empty Visitor which |
1207 | 1207 |
/// does not observe the Bfs events. If you want to observe the bfs |
1208 | 1208 |
/// events you should implement your own Visitor class. |
1209 | 1209 |
/// \tparam _Traits Traits class to set various data types used by the |
1210 | 1210 |
/// algorithm. The default traits class is |
1211 | 1211 |
/// \ref BfsVisitDefaultTraits "BfsVisitDefaultTraits<_Digraph>". |
1212 | 1212 |
/// See \ref BfsVisitDefaultTraits for the documentation of |
1213 | 1213 |
/// a Bfs visit traits class. |
1214 | 1214 |
#ifdef DOXYGEN |
1215 | 1215 |
template <typename _Digraph, typename _Visitor, typename _Traits> |
1216 | 1216 |
#else |
1217 | 1217 |
template <typename _Digraph = ListDigraph, |
1218 | 1218 |
typename _Visitor = BfsVisitor<_Digraph>, |
1219 | 1219 |
typename _Traits = BfsDefaultTraits<_Digraph> > |
1220 | 1220 |
#endif |
1221 | 1221 |
class BfsVisit { |
1222 | 1222 |
public: |
1223 | 1223 |
|
1224 | 1224 |
/// \brief \ref Exception for uninitialized parameters. |
1225 | 1225 |
/// |
1226 | 1226 |
/// This error represents problems in the initialization |
1227 | 1227 |
/// of the parameters of the algorithms. |
1228 | 1228 |
class UninitializedParameter : public lemon::UninitializedParameter { |
1229 | 1229 |
public: |
1230 | 1230 |
virtual const char* what() const throw() |
1231 | 1231 |
{ |
1232 | 1232 |
return "lemon::BfsVisit::UninitializedParameter"; |
1233 | 1233 |
} |
1234 | 1234 |
}; |
1235 | 1235 |
|
1236 | 1236 |
typedef _Traits Traits; |
1237 | 1237 |
|
1238 | 1238 |
typedef typename Traits::Digraph Digraph; |
1239 | 1239 |
|
1240 | 1240 |
typedef _Visitor Visitor; |
1241 | 1241 |
|
1242 | 1242 |
///The type of the map indicating which nodes are reached. |
1243 | 1243 |
typedef typename Traits::ReachedMap ReachedMap; |
1244 | 1244 |
|
1245 | 1245 |
private: |
1246 | 1246 |
|
1247 | 1247 |
typedef typename Digraph::Node Node; |
1248 | 1248 |
typedef typename Digraph::NodeIt NodeIt; |
1249 | 1249 |
typedef typename Digraph::Arc Arc; |
1250 | 1250 |
typedef typename Digraph::OutArcIt OutArcIt; |
1251 | 1251 |
|
1252 | 1252 |
/// Pointer to the underlying digraph. |
1253 | 1253 |
const Digraph *_digraph; |
1254 | 1254 |
/// Pointer to the visitor object. |
1255 | 1255 |
Visitor *_visitor; |
1256 | 1256 |
///Pointer to the map of reached status of the nodes. |
1257 | 1257 |
ReachedMap *_reached; |
1258 | 1258 |
///Indicates if \ref _reached is locally allocated (\c true) or not. |
1259 | 1259 |
bool local_reached; |
1260 | 1260 |
|
1261 | 1261 |
std::vector<typename Digraph::Node> _list; |
1262 | 1262 |
int _list_front, _list_back; |
1263 | 1263 |
|
1264 | 1264 |
/// \brief Creates the maps if necessary. |
1265 | 1265 |
/// |
1266 | 1266 |
/// Creates the maps if necessary. |
1267 | 1267 |
void create_maps() { |
1268 | 1268 |
if(!_reached) { |
1269 | 1269 |
local_reached = true; |
1270 | 1270 |
_reached = Traits::createReachedMap(*_digraph); |
1271 | 1271 |
} |
1272 | 1272 |
} |
1273 | 1273 |
|
1274 | 1274 |
protected: |
1275 | 1275 |
|
1276 | 1276 |
BfsVisit() {} |
1277 | 1277 |
|
1278 | 1278 |
public: |
1279 | 1279 |
|
1280 | 1280 |
typedef BfsVisit Create; |
1281 | 1281 |
|
1282 | 1282 |
/// \name Named template parameters |
1283 | 1283 |
|
1284 | 1284 |
///@{ |
1285 | 1285 |
template <class T> |
1286 | 1286 |
struct DefReachedMapTraits : public Traits { |
1287 | 1287 |
typedef T ReachedMap; |
1288 | 1288 |
static ReachedMap *createReachedMap(const Digraph &digraph) { |
1289 | 1289 |
throw UninitializedParameter(); |
1290 | 1290 |
} |
1291 | 1291 |
}; |
1292 | 1292 |
/// \brief \ref named-templ-param "Named parameter" for setting |
1293 | 1293 |
/// ReachedMap type |
1294 | 1294 |
/// |
1295 | 1295 |
/// \ref named-templ-param "Named parameter" for setting ReachedMap type |
1296 | 1296 |
template <class T> |
1297 | 1297 |
struct DefReachedMap : public BfsVisit< Digraph, Visitor, |
1298 | 1298 |
DefReachedMapTraits<T> > { |
1299 | 1299 |
typedef BfsVisit< Digraph, Visitor, DefReachedMapTraits<T> > Create; |
1300 | 1300 |
}; |
1301 | 1301 |
///@} |
1302 | 1302 |
|
1303 | 1303 |
public: |
1304 | 1304 |
|
1305 | 1305 |
/// \brief Constructor. |
1306 | 1306 |
/// |
1307 | 1307 |
/// Constructor. |
1308 | 1308 |
/// |
1309 | 1309 |
/// \param digraph the digraph the algorithm will run on. |
1310 | 1310 |
/// \param visitor The visitor of the algorithm. |
1311 | 1311 |
/// |
1312 | 1312 |
BfsVisit(const Digraph& digraph, Visitor& visitor) |
1313 | 1313 |
: _digraph(&digraph), _visitor(&visitor), |
1314 | 1314 |
_reached(0), local_reached(false) {} |
1315 | 1315 |
|
1316 | 1316 |
/// \brief Destructor. |
1317 | 1317 |
/// |
1318 | 1318 |
/// Destructor. |
1319 | 1319 |
~BfsVisit() { |
1320 | 1320 |
if(local_reached) delete _reached; |
1321 | 1321 |
} |
1322 | 1322 |
|
1323 | 1323 |
/// \brief Sets the map indicating if a node is reached. |
1324 | 1324 |
/// |
1325 | 1325 |
/// Sets the map indicating if a node is reached. |
1326 | 1326 |
/// If you don't use this function before calling \ref run(), |
1327 | 1327 |
/// it will allocate one. The destuctor deallocates this |
1328 | 1328 |
/// automatically allocated map, of course. |
1329 | 1329 |
/// \return <tt> (*this) </tt> |
1330 | 1330 |
BfsVisit &reachedMap(ReachedMap &m) { |
1331 | 1331 |
if(local_reached) { |
1332 | 1332 |
delete _reached; |
1333 | 1333 |
local_reached = false; |
1334 | 1334 |
} |
1335 | 1335 |
_reached = &m; |
1336 | 1336 |
return *this; |
1337 | 1337 |
} |
1338 | 1338 |
|
1339 | 1339 |
public: |
1340 | 1340 |
/// \name Execution control |
1341 | 1341 |
/// The simplest way to execute the algorithm is to use |
1342 | 1342 |
/// one of the member functions called \c run(...). |
1343 | 1343 |
/// \n |
1344 | 1344 |
/// If you need more control on the execution, |
1345 | 1345 |
/// first you must call \ref init(), then you can adda source node |
1346 | 1346 |
/// with \ref addSource(). |
1347 | 1347 |
/// Finally \ref start() will perform the actual path |
1348 | 1348 |
/// computation. |
1349 | 1349 |
|
1350 | 1350 |
/// @{ |
1351 | 1351 |
/// \brief Initializes the internal data structures. |
1352 | 1352 |
/// |
1353 | 1353 |
/// Initializes the internal data structures. |
1354 | 1354 |
/// |
1355 | 1355 |
void init() { |
1356 | 1356 |
create_maps(); |
1357 | 1357 |
_list.resize(countNodes(*_digraph)); |
1358 | 1358 |
_list_front = _list_back = -1; |
1359 | 1359 |
for (NodeIt u(*_digraph) ; u != INVALID ; ++u) { |
1360 | 1360 |
_reached->set(u, false); |
1361 | 1361 |
} |
1362 | 1362 |
} |
1363 | 1363 |
|
1364 | 1364 |
/// \brief Adds a new source node. |
1365 | 1365 |
/// |
1366 | 1366 |
/// Adds a new source node to the set of nodes to be processed. |
1367 | 1367 |
void addSource(Node s) { |
1368 | 1368 |
if(!(*_reached)[s]) { |
1369 | 1369 |
_reached->set(s,true); |
1370 | 1370 |
_visitor->start(s); |
1371 | 1371 |
_visitor->reach(s); |
1372 | 1372 |
_list[++_list_back] = s; |
1373 | 1373 |
} |
1374 | 1374 |
} |
1375 | 1375 |
|
1376 | 1376 |
/// \brief Processes the next node. |
1377 | 1377 |
/// |
1378 | 1378 |
/// Processes the next node. |
1379 | 1379 |
/// |
1380 | 1380 |
/// \return The processed node. |
1381 | 1381 |
/// |
1382 | 1382 |
/// \pre The queue must not be empty! |
1383 | 1383 |
Node processNextNode() { |
1384 | 1384 |
Node n = _list[++_list_front]; |
1385 | 1385 |
_visitor->process(n); |
1386 | 1386 |
Arc e; |
1387 | 1387 |
for (_digraph->firstOut(e, n); e != INVALID; _digraph->nextOut(e)) { |
1388 | 1388 |
Node m = _digraph->target(e); |
1389 | 1389 |
if (!(*_reached)[m]) { |
1390 | 1390 |
_visitor->discover(e); |
1391 | 1391 |
_visitor->reach(m); |
1392 | 1392 |
_reached->set(m, true); |
1393 | 1393 |
_list[++_list_back] = m; |
1394 | 1394 |
} else { |
1395 | 1395 |
_visitor->examine(e); |
1396 | 1396 |
} |
1397 | 1397 |
} |
1398 | 1398 |
return n; |
1399 | 1399 |
} |
1400 | 1400 |
|
1401 | 1401 |
/// \brief Processes the next node. |
1402 | 1402 |
/// |
1403 | 1403 |
/// Processes the next node. And checks that the given target node |
1404 | 1404 |
/// is reached. If the target node is reachable from the processed |
1405 | 1405 |
/// node then the reached parameter will be set true. The reached |
1406 | 1406 |
/// parameter should be initially false. |
1407 | 1407 |
/// |
1408 | 1408 |
/// \param target The target node. |
1409 | 1409 |
/// \retval reach Indicates that the target node is reached. |
1410 | 1410 |
/// \return The processed node. |
1411 | 1411 |
/// |
1412 | 1412 |
/// \warning The queue must not be empty! |
1413 | 1413 |
Node processNextNode(Node target, bool& reach) { |
1414 | 1414 |
Node n = _list[++_list_front]; |
1415 | 1415 |
_visitor->process(n); |
1416 | 1416 |
Arc e; |
1417 | 1417 |
for (_digraph->firstOut(e, n); e != INVALID; _digraph->nextOut(e)) { |
1418 | 1418 |
Node m = _digraph->target(e); |
1419 | 1419 |
if (!(*_reached)[m]) { |
1420 | 1420 |
_visitor->discover(e); |
1421 | 1421 |
_visitor->reach(m); |
1422 | 1422 |
_reached->set(m, true); |
1423 | 1423 |
_list[++_list_back] = m; |
1424 | 1424 |
reach = reach || (target == m); |
1425 | 1425 |
} else { |
1426 | 1426 |
_visitor->examine(e); |
1427 | 1427 |
} |
1428 | 1428 |
} |
1429 | 1429 |
return n; |
1430 | 1430 |
} |
1431 | 1431 |
|
1432 | 1432 |
/// \brief Processes the next node. |
1433 | 1433 |
/// |
1434 | 1434 |
/// Processes the next node. And checks that at least one of |
1435 | 1435 |
/// reached node has true value in the \c nm node map. If one node |
1436 | 1436 |
/// with true value is reachable from the processed node then the |
1437 | 1437 |
/// rnode parameter will be set to the first of such nodes. |
1438 | 1438 |
/// |
1439 | 1439 |
/// \param nm The node map of possible targets. |
1440 | 1440 |
/// \retval rnode The reached target node. |
1441 | 1441 |
/// \return The processed node. |
1442 | 1442 |
/// |
1443 | 1443 |
/// \warning The queue must not be empty! |
1444 | 1444 |
template <typename NM> |
1445 | 1445 |
Node processNextNode(const NM& nm, Node& rnode) { |
1446 | 1446 |
Node n = _list[++_list_front]; |
1447 | 1447 |
_visitor->process(n); |
1448 | 1448 |
Arc e; |
1449 | 1449 |
for (_digraph->firstOut(e, n); e != INVALID; _digraph->nextOut(e)) { |
1450 | 1450 |
Node m = _digraph->target(e); |
1451 | 1451 |
if (!(*_reached)[m]) { |
1452 | 1452 |
_visitor->discover(e); |
1453 | 1453 |
_visitor->reach(m); |
1454 | 1454 |
_reached->set(m, true); |
1455 | 1455 |
_list[++_list_back] = m; |
1456 | 1456 |
if (nm[m] && rnode == INVALID) rnode = m; |
1457 | 1457 |
} else { |
1458 | 1458 |
_visitor->examine(e); |
1459 | 1459 |
} |
1460 | 1460 |
} |
1461 | 1461 |
return n; |
1462 | 1462 |
} |
1463 | 1463 |
|
1464 | 1464 |
/// \brief Next node to be processed. |
1465 | 1465 |
/// |
1466 | 1466 |
/// Next node to be processed. |
1467 | 1467 |
/// |
1468 | 1468 |
/// \return The next node to be processed or INVALID if the stack is |
1469 | 1469 |
/// empty. |
1470 | 1470 |
Node nextNode() { |
1471 | 1471 |
return _list_front != _list_back ? _list[_list_front + 1] : INVALID; |
1472 | 1472 |
} |
1473 | 1473 |
|
1474 | 1474 |
/// \brief Returns \c false if there are nodes |
1475 | 1475 |
/// to be processed in the queue |
1476 | 1476 |
/// |
1477 | 1477 |
/// Returns \c false if there are nodes |
1478 | 1478 |
/// to be processed in the queue |
1479 | 1479 |
bool emptyQueue() { return _list_front == _list_back; } |
1480 | 1480 |
|
1481 | 1481 |
/// \brief Returns the number of the nodes to be processed. |
1482 | 1482 |
/// |
1483 | 1483 |
/// Returns the number of the nodes to be processed in the queue. |
1484 | 1484 |
int queueSize() { return _list_back - _list_front; } |
1485 | 1485 |
|
1486 | 1486 |
/// \brief Executes the algorithm. |
1487 | 1487 |
/// |
1488 | 1488 |
/// Executes the algorithm. |
1489 | 1489 |
/// |
1490 | 1490 |
/// \pre init() must be called and at least one node should be added |
1491 | 1491 |
/// with addSource() before using this function. |
1492 | 1492 |
void start() { |
1493 | 1493 |
while ( !emptyQueue() ) processNextNode(); |
1494 | 1494 |
} |
1495 | 1495 |
|
1496 | 1496 |
/// \brief Executes the algorithm until \c dest is reached. |
1497 | 1497 |
/// |
1498 | 1498 |
/// Executes the algorithm until \c dest is reached. |
1499 | 1499 |
/// |
1500 | 1500 |
/// \pre init() must be called and at least one node should be added |
1501 | 1501 |
/// with addSource() before using this function. |
1502 | 1502 |
void start(Node dest) { |
1503 | 1503 |
bool reach = false; |
1504 | 1504 |
while ( !emptyQueue() && !reach ) processNextNode(dest, reach); |
1505 | 1505 |
} |
1506 | 1506 |
|
1507 | 1507 |
/// \brief Executes the algorithm until a condition is met. |
1508 | 1508 |
/// |
1509 | 1509 |
/// Executes the algorithm until a condition is met. |
1510 | 1510 |
/// |
1511 | 1511 |
/// \pre init() must be called and at least one node should be added |
1512 | 1512 |
/// with addSource() before using this function. |
1513 | 1513 |
/// |
1514 | 1514 |
///\param nm must be a bool (or convertible) node map. The |
1515 | 1515 |
///algorithm will stop when it reaches a node \c v with |
1516 | 1516 |
/// <tt>nm[v]</tt> true. |
1517 | 1517 |
/// |
1518 | 1518 |
///\return The reached node \c v with <tt>nm[v]</tt> true or |
1519 | 1519 |
///\c INVALID if no such node was found. |
1520 | 1520 |
template <typename NM> |
1521 | 1521 |
Node start(const NM &nm) { |
1522 | 1522 |
Node rnode = INVALID; |
1523 | 1523 |
while ( !emptyQueue() && rnode == INVALID ) { |
1524 | 1524 |
processNextNode(nm, rnode); |
1525 | 1525 |
} |
1526 | 1526 |
return rnode; |
1527 | 1527 |
} |
1528 | 1528 |
|
1529 | 1529 |
/// \brief Runs %BFSVisit algorithm from node \c s. |
1530 | 1530 |
/// |
1531 | 1531 |
/// This method runs the %BFS algorithm from a root node \c s. |
1532 | 1532 |
/// \note b.run(s) is just a shortcut of the following code. |
1533 | 1533 |
///\code |
1534 | 1534 |
/// b.init(); |
1535 | 1535 |
/// b.addSource(s); |
1536 | 1536 |
/// b.start(); |
1537 | 1537 |
///\endcode |
1538 | 1538 |
void run(Node s) { |
1539 | 1539 |
init(); |
1540 | 1540 |
addSource(s); |
1541 | 1541 |
start(); |
1542 | 1542 |
} |
1543 | 1543 |
|
1544 | 1544 |
/// \brief Runs %BFSVisit algorithm to visit all nodes in the digraph. |
1545 | 1545 |
/// |
1546 | 1546 |
/// This method runs the %BFS algorithm in order to |
1547 | 1547 |
/// compute the %BFS path to each node. The algorithm computes |
1548 | 1548 |
/// - The %BFS tree. |
1549 | 1549 |
/// - The distance of each node from the root in the %BFS tree. |
1550 | 1550 |
/// |
1551 | 1551 |
///\note b.run() is just a shortcut of the following code. |
1552 | 1552 |
///\code |
1553 | 1553 |
/// b.init(); |
1554 | 1554 |
/// for (NodeIt it(digraph); it != INVALID; ++it) { |
1555 | 1555 |
/// if (!b.reached(it)) { |
1556 | 1556 |
/// b.addSource(it); |
1557 | 1557 |
/// b.start(); |
1558 | 1558 |
/// } |
1559 | 1559 |
/// } |
1560 | 1560 |
///\endcode |
1561 | 1561 |
void run() { |
1562 | 1562 |
init(); |
1563 | 1563 |
for (NodeIt it(*_digraph); it != INVALID; ++it) { |
1564 | 1564 |
if (!reached(it)) { |
1565 | 1565 |
addSource(it); |
1566 | 1566 |
start(); |
1567 | 1567 |
} |
1568 | 1568 |
} |
1569 | 1569 |
} |
1570 | 1570 |
///@} |
1571 | 1571 |
|
1572 | 1572 |
/// \name Query Functions |
1573 | 1573 |
/// The result of the %BFS algorithm can be obtained using these |
1574 | 1574 |
/// functions.\n |
1575 | 1575 |
/// Before the use of these functions, |
1576 | 1576 |
/// either run() or start() must be called. |
1577 | 1577 |
///@{ |
1578 | 1578 |
|
1579 | 1579 |
/// \brief Checks if a node is reachable from the root. |
1580 | 1580 |
/// |
1581 | 1581 |
/// Returns \c true if \c v is reachable from the root(s). |
1582 | 1582 |
/// \warning The source nodes are inditated as unreachable. |
1583 | 1583 |
/// \pre Either \ref run() or \ref start() |
1584 | 1584 |
/// must be called before using this function. |
1585 | 1585 |
/// |
1586 | 1586 |
bool reached(Node v) { return (*_reached)[v]; } |
1587 | 1587 |
///@} |
1588 | 1588 |
}; |
1589 | 1589 |
|
1590 | 1590 |
} //END OF NAMESPACE LEMON |
1591 | 1591 |
|
1592 | 1592 |
#endif |
1593 | 1593 |
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_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/graph_utils.h> |
28 | 28 |
#include <lemon/bits/path_dump.h> |
29 | 29 |
#include <lemon/bits/invalid.h> |
30 | 30 |
#include <lemon/error.h> |
31 | 31 |
#include <lemon/maps.h> |
32 | 32 |
|
33 | 33 |
#include <lemon/concept_check.h> |
34 | 34 |
|
35 | 35 |
namespace lemon { |
36 | 36 |
|
37 | 37 |
|
38 | 38 |
///Default traits class of Dfs class. |
39 | 39 |
|
40 | 40 |
///Default traits class of Dfs class. |
41 | 41 |
///\tparam GR Digraph type. |
42 | 42 |
template<class GR> |
43 | 43 |
struct DfsDefaultTraits |
44 | 44 |
{ |
45 | 45 |
///The digraph type the algorithm runs on. |
46 | 46 |
typedef GR Digraph; |
47 | 47 |
///\brief The type of the map that stores the last |
48 | 48 |
///arcs of the %DFS paths. |
49 | 49 |
/// |
50 | 50 |
///The type of the map that stores the last |
51 | 51 |
///arcs of the %DFS paths. |
52 | 52 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
53 | 53 |
/// |
54 | 54 |
typedef typename Digraph::template NodeMap<typename GR::Arc> PredMap; |
55 | 55 |
///Instantiates a PredMap. |
56 | 56 |
|
57 | 57 |
///This function instantiates a \ref PredMap. |
58 | 58 |
///\param G is the digraph, to which we would like to define the PredMap. |
59 | 59 |
///\todo The digraph alone may be insufficient to initialize |
60 | 60 |
static PredMap *createPredMap(const GR &G) |
61 | 61 |
{ |
62 | 62 |
return new PredMap(G); |
63 | 63 |
} |
64 | 64 |
|
65 | 65 |
///The type of the map that indicates which nodes are processed. |
66 | 66 |
|
67 | 67 |
///The type of the map that indicates which nodes are processed. |
68 | 68 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
69 | 69 |
///\todo named parameter to set this type, function to read and write. |
70 | 70 |
typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
71 | 71 |
///Instantiates a ProcessedMap. |
72 | 72 |
|
73 | 73 |
///This function instantiates a \ref ProcessedMap. |
74 | 74 |
///\param g is the digraph, to which |
75 | 75 |
///we would like to define the \ref ProcessedMap |
76 | 76 |
#ifdef DOXYGEN |
77 | 77 |
static ProcessedMap *createProcessedMap(const GR &g) |
78 | 78 |
#else |
79 | 79 |
static ProcessedMap *createProcessedMap(const GR &) |
80 | 80 |
#endif |
81 | 81 |
{ |
82 | 82 |
return new ProcessedMap(); |
83 | 83 |
} |
84 | 84 |
///The type of the map that indicates which nodes are reached. |
85 | 85 |
|
86 | 86 |
///The type of the map that indicates which nodes are reached. |
87 | 87 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
88 | 88 |
///\todo named parameter to set this type, function to read and write. |
89 | 89 |
typedef typename Digraph::template NodeMap<bool> ReachedMap; |
90 | 90 |
///Instantiates a ReachedMap. |
91 | 91 |
|
92 | 92 |
///This function instantiates a \ref ReachedMap. |
93 | 93 |
///\param G is the digraph, to which |
94 | 94 |
///we would like to define the \ref ReachedMap. |
95 | 95 |
static ReachedMap *createReachedMap(const GR &G) |
96 | 96 |
{ |
97 | 97 |
return new ReachedMap(G); |
98 | 98 |
} |
99 | 99 |
///The type of the map that stores the dists of the nodes. |
100 | 100 |
|
101 | 101 |
///The type of the map that stores the dists of the nodes. |
102 | 102 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
103 | 103 |
/// |
104 | 104 |
typedef typename Digraph::template NodeMap<int> DistMap; |
105 | 105 |
///Instantiates a DistMap. |
106 | 106 |
|
107 | 107 |
///This function instantiates a \ref DistMap. |
108 | 108 |
///\param G is the digraph, to which we would like to define the \ref DistMap |
109 | 109 |
static DistMap *createDistMap(const GR &G) |
110 | 110 |
{ |
111 | 111 |
return new DistMap(G); |
112 | 112 |
} |
113 | 113 |
}; |
114 | 114 |
|
115 | 115 |
///%DFS algorithm class. |
116 | 116 |
|
117 | 117 |
///\ingroup search |
118 | 118 |
///This class provides an efficient implementation of the %DFS algorithm. |
119 | 119 |
/// |
120 | 120 |
///\tparam GR The digraph type the algorithm runs on. The default value is |
121 | 121 |
///\ref ListDigraph. The value of GR is not used directly by Dfs, it |
122 | 122 |
///is only passed to \ref DfsDefaultTraits. |
123 | 123 |
///\tparam TR Traits class to set various data types used by the algorithm. |
124 | 124 |
///The default traits class is |
125 | 125 |
///\ref DfsDefaultTraits "DfsDefaultTraits<GR>". |
126 | 126 |
///See \ref DfsDefaultTraits for the documentation of |
127 | 127 |
///a Dfs traits class. |
128 | 128 |
#ifdef DOXYGEN |
129 | 129 |
template <typename GR, |
130 | 130 |
typename TR> |
131 | 131 |
#else |
132 | 132 |
template <typename GR=ListDigraph, |
133 | 133 |
typename TR=DfsDefaultTraits<GR> > |
134 | 134 |
#endif |
135 | 135 |
class Dfs { |
136 | 136 |
public: |
137 | 137 |
/** |
138 | 138 |
* \brief \ref Exception for uninitialized parameters. |
139 | 139 |
* |
140 | 140 |
* This error represents problems in the initialization |
141 | 141 |
* of the parameters of the algorithms. |
142 | 142 |
*/ |
143 | 143 |
class UninitializedParameter : public lemon::UninitializedParameter { |
144 | 144 |
public: |
145 | 145 |
virtual const char* what() const throw() { |
146 | 146 |
return "lemon::Dfs::UninitializedParameter"; |
147 | 147 |
} |
148 | 148 |
}; |
149 | 149 |
|
150 | 150 |
typedef TR Traits; |
151 | 151 |
///The type of the underlying digraph. |
152 | 152 |
typedef typename TR::Digraph Digraph; |
153 | 153 |
///\e |
154 | 154 |
typedef typename Digraph::Node Node; |
155 | 155 |
///\e |
156 | 156 |
typedef typename Digraph::NodeIt NodeIt; |
157 | 157 |
///\e |
158 | 158 |
typedef typename Digraph::Arc Arc; |
159 | 159 |
///\e |
160 | 160 |
typedef typename Digraph::OutArcIt OutArcIt; |
161 | 161 |
|
162 | 162 |
///\brief The type of the map that stores the last |
163 | 163 |
///arcs of the %DFS paths. |
164 | 164 |
typedef typename TR::PredMap PredMap; |
165 | 165 |
///The type of the map indicating which nodes are reached. |
166 | 166 |
typedef typename TR::ReachedMap ReachedMap; |
167 | 167 |
///The type of the map indicating which nodes are processed. |
168 | 168 |
typedef typename TR::ProcessedMap ProcessedMap; |
169 | 169 |
///The type of the map that stores the dists of the nodes. |
170 | 170 |
typedef typename TR::DistMap DistMap; |
171 | 171 |
private: |
172 | 172 |
/// Pointer to the underlying digraph. |
173 | 173 |
const Digraph *G; |
174 | 174 |
///Pointer to the map of predecessors arcs. |
175 | 175 |
PredMap *_pred; |
176 | 176 |
///Indicates if \ref _pred is locally allocated (\c true) or not. |
177 | 177 |
bool local_pred; |
178 | 178 |
///Pointer to the map of distances. |
179 | 179 |
DistMap *_dist; |
180 | 180 |
///Indicates if \ref _dist is locally allocated (\c true) or not. |
181 | 181 |
bool local_dist; |
182 | 182 |
///Pointer to the map of reached status of the nodes. |
183 | 183 |
ReachedMap *_reached; |
184 | 184 |
///Indicates if \ref _reached is locally allocated (\c true) or not. |
185 | 185 |
bool local_reached; |
186 | 186 |
///Pointer to the map of processed status of the nodes. |
187 | 187 |
ProcessedMap *_processed; |
188 | 188 |
///Indicates if \ref _processed is locally allocated (\c true) or not. |
189 | 189 |
bool local_processed; |
190 | 190 |
|
191 | 191 |
std::vector<typename Digraph::OutArcIt> _stack; |
192 | 192 |
int _stack_head; |
193 | 193 |
|
194 | 194 |
///Creates the maps if necessary. |
195 | 195 |
|
196 | 196 |
///\todo Better memory allocation (instead of new). |
197 | 197 |
void create_maps() |
198 | 198 |
{ |
199 | 199 |
if(!_pred) { |
200 | 200 |
local_pred = true; |
201 | 201 |
_pred = Traits::createPredMap(*G); |
202 | 202 |
} |
203 | 203 |
if(!_dist) { |
204 | 204 |
local_dist = true; |
205 | 205 |
_dist = Traits::createDistMap(*G); |
206 | 206 |
} |
207 | 207 |
if(!_reached) { |
208 | 208 |
local_reached = true; |
209 | 209 |
_reached = Traits::createReachedMap(*G); |
210 | 210 |
} |
211 | 211 |
if(!_processed) { |
212 | 212 |
local_processed = true; |
213 | 213 |
_processed = Traits::createProcessedMap(*G); |
214 | 214 |
} |
215 | 215 |
} |
216 | 216 |
|
217 | 217 |
protected: |
218 | 218 |
|
219 | 219 |
Dfs() {} |
220 | 220 |
|
221 | 221 |
public: |
222 | 222 |
|
223 | 223 |
typedef Dfs Create; |
224 | 224 |
|
225 | 225 |
///\name Named template parameters |
226 | 226 |
|
227 | 227 |
///@{ |
228 | 228 |
|
229 | 229 |
template <class T> |
230 | 230 |
struct DefPredMapTraits : public Traits { |
231 | 231 |
typedef T PredMap; |
232 | 232 |
static PredMap *createPredMap(const Digraph &G) |
233 | 233 |
{ |
234 | 234 |
throw UninitializedParameter(); |
235 | 235 |
} |
236 | 236 |
}; |
237 | 237 |
///\brief \ref named-templ-param "Named parameter" for setting |
238 | 238 |
///PredMap type |
239 | 239 |
/// |
240 | 240 |
///\ref named-templ-param "Named parameter" for setting PredMap type |
241 | 241 |
/// |
242 | 242 |
template <class T> |
243 | 243 |
struct DefPredMap : public Dfs<Digraph, DefPredMapTraits<T> > { |
244 | 244 |
typedef Dfs<Digraph, DefPredMapTraits<T> > Create; |
245 | 245 |
}; |
246 | 246 |
|
247 | 247 |
|
248 | 248 |
template <class T> |
249 | 249 |
struct DefDistMapTraits : public Traits { |
250 | 250 |
typedef T DistMap; |
251 | 251 |
static DistMap *createDistMap(const Digraph &) |
252 | 252 |
{ |
253 | 253 |
throw UninitializedParameter(); |
254 | 254 |
} |
255 | 255 |
}; |
256 | 256 |
///\brief \ref named-templ-param "Named parameter" for setting |
257 | 257 |
///DistMap type |
258 | 258 |
/// |
259 | 259 |
///\ref named-templ-param "Named parameter" for setting DistMap |
260 | 260 |
///type |
261 | 261 |
template <class T> |
262 | 262 |
struct DefDistMap { |
263 | 263 |
typedef Dfs<Digraph, DefDistMapTraits<T> > Create; |
264 | 264 |
}; |
265 | 265 |
|
266 | 266 |
template <class T> |
267 | 267 |
struct DefReachedMapTraits : public Traits { |
268 | 268 |
typedef T ReachedMap; |
269 | 269 |
static ReachedMap *createReachedMap(const Digraph &) |
270 | 270 |
{ |
271 | 271 |
throw UninitializedParameter(); |
272 | 272 |
} |
273 | 273 |
}; |
274 | 274 |
///\brief \ref named-templ-param "Named parameter" for setting |
275 | 275 |
///ReachedMap type |
276 | 276 |
/// |
277 | 277 |
///\ref named-templ-param "Named parameter" for setting ReachedMap type |
278 | 278 |
/// |
279 | 279 |
template <class T> |
280 | 280 |
struct DefReachedMap : public Dfs< Digraph, DefReachedMapTraits<T> > { |
281 | 281 |
typedef Dfs< Digraph, DefReachedMapTraits<T> > Create; |
282 | 282 |
}; |
283 | 283 |
|
284 | 284 |
template <class T> |
285 | 285 |
struct DefProcessedMapTraits : public Traits { |
286 | 286 |
typedef T ProcessedMap; |
287 | 287 |
static ProcessedMap *createProcessedMap(const Digraph &) |
288 | 288 |
{ |
289 | 289 |
throw UninitializedParameter(); |
290 | 290 |
} |
291 | 291 |
}; |
292 | 292 |
///\brief \ref named-templ-param "Named parameter" for setting |
293 | 293 |
///ProcessedMap type |
294 | 294 |
/// |
295 | 295 |
///\ref named-templ-param "Named parameter" for setting ProcessedMap type |
296 | 296 |
/// |
297 | 297 |
template <class T> |
298 | 298 |
struct DefProcessedMap : public Dfs< Digraph, DefProcessedMapTraits<T> > { |
299 | 299 |
typedef Dfs< Digraph, DefProcessedMapTraits<T> > Create; |
300 | 300 |
}; |
301 | 301 |
|
302 | 302 |
struct DefDigraphProcessedMapTraits : public Traits { |
303 | 303 |
typedef typename Digraph::template NodeMap<bool> ProcessedMap; |
304 | 304 |
static ProcessedMap *createProcessedMap(const Digraph &G) |
305 | 305 |
{ |
306 | 306 |
return new ProcessedMap(G); |
307 | 307 |
} |
308 | 308 |
}; |
309 | 309 |
///\brief \ref named-templ-param "Named parameter" |
310 | 310 |
///for setting the ProcessedMap type to be Digraph::NodeMap<bool>. |
311 | 311 |
/// |
312 | 312 |
///\ref named-templ-param "Named parameter" |
313 | 313 |
///for setting the ProcessedMap type to be Digraph::NodeMap<bool>. |
314 | 314 |
///If you don't set it explicitely, it will be automatically allocated. |
315 | 315 |
template <class T> |
316 | 316 |
class DefProcessedMapToBeDefaultMap : |
317 | 317 |
public Dfs< Digraph, DefDigraphProcessedMapTraits> { |
318 | 318 |
typedef Dfs< Digraph, DefDigraphProcessedMapTraits> Create; |
319 | 319 |
}; |
320 | 320 |
|
321 | 321 |
///@} |
322 | 322 |
|
323 | 323 |
public: |
324 | 324 |
|
325 | 325 |
///Constructor. |
326 | 326 |
|
327 | 327 |
///\param _G the digraph the algorithm will run on. |
328 | 328 |
/// |
329 | 329 |
Dfs(const Digraph& _G) : |
330 | 330 |
G(&_G), |
331 | 331 |
_pred(NULL), local_pred(false), |
332 | 332 |
_dist(NULL), local_dist(false), |
333 | 333 |
_reached(NULL), local_reached(false), |
334 | 334 |
_processed(NULL), local_processed(false) |
335 | 335 |
{ } |
336 | 336 |
|
337 | 337 |
///Destructor. |
338 | 338 |
~Dfs() |
339 | 339 |
{ |
340 | 340 |
if(local_pred) delete _pred; |
341 | 341 |
if(local_dist) delete _dist; |
342 | 342 |
if(local_reached) delete _reached; |
343 | 343 |
if(local_processed) delete _processed; |
344 | 344 |
} |
345 | 345 |
|
346 | 346 |
///Sets the map storing the predecessor arcs. |
347 | 347 |
|
348 | 348 |
///Sets the map storing the predecessor arcs. |
349 | 349 |
///If you don't use this function before calling \ref run(), |
350 | 350 |
///it will allocate one. The destuctor deallocates this |
351 | 351 |
///automatically allocated map, of course. |
352 | 352 |
///\return <tt> (*this) </tt> |
353 | 353 |
Dfs &predMap(PredMap &m) |
354 | 354 |
{ |
355 | 355 |
if(local_pred) { |
356 | 356 |
delete _pred; |
357 | 357 |
local_pred=false; |
358 | 358 |
} |
359 | 359 |
_pred = &m; |
360 | 360 |
return *this; |
361 | 361 |
} |
362 | 362 |
|
363 | 363 |
///Sets the map storing the distances calculated by the algorithm. |
364 | 364 |
|
365 | 365 |
///Sets the map storing the distances calculated by the algorithm. |
366 | 366 |
///If you don't use this function before calling \ref run(), |
367 | 367 |
///it will allocate one. The destuctor deallocates this |
368 | 368 |
///automatically allocated map, of course. |
369 | 369 |
///\return <tt> (*this) </tt> |
370 | 370 |
Dfs &distMap(DistMap &m) |
371 | 371 |
{ |
372 | 372 |
if(local_dist) { |
373 | 373 |
delete _dist; |
374 | 374 |
local_dist=false; |
375 | 375 |
} |
376 | 376 |
_dist = &m; |
377 | 377 |
return *this; |
378 | 378 |
} |
379 | 379 |
|
380 | 380 |
///Sets the map indicating if a node is reached. |
381 | 381 |
|
382 | 382 |
///Sets the map indicating if a node is reached. |
383 | 383 |
///If you don't use this function before calling \ref run(), |
384 | 384 |
///it will allocate one. The destuctor deallocates this |
385 | 385 |
///automatically allocated map, of course. |
386 | 386 |
///\return <tt> (*this) </tt> |
387 | 387 |
Dfs &reachedMap(ReachedMap &m) |
388 | 388 |
{ |
389 | 389 |
if(local_reached) { |
390 | 390 |
delete _reached; |
391 | 391 |
local_reached=false; |
392 | 392 |
} |
393 | 393 |
_reached = &m; |
394 | 394 |
return *this; |
395 | 395 |
} |
396 | 396 |
|
397 | 397 |
///Sets the map indicating if a node is processed. |
398 | 398 |
|
399 | 399 |
///Sets the map indicating if a node is processed. |
400 | 400 |
///If you don't use this function before calling \ref run(), |
401 | 401 |
///it will allocate one. The destuctor deallocates this |
402 | 402 |
///automatically allocated map, of course. |
403 | 403 |
///\return <tt> (*this) </tt> |
404 | 404 |
Dfs &processedMap(ProcessedMap &m) |
405 | 405 |
{ |
406 | 406 |
if(local_processed) { |
407 | 407 |
delete _processed; |
408 | 408 |
local_processed=false; |
409 | 409 |
} |
410 | 410 |
_processed = &m; |
411 | 411 |
return *this; |
412 | 412 |
} |
413 | 413 |
|
414 | 414 |
public: |
415 | 415 |
///\name Execution control |
416 | 416 |
///The simplest way to execute the algorithm is to use |
417 | 417 |
///one of the member functions called \c run(...). |
418 | 418 |
///\n |
419 | 419 |
///If you need more control on the execution, |
420 | 420 |
///first you must call \ref init(), then you can add a source node |
421 | 421 |
///with \ref addSource(). |
422 | 422 |
///Finally \ref start() will perform the actual path |
423 | 423 |
///computation. |
424 | 424 |
|
425 | 425 |
///@{ |
426 | 426 |
|
427 | 427 |
///Initializes the internal data structures. |
428 | 428 |
|
429 | 429 |
///Initializes the internal data structures. |
430 | 430 |
/// |
431 | 431 |
void init() |
432 | 432 |
{ |
433 | 433 |
create_maps(); |
434 | 434 |
_stack.resize(countNodes(*G)); |
435 | 435 |
_stack_head=-1; |
436 | 436 |
for ( NodeIt u(*G) ; u!=INVALID ; ++u ) { |
437 | 437 |
_pred->set(u,INVALID); |
438 | 438 |
// _predNode->set(u,INVALID); |
439 | 439 |
_reached->set(u,false); |
440 | 440 |
_processed->set(u,false); |
441 | 441 |
} |
442 | 442 |
} |
443 | 443 |
|
444 | 444 |
///Adds a new source node. |
445 | 445 |
|
446 | 446 |
///Adds a new source node to the set of nodes to be processed. |
447 | 447 |
/// |
448 | 448 |
///\warning dists are wrong (or at least strange) |
449 | 449 |
///in case of multiple sources. |
450 | 450 |
void addSource(Node s) |
451 | 451 |
{ |
452 | 452 |
if(!(*_reached)[s]) |
453 | 453 |
{ |
454 | 454 |
_reached->set(s,true); |
455 | 455 |
_pred->set(s,INVALID); |
456 | 456 |
OutArcIt e(*G,s); |
457 | 457 |
if(e!=INVALID) { |
458 | 458 |
_stack[++_stack_head]=e; |
459 | 459 |
_dist->set(s,_stack_head); |
460 | 460 |
} |
461 | 461 |
else { |
462 | 462 |
_processed->set(s,true); |
463 | 463 |
_dist->set(s,0); |
464 | 464 |
} |
465 | 465 |
} |
466 | 466 |
} |
467 | 467 |
|
468 | 468 |
///Processes the next arc. |
469 | 469 |
|
470 | 470 |
///Processes the next arc. |
471 | 471 |
/// |
472 | 472 |
///\return The processed arc. |
473 | 473 |
/// |
474 | 474 |
///\pre The stack must not be empty! |
475 | 475 |
Arc processNextArc() |
476 | 476 |
{ |
477 | 477 |
Node m; |
478 | 478 |
Arc e=_stack[_stack_head]; |
479 | 479 |
if(!(*_reached)[m=G->target(e)]) { |
480 | 480 |
_pred->set(m,e); |
481 | 481 |
_reached->set(m,true); |
482 | 482 |
++_stack_head; |
483 | 483 |
_stack[_stack_head] = OutArcIt(*G, m); |
484 | 484 |
_dist->set(m,_stack_head); |
485 | 485 |
} |
486 | 486 |
else { |
487 | 487 |
m=G->source(e); |
488 | 488 |
++_stack[_stack_head]; |
489 | 489 |
} |
490 | 490 |
while(_stack_head>=0 && _stack[_stack_head]==INVALID) { |
491 | 491 |
_processed->set(m,true); |
492 | 492 |
--_stack_head; |
493 | 493 |
if(_stack_head>=0) { |
494 | 494 |
m=G->source(_stack[_stack_head]); |
495 | 495 |
++_stack[_stack_head]; |
496 | 496 |
} |
497 | 497 |
} |
498 | 498 |
return e; |
499 | 499 |
} |
500 | 500 |
///Next arc to be processed. |
501 | 501 |
|
502 | 502 |
///Next arc to be processed. |
503 | 503 |
/// |
504 | 504 |
///\return The next arc to be processed or INVALID if the stack is |
505 | 505 |
/// empty. |
506 | 506 |
OutArcIt nextArc() |
507 | 507 |
{ |
508 | 508 |
return _stack_head>=0?_stack[_stack_head]:INVALID; |
509 | 509 |
} |
510 | 510 |
|
511 | 511 |
///\brief Returns \c false if there are nodes |
512 | 512 |
///to be processed in the queue |
513 | 513 |
/// |
514 | 514 |
///Returns \c false if there are nodes |
515 | 515 |
///to be processed in the queue |
516 | 516 |
bool emptyQueue() { return _stack_head<0; } |
517 | 517 |
///Returns the number of the nodes to be processed. |
518 | 518 |
|
519 | 519 |
///Returns the number of the nodes to be processed in the queue. |
520 | 520 |
int queueSize() { return _stack_head+1; } |
521 | 521 |
|
522 | 522 |
///Executes the algorithm. |
523 | 523 |
|
524 | 524 |
///Executes the algorithm. |
525 | 525 |
/// |
526 | 526 |
///\pre init() must be called and at least one node should be added |
527 | 527 |
///with addSource() before using this function. |
528 | 528 |
/// |
529 | 529 |
///This method runs the %DFS algorithm from the root node(s) |
530 | 530 |
///in order to |
531 | 531 |
///compute the |
532 | 532 |
///%DFS path to each node. The algorithm computes |
533 | 533 |
///- The %DFS tree. |
534 | 534 |
///- The distance of each node from the root(s) in the %DFS tree. |
535 | 535 |
/// |
536 | 536 |
void start() |
537 | 537 |
{ |
538 | 538 |
while ( !emptyQueue() ) processNextArc(); |
539 | 539 |
} |
540 | 540 |
|
541 | 541 |
///Executes the algorithm until \c dest is reached. |
542 | 542 |
|
543 | 543 |
///Executes the algorithm until \c dest is reached. |
544 | 544 |
/// |
545 | 545 |
///\pre init() must be called and at least one node should be added |
546 | 546 |
///with addSource() before using this function. |
547 | 547 |
/// |
548 | 548 |
///This method runs the %DFS algorithm from the root node(s) |
549 | 549 |
///in order to |
550 | 550 |
///compute the |
551 | 551 |
///%DFS path to \c dest. The algorithm computes |
552 | 552 |
///- The %DFS path to \c dest. |
553 | 553 |
///- The distance of \c dest from the root(s) in the %DFS tree. |
554 | 554 |
/// |
555 | 555 |
void start(Node dest) |
556 | 556 |
{ |
557 | 557 |
while ( !emptyQueue() && G->target(_stack[_stack_head])!=dest ) |
558 | 558 |
processNextArc(); |
559 | 559 |
} |
560 | 560 |
|
561 | 561 |
///Executes the algorithm until a condition is met. |
562 | 562 |
|
563 | 563 |
///Executes the algorithm until a condition is met. |
564 | 564 |
/// |
565 | 565 |
///\pre init() must be called and at least one node should be added |
566 | 566 |
///with addSource() before using this function. |
567 | 567 |
/// |
568 | 568 |
///\param em must be a bool (or convertible) arc map. The algorithm |
569 | 569 |
///will stop when it reaches an arc \c e with <tt>em[e]</tt> true. |
570 | 570 |
/// |
571 | 571 |
///\return The reached arc \c e with <tt>em[e]</tt> true or |
572 | 572 |
///\c INVALID if no such arc was found. |
573 | 573 |
/// |
574 | 574 |
///\warning Contrary to \ref Bfs and \ref Dijkstra, \c em is an arc map, |
575 | 575 |
///not a node map. |
576 | 576 |
template<class EM> |
577 | 577 |
Arc start(const EM &em) |
578 | 578 |
{ |
579 | 579 |
while ( !emptyQueue() && !em[_stack[_stack_head]] ) |
580 | 580 |
processNextArc(); |
581 | 581 |
return emptyQueue() ? INVALID : _stack[_stack_head]; |
582 | 582 |
} |
583 | 583 |
|
584 | 584 |
///Runs %DFS algorithm to visit all nodes in the digraph. |
585 | 585 |
|
586 | 586 |
///This method runs the %DFS algorithm in order to |
587 | 587 |
///compute the |
588 | 588 |
///%DFS path to each node. The algorithm computes |
589 | 589 |
///- The %DFS tree. |
590 | 590 |
///- The distance of each node from the root in the %DFS tree. |
591 | 591 |
/// |
592 | 592 |
///\note d.run() is just a shortcut of the following code. |
593 | 593 |
///\code |
594 | 594 |
/// d.init(); |
595 | 595 |
/// for (NodeIt it(digraph); it != INVALID; ++it) { |
596 | 596 |
/// if (!d.reached(it)) { |
597 | 597 |
/// d.addSource(it); |
598 | 598 |
/// d.start(); |
599 | 599 |
/// } |
600 | 600 |
/// } |
601 | 601 |
///\endcode |
602 | 602 |
void run() { |
603 | 603 |
init(); |
604 | 604 |
for (NodeIt it(*G); it != INVALID; ++it) { |
605 | 605 |
if (!reached(it)) { |
606 | 606 |
addSource(it); |
607 | 607 |
start(); |
608 | 608 |
} |
609 | 609 |
} |
610 | 610 |
} |
611 | 611 |
|
612 | 612 |
///Runs %DFS algorithm from node \c s. |
613 | 613 |
|
614 | 614 |
///This method runs the %DFS algorithm from a root node \c s |
615 | 615 |
///in order to |
616 | 616 |
///compute the |
617 | 617 |
///%DFS path to each node. The algorithm computes |
618 | 618 |
///- The %DFS tree. |
619 | 619 |
///- The distance of each node from the root in the %DFS tree. |
620 | 620 |
/// |
621 | 621 |
///\note d.run(s) is just a shortcut of the following code. |
622 | 622 |
///\code |
623 | 623 |
/// d.init(); |
624 | 624 |
/// d.addSource(s); |
625 | 625 |
/// d.start(); |
626 | 626 |
///\endcode |
627 | 627 |
void run(Node s) { |
628 | 628 |
init(); |
629 | 629 |
addSource(s); |
630 | 630 |
start(); |
631 | 631 |
} |
632 | 632 |
|
633 | 633 |
///Finds the %DFS path between \c s and \c t. |
634 | 634 |
|
635 | 635 |
///Finds the %DFS path between \c s and \c t. |
636 | 636 |
/// |
637 | 637 |
///\return The length of the %DFS s---t path if there exists one, |
638 | 638 |
///0 otherwise. |
639 | 639 |
///\note Apart from the return value, d.run(s,t) is |
640 | 640 |
///just a shortcut of the following code. |
641 | 641 |
///\code |
642 | 642 |
/// d.init(); |
643 | 643 |
/// d.addSource(s); |
644 | 644 |
/// d.start(t); |
645 | 645 |
///\endcode |
646 | 646 |
int run(Node s,Node t) { |
647 | 647 |
init(); |
648 | 648 |
addSource(s); |
649 | 649 |
start(t); |
650 | 650 |
return reached(t)?_stack_head+1:0; |
651 | 651 |
} |
652 | 652 |
|
653 | 653 |
///@} |
654 | 654 |
|
655 | 655 |
///\name Query Functions |
656 | 656 |
///The result of the %DFS algorithm can be obtained using these |
657 | 657 |
///functions.\n |
658 | 658 |
///Before the use of these functions, |
659 | 659 |
///either run() or start() must be called. |
660 | 660 |
|
661 | 661 |
///@{ |
662 | 662 |
|
663 | 663 |
typedef PredMapPath<Digraph, PredMap> Path; |
664 | 664 |
|
665 | 665 |
///Gives back the shortest path. |
666 | 666 |
|
667 | 667 |
///Gives back the shortest path. |
668 | 668 |
///\pre The \c t should be reachable from the source. |
669 | 669 |
Path path(Node t) |
670 | 670 |
{ |
671 | 671 |
return Path(*G, *_pred, t); |
672 | 672 |
} |
673 | 673 |
|
674 | 674 |
///The distance of a node from the root(s). |
675 | 675 |
|
676 | 676 |
///Returns the distance of a node from the root(s). |
677 | 677 |
///\pre \ref run() must be called before using this function. |
678 | 678 |
///\warning If node \c v is unreachable from the root(s) then the return |
679 | 679 |
///value of this funcion is undefined. |
680 | 680 |
int dist(Node v) const { return (*_dist)[v]; } |
681 | 681 |
|
682 | 682 |
///Returns the 'previous arc' of the %DFS tree. |
683 | 683 |
|
684 | 684 |
///For a node \c v it returns the 'previous arc' |
685 | 685 |
///of the %DFS path, |
686 | 686 |
///i.e. it returns the last arc of a %DFS path from the root(s) to \c |
687 | 687 |
///v. It is \ref INVALID |
688 | 688 |
///if \c v is unreachable from the root(s) or \c v is a root. The |
689 | 689 |
///%DFS tree used here is equal to the %DFS tree used in |
690 | 690 |
///\ref predNode(). |
691 | 691 |
///\pre Either \ref run() or \ref start() must be called before using |
692 | 692 |
///this function. |
693 | 693 |
Arc predArc(Node v) const { return (*_pred)[v];} |
694 | 694 |
|
695 | 695 |
///Returns the 'previous node' of the %DFS tree. |
696 | 696 |
|
697 | 697 |
///For a node \c v it returns the 'previous node' |
698 | 698 |
///of the %DFS tree, |
699 | 699 |
///i.e. it returns the last but one node from a %DFS path from the |
700 | 700 |
///root(s) to \c v. |
701 | 701 |
///It is INVALID if \c v is unreachable from the root(s) or |
702 | 702 |
///if \c v itself a root. |
703 | 703 |
///The %DFS tree used here is equal to the %DFS |
704 | 704 |
///tree used in \ref predArc(). |
705 | 705 |
///\pre Either \ref run() or \ref start() must be called before |
706 | 706 |
///using this function. |
707 | 707 |
Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID: |
708 | 708 |
G->source((*_pred)[v]); } |
709 | 709 |
|
710 | 710 |
///Returns a reference to the NodeMap of distances. |
711 | 711 |
|
712 | 712 |
///Returns a reference to the NodeMap of distances. |
713 | 713 |
///\pre Either \ref run() or \ref init() must |
714 | 714 |
///be called before using this function. |
715 | 715 |
const DistMap &distMap() const { return *_dist;} |
716 | 716 |
|
717 | 717 |
///Returns a reference to the %DFS arc-tree map. |
718 | 718 |
|
719 | 719 |
///Returns a reference to the NodeMap of the arcs of the |
720 | 720 |
///%DFS tree. |
721 | 721 |
///\pre Either \ref run() or \ref init() |
722 | 722 |
///must be called before using this function. |
723 | 723 |
const PredMap &predMap() const { return *_pred;} |
724 | 724 |
|
725 | 725 |
///Checks if a node is reachable from the root. |
726 | 726 |
|
727 | 727 |
///Returns \c true if \c v is reachable from the root(s). |
728 | 728 |
///\warning The source nodes are inditated as unreachable. |
729 | 729 |
///\pre Either \ref run() or \ref start() |
730 | 730 |
///must be called before using this function. |
731 | 731 |
/// |
732 | 732 |
bool reached(Node v) { return (*_reached)[v]; } |
733 | 733 |
|
734 | 734 |
///@} |
735 | 735 |
}; |
736 | 736 |
|
737 | 737 |
///Default traits class of Dfs function. |
738 | 738 |
|
739 | 739 |
///Default traits class of Dfs function. |
740 | 740 |
///\tparam GR Digraph type. |
741 | 741 |
template<class GR> |
742 | 742 |
struct DfsWizardDefaultTraits |
743 | 743 |
{ |
744 | 744 |
///The digraph type the algorithm runs on. |
745 | 745 |
typedef GR Digraph; |
746 | 746 |
///\brief The type of the map that stores the last |
747 | 747 |
///arcs of the %DFS paths. |
748 | 748 |
/// |
749 | 749 |
///The type of the map that stores the last |
750 | 750 |
///arcs of the %DFS paths. |
751 | 751 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
752 | 752 |
/// |
753 | 753 |
typedef NullMap<typename Digraph::Node,typename GR::Arc> PredMap; |
754 | 754 |
///Instantiates a PredMap. |
755 | 755 |
|
756 | 756 |
///This function instantiates a \ref PredMap. |
757 | 757 |
///\param g is the digraph, to which we would like to define the PredMap. |
758 | 758 |
///\todo The digraph alone may be insufficient to initialize |
759 | 759 |
#ifdef DOXYGEN |
760 | 760 |
static PredMap *createPredMap(const GR &g) |
761 | 761 |
#else |
762 | 762 |
static PredMap *createPredMap(const GR &) |
763 | 763 |
#endif |
764 | 764 |
{ |
765 | 765 |
return new PredMap(); |
766 | 766 |
} |
767 | 767 |
|
768 | 768 |
///The type of the map that indicates which nodes are processed. |
769 | 769 |
|
770 | 770 |
///The type of the map that indicates which nodes are processed. |
771 | 771 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
772 | 772 |
///\todo named parameter to set this type, function to read and write. |
773 | 773 |
typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
774 | 774 |
///Instantiates a ProcessedMap. |
775 | 775 |
|
776 | 776 |
///This function instantiates a \ref ProcessedMap. |
777 | 777 |
///\param g is the digraph, to which |
778 | 778 |
///we would like to define the \ref ProcessedMap |
779 | 779 |
#ifdef DOXYGEN |
780 | 780 |
static ProcessedMap *createProcessedMap(const GR &g) |
781 | 781 |
#else |
782 | 782 |
static ProcessedMap *createProcessedMap(const GR &) |
783 | 783 |
#endif |
784 | 784 |
{ |
785 | 785 |
return new ProcessedMap(); |
786 | 786 |
} |
787 | 787 |
///The type of the map that indicates which nodes are reached. |
788 | 788 |
|
789 | 789 |
///The type of the map that indicates which nodes are reached. |
790 | 790 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
791 | 791 |
///\todo named parameter to set this type, function to read and write. |
792 | 792 |
typedef typename Digraph::template NodeMap<bool> ReachedMap; |
793 | 793 |
///Instantiates a ReachedMap. |
794 | 794 |
|
795 | 795 |
///This function instantiates a \ref ReachedMap. |
796 | 796 |
///\param G is the digraph, to which |
797 | 797 |
///we would like to define the \ref ReachedMap. |
798 | 798 |
static ReachedMap *createReachedMap(const GR &G) |
799 | 799 |
{ |
800 | 800 |
return new ReachedMap(G); |
801 | 801 |
} |
802 | 802 |
///The type of the map that stores the dists of the nodes. |
803 | 803 |
|
804 | 804 |
///The type of the map that stores the dists of the nodes. |
805 | 805 |
///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
806 | 806 |
/// |
807 | 807 |
typedef NullMap<typename Digraph::Node,int> DistMap; |
808 | 808 |
///Instantiates a DistMap. |
809 | 809 |
|
810 | 810 |
///This function instantiates a \ref DistMap. |
811 | 811 |
///\param g is the digraph, to which we would like to define the \ref DistMap |
812 | 812 |
#ifdef DOXYGEN |
813 | 813 |
static DistMap *createDistMap(const GR &g) |
814 | 814 |
#else |
815 | 815 |
static DistMap *createDistMap(const GR &) |
816 | 816 |
#endif |
817 | 817 |
{ |
818 | 818 |
return new DistMap(); |
819 | 819 |
} |
820 | 820 |
}; |
821 | 821 |
|
822 | 822 |
/// Default traits used by \ref DfsWizard |
823 | 823 |
|
824 | 824 |
/// To make it easier to use Dfs algorithm |
825 | 825 |
///we have created a wizard class. |
826 | 826 |
/// This \ref DfsWizard class needs default traits, |
827 | 827 |
///as well as the \ref Dfs class. |
828 | 828 |
/// The \ref DfsWizardBase is a class to be the default traits of the |
829 | 829 |
/// \ref DfsWizard class. |
830 | 830 |
template<class GR> |
831 | 831 |
class DfsWizardBase : public DfsWizardDefaultTraits<GR> |
832 | 832 |
{ |
833 | 833 |
|
834 | 834 |
typedef DfsWizardDefaultTraits<GR> Base; |
835 | 835 |
protected: |
836 | 836 |
/// Type of the nodes in the digraph. |
837 | 837 |
typedef typename Base::Digraph::Node Node; |
838 | 838 |
|
839 | 839 |
/// Pointer to the underlying digraph. |
840 | 840 |
void *_g; |
841 | 841 |
///Pointer to the map of reached nodes. |
842 | 842 |
void *_reached; |
843 | 843 |
///Pointer to the map of processed nodes. |
844 | 844 |
void *_processed; |
845 | 845 |
///Pointer to the map of predecessors arcs. |
846 | 846 |
void *_pred; |
847 | 847 |
///Pointer to the map of distances. |
848 | 848 |
void *_dist; |
849 | 849 |
///Pointer to the source node. |
850 | 850 |
Node _source; |
851 | 851 |
|
852 | 852 |
public: |
853 | 853 |
/// Constructor. |
854 | 854 |
|
855 | 855 |
/// This constructor does not require parameters, therefore it initiates |
856 | 856 |
/// all of the attributes to default values (0, INVALID). |
857 | 857 |
DfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0), |
858 | 858 |
_dist(0), _source(INVALID) {} |
859 | 859 |
|
860 | 860 |
/// Constructor. |
861 | 861 |
|
862 | 862 |
/// This constructor requires some parameters, |
863 | 863 |
/// listed in the parameters list. |
864 | 864 |
/// Others are initiated to 0. |
865 | 865 |
/// \param g is the initial value of \ref _g |
866 | 866 |
/// \param s is the initial value of \ref _source |
867 | 867 |
DfsWizardBase(const GR &g, Node s=INVALID) : |
868 | 868 |
_g(reinterpret_cast<void*>(const_cast<GR*>(&g))), |
869 | 869 |
_reached(0), _processed(0), _pred(0), _dist(0), _source(s) {} |
870 | 870 |
|
871 | 871 |
}; |
872 | 872 |
|
873 | 873 |
/// A class to make the usage of the Dfs algorithm easier |
874 | 874 |
|
875 | 875 |
/// This class is created to make it easier to use the Dfs algorithm. |
876 | 876 |
/// It uses the functions and features of the plain \ref Dfs, |
877 | 877 |
/// but it is much simpler to use it. |
878 | 878 |
/// |
879 | 879 |
/// Simplicity means that the way to change the types defined |
880 | 880 |
/// in the traits class is based on functions that returns the new class |
881 | 881 |
/// and not on templatable built-in classes. |
882 | 882 |
/// When using the plain \ref Dfs |
883 | 883 |
/// the new class with the modified type comes from |
884 | 884 |
/// the original class by using the :: |
885 | 885 |
/// operator. In the case of \ref DfsWizard only |
886 | 886 |
/// a function have to be called and it will |
887 | 887 |
/// return the needed class. |
888 | 888 |
/// |
889 | 889 |
/// It does not have own \ref run method. When its \ref run method is called |
890 | 890 |
/// it initiates a plain \ref Dfs object, and calls the \ref Dfs::run |
891 | 891 |
/// method of it. |
892 | 892 |
template<class TR> |
893 | 893 |
class DfsWizard : public TR |
894 | 894 |
{ |
895 | 895 |
typedef TR Base; |
896 | 896 |
|
897 | 897 |
///The type of the underlying digraph. |
898 | 898 |
typedef typename TR::Digraph Digraph; |
899 | 899 |
//\e |
900 | 900 |
typedef typename Digraph::Node Node; |
901 | 901 |
//\e |
902 | 902 |
typedef typename Digraph::NodeIt NodeIt; |
903 | 903 |
//\e |
904 | 904 |
typedef typename Digraph::Arc Arc; |
905 | 905 |
//\e |
906 | 906 |
typedef typename Digraph::OutArcIt OutArcIt; |
907 | 907 |
|
908 | 908 |
///\brief The type of the map that stores |
909 | 909 |
///the reached nodes |
910 | 910 |
typedef typename TR::ReachedMap ReachedMap; |
911 | 911 |
///\brief The type of the map that stores |
912 | 912 |
///the processed nodes |
913 | 913 |
typedef typename TR::ProcessedMap ProcessedMap; |
914 | 914 |
///\brief The type of the map that stores the last |
915 | 915 |
///arcs of the %DFS paths. |
916 | 916 |
typedef typename TR::PredMap PredMap; |
917 | 917 |
///The type of the map that stores the distances of the nodes. |
918 | 918 |
typedef typename TR::DistMap DistMap; |
919 | 919 |
|
920 | 920 |
public: |
921 | 921 |
/// Constructor. |
922 | 922 |
DfsWizard() : TR() {} |
923 | 923 |
|
924 | 924 |
/// Constructor that requires parameters. |
925 | 925 |
|
926 | 926 |
/// Constructor that requires parameters. |
927 | 927 |
/// These parameters will be the default values for the traits class. |
928 | 928 |
DfsWizard(const Digraph &g, Node s=INVALID) : |
929 | 929 |
TR(g,s) {} |
930 | 930 |
|
931 | 931 |
///Copy constructor |
932 | 932 |
DfsWizard(const TR &b) : TR(b) {} |
933 | 933 |
|
934 | 934 |
~DfsWizard() {} |
935 | 935 |
|
936 | 936 |
///Runs Dfs algorithm from a given node. |
937 | 937 |
|
938 | 938 |
///Runs Dfs algorithm from a given node. |
939 | 939 |
///The node can be given by the \ref source function. |
940 | 940 |
void run() |
941 | 941 |
{ |
942 | 942 |
if(Base::_source==INVALID) throw UninitializedParameter(); |
943 | 943 |
Dfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g)); |
944 | 944 |
if(Base::_reached) |
945 | 945 |
alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached)); |
946 | 946 |
if(Base::_processed) |
947 | 947 |
alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed)); |
948 | 948 |
if(Base::_pred) |
949 | 949 |
alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred)); |
950 | 950 |
if(Base::_dist) |
951 | 951 |
alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist)); |
952 | 952 |
alg.run(Base::_source); |
953 | 953 |
} |
954 | 954 |
|
955 | 955 |
///Runs Dfs algorithm from the given node. |
956 | 956 |
|
957 | 957 |
///Runs Dfs algorithm from the given node. |
958 | 958 |
///\param s is the given source. |
959 | 959 |
void run(Node s) |
960 | 960 |
{ |
961 | 961 |
Base::_source=s; |
962 | 962 |
run(); |
963 | 963 |
} |
964 | 964 |
|
965 | 965 |
template<class T> |
966 | 966 |
struct DefPredMapBase : public Base { |
967 | 967 |
typedef T PredMap; |
968 | 968 |
static PredMap *createPredMap(const Digraph &) { return 0; }; |
969 | 969 |
DefPredMapBase(const TR &b) : TR(b) {} |
970 | 970 |
}; |
971 | 971 |
|
972 | 972 |
///\brief \ref named-templ-param "Named parameter" |
973 | 973 |
///function for setting PredMap type |
974 | 974 |
/// |
975 | 975 |
/// \ref named-templ-param "Named parameter" |
976 | 976 |
///function for setting PredMap type |
977 | 977 |
/// |
978 | 978 |
template<class T> |
979 | 979 |
DfsWizard<DefPredMapBase<T> > predMap(const T &t) |
980 | 980 |
{ |
981 | 981 |
Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t)); |
982 | 982 |
return DfsWizard<DefPredMapBase<T> >(*this); |
983 | 983 |
} |
984 | 984 |
|
985 | 985 |
|
986 | 986 |
template<class T> |
987 | 987 |
struct DefReachedMapBase : public Base { |
988 | 988 |
typedef T ReachedMap; |
989 | 989 |
static ReachedMap *createReachedMap(const Digraph &) { return 0; }; |
990 | 990 |
DefReachedMapBase(const TR &b) : TR(b) {} |
991 | 991 |
}; |
992 | 992 |
|
993 | 993 |
///\brief \ref named-templ-param "Named parameter" |
994 | 994 |
///function for setting ReachedMap |
995 | 995 |
/// |
996 | 996 |
/// \ref named-templ-param "Named parameter" |
997 | 997 |
///function for setting ReachedMap |
998 | 998 |
/// |
999 | 999 |
template<class T> |
1000 | 1000 |
DfsWizard<DefReachedMapBase<T> > reachedMap(const T &t) |
1001 | 1001 |
{ |
1002 |
Base:: |
|
1002 |
Base::_reached=reinterpret_cast<void*>(const_cast<T*>(&t)); |
|
1003 | 1003 |
return DfsWizard<DefReachedMapBase<T> >(*this); |
1004 | 1004 |
} |
1005 | 1005 |
|
1006 | 1006 |
|
1007 | 1007 |
template<class T> |
1008 | 1008 |
struct DefProcessedMapBase : public Base { |
1009 | 1009 |
typedef T ProcessedMap; |
1010 | 1010 |
static ProcessedMap *createProcessedMap(const Digraph &) { return 0; }; |
1011 | 1011 |
DefProcessedMapBase(const TR &b) : TR(b) {} |
1012 | 1012 |
}; |
1013 | 1013 |
|
1014 | 1014 |
///\brief \ref named-templ-param "Named parameter" |
1015 | 1015 |
///function for setting ProcessedMap |
1016 | 1016 |
/// |
1017 | 1017 |
/// \ref named-templ-param "Named parameter" |
1018 | 1018 |
///function for setting ProcessedMap |
1019 | 1019 |
/// |
1020 | 1020 |
template<class T> |
1021 | 1021 |
DfsWizard<DefProcessedMapBase<T> > processedMap(const T &t) |
1022 | 1022 |
{ |
1023 |
Base:: |
|
1023 |
Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t)); |
|
1024 | 1024 |
return DfsWizard<DefProcessedMapBase<T> >(*this); |
1025 | 1025 |
} |
1026 | 1026 |
|
1027 | 1027 |
template<class T> |
1028 | 1028 |
struct DefDistMapBase : public Base { |
1029 | 1029 |
typedef T DistMap; |
1030 | 1030 |
static DistMap *createDistMap(const Digraph &) { return 0; }; |
1031 | 1031 |
DefDistMapBase(const TR &b) : TR(b) {} |
1032 | 1032 |
}; |
1033 | 1033 |
|
1034 | 1034 |
///\brief \ref named-templ-param "Named parameter" |
1035 | 1035 |
///function for setting DistMap type |
1036 | 1036 |
/// |
1037 | 1037 |
/// \ref named-templ-param "Named parameter" |
1038 | 1038 |
///function for setting DistMap type |
1039 | 1039 |
/// |
1040 | 1040 |
template<class T> |
1041 | 1041 |
DfsWizard<DefDistMapBase<T> > distMap(const T &t) |
1042 | 1042 |
{ |
1043 | 1043 |
Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1044 | 1044 |
return DfsWizard<DefDistMapBase<T> >(*this); |
1045 | 1045 |
} |
1046 | 1046 |
|
1047 | 1047 |
/// Sets the source node, from which the Dfs algorithm runs. |
1048 | 1048 |
|
1049 | 1049 |
/// Sets the source node, from which the Dfs algorithm runs. |
1050 | 1050 |
/// \param s is the source node. |
1051 | 1051 |
DfsWizard<TR> &source(Node s) |
1052 | 1052 |
{ |
1053 | 1053 |
Base::_source=s; |
1054 | 1054 |
return *this; |
1055 | 1055 |
} |
1056 | 1056 |
|
1057 | 1057 |
}; |
1058 | 1058 |
|
1059 | 1059 |
///Function type interface for Dfs algorithm. |
1060 | 1060 |
|
1061 | 1061 |
///\ingroup search |
1062 | 1062 |
///Function type interface for Dfs algorithm. |
1063 | 1063 |
/// |
1064 | 1064 |
///This function also has several |
1065 | 1065 |
///\ref named-templ-func-param "named parameters", |
1066 | 1066 |
///they are declared as the members of class \ref DfsWizard. |
1067 | 1067 |
///The following |
1068 | 1068 |
///example shows how to use these parameters. |
1069 | 1069 |
///\code |
1070 | 1070 |
/// dfs(g,source).predMap(preds).run(); |
1071 | 1071 |
///\endcode |
1072 | 1072 |
///\warning Don't forget to put the \ref DfsWizard::run() "run()" |
1073 | 1073 |
///to the end of the parameter list. |
1074 | 1074 |
///\sa DfsWizard |
1075 | 1075 |
///\sa Dfs |
1076 | 1076 |
template<class GR> |
1077 | 1077 |
DfsWizard<DfsWizardBase<GR> > |
1078 | 1078 |
dfs(const GR &g,typename GR::Node s=INVALID) |
1079 | 1079 |
{ |
1080 | 1080 |
return DfsWizard<DfsWizardBase<GR> >(g,s); |
1081 | 1081 |
} |
1082 | 1082 |
|
1083 | 1083 |
#ifdef DOXYGEN |
1084 | 1084 |
/// \brief Visitor class for dfs. |
1085 | 1085 |
/// |
1086 | 1086 |
/// It gives a simple interface for a functional interface for dfs |
1087 | 1087 |
/// traversal. The traversal on a linear data structure. |
1088 | 1088 |
template <typename _Digraph> |
1089 | 1089 |
struct DfsVisitor { |
1090 | 1090 |
typedef _Digraph Digraph; |
1091 | 1091 |
typedef typename Digraph::Arc Arc; |
1092 | 1092 |
typedef typename Digraph::Node Node; |
1093 | 1093 |
/// \brief Called when the arc reach a node. |
1094 | 1094 |
/// |
1095 | 1095 |
/// It is called when the dfs find an arc which target is not |
1096 | 1096 |
/// reached yet. |
1097 | 1097 |
void discover(const Arc& arc) {} |
1098 | 1098 |
/// \brief Called when the node reached first time. |
1099 | 1099 |
/// |
1100 | 1100 |
/// It is Called when the node reached first time. |
1101 | 1101 |
void reach(const Node& node) {} |
1102 | 1102 |
/// \brief Called when we step back on an arc. |
1103 | 1103 |
/// |
1104 | 1104 |
/// It is called when the dfs should step back on the arc. |
1105 | 1105 |
void backtrack(const Arc& arc) {} |
1106 | 1106 |
/// \brief Called when we step back from the node. |
1107 | 1107 |
/// |
1108 | 1108 |
/// It is called when we step back from the node. |
1109 | 1109 |
void leave(const Node& node) {} |
1110 | 1110 |
/// \brief Called when the arc examined but target of the arc |
1111 | 1111 |
/// already discovered. |
1112 | 1112 |
/// |
1113 | 1113 |
/// It called when the arc examined but the target of the arc |
1114 | 1114 |
/// already discovered. |
1115 | 1115 |
void examine(const Arc& arc) {} |
1116 | 1116 |
/// \brief Called for the source node of the dfs. |
1117 | 1117 |
/// |
1118 | 1118 |
/// It is called for the source node of the dfs. |
1119 | 1119 |
void start(const Node& node) {} |
1120 | 1120 |
/// \brief Called when we leave the source node of the dfs. |
1121 | 1121 |
/// |
1122 | 1122 |
/// It is called when we leave the source node of the dfs. |
1123 | 1123 |
void stop(const Node& node) {} |
1124 | 1124 |
|
1125 | 1125 |
}; |
1126 | 1126 |
#else |
1127 | 1127 |
template <typename _Digraph> |
1128 | 1128 |
struct DfsVisitor { |
1129 | 1129 |
typedef _Digraph Digraph; |
1130 | 1130 |
typedef typename Digraph::Arc Arc; |
1131 | 1131 |
typedef typename Digraph::Node Node; |
1132 | 1132 |
void discover(const Arc&) {} |
1133 | 1133 |
void reach(const Node&) {} |
1134 | 1134 |
void backtrack(const Arc&) {} |
1135 | 1135 |
void leave(const Node&) {} |
1136 | 1136 |
void examine(const Arc&) {} |
1137 | 1137 |
void start(const Node&) {} |
1138 | 1138 |
void stop(const Node&) {} |
1139 | 1139 |
|
1140 | 1140 |
template <typename _Visitor> |
1141 | 1141 |
struct Constraints { |
1142 | 1142 |
void constraints() { |
1143 | 1143 |
Arc arc; |
1144 | 1144 |
Node node; |
1145 | 1145 |
visitor.discover(arc); |
1146 | 1146 |
visitor.reach(node); |
1147 | 1147 |
visitor.backtrack(arc); |
1148 | 1148 |
visitor.leave(node); |
1149 | 1149 |
visitor.examine(arc); |
1150 | 1150 |
visitor.start(node); |
1151 | 1151 |
visitor.stop(arc); |
1152 | 1152 |
} |
1153 | 1153 |
_Visitor& visitor; |
1154 | 1154 |
}; |
1155 | 1155 |
}; |
1156 | 1156 |
#endif |
1157 | 1157 |
|
1158 | 1158 |
/// \brief Default traits class of DfsVisit class. |
1159 | 1159 |
/// |
1160 | 1160 |
/// Default traits class of DfsVisit class. |
1161 | 1161 |
/// \tparam _Digraph Digraph type. |
1162 | 1162 |
template<class _Digraph> |
1163 | 1163 |
struct DfsVisitDefaultTraits { |
1164 | 1164 |
|
1165 | 1165 |
/// \brief The digraph type the algorithm runs on. |
1166 | 1166 |
typedef _Digraph Digraph; |
1167 | 1167 |
|
1168 | 1168 |
/// \brief The type of the map that indicates which nodes are reached. |
1169 | 1169 |
/// |
1170 | 1170 |
/// The type of the map that indicates which nodes are reached. |
1171 | 1171 |
/// It must meet the \ref concepts::WriteMap "WriteMap" concept. |
1172 | 1172 |
/// \todo named parameter to set this type, function to read and write. |
1173 | 1173 |
typedef typename Digraph::template NodeMap<bool> ReachedMap; |
1174 | 1174 |
|
1175 | 1175 |
/// \brief Instantiates a ReachedMap. |
1176 | 1176 |
/// |
1177 | 1177 |
/// This function instantiates a \ref ReachedMap. |
1178 | 1178 |
/// \param digraph is the digraph, to which |
1179 | 1179 |
/// we would like to define the \ref ReachedMap. |
1180 | 1180 |
static ReachedMap *createReachedMap(const Digraph &digraph) { |
1181 | 1181 |
return new ReachedMap(digraph); |
1182 | 1182 |
} |
1183 | 1183 |
|
1184 | 1184 |
}; |
1185 | 1185 |
|
1186 | 1186 |
/// %DFS Visit algorithm class. |
1187 | 1187 |
|
1188 | 1188 |
/// \ingroup search |
1189 | 1189 |
/// This class provides an efficient implementation of the %DFS algorithm |
1190 | 1190 |
/// with visitor interface. |
1191 | 1191 |
/// |
1192 | 1192 |
/// The %DfsVisit class provides an alternative interface to the Dfs |
1193 | 1193 |
/// class. It works with callback mechanism, the DfsVisit object calls |
1194 | 1194 |
/// on every dfs event the \c Visitor class member functions. |
1195 | 1195 |
/// |
1196 | 1196 |
/// \tparam _Digraph The digraph type the algorithm runs on. The default value is |
1197 | 1197 |
/// \ref ListDigraph. The value of _Digraph is not used directly by Dfs, it |
1198 | 1198 |
/// is only passed to \ref DfsDefaultTraits. |
1199 | 1199 |
/// \tparam _Visitor The Visitor object for the algorithm. The |
1200 | 1200 |
/// \ref DfsVisitor "DfsVisitor<_Digraph>" is an empty Visitor which |
1201 | 1201 |
/// does not observe the Dfs events. If you want to observe the dfs |
1202 | 1202 |
/// events you should implement your own Visitor class. |
1203 | 1203 |
/// \tparam _Traits Traits class to set various data types used by the |
1204 | 1204 |
/// algorithm. The default traits class is |
1205 | 1205 |
/// \ref DfsVisitDefaultTraits "DfsVisitDefaultTraits<_Digraph>". |
1206 | 1206 |
/// See \ref DfsVisitDefaultTraits for the documentation of |
1207 | 1207 |
/// a Dfs visit traits class. |
1208 | 1208 |
/// |
1209 | 1209 |
/// \author Jacint Szabo, Alpar Juttner and Balazs Dezso |
1210 | 1210 |
#ifdef DOXYGEN |
1211 | 1211 |
template <typename _Digraph, typename _Visitor, typename _Traits> |
1212 | 1212 |
#else |
1213 | 1213 |
template <typename _Digraph = ListDigraph, |
1214 | 1214 |
typename _Visitor = DfsVisitor<_Digraph>, |
1215 | 1215 |
typename _Traits = DfsDefaultTraits<_Digraph> > |
1216 | 1216 |
#endif |
1217 | 1217 |
class DfsVisit { |
1218 | 1218 |
public: |
1219 | 1219 |
|
1220 | 1220 |
/// \brief \ref Exception for uninitialized parameters. |
1221 | 1221 |
/// |
1222 | 1222 |
/// This error represents problems in the initialization |
1223 | 1223 |
/// of the parameters of the algorithms. |
1224 | 1224 |
class UninitializedParameter : public lemon::UninitializedParameter { |
1225 | 1225 |
public: |
1226 | 1226 |
virtual const char* what() const throw() |
1227 | 1227 |
{ |
1228 | 1228 |
return "lemon::DfsVisit::UninitializedParameter"; |
1229 | 1229 |
} |
1230 | 1230 |
}; |
1231 | 1231 |
|
1232 | 1232 |
typedef _Traits Traits; |
1233 | 1233 |
|
1234 | 1234 |
typedef typename Traits::Digraph Digraph; |
1235 | 1235 |
|
1236 | 1236 |
typedef _Visitor Visitor; |
1237 | 1237 |
|
1238 | 1238 |
///The type of the map indicating which nodes are reached. |
1239 | 1239 |
typedef typename Traits::ReachedMap ReachedMap; |
1240 | 1240 |
|
1241 | 1241 |
private: |
1242 | 1242 |
|
1243 | 1243 |
typedef typename Digraph::Node Node; |
1244 | 1244 |
typedef typename Digraph::NodeIt NodeIt; |
1245 | 1245 |
typedef typename Digraph::Arc Arc; |
1246 | 1246 |
typedef typename Digraph::OutArcIt OutArcIt; |
1247 | 1247 |
|
1248 | 1248 |
/// Pointer to the underlying digraph. |
1249 | 1249 |
const Digraph *_digraph; |
1250 | 1250 |
/// Pointer to the visitor object. |
1251 | 1251 |
Visitor *_visitor; |
1252 | 1252 |
///Pointer to the map of reached status of the nodes. |
1253 | 1253 |
ReachedMap *_reached; |
1254 | 1254 |
///Indicates if \ref _reached is locally allocated (\c true) or not. |
1255 | 1255 |
bool local_reached; |
1256 | 1256 |
|
1257 | 1257 |
std::vector<typename Digraph::Arc> _stack; |
1258 | 1258 |
int _stack_head; |
1259 | 1259 |
|
1260 | 1260 |
/// \brief Creates the maps if necessary. |
1261 | 1261 |
/// |
1262 | 1262 |
/// Creates the maps if necessary. |
1263 | 1263 |
void create_maps() { |
1264 | 1264 |
if(!_reached) { |
1265 | 1265 |
local_reached = true; |
1266 | 1266 |
_reached = Traits::createReachedMap(*_digraph); |
1267 | 1267 |
} |
1268 | 1268 |
} |
1269 | 1269 |
|
1270 | 1270 |
protected: |
1271 | 1271 |
|
1272 | 1272 |
DfsVisit() {} |
1273 | 1273 |
|
1274 | 1274 |
public: |
1275 | 1275 |
|
1276 | 1276 |
typedef DfsVisit Create; |
1277 | 1277 |
|
1278 | 1278 |
/// \name Named template parameters |
1279 | 1279 |
|
1280 | 1280 |
///@{ |
1281 | 1281 |
template <class T> |
1282 | 1282 |
struct DefReachedMapTraits : public Traits { |
1283 | 1283 |
typedef T ReachedMap; |
1284 | 1284 |
static ReachedMap *createReachedMap(const Digraph &digraph) { |
1285 | 1285 |
throw UninitializedParameter(); |
1286 | 1286 |
} |
1287 | 1287 |
}; |
1288 | 1288 |
/// \brief \ref named-templ-param "Named parameter" for setting |
1289 | 1289 |
/// ReachedMap type |
1290 | 1290 |
/// |
1291 | 1291 |
/// \ref named-templ-param "Named parameter" for setting ReachedMap type |
1292 | 1292 |
template <class T> |
1293 | 1293 |
struct DefReachedMap : public DfsVisit< Digraph, Visitor, |
1294 | 1294 |
DefReachedMapTraits<T> > { |
1295 | 1295 |
typedef DfsVisit< Digraph, Visitor, DefReachedMapTraits<T> > Create; |
1296 | 1296 |
}; |
1297 | 1297 |
///@} |
1298 | 1298 |
|
1299 | 1299 |
public: |
1300 | 1300 |
|
1301 | 1301 |
/// \brief Constructor. |
1302 | 1302 |
/// |
1303 | 1303 |
/// Constructor. |
1304 | 1304 |
/// |
1305 | 1305 |
/// \param digraph the digraph the algorithm will run on. |
1306 | 1306 |
/// \param visitor The visitor of the algorithm. |
1307 | 1307 |
/// |
1308 | 1308 |
DfsVisit(const Digraph& digraph, Visitor& visitor) |
1309 | 1309 |
: _digraph(&digraph), _visitor(&visitor), |
1310 | 1310 |
_reached(0), local_reached(false) {} |
1311 | 1311 |
|
1312 | 1312 |
/// \brief Destructor. |
1313 | 1313 |
/// |
1314 | 1314 |
/// Destructor. |
1315 | 1315 |
~DfsVisit() { |
1316 | 1316 |
if(local_reached) delete _reached; |
1317 | 1317 |
} |
1318 | 1318 |
|
1319 | 1319 |
/// \brief Sets the map indicating if a node is reached. |
1320 | 1320 |
/// |
1321 | 1321 |
/// Sets the map indicating if a node is reached. |
1322 | 1322 |
/// If you don't use this function before calling \ref run(), |
1323 | 1323 |
/// it will allocate one. The destuctor deallocates this |
1324 | 1324 |
/// automatically allocated map, of course. |
1325 | 1325 |
/// \return <tt> (*this) </tt> |
1326 | 1326 |
DfsVisit &reachedMap(ReachedMap &m) { |
1327 | 1327 |
if(local_reached) { |
1328 | 1328 |
delete _reached; |
1329 | 1329 |
local_reached=false; |
1330 | 1330 |
} |
1331 | 1331 |
_reached = &m; |
1332 | 1332 |
return *this; |
1333 | 1333 |
} |
1334 | 1334 |
|
1335 | 1335 |
public: |
1336 | 1336 |
/// \name Execution control |
1337 | 1337 |
/// The simplest way to execute the algorithm is to use |
1338 | 1338 |
/// one of the member functions called \c run(...). |
1339 | 1339 |
/// \n |
1340 | 1340 |
/// If you need more control on the execution, |
1341 | 1341 |
/// first you must call \ref init(), then you can adda source node |
1342 | 1342 |
/// with \ref addSource(). |
1343 | 1343 |
/// Finally \ref start() will perform the actual path |
1344 | 1344 |
/// computation. |
1345 | 1345 |
|
1346 | 1346 |
/// @{ |
1347 | 1347 |
/// \brief Initializes the internal data structures. |
1348 | 1348 |
/// |
1349 | 1349 |
/// Initializes the internal data structures. |
1350 | 1350 |
/// |
1351 | 1351 |
void init() { |
1352 | 1352 |
create_maps(); |
1353 | 1353 |
_stack.resize(countNodes(*_digraph)); |
1354 | 1354 |
_stack_head = -1; |
1355 | 1355 |
for (NodeIt u(*_digraph) ; u != INVALID ; ++u) { |
1356 | 1356 |
_reached->set(u, false); |
1357 | 1357 |
} |
1358 | 1358 |
} |
1359 | 1359 |
|
1360 | 1360 |
/// \brief Adds a new source node. |
1361 | 1361 |
/// |
1362 | 1362 |
/// Adds a new source node to the set of nodes to be processed. |
1363 | 1363 |
void addSource(Node s) { |
1364 | 1364 |
if(!(*_reached)[s]) { |
1365 | 1365 |
_reached->set(s,true); |
1366 | 1366 |
_visitor->start(s); |
1367 | 1367 |
_visitor->reach(s); |
1368 | 1368 |
Arc e; |
1369 | 1369 |
_digraph->firstOut(e, s); |
1370 | 1370 |
if (e != INVALID) { |
1371 | 1371 |
_stack[++_stack_head] = e; |
1372 | 1372 |
} else { |
1373 | 1373 |
_visitor->leave(s); |
1374 | 1374 |
} |
1375 | 1375 |
} |
1376 | 1376 |
} |
1377 | 1377 |
|
1378 | 1378 |
/// \brief Processes the next arc. |
1379 | 1379 |
/// |
1380 | 1380 |
/// Processes the next arc. |
1381 | 1381 |
/// |
1382 | 1382 |
/// \return The processed arc. |
1383 | 1383 |
/// |
1384 | 1384 |
/// \pre The stack must not be empty! |
1385 | 1385 |
Arc processNextArc() { |
1386 | 1386 |
Arc e = _stack[_stack_head]; |
1387 | 1387 |
Node m = _digraph->target(e); |
1388 | 1388 |
if(!(*_reached)[m]) { |
1389 | 1389 |
_visitor->discover(e); |
1390 | 1390 |
_visitor->reach(m); |
1391 | 1391 |
_reached->set(m, true); |
1392 | 1392 |
_digraph->firstOut(_stack[++_stack_head], m); |
1393 | 1393 |
} else { |
1394 | 1394 |
_visitor->examine(e); |
1395 | 1395 |
m = _digraph->source(e); |
1396 | 1396 |
_digraph->nextOut(_stack[_stack_head]); |
1397 | 1397 |
} |
1398 | 1398 |
while (_stack_head>=0 && _stack[_stack_head] == INVALID) { |
1399 | 1399 |
_visitor->leave(m); |
1400 | 1400 |
--_stack_head; |
1401 | 1401 |
if (_stack_head >= 0) { |
1402 | 1402 |
_visitor->backtrack(_stack[_stack_head]); |
1403 | 1403 |
m = _digraph->source(_stack[_stack_head]); |
1404 | 1404 |
_digraph->nextOut(_stack[_stack_head]); |
1405 | 1405 |
} else { |
1406 | 1406 |
_visitor->stop(m); |
1407 | 1407 |
} |
1408 | 1408 |
} |
1409 | 1409 |
return e; |
1410 | 1410 |
} |
1411 | 1411 |
|
1412 | 1412 |
/// \brief Next arc to be processed. |
1413 | 1413 |
/// |
1414 | 1414 |
/// Next arc to be processed. |
1415 | 1415 |
/// |
1416 | 1416 |
/// \return The next arc to be processed or INVALID if the stack is |
1417 | 1417 |
/// empty. |
1418 | 1418 |
Arc nextArc() { |
1419 | 1419 |
return _stack_head >= 0 ? _stack[_stack_head] : INVALID; |
1420 | 1420 |
} |
1421 | 1421 |
|
1422 | 1422 |
/// \brief Returns \c false if there are nodes |
1423 | 1423 |
/// to be processed in the queue |
1424 | 1424 |
/// |
1425 | 1425 |
/// Returns \c false if there are nodes |
1426 | 1426 |
/// to be processed in the queue |
1427 | 1427 |
bool emptyQueue() { return _stack_head < 0; } |
1428 | 1428 |
|
1429 | 1429 |
/// \brief Returns the number of the nodes to be processed. |
1430 | 1430 |
/// |
1431 | 1431 |
/// Returns the number of the nodes to be processed in the queue. |
1432 | 1432 |
int queueSize() { return _stack_head + 1; } |
1433 | 1433 |
|
1434 | 1434 |
/// \brief Executes the algorithm. |
1435 | 1435 |
/// |
1436 | 1436 |
/// Executes the algorithm. |
1437 | 1437 |
/// |
1438 | 1438 |
/// \pre init() must be called and at least one node should be added |
1439 | 1439 |
/// with addSource() before using this function. |
1440 | 1440 |
void start() { |
1441 | 1441 |
while ( !emptyQueue() ) processNextArc(); |
1442 | 1442 |
} |
1443 | 1443 |
|
1444 | 1444 |
/// \brief Executes the algorithm until \c dest is reached. |
1445 | 1445 |
/// |
1446 | 1446 |
/// Executes the algorithm until \c dest is reached. |
1447 | 1447 |
/// |
1448 | 1448 |
/// \pre init() must be called and at least one node should be added |
1449 | 1449 |
/// with addSource() before using this function. |
1450 | 1450 |
void start(Node dest) { |
1451 | 1451 |
while ( !emptyQueue() && _digraph->target(_stack[_stack_head]) != dest ) |
1452 | 1452 |
processNextArc(); |
1453 | 1453 |
} |
1454 | 1454 |
|
1455 | 1455 |
/// \brief Executes the algorithm until a condition is met. |
1456 | 1456 |
/// |
1457 | 1457 |
/// Executes the algorithm until a condition is met. |
1458 | 1458 |
/// |
1459 | 1459 |
/// \pre init() must be called and at least one node should be added |
1460 | 1460 |
/// with addSource() before using this function. |
1461 | 1461 |
/// |
1462 | 1462 |
/// \param em must be a bool (or convertible) arc map. The algorithm |
1463 | 1463 |
/// will stop when it reaches an arc \c e with <tt>em[e]</tt> true. |
1464 | 1464 |
/// |
1465 | 1465 |
///\return The reached arc \c e with <tt>em[e]</tt> true or |
1466 | 1466 |
///\c INVALID if no such arc was found. |
1467 | 1467 |
/// |
1468 | 1468 |
/// \warning Contrary to \ref Bfs and \ref Dijkstra, \c em is an arc map, |
1469 | 1469 |
/// not a node map. |
1470 | 1470 |
template <typename EM> |
1471 | 1471 |
Arc start(const EM &em) { |
1472 | 1472 |
while ( !emptyQueue() && !em[_stack[_stack_head]] ) |
1473 | 1473 |
processNextArc(); |
1474 | 1474 |
return emptyQueue() ? INVALID : _stack[_stack_head]; |
1475 | 1475 |
} |
1476 | 1476 |
|
1477 | 1477 |
/// \brief Runs %DFSVisit algorithm from node \c s. |
1478 | 1478 |
/// |
1479 | 1479 |
/// This method runs the %DFS algorithm from a root node \c s. |
1480 | 1480 |
/// \note d.run(s) is just a shortcut of the following code. |
1481 | 1481 |
///\code |
1482 | 1482 |
/// d.init(); |
1483 | 1483 |
/// d.addSource(s); |
1484 | 1484 |
/// d.start(); |
1485 | 1485 |
///\endcode |
1486 | 1486 |
void run(Node s) { |
1487 | 1487 |
init(); |
1488 | 1488 |
addSource(s); |
1489 | 1489 |
start(); |
1490 | 1490 |
} |
1491 | 1491 |
|
1492 | 1492 |
/// \brief Runs %DFSVisit algorithm to visit all nodes in the digraph. |
1493 | 1493 |
|
1494 | 1494 |
/// This method runs the %DFS algorithm in order to |
1495 | 1495 |
/// compute the %DFS path to each node. The algorithm computes |
1496 | 1496 |
/// - The %DFS tree. |
1497 | 1497 |
/// - The distance of each node from the root in the %DFS tree. |
1498 | 1498 |
/// |
1499 | 1499 |
///\note d.run() is just a shortcut of the following code. |
1500 | 1500 |
///\code |
1501 | 1501 |
/// d.init(); |
1502 | 1502 |
/// for (NodeIt it(digraph); it != INVALID; ++it) { |
1503 | 1503 |
/// if (!d.reached(it)) { |
1504 | 1504 |
/// d.addSource(it); |
1505 | 1505 |
/// d.start(); |
1506 | 1506 |
/// } |
1507 | 1507 |
/// } |
1508 | 1508 |
///\endcode |
1509 | 1509 |
void run() { |
1510 | 1510 |
init(); |
1511 | 1511 |
for (NodeIt it(*_digraph); it != INVALID; ++it) { |
1512 | 1512 |
if (!reached(it)) { |
1513 | 1513 |
addSource(it); |
1514 | 1514 |
start(); |
1515 | 1515 |
} |
1516 | 1516 |
} |
1517 | 1517 |
} |
1518 | 1518 |
///@} |
1519 | 1519 |
|
1520 | 1520 |
/// \name Query Functions |
1521 | 1521 |
/// The result of the %DFS algorithm can be obtained using these |
1522 | 1522 |
/// functions.\n |
1523 | 1523 |
/// Before the use of these functions, |
1524 | 1524 |
/// either run() or start() must be called. |
1525 | 1525 |
///@{ |
1526 | 1526 |
/// \brief Checks if a node is reachable from the root. |
1527 | 1527 |
/// |
1528 | 1528 |
/// Returns \c true if \c v is reachable from the root(s). |
1529 | 1529 |
/// \warning The source nodes are inditated as unreachable. |
1530 | 1530 |
/// \pre Either \ref run() or \ref start() |
1531 | 1531 |
/// must be called before using this function. |
1532 | 1532 |
/// |
1533 | 1533 |
bool reached(Node v) { return (*_reached)[v]; } |
1534 | 1534 |
///@} |
1535 | 1535 |
}; |
1536 | 1536 |
|
1537 | 1537 |
|
1538 | 1538 |
} //END OF NAMESPACE LEMON |
1539 | 1539 |
|
1540 | 1540 |
#endif |
1541 | 1541 |
|
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