1 | // -*- c++ -*- |
---|
2 | #ifndef LEMON_BFS_DFS_H |
---|
3 | #define LEMON_BFS_DFS_H |
---|
4 | |
---|
5 | /// \ingroup galgs |
---|
6 | /// \file |
---|
7 | /// \brief Bfs and dfs iterators. |
---|
8 | /// |
---|
9 | /// This file contains bfs and dfs iterator classes. |
---|
10 | /// |
---|
11 | // /// \author Marton Makai |
---|
12 | |
---|
13 | #include <queue> |
---|
14 | #include <stack> |
---|
15 | #include <utility> |
---|
16 | |
---|
17 | #include <lemon/invalid.h> |
---|
18 | |
---|
19 | namespace lemon { |
---|
20 | namespace marci { |
---|
21 | |
---|
22 | /// Bfs searches for the nodes wich are not marked in |
---|
23 | /// \c reached_map |
---|
24 | /// RM have to be a read-write bool node-map. |
---|
25 | /// \ingroup galgs |
---|
26 | template <typename Graph, /*typename OutEdgeIt,*/ |
---|
27 | typename RM/*=typename Graph::NodeMap<bool>*/ > |
---|
28 | class BfsIterator { |
---|
29 | public: |
---|
30 | typedef RM ReachedMap; |
---|
31 | protected: |
---|
32 | typedef typename Graph::Node Node; |
---|
33 | typedef typename Graph::Edge Edge; |
---|
34 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
35 | const Graph* graph; |
---|
36 | std::queue<Node> bfs_queue; |
---|
37 | ReachedMap* reached_map; |
---|
38 | bool b_node_newly_reached; |
---|
39 | //OutEdgeIt actual_edge; |
---|
40 | Edge actual_edge; |
---|
41 | /// \e |
---|
42 | BfsIterator(const Graph& _graph) : graph(&_graph), reached_map(0) { } |
---|
43 | /// RM have to be set before any bfs operation. |
---|
44 | BfsIterator<Graph, RM>& setReached(RM& _reached_map) { |
---|
45 | reached_map=&_reached_map; |
---|
46 | } |
---|
47 | public: |
---|
48 | /// In that constructor \c _reached_map have to be a reference |
---|
49 | /// for a bool bode-map. The algorithm will search for the |
---|
50 | /// initially \c false nodes |
---|
51 | /// in a bfs order. |
---|
52 | BfsIterator(const Graph& _graph, ReachedMap& _reached_map) : |
---|
53 | graph(&_graph), reached_map(&_reached_map) { } |
---|
54 | /// The same as above, but the map storing the reached nodes |
---|
55 | /// is constructed dynamically to everywhere false. |
---|
56 | /// \deprecated |
---|
57 | // BfsIterator(const Graph& _graph) : |
---|
58 | // graph(&_graph), reached_map(new ReachedMap(*graph /*, false*/)), |
---|
59 | // own_reached_map(true) { } |
---|
60 | // /// The map storing the reached nodes have to be destroyed if |
---|
61 | // /// it was constructed dynamically |
---|
62 | // ~BfsIterator() { if (own_reached_map) delete reached_map; } |
---|
63 | /// This method markes \c s reached. |
---|
64 | /// If the queue is empty, then \c s is pushed in the bfs queue |
---|
65 | /// and the first out-edge is processed. |
---|
66 | /// If the queue is not empty, then \c s is simply pushed. |
---|
67 | BfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& pushAndSetReached(Node s) { |
---|
68 | reached_map->set(s, true); |
---|
69 | if (bfs_queue.empty()) { |
---|
70 | bfs_queue.push(s); |
---|
71 | actual_edge=OutEdgeIt(*graph, s); |
---|
72 | //graph->first(actual_edge, s); |
---|
73 | if (actual_edge!=INVALID) { |
---|
74 | Node w=graph->head(actual_edge); |
---|
75 | if (!(*reached_map)[w]) { |
---|
76 | bfs_queue.push(w); |
---|
77 | reached_map->set(w, true); |
---|
78 | b_node_newly_reached=true; |
---|
79 | } else { |
---|
80 | b_node_newly_reached=false; |
---|
81 | } |
---|
82 | } |
---|
83 | } else { |
---|
84 | bfs_queue.push(s); |
---|
85 | } |
---|
86 | return *this; |
---|
87 | } |
---|
88 | /// As \c BfsIterator<Graph, ReachedMap> works as an edge-iterator, |
---|
89 | /// its \c operator++() iterates on the edges in a bfs order. |
---|
90 | BfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& |
---|
91 | operator++() { |
---|
92 | if (actual_edge!=INVALID) { |
---|
93 | actual_edge=++OutEdgeIt(*graph, actual_edge); |
---|
94 | //++actual_edge; |
---|
95 | if (actual_edge!=INVALID) { |
---|
96 | Node w=graph->head(actual_edge); |
---|
97 | if (!(*reached_map)[w]) { |
---|
98 | bfs_queue.push(w); |
---|
99 | reached_map->set(w, true); |
---|
100 | b_node_newly_reached=true; |
---|
101 | } else { |
---|
102 | b_node_newly_reached=false; |
---|
103 | } |
---|
104 | } |
---|
105 | } else { |
---|
106 | bfs_queue.pop(); |
---|
107 | if (!bfs_queue.empty()) { |
---|
108 | actual_edge=OutEdgeIt(*graph, bfs_queue.front()); |
---|
109 | //graph->first(actual_edge, bfs_queue.front()); |
---|
110 | if (actual_edge!=INVALID) { |
---|
111 | Node w=graph->head(actual_edge); |
---|
112 | if (!(*reached_map)[w]) { |
---|
113 | bfs_queue.push(w); |
---|
114 | reached_map->set(w, true); |
---|
115 | b_node_newly_reached=true; |
---|
116 | } else { |
---|
117 | b_node_newly_reached=false; |
---|
118 | } |
---|
119 | } |
---|
120 | } |
---|
121 | } |
---|
122 | return *this; |
---|
123 | } |
---|
124 | /// Returns true iff the algorithm is finished. |
---|
125 | bool finished() const { return bfs_queue.empty(); } |
---|
126 | /// The conversion operator makes for converting the bfs-iterator |
---|
127 | /// to an \c out-edge-iterator. |
---|
128 | ///\bug Edge have to be in LEMON 0.2 |
---|
129 | operator Edge() const { return actual_edge; } |
---|
130 | /// Returns if b-node has been reached just now. |
---|
131 | bool isBNodeNewlyReached() const { return b_node_newly_reached; } |
---|
132 | /// Returns if a-node is examined. |
---|
133 | bool isANodeExamined() const { return actual_edge==INVALID; } |
---|
134 | /// Returns a-node of the actual edge, so does if the edge is invalid. |
---|
135 | Node tail() const { return bfs_queue.front(); } |
---|
136 | /// \pre The actual edge have to be valid. |
---|
137 | Node head() const { return graph->head(actual_edge); } |
---|
138 | /// Guess what? |
---|
139 | /// \deprecated |
---|
140 | const ReachedMap& reachedMap() const { return *reached_map; } |
---|
141 | /// Guess what? |
---|
142 | /// \deprecated |
---|
143 | typename ReachedMap::ValueType reached(const Node& n) const { |
---|
144 | return (*reached_map)[n]; |
---|
145 | } |
---|
146 | /// Guess what? |
---|
147 | /// \deprecated |
---|
148 | const std::queue<Node>& getBfsQueue() const { return bfs_queue; } |
---|
149 | }; |
---|
150 | |
---|
151 | /// Bfs searches for the nodes wich are not marked in |
---|
152 | /// \c reached_map |
---|
153 | /// RM have to work as a read-write bool Node-map, |
---|
154 | /// PM is a write edge node-map and |
---|
155 | /// PNM is a write node node-map and |
---|
156 | /// DM is a read-write node-map of integral value, have to be. |
---|
157 | /// \ingroup galgs |
---|
158 | template <typename Graph, |
---|
159 | typename RM=typename Graph::template NodeMap<bool>, |
---|
160 | typename PM |
---|
161 | =typename Graph::template NodeMap<typename Graph::Edge>, |
---|
162 | typename PNM |
---|
163 | =typename Graph::template NodeMap<typename Graph::Node>, |
---|
164 | typename DM=typename Graph::template NodeMap<int> > |
---|
165 | class Bfs : public BfsIterator<Graph, RM> { |
---|
166 | typedef BfsIterator<Graph, RM> Parent; |
---|
167 | public: |
---|
168 | typedef RM ReachedMap; |
---|
169 | typedef PM PredMap; |
---|
170 | typedef PNM PredNodeMap; |
---|
171 | typedef DM DistMap; |
---|
172 | protected: |
---|
173 | typedef typename Parent::Node Node; |
---|
174 | PredMap* pred_map; |
---|
175 | PredNodeMap* pred_node_map; |
---|
176 | DistMap* dist_map; |
---|
177 | /// \e |
---|
178 | Bfs<Graph, RM, PM, PNM, DM> |
---|
179 | (const Graph& _graph) : BfsIterator<Graph, RM>(_graph) { } |
---|
180 | /// PM have to be set before any bfs operation. |
---|
181 | Bfs<Graph, RM, PM, PNM, DM>& |
---|
182 | setPredMap(PredMap& _pred_map) { |
---|
183 | pred_map=&_pred_map; |
---|
184 | } |
---|
185 | /// PredNodeMap have to be set before any bfs operation. |
---|
186 | Bfs<Graph, RM, PM, PNM, DM>& |
---|
187 | setPredNodeMap(PredNodeMap& _pred_node_map) { |
---|
188 | pred_node_map=&_pred_node_map; |
---|
189 | } |
---|
190 | /// DistMap have to be set before any bfs operation. |
---|
191 | Bfs<Graph, RM, PM, PNM, DM>& |
---|
192 | setDistMap(DistMap& _dist_map) { |
---|
193 | dist_map=&_dist_map; |
---|
194 | } |
---|
195 | public: |
---|
196 | /// The algorithm will search in a bfs order for |
---|
197 | /// the nodes which are \c false initially. |
---|
198 | /// The constructor makes no initial changes on the maps. |
---|
199 | Bfs<Graph, RM, PM, PNM, DM> |
---|
200 | (const Graph& _graph, ReachedMap& _reached_map, |
---|
201 | PredMap& _pred_map, PredNodeMap& _pred_node_map, |
---|
202 | DistMap& _dist_map) : BfsIterator<Graph, RM>(_graph, _reached_map), |
---|
203 | pred_map(&_pred_map), pred_node_map(&_pred_node_map), |
---|
204 | dist_map(&_dist_map) { } |
---|
205 | /// \c s is marked to be reached and pushed in the bfs queue. |
---|
206 | /// If the queue is empty, then the first out-edge is processed. |
---|
207 | /// If \c s was not marked previously, then |
---|
208 | /// in addition its pred_map is set to be \c INVALID, |
---|
209 | /// and dist_map to \c 0. |
---|
210 | /// if \c s was marked previuosly, then it is simply pushed. |
---|
211 | Bfs<Graph, RM, PM, PNM, DM>& push(Node s) { |
---|
212 | if ((*(this->reached_map))[s]) { |
---|
213 | Parent::pushAndSetReached(s); |
---|
214 | } else { |
---|
215 | Parent::pushAndSetReached(s); |
---|
216 | pred_map->set(s, INVALID); |
---|
217 | pred_node_map->set(s, INVALID); |
---|
218 | dist_map->set(s, 0); |
---|
219 | } |
---|
220 | return *this; |
---|
221 | } |
---|
222 | /// A bfs is processed from \c s. |
---|
223 | Bfs<Graph, RM, PM, PNM, DM>& run(Node s) { |
---|
224 | push(s); |
---|
225 | while (!this->finished()) this->operator++(); |
---|
226 | return *this; |
---|
227 | } |
---|
228 | /// Beside the bfs iteration, \c pred_map and \dist_map are saved in a |
---|
229 | /// newly reached node. |
---|
230 | Bfs<Graph, RM, PM, PNM, DM>& operator++() { |
---|
231 | Parent::operator++(); |
---|
232 | if ((this->actual_edge)!=INVALID && this->b_node_newly_reached) |
---|
233 | { |
---|
234 | pred_map->set(this->head(), this->actual_edge); |
---|
235 | pred_node_map->set(this->head(), this->tail()); |
---|
236 | dist_map->set(this->head(), (*dist_map)[this->tail()]); |
---|
237 | } |
---|
238 | return *this; |
---|
239 | } |
---|
240 | /// Guess what? |
---|
241 | /// \deprecated |
---|
242 | const PredMap& predMap() const { return *pred_map; } |
---|
243 | /// Guess what? |
---|
244 | /// \deprecated |
---|
245 | typename PredMap::ValueType pred(const Node& n) const { |
---|
246 | return (*pred_map)[n]; |
---|
247 | } |
---|
248 | /// Guess what? |
---|
249 | /// \deprecated |
---|
250 | const PredNodeMap& predNodeMap() const { return *pred_node_map; } |
---|
251 | /// Guess what? |
---|
252 | /// \deprecated |
---|
253 | typename PredNodeMap::ValueType predNode(const Node& n) const { |
---|
254 | return (*pred_node_map)[n]; |
---|
255 | } |
---|
256 | /// Guess what? |
---|
257 | /// \deprecated |
---|
258 | const DistMap& distMap() const { return *dist_map; } |
---|
259 | /// Guess what? |
---|
260 | /// \deprecated |
---|
261 | typename DistMap::ValueType dist(const Node& n) const { |
---|
262 | return (*dist_map)[n]; |
---|
263 | } |
---|
264 | }; |
---|
265 | |
---|
266 | // template <typename Graph, |
---|
267 | // typename RM=typename Graph::template NodeMap<bool>, |
---|
268 | // typename PM |
---|
269 | // =typename Graph::template NodeMap<typename Graph::Edge>, |
---|
270 | // typename PredNodeMap |
---|
271 | // =typename Graph::template NodeMap<typename Graph::Node>, |
---|
272 | // typename DistMap=typename Graph::template NodeMap<int> > |
---|
273 | // class BfsWizard : public Bfs<Graph> { |
---|
274 | // public: |
---|
275 | // typedef Bfs<Graph, PM, PredNodeMap, DistMap> Parent; |
---|
276 | // protected: |
---|
277 | // typedef typename Parent::Node Node; |
---|
278 | // bool own_reached_map; |
---|
279 | // bool own_pred_map; |
---|
280 | // bool own_pred_node_map; |
---|
281 | // bool own_dist_map; |
---|
282 | |
---|
283 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
284 | // makeRreached() { |
---|
285 | // own_reached_map=true; |
---|
286 | // reached=new ReachedMap(*graph, false); |
---|
287 | // } |
---|
288 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
289 | // deleteReachedMap() { |
---|
290 | // own_reached_map=false; |
---|
291 | // delete reached; |
---|
292 | // } |
---|
293 | |
---|
294 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
295 | // makePM() { |
---|
296 | // own_pred_map=true; |
---|
297 | // pred_map=new PM(*graph, INVALID); |
---|
298 | // } |
---|
299 | // BfsWizard<Graph, ReachedMap, PM, PredNodeMap, DistMap>& |
---|
300 | // deletePM() { |
---|
301 | // own_pred_map=false; |
---|
302 | // delete pred_map; |
---|
303 | // } |
---|
304 | |
---|
305 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
306 | // makePredNodeMap() { |
---|
307 | // own_pred_node_map=true; |
---|
308 | // pred_node_map=new PredNodeMap(*graph, INVALID); |
---|
309 | // } |
---|
310 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
311 | // deletePredNodeMap() { |
---|
312 | // own_pred_node_map=false; |
---|
313 | // delete pred_node_map; |
---|
314 | // } |
---|
315 | |
---|
316 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
317 | // makeDistMap() { |
---|
318 | // own_dist_map=true; |
---|
319 | // dist_map=new DistMap(*graph, 0); |
---|
320 | // } |
---|
321 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
322 | // deleteDistMap() { |
---|
323 | // own_dist_map=false; |
---|
324 | // delete dist_map; |
---|
325 | // } |
---|
326 | |
---|
327 | // public: |
---|
328 | // /// User friendly Bfs class. |
---|
329 | // /// The maps which are not explicitly given by the user are |
---|
330 | // /// constructed with false, INVALID, INVALID and 0 values. |
---|
331 | // /// For the user defined maps, the values are not modified, and |
---|
332 | // /// the bfs is processed without any preset on maps. Therefore, |
---|
333 | // /// the bfs will search only the nodes which are set false previously |
---|
334 | // /// in reached, and in the nodes wich are not newly reached by the |
---|
335 | // /// search, the map values are not modified. |
---|
336 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap> |
---|
337 | // (const Graph& _graph) : |
---|
338 | // own_reached_map(false), |
---|
339 | // own_pred_map(false), |
---|
340 | // own_pred_node_map(false), |
---|
341 | // own_dist_map(false) { |
---|
342 | // } |
---|
343 | |
---|
344 | // /// \e |
---|
345 | // ~BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>() { |
---|
346 | // if (own_reached_map) deleteReachedMap(); |
---|
347 | // if (own_pred_map) deletePM(); |
---|
348 | // if (own_pred_node_map) deletePredNodeMap(); |
---|
349 | // if (own_dist_map) deleteDistMap(); |
---|
350 | // } |
---|
351 | |
---|
352 | // /// \e |
---|
353 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
354 | // setReachedMap(ReachedMap& _reached) { |
---|
355 | // if (own_reached_map) deleteReachedMap(); |
---|
356 | // Parent::setReachedMap(_reached); |
---|
357 | // } |
---|
358 | // /// \e |
---|
359 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
360 | // setPM(PM& _pred) { |
---|
361 | // if (own_pred_map) deletePM(); |
---|
362 | // Parent::setPM(_pred); |
---|
363 | // } |
---|
364 | // /// \e |
---|
365 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
366 | // setPredNodeMap(PredNodeMap& _pred_node) { |
---|
367 | // if (own_pred_node_map) deletePredNodeMap(); |
---|
368 | // Parent::setPredNodeMap(_pred_node); |
---|
369 | // } |
---|
370 | // /// \e |
---|
371 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
372 | // setDistMap(DistMap& _dist) { |
---|
373 | // if (own_dist_map) deleteDistMap(); |
---|
374 | // Parent::setDistMap(_dist); |
---|
375 | // } |
---|
376 | |
---|
377 | // /// \e |
---|
378 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
379 | // push(Node s) { |
---|
380 | // if (!reached) makeReachedMap(); |
---|
381 | // if (!pred_map) makePMMap(); |
---|
382 | // if (!pred_node_map) makePredNodeMap(); |
---|
383 | // if (!dist_map) makeDistMap(); |
---|
384 | // push(s); |
---|
385 | // return *this; |
---|
386 | // } |
---|
387 | |
---|
388 | // /// \e |
---|
389 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
390 | // operator++() { |
---|
391 | // if (!reached) makeRM(); |
---|
392 | // if (!pred_map) makePMMap(); |
---|
393 | // if (!pred_node_map) makePredNodeMap(); |
---|
394 | // if (!dist_map) makeDistMap(); |
---|
395 | // ++(*this); |
---|
396 | // return *this; |
---|
397 | // } |
---|
398 | |
---|
399 | // /// \e |
---|
400 | // BfsWizard<Graph, RM, PM, PredNodeMap, DistMap>& |
---|
401 | // run(Node s) { |
---|
402 | // if (!reached) makeRM(); |
---|
403 | // if (!pred_map) makePMMap(); |
---|
404 | // if (!pred_node_map) makePredNodeMap(); |
---|
405 | // if (!dist_map) makeDistMap(); |
---|
406 | // run(s); |
---|
407 | // return *this; |
---|
408 | // } |
---|
409 | |
---|
410 | // }; |
---|
411 | |
---|
412 | |
---|
413 | /// Dfs searches for the nodes wich are not marked in |
---|
414 | /// \c reached_map |
---|
415 | /// Reached have to be a read-write bool Node-map. |
---|
416 | /// \ingroup galgs |
---|
417 | template <typename Graph, /*typename OutEdgeIt,*/ |
---|
418 | typename ReachedMap/*=typename Graph::NodeMap<bool>*/ > |
---|
419 | class DfsIterator { |
---|
420 | protected: |
---|
421 | typedef typename Graph::Node Node; |
---|
422 | typedef typename Graph::Edge Edge; |
---|
423 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
424 | const Graph* graph; |
---|
425 | std::stack<OutEdgeIt> dfs_stack; |
---|
426 | bool b_node_newly_reached; |
---|
427 | Edge actual_edge; |
---|
428 | Node actual_node; |
---|
429 | ReachedMap& reached; |
---|
430 | bool own_reached_map; |
---|
431 | public: |
---|
432 | /// In that constructor \c _reached have to be a reference |
---|
433 | /// for a bool node-map. The algorithm will search in a dfs order for |
---|
434 | /// the nodes which are \c false initially |
---|
435 | DfsIterator(const Graph& _graph, ReachedMap& _reached) : |
---|
436 | graph(&_graph), reached(_reached), |
---|
437 | own_reached_map(false) { } |
---|
438 | /// The same as above, but the map of reached nodes is |
---|
439 | /// constructed dynamically |
---|
440 | /// to everywhere false. |
---|
441 | DfsIterator(const Graph& _graph) : |
---|
442 | graph(&_graph), reached(*(new ReachedMap(*graph /*, false*/))), |
---|
443 | own_reached_map(true) { } |
---|
444 | ~DfsIterator() { if (own_reached_map) delete &reached; } |
---|
445 | /// This method markes s reached and first out-edge is processed. |
---|
446 | DfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& pushAndSetReached(Node s) { |
---|
447 | actual_node=s; |
---|
448 | reached.set(s, true); |
---|
449 | OutEdgeIt e(*graph, s); |
---|
450 | //graph->first(e, s); |
---|
451 | dfs_stack.push(e); |
---|
452 | return *this; |
---|
453 | } |
---|
454 | /// As \c DfsIterator<Graph, ReachedMap> works as an edge-iterator, |
---|
455 | /// its \c operator++() iterates on the edges in a dfs order. |
---|
456 | DfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& |
---|
457 | operator++() { |
---|
458 | actual_edge=dfs_stack.top(); |
---|
459 | if (actual_edge!=INVALID/*.valid()*/) { |
---|
460 | Node w=graph->head(actual_edge); |
---|
461 | actual_node=w; |
---|
462 | if (!reached[w]) { |
---|
463 | OutEdgeIt e(*graph, w); |
---|
464 | //graph->first(e, w); |
---|
465 | dfs_stack.push(e); |
---|
466 | reached.set(w, true); |
---|
467 | b_node_newly_reached=true; |
---|
468 | } else { |
---|
469 | actual_node=graph->tail(actual_edge); |
---|
470 | ++dfs_stack.top(); |
---|
471 | b_node_newly_reached=false; |
---|
472 | } |
---|
473 | } else { |
---|
474 | //actual_node=G.aNode(dfs_stack.top()); |
---|
475 | dfs_stack.pop(); |
---|
476 | } |
---|
477 | return *this; |
---|
478 | } |
---|
479 | /// Returns true iff the algorithm is finished. |
---|
480 | bool finished() const { return dfs_stack.empty(); } |
---|
481 | /// The conversion operator makes for converting the bfs-iterator |
---|
482 | /// to an \c out-edge-iterator. |
---|
483 | ///\bug Edge have to be in LEMON 0.2 |
---|
484 | operator Edge() const { return actual_edge; } |
---|
485 | /// Returns if b-node has been reached just now. |
---|
486 | bool isBNodeNewlyReached() const { return b_node_newly_reached; } |
---|
487 | /// Returns if a-node is examined. |
---|
488 | bool isANodeExamined() const { return actual_edge==INVALID; } |
---|
489 | /// Returns a-node of the actual edge, so does if the edge is invalid. |
---|
490 | Node tail() const { return actual_node; /*FIXME*/} |
---|
491 | /// Returns b-node of the actual edge. |
---|
492 | /// \pre The actual edge have to be valid. |
---|
493 | Node head() const { return graph->head(actual_edge); } |
---|
494 | /// Guess what? |
---|
495 | /// \deprecated |
---|
496 | const ReachedMap& getReachedMap() const { return reached; } |
---|
497 | /// Guess what? |
---|
498 | /// \deprecated |
---|
499 | const std::stack<OutEdgeIt>& getDfsStack() const { return dfs_stack; } |
---|
500 | }; |
---|
501 | |
---|
502 | /// Dfs searches for the nodes wich are not marked in |
---|
503 | /// \c reached_map |
---|
504 | /// Reached is a read-write bool node-map, |
---|
505 | /// Pred is a write node-map, have to be. |
---|
506 | /// \ingroup galgs |
---|
507 | template <typename Graph, |
---|
508 | typename ReachedMap=typename Graph::template NodeMap<bool>, |
---|
509 | typename PredMap |
---|
510 | =typename Graph::template NodeMap<typename Graph::Edge> > |
---|
511 | class Dfs : public DfsIterator<Graph, ReachedMap> { |
---|
512 | typedef DfsIterator<Graph, ReachedMap> Parent; |
---|
513 | protected: |
---|
514 | typedef typename Parent::Node Node; |
---|
515 | PredMap& pred; |
---|
516 | public: |
---|
517 | /// The algorithm will search in a dfs order for |
---|
518 | /// the nodes which are \c false initially. |
---|
519 | /// The constructor makes no initial changes on the maps. |
---|
520 | Dfs<Graph, ReachedMap, PredMap>(const Graph& _graph, ReachedMap& _reached, PredMap& _pred) : DfsIterator<Graph, ReachedMap>(_graph, _reached), pred(_pred) { } |
---|
521 | /// \c s is marked to be reached and pushed in the bfs queue. |
---|
522 | /// If the queue is empty, then the first out-edge is processed. |
---|
523 | /// If \c s was not marked previously, then |
---|
524 | /// in addition its pred is set to be \c INVALID. |
---|
525 | /// if \c s was marked previuosly, then it is simply pushed. |
---|
526 | Dfs<Graph, ReachedMap, PredMap>& push(Node s) { |
---|
527 | if (this->reached[s]) { |
---|
528 | Parent::pushAndSetReached(s); |
---|
529 | } else { |
---|
530 | Parent::pushAndSetReached(s); |
---|
531 | pred.set(s, INVALID); |
---|
532 | } |
---|
533 | return *this; |
---|
534 | } |
---|
535 | /// A bfs is processed from \c s. |
---|
536 | Dfs<Graph, ReachedMap, PredMap>& run(Node s) { |
---|
537 | push(s); |
---|
538 | while (!this->finished()) this->operator++(); |
---|
539 | return *this; |
---|
540 | } |
---|
541 | /// Beside the dfs iteration, \c pred is saved in a |
---|
542 | /// newly reached node. |
---|
543 | Dfs<Graph, ReachedMap, PredMap>& operator++() { |
---|
544 | Parent::operator++(); |
---|
545 | if (this->graph->valid(this->actual_edge) && this->b_node_newly_reached) |
---|
546 | { |
---|
547 | pred.set(this->head(), this->actual_edge); |
---|
548 | } |
---|
549 | return *this; |
---|
550 | } |
---|
551 | /// Guess what? |
---|
552 | /// \deprecated |
---|
553 | const PredMap& getPredMap() const { return pred; } |
---|
554 | }; |
---|
555 | |
---|
556 | } // namespace marci |
---|
557 | } // namespace lemon |
---|
558 | |
---|
559 | #endif //LEMON_BFS_DFS_H |
---|