1 | // -*- c++ -*- |
---|
2 | #ifndef HUGO_BFS_DFS_H |
---|
3 | #define HUGO_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 <hugo/invalid.h> |
---|
18 | |
---|
19 | namespace hugo { |
---|
20 | |
---|
21 | /// Bfs searches for the nodes wich are not marked in |
---|
22 | /// \c reached_map |
---|
23 | /// Reached have to be a read-write bool node-map. |
---|
24 | /// \ingroup galgs |
---|
25 | template <typename Graph, /*typename OutEdgeIt,*/ |
---|
26 | typename ReachedMap/*=typename Graph::NodeMap<bool>*/ > |
---|
27 | class BfsIterator { |
---|
28 | protected: |
---|
29 | typedef typename Graph::Node Node; |
---|
30 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
31 | const Graph* graph; |
---|
32 | std::queue<Node> bfs_queue; |
---|
33 | ReachedMap& reached; |
---|
34 | bool b_node_newly_reached; |
---|
35 | OutEdgeIt actual_edge; |
---|
36 | bool own_reached_map; |
---|
37 | public: |
---|
38 | /// In that constructor \c _reached have to be a reference |
---|
39 | /// for a bool bode-map. The algorithm will search for the |
---|
40 | /// initially \c false nodes |
---|
41 | /// in a bfs order. |
---|
42 | BfsIterator(const Graph& _graph, ReachedMap& _reached) : |
---|
43 | graph(&_graph), reached(_reached), |
---|
44 | own_reached_map(false) { } |
---|
45 | /// The same as above, but the map storing the reached nodes |
---|
46 | /// is constructed dynamically to everywhere false. |
---|
47 | /// \deprecated |
---|
48 | BfsIterator(const Graph& _graph) : |
---|
49 | graph(&_graph), reached(*(new ReachedMap(*graph /*, false*/))), |
---|
50 | own_reached_map(true) { } |
---|
51 | /// The map storing the reached nodes have to be destroyed if |
---|
52 | /// it was constructed dynamically |
---|
53 | ~BfsIterator() { if (own_reached_map) delete &reached; } |
---|
54 | /// This method markes \c s reached. |
---|
55 | /// If the queue is empty, then \c s is pushed in the bfs queue |
---|
56 | /// and the first out-edge is processed. |
---|
57 | /// If the queue is not empty, then \c s is simply pushed. |
---|
58 | void pushAndSetReached(Node s) { |
---|
59 | reached.set(s, true); |
---|
60 | if (bfs_queue.empty()) { |
---|
61 | bfs_queue.push(s); |
---|
62 | graph->first(actual_edge, s); |
---|
63 | if (graph->valid(actual_edge)) { |
---|
64 | Node w=graph->bNode(actual_edge); |
---|
65 | if (!reached[w]) { |
---|
66 | bfs_queue.push(w); |
---|
67 | reached.set(w, true); |
---|
68 | b_node_newly_reached=true; |
---|
69 | } else { |
---|
70 | b_node_newly_reached=false; |
---|
71 | } |
---|
72 | } |
---|
73 | } else { |
---|
74 | bfs_queue.push(s); |
---|
75 | } |
---|
76 | } |
---|
77 | /// As \c BfsIterator<Graph, ReachedMap> works as an edge-iterator, |
---|
78 | /// its \c operator++() iterates on the edges in a bfs order. |
---|
79 | BfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& |
---|
80 | operator++() { |
---|
81 | if (graph->valid(actual_edge)) { |
---|
82 | graph->next(actual_edge); |
---|
83 | if (graph->valid(actual_edge)) { |
---|
84 | Node w=graph->bNode(actual_edge); |
---|
85 | if (!reached[w]) { |
---|
86 | bfs_queue.push(w); |
---|
87 | reached.set(w, true); |
---|
88 | b_node_newly_reached=true; |
---|
89 | } else { |
---|
90 | b_node_newly_reached=false; |
---|
91 | } |
---|
92 | } |
---|
93 | } else { |
---|
94 | bfs_queue.pop(); |
---|
95 | if (!bfs_queue.empty()) { |
---|
96 | graph->first(actual_edge, bfs_queue.front()); |
---|
97 | if (graph->valid(actual_edge)) { |
---|
98 | Node w=graph->bNode(actual_edge); |
---|
99 | if (!reached[w]) { |
---|
100 | bfs_queue.push(w); |
---|
101 | reached.set(w, true); |
---|
102 | b_node_newly_reached=true; |
---|
103 | } else { |
---|
104 | b_node_newly_reached=false; |
---|
105 | } |
---|
106 | } |
---|
107 | } |
---|
108 | } |
---|
109 | return *this; |
---|
110 | } |
---|
111 | /// Returns true iff the algorithm is finished. |
---|
112 | bool finished() const { return bfs_queue.empty(); } |
---|
113 | /// The conversion operator makes for converting the bfs-iterator |
---|
114 | /// to an \c out-edge-iterator. |
---|
115 | ///\bug Edge have to be in HUGO 0.2 |
---|
116 | operator OutEdgeIt() const { return actual_edge; } |
---|
117 | /// Returns if b-node has been reached just now. |
---|
118 | bool isBNodeNewlyReached() const { return b_node_newly_reached; } |
---|
119 | /// Returns if a-node is examined. |
---|
120 | bool isANodeExamined() const { return !(graph->valid(actual_edge)); } |
---|
121 | /// Returns a-node of the actual edge, so does if the edge is invalid. |
---|
122 | Node aNode() const { return bfs_queue.front(); } |
---|
123 | /// \pre The actual edge have to be valid. |
---|
124 | Node bNode() const { return graph->bNode(actual_edge); } |
---|
125 | /// Guess what? |
---|
126 | /// \deprecated |
---|
127 | const ReachedMap& getReachedMap() const { return reached; } |
---|
128 | /// Guess what? |
---|
129 | /// \deprecated |
---|
130 | const std::queue<Node>& getBfsQueue() const { return bfs_queue; } |
---|
131 | }; |
---|
132 | |
---|
133 | /// Bfs searches for the nodes wich are not marked in |
---|
134 | /// \c reached_map |
---|
135 | /// Reached have to work as a read-write bool Node-map, |
---|
136 | /// Pred is a write edge node-map and |
---|
137 | /// Dist is a read-write node-map of integral value, have to be. |
---|
138 | /// \ingroup galgs |
---|
139 | template <typename Graph, |
---|
140 | typename ReachedMap=typename Graph::template NodeMap<bool>, |
---|
141 | typename PredMap |
---|
142 | =typename Graph::template NodeMap<typename Graph::Edge>, |
---|
143 | typename DistMap=typename Graph::template NodeMap<int> > |
---|
144 | class Bfs : public BfsIterator<Graph, ReachedMap> { |
---|
145 | typedef BfsIterator<Graph, ReachedMap> Parent; |
---|
146 | protected: |
---|
147 | typedef typename Parent::Node Node; |
---|
148 | PredMap& pred; |
---|
149 | DistMap& dist; |
---|
150 | public: |
---|
151 | /// The algorithm will search in a bfs order for |
---|
152 | /// the nodes which are \c false initially. |
---|
153 | /// The constructor makes no initial changes on the maps. |
---|
154 | Bfs<Graph, ReachedMap, PredMap, DistMap>(const Graph& _graph, ReachedMap& _reached, PredMap& _pred, DistMap& _dist) : |
---|
155 | BfsIterator<Graph, ReachedMap>(_graph, _reached), |
---|
156 | pred(_pred), dist(_dist) { } |
---|
157 | /// \c s is marked to be reached and pushed in the bfs queue. |
---|
158 | /// If the queue is empty, then the first out-edge is processed. |
---|
159 | /// If \c s was not marked previously, then |
---|
160 | /// in addition its pred is set to be \c INVALID, and dist to \c 0. |
---|
161 | /// if \c s was marked previuosly, then it is simply pushed. |
---|
162 | void push(Node s) { |
---|
163 | if (this->reached[s]) { |
---|
164 | Parent::pushAndSetReached(s); |
---|
165 | } else { |
---|
166 | Parent::pushAndSetReached(s); |
---|
167 | pred.set(s, INVALID); |
---|
168 | dist.set(s, 0); |
---|
169 | } |
---|
170 | } |
---|
171 | /// A bfs is processed from \c s. |
---|
172 | void run(Node s) { |
---|
173 | push(s); |
---|
174 | while (!this->finished()) this->operator++(); |
---|
175 | } |
---|
176 | /// Beside the bfs iteration, \c pred and \dist are saved in a |
---|
177 | /// newly reached node. |
---|
178 | Bfs<Graph, ReachedMap, PredMap, DistMap>& operator++() { |
---|
179 | Parent::operator++(); |
---|
180 | if (this->graph->valid(this->actual_edge) && this->b_node_newly_reached) |
---|
181 | { |
---|
182 | pred.set(this->bNode(), this->actual_edge); |
---|
183 | dist.set(this->bNode(), dist[this->aNode()]); |
---|
184 | } |
---|
185 | return *this; |
---|
186 | } |
---|
187 | /// Guess what? |
---|
188 | /// \deprecated |
---|
189 | const PredMap& getPredMap() const { return pred; } |
---|
190 | /// Guess what? |
---|
191 | /// \deprecated |
---|
192 | const DistMap& getDistMap() const { return dist; } |
---|
193 | }; |
---|
194 | |
---|
195 | /// Dfs searches for the nodes wich are not marked in |
---|
196 | /// \c reached_map |
---|
197 | /// Reached have to be a read-write bool Node-map. |
---|
198 | /// \ingroup galgs |
---|
199 | template <typename Graph, /*typename OutEdgeIt,*/ |
---|
200 | typename ReachedMap/*=typename Graph::NodeMap<bool>*/ > |
---|
201 | class DfsIterator { |
---|
202 | protected: |
---|
203 | typedef typename Graph::Node Node; |
---|
204 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
205 | const Graph* graph; |
---|
206 | std::stack<OutEdgeIt> dfs_stack; |
---|
207 | bool b_node_newly_reached; |
---|
208 | OutEdgeIt actual_edge; |
---|
209 | Node actual_node; |
---|
210 | ReachedMap& reached; |
---|
211 | bool own_reached_map; |
---|
212 | public: |
---|
213 | /// In that constructor \c _reached have to be a reference |
---|
214 | /// for a bool node-map. The algorithm will search in a dfs order for |
---|
215 | /// the nodes which are \c false initially |
---|
216 | DfsIterator(const Graph& _graph, ReachedMap& _reached) : |
---|
217 | graph(&_graph), reached(_reached), |
---|
218 | own_reached_map(false) { } |
---|
219 | /// The same as above, but the map of reached nodes is |
---|
220 | /// constructed dynamically |
---|
221 | /// to everywhere false. |
---|
222 | DfsIterator(const Graph& _graph) : |
---|
223 | graph(&_graph), reached(*(new ReachedMap(*graph /*, false*/))), |
---|
224 | own_reached_map(true) { } |
---|
225 | ~DfsIterator() { if (own_reached_map) delete &reached; } |
---|
226 | /// This method markes s reached and first out-edge is processed. |
---|
227 | void pushAndSetReached(Node s) { |
---|
228 | actual_node=s; |
---|
229 | reached.set(s, true); |
---|
230 | OutEdgeIt e; |
---|
231 | graph->first(e, s); |
---|
232 | dfs_stack.push(e); |
---|
233 | } |
---|
234 | /// As \c DfsIterator<Graph, ReachedMap> works as an edge-iterator, |
---|
235 | /// its \c operator++() iterates on the edges in a dfs order. |
---|
236 | DfsIterator<Graph, /*OutEdgeIt,*/ ReachedMap>& |
---|
237 | operator++() { |
---|
238 | actual_edge=dfs_stack.top(); |
---|
239 | //actual_node=G.aNode(actual_edge); |
---|
240 | if (graph->valid(actual_edge)/*.valid()*/) { |
---|
241 | Node w=graph->bNode(actual_edge); |
---|
242 | actual_node=w; |
---|
243 | if (!reached[w]) { |
---|
244 | OutEdgeIt e; |
---|
245 | graph->first(e, w); |
---|
246 | dfs_stack.push(e); |
---|
247 | reached.set(w, true); |
---|
248 | b_node_newly_reached=true; |
---|
249 | } else { |
---|
250 | actual_node=graph->aNode(actual_edge); |
---|
251 | graph->next(dfs_stack.top()); |
---|
252 | b_node_newly_reached=false; |
---|
253 | } |
---|
254 | } else { |
---|
255 | //actual_node=G.aNode(dfs_stack.top()); |
---|
256 | dfs_stack.pop(); |
---|
257 | } |
---|
258 | return *this; |
---|
259 | } |
---|
260 | /// Returns true iff the algorithm is finished. |
---|
261 | bool finished() const { return dfs_stack.empty(); } |
---|
262 | /// The conversion operator makes for converting the bfs-iterator |
---|
263 | /// to an \c out-edge-iterator. |
---|
264 | ///\bug Edge have to be in HUGO 0.2 |
---|
265 | operator OutEdgeIt() const { return actual_edge; } |
---|
266 | /// Returns if b-node has been reached just now. |
---|
267 | bool isBNodeNewlyReached() const { return b_node_newly_reached; } |
---|
268 | /// Returns if a-node is examined. |
---|
269 | bool isANodeExamined() const { return !(graph->valid(actual_edge)); } |
---|
270 | /// Returns a-node of the actual edge, so does if the edge is invalid. |
---|
271 | Node aNode() const { return actual_node; /*FIXME*/} |
---|
272 | /// Returns b-node of the actual edge. |
---|
273 | /// \pre The actual edge have to be valid. |
---|
274 | Node bNode() const { return graph->bNode(actual_edge); } |
---|
275 | /// Guess what? |
---|
276 | /// \deprecated |
---|
277 | const ReachedMap& getReachedMap() const { return reached; } |
---|
278 | /// Guess what? |
---|
279 | /// \deprecated |
---|
280 | const std::stack<OutEdgeIt>& getDfsStack() const { return dfs_stack; } |
---|
281 | }; |
---|
282 | |
---|
283 | /// Dfs searches for the nodes wich are not marked in |
---|
284 | /// \c reached_map |
---|
285 | /// Reached is a read-write bool node-map, |
---|
286 | /// Pred is a write node-map, have to be. |
---|
287 | /// \ingroup galgs |
---|
288 | template <typename Graph, |
---|
289 | typename ReachedMap=typename Graph::template NodeMap<bool>, |
---|
290 | typename PredMap |
---|
291 | =typename Graph::template NodeMap<typename Graph::Edge> > |
---|
292 | class Dfs : public DfsIterator<Graph, ReachedMap> { |
---|
293 | typedef DfsIterator<Graph, ReachedMap> Parent; |
---|
294 | protected: |
---|
295 | typedef typename Parent::Node Node; |
---|
296 | PredMap& pred; |
---|
297 | public: |
---|
298 | /// The algorithm will search in a dfs order for |
---|
299 | /// the nodes which are \c false initially. |
---|
300 | /// The constructor makes no initial changes on the maps. |
---|
301 | Dfs<Graph, ReachedMap, PredMap>(const Graph& _graph, ReachedMap& _reached, PredMap& _pred) : DfsIterator<Graph, ReachedMap>(_graph, _reached), pred(_pred) { } |
---|
302 | /// \c s is marked to be reached and pushed in the bfs queue. |
---|
303 | /// If the queue is empty, then the first out-edge is processed. |
---|
304 | /// If \c s was not marked previously, then |
---|
305 | /// in addition its pred is set to be \c INVALID. |
---|
306 | /// if \c s was marked previuosly, then it is simply pushed. |
---|
307 | void push(Node s) { |
---|
308 | if (this->reached[s]) { |
---|
309 | Parent::pushAndSetReached(s); |
---|
310 | } else { |
---|
311 | Parent::pushAndSetReached(s); |
---|
312 | pred.set(s, INVALID); |
---|
313 | } |
---|
314 | } |
---|
315 | /// A bfs is processed from \c s. |
---|
316 | void run(Node s) { |
---|
317 | push(s); |
---|
318 | while (!this->finished()) this->operator++(); |
---|
319 | } |
---|
320 | /// Beside the dfs iteration, \c pred is saved in a |
---|
321 | /// newly reached node. |
---|
322 | Dfs<Graph, ReachedMap, PredMap>& operator++() { |
---|
323 | Parent::operator++(); |
---|
324 | if (this->graph->valid(this->actual_edge) && this->b_node_newly_reached) |
---|
325 | { |
---|
326 | pred.set(this->bNode(), this->actual_edge); |
---|
327 | } |
---|
328 | return *this; |
---|
329 | } |
---|
330 | /// Guess what? |
---|
331 | /// \deprecated |
---|
332 | const PredMap& getPredMap() const { return pred; } |
---|
333 | }; |
---|
334 | |
---|
335 | |
---|
336 | } // namespace hugo |
---|
337 | |
---|
338 | #endif //HUGO_BFS_DFS_H |
---|