1 | /* -*- mode: C++; indent-tabs-mode: nil; -*- |
---|
2 | * |
---|
3 | * This file is a part of LEMON, a generic C++ optimization library. |
---|
4 | * |
---|
5 | * Copyright (C) 2017 |
---|
6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
---|
7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
---|
8 | * |
---|
9 | * Permission to use, modify and distribute this software is granted |
---|
10 | * provided that this copyright notice appears in all copies. For |
---|
11 | * precise terms see the accompanying LICENSE file. |
---|
12 | * |
---|
13 | * This software is provided "AS IS" with no warranty of any kind, |
---|
14 | * express or implied, and with no claim as to its suitability for any |
---|
15 | * purpose. |
---|
16 | * |
---|
17 | */ |
---|
18 | |
---|
19 | #ifndef LEMON_COMPACT_GRAPH_H |
---|
20 | #define LEMON_COMPACT_GRAPH_H |
---|
21 | |
---|
22 | ///\ingroup graphs |
---|
23 | ///\file |
---|
24 | ///\brief CompactDigraph class. |
---|
25 | |
---|
26 | #include <lemon/core.h> |
---|
27 | #include <lemon/bits/graph_extender.h> |
---|
28 | |
---|
29 | #include <algorithm> |
---|
30 | |
---|
31 | namespace lemon { |
---|
32 | |
---|
33 | class CompactDigraphBase { |
---|
34 | |
---|
35 | public: |
---|
36 | |
---|
37 | CompactDigraphBase() |
---|
38 | : built(false), node_num(0), arc_num(0), |
---|
39 | node_first_out(NULL), |
---|
40 | arc_target(NULL) {} |
---|
41 | |
---|
42 | ~CompactDigraphBase() { |
---|
43 | if (built) { |
---|
44 | delete[] node_first_out; |
---|
45 | delete[] arc_target; |
---|
46 | } |
---|
47 | } |
---|
48 | |
---|
49 | class Node { |
---|
50 | friend class CompactDigraphBase; |
---|
51 | protected: |
---|
52 | int id; |
---|
53 | Node(int _id) : id(_id) {} |
---|
54 | public: |
---|
55 | Node() {} |
---|
56 | Node (Invalid) : id(-1) {} |
---|
57 | bool operator==(const Node& node) const { return id == node.id; } |
---|
58 | bool operator!=(const Node& node) const { return id != node.id; } |
---|
59 | bool operator<(const Node& node) const { return id < node.id; } |
---|
60 | }; |
---|
61 | |
---|
62 | class Arc { |
---|
63 | friend class CompactDigraphBase; |
---|
64 | protected: |
---|
65 | int id; |
---|
66 | int source; |
---|
67 | Arc(int _id, int _source) : id(_id), source(_source) {} |
---|
68 | public: |
---|
69 | Arc() { } |
---|
70 | Arc (Invalid) : id(-1), source(-1) {} |
---|
71 | bool operator==(const Arc& arc) const { return id == arc.id; } |
---|
72 | bool operator!=(const Arc& arc) const { return id != arc.id; } |
---|
73 | bool operator<(const Arc& arc) const { return id < arc.id; } |
---|
74 | }; |
---|
75 | |
---|
76 | Node source(const Arc& e) const { return Node(e.source); } |
---|
77 | Node target(const Arc& e) const { return Node(arc_target[e.id]); } |
---|
78 | |
---|
79 | void first(Node& n) const { n.id = node_num - 1; } |
---|
80 | static void next(Node& n) { --n.id; } |
---|
81 | |
---|
82 | private: |
---|
83 | |
---|
84 | void nextSource(Arc& e) const { |
---|
85 | if (e.id == -1) return; |
---|
86 | int last = node_first_out[e.source] - 1; |
---|
87 | while (e.id == last) { |
---|
88 | --e.source; |
---|
89 | last = node_first_out[e.source] - 1; |
---|
90 | } |
---|
91 | } |
---|
92 | |
---|
93 | public: |
---|
94 | |
---|
95 | void first(Arc& e) const { |
---|
96 | e.id = arc_num - 1; |
---|
97 | e.source = node_num - 1; |
---|
98 | nextSource(e); |
---|
99 | } |
---|
100 | void next(Arc& e) const { |
---|
101 | --e.id; |
---|
102 | nextSource(e); |
---|
103 | } |
---|
104 | |
---|
105 | void firstOut(Arc& e, const Node& n) const { |
---|
106 | e.source = n.id; |
---|
107 | e.id = node_first_out[n.id]; |
---|
108 | if (e.id == node_first_out[n.id + 1]) e = INVALID; |
---|
109 | } |
---|
110 | void nextOut(Arc& e) const { |
---|
111 | ++e.id; |
---|
112 | if (e.id == node_first_out[e.source + 1]) e = INVALID; |
---|
113 | } |
---|
114 | |
---|
115 | void firstIn(Arc& e, const Node& n) const { |
---|
116 | first(e); |
---|
117 | while(e != INVALID && target(e) != n) { |
---|
118 | next(e); |
---|
119 | } |
---|
120 | } |
---|
121 | void nextIn(Arc& e) const { |
---|
122 | Node arcTarget = target(e); |
---|
123 | do { |
---|
124 | next(e); |
---|
125 | } while(e != INVALID && target(e) != arcTarget); |
---|
126 | } |
---|
127 | |
---|
128 | static int id(const Node& n) { return n.id; } |
---|
129 | static Node nodeFromId(int id) { return Node(id); } |
---|
130 | int maxNodeId() const { return node_num - 1; } |
---|
131 | |
---|
132 | static int id(const Arc& e) { return e.id; } |
---|
133 | Arc arcFromId(int id) const { |
---|
134 | int *l = std::upper_bound(node_first_out, node_first_out + node_num, id) - 1; |
---|
135 | int src = l - node_first_out; |
---|
136 | return Arc(id, src); |
---|
137 | } |
---|
138 | int maxArcId() const { return arc_num - 1; } |
---|
139 | |
---|
140 | typedef True NodeNumTag; |
---|
141 | typedef True ArcNumTag; |
---|
142 | |
---|
143 | int nodeNum() const { return node_num; } |
---|
144 | int arcNum() const { return arc_num; } |
---|
145 | |
---|
146 | private: |
---|
147 | |
---|
148 | template <typename Digraph, typename NodeRefMap> |
---|
149 | class ArcLess { |
---|
150 | public: |
---|
151 | typedef typename Digraph::Arc Arc; |
---|
152 | |
---|
153 | ArcLess(const Digraph &_graph, const NodeRefMap& _nodeRef) |
---|
154 | : digraph(_graph), nodeRef(_nodeRef) {} |
---|
155 | |
---|
156 | bool operator()(const Arc& left, const Arc& right) const { |
---|
157 | return nodeRef[digraph.target(left)] < nodeRef[digraph.target(right)]; |
---|
158 | } |
---|
159 | private: |
---|
160 | const Digraph& digraph; |
---|
161 | const NodeRefMap& nodeRef; |
---|
162 | }; |
---|
163 | |
---|
164 | public: |
---|
165 | |
---|
166 | typedef True BuildTag; |
---|
167 | |
---|
168 | void clear() { |
---|
169 | if (built) { |
---|
170 | delete[] node_first_out; |
---|
171 | delete[] arc_target; |
---|
172 | } |
---|
173 | built = false; |
---|
174 | node_num = 0; |
---|
175 | arc_num = 0; |
---|
176 | } |
---|
177 | |
---|
178 | template <typename Digraph, typename NodeRefMap, typename ArcRefMap> |
---|
179 | void build(const Digraph& digraph, NodeRefMap& nodeRef, ArcRefMap& arcRef) { |
---|
180 | typedef typename Digraph::Node GNode; |
---|
181 | typedef typename Digraph::Arc GArc; |
---|
182 | |
---|
183 | built = true; |
---|
184 | |
---|
185 | node_num = countNodes(digraph); |
---|
186 | arc_num = countArcs(digraph); |
---|
187 | |
---|
188 | node_first_out = new int[node_num + 1]; |
---|
189 | |
---|
190 | arc_target = new int[arc_num]; |
---|
191 | |
---|
192 | int node_index = 0; |
---|
193 | for (typename Digraph::NodeIt n(digraph); n != INVALID; ++n) { |
---|
194 | nodeRef[n] = Node(node_index); |
---|
195 | ++node_index; |
---|
196 | } |
---|
197 | |
---|
198 | ArcLess<Digraph, NodeRefMap> arcLess(digraph, nodeRef); |
---|
199 | |
---|
200 | int arc_index = 0; |
---|
201 | for (typename Digraph::NodeIt n(digraph); n != INVALID; ++n) { |
---|
202 | int source = nodeRef[n].id; |
---|
203 | std::vector<GArc> arcs; |
---|
204 | for (typename Digraph::OutArcIt e(digraph, n); e != INVALID; ++e) { |
---|
205 | arcs.push_back(e); |
---|
206 | } |
---|
207 | if (!arcs.empty()) { |
---|
208 | node_first_out[source] = arc_index; |
---|
209 | std::sort(arcs.begin(), arcs.end(), arcLess); |
---|
210 | for (typename std::vector<GArc>::iterator it = arcs.begin(); |
---|
211 | it != arcs.end(); ++it) { |
---|
212 | int target = nodeRef[digraph.target(*it)].id; |
---|
213 | arcRef[*it] = Arc(arc_index, source); |
---|
214 | arc_target[arc_index] = target; |
---|
215 | ++arc_index; |
---|
216 | } |
---|
217 | } else { |
---|
218 | node_first_out[source] = arc_index; |
---|
219 | } |
---|
220 | } |
---|
221 | node_first_out[node_num] = arc_num; |
---|
222 | } |
---|
223 | |
---|
224 | template <typename ArcListIterator> |
---|
225 | void build(int n, ArcListIterator first, ArcListIterator last) { |
---|
226 | built = true; |
---|
227 | |
---|
228 | node_num = n; |
---|
229 | arc_num = static_cast<int>(std::distance(first, last)); |
---|
230 | |
---|
231 | node_first_out = new int[node_num + 1]; |
---|
232 | |
---|
233 | arc_target = new int[arc_num]; |
---|
234 | |
---|
235 | int arc_index = 0; |
---|
236 | for (int i = 0; i != node_num; ++i) { |
---|
237 | node_first_out[i] = arc_index; |
---|
238 | for ( ; first != last && (*first).first == i; ++first) { |
---|
239 | int j = (*first).second; |
---|
240 | LEMON_ASSERT(j >= 0 && j < node_num, |
---|
241 | "Wrong arc list for CompactDigraph::build()"); |
---|
242 | arc_target[arc_index] = j; |
---|
243 | ++arc_index; |
---|
244 | } |
---|
245 | } |
---|
246 | LEMON_ASSERT(first == last, |
---|
247 | "Wrong arc list for CompactDigraph::build()"); |
---|
248 | node_first_out[node_num] = arc_num; |
---|
249 | } |
---|
250 | |
---|
251 | protected: |
---|
252 | bool built; |
---|
253 | int node_num; |
---|
254 | int arc_num; |
---|
255 | int *node_first_out; |
---|
256 | int *arc_target; |
---|
257 | }; |
---|
258 | |
---|
259 | typedef DigraphExtender<CompactDigraphBase> ExtendedCompactDigraphBase; |
---|
260 | |
---|
261 | |
---|
262 | /// \ingroup graphs |
---|
263 | /// |
---|
264 | /// \brief A static directed graph class. |
---|
265 | /// |
---|
266 | /// \ref CompactDigraph is a highly efficient digraph implementation |
---|
267 | /// similar to \ref StaticDigraph. It is more memory efficient but does |
---|
268 | /// not provide efficient iteration over incoming arcs. |
---|
269 | /// |
---|
270 | /// It stores only one \c int values for each node and one \c int value |
---|
271 | /// for each arc. Its \ref InArcIt implementation is inefficient and |
---|
272 | /// provided only for compatibility with the \ref concepts::Digraph "Digraph concept". |
---|
273 | /// |
---|
274 | /// This type fully conforms to the \ref concepts::Digraph "Digraph concept". |
---|
275 | /// Most of its member functions and nested classes are documented |
---|
276 | /// only in the concept class. |
---|
277 | /// |
---|
278 | /// \sa concepts::Digraph |
---|
279 | class CompactDigraph : public ExtendedCompactDigraphBase { |
---|
280 | |
---|
281 | private: |
---|
282 | /// Graphs are \e not copy constructible. Use DigraphCopy instead. |
---|
283 | CompactDigraph(const CompactDigraph &) : ExtendedCompactDigraphBase() {}; |
---|
284 | /// \brief Assignment of a graph to another one is \e not allowed. |
---|
285 | /// Use DigraphCopy instead. |
---|
286 | void operator=(const CompactDigraph&) {} |
---|
287 | |
---|
288 | public: |
---|
289 | |
---|
290 | typedef ExtendedCompactDigraphBase Parent; |
---|
291 | |
---|
292 | public: |
---|
293 | |
---|
294 | /// \brief Constructor |
---|
295 | /// |
---|
296 | /// Default constructor. |
---|
297 | CompactDigraph() : Parent() {} |
---|
298 | |
---|
299 | /// \brief The node with the given index. |
---|
300 | /// |
---|
301 | /// This function returns the node with the given index. |
---|
302 | /// \sa index() |
---|
303 | static Node node(int ix) { return Parent::nodeFromId(ix); } |
---|
304 | |
---|
305 | /// \brief The arc with the given index. |
---|
306 | /// |
---|
307 | /// This function returns the arc with the given index. |
---|
308 | /// \sa index() |
---|
309 | Arc arc(int ix) { return arcFromId(ix); } |
---|
310 | |
---|
311 | /// \brief The index of the given node. |
---|
312 | /// |
---|
313 | /// This function returns the index of the the given node. |
---|
314 | /// \sa node() |
---|
315 | static int index(Node node) { return Parent::id(node); } |
---|
316 | |
---|
317 | /// \brief The index of the given arc. |
---|
318 | /// |
---|
319 | /// This function returns the index of the the given arc. |
---|
320 | /// \sa arc() |
---|
321 | static int index(Arc arc) { return Parent::id(arc); } |
---|
322 | |
---|
323 | /// \brief Number of nodes. |
---|
324 | /// |
---|
325 | /// This function returns the number of nodes. |
---|
326 | int nodeNum() const { return node_num; } |
---|
327 | |
---|
328 | /// \brief Number of arcs. |
---|
329 | /// |
---|
330 | /// This function returns the number of arcs. |
---|
331 | int arcNum() const { return arc_num; } |
---|
332 | |
---|
333 | /// \brief Build the digraph copying another digraph. |
---|
334 | /// |
---|
335 | /// This function builds the digraph copying another digraph of any |
---|
336 | /// kind. It can be called more than once, but in such case, the whole |
---|
337 | /// structure and all maps will be cleared and rebuilt. |
---|
338 | /// |
---|
339 | /// This method also makes possible to copy a digraph to a CompactDigraph |
---|
340 | /// structure using \ref DigraphCopy. |
---|
341 | /// |
---|
342 | /// \param digraph An existing digraph to be copied. |
---|
343 | /// \param nodeRef The node references will be copied into this map. |
---|
344 | /// Its key type must be \c Digraph::Node and its value type must be |
---|
345 | /// \c CompactDigraph::Node. |
---|
346 | /// It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" |
---|
347 | /// concept. |
---|
348 | /// \param arcRef The arc references will be copied into this map. |
---|
349 | /// Its key type must be \c Digraph::Arc and its value type must be |
---|
350 | /// \c CompactDigraph::Arc. |
---|
351 | /// It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
---|
352 | /// |
---|
353 | /// \note If you do not need the arc references, then you could use |
---|
354 | /// \ref NullMap for the last parameter. However the node references |
---|
355 | /// are required by the function itself, thus they must be readable |
---|
356 | /// from the map. |
---|
357 | template <typename Digraph, typename NodeRefMap, typename ArcRefMap> |
---|
358 | void build(const Digraph& digraph, NodeRefMap& nodeRef, ArcRefMap& arcRef) { |
---|
359 | if (built) Parent::clear(); |
---|
360 | Parent::build(digraph, nodeRef, arcRef); |
---|
361 | } |
---|
362 | |
---|
363 | /// \brief Build the digraph from an arc list. |
---|
364 | /// |
---|
365 | /// This function builds the digraph from the given arc list. |
---|
366 | /// It can be called more than once, but in such case, the whole |
---|
367 | /// structure and all maps will be cleared and rebuilt. |
---|
368 | /// |
---|
369 | /// The list of the arcs must be given in the range <tt>[begin, end)</tt> |
---|
370 | /// specified by STL compatible itartors whose \c value_type must be |
---|
371 | /// <tt>std::pair<int,int></tt>. |
---|
372 | /// Each arc must be specified by a pair of integer indices |
---|
373 | /// from the range <tt>[0..n-1]</tt>. <i>The pairs must be in a |
---|
374 | /// non-decreasing order with respect to their first values.</i> |
---|
375 | /// If the k-th pair in the list is <tt>(i,j)</tt>, then |
---|
376 | /// <tt>arc(k-1)</tt> will connect <tt>node(i)</tt> to <tt>node(j)</tt>. |
---|
377 | /// |
---|
378 | /// \param n The number of nodes. |
---|
379 | /// \param begin An iterator pointing to the beginning of the arc list. |
---|
380 | /// \param end An iterator pointing to the end of the arc list. |
---|
381 | /// |
---|
382 | /// For example, a simple digraph can be constructed like this. |
---|
383 | /// \code |
---|
384 | /// std::vector<std::pair<int,int> > arcs; |
---|
385 | /// arcs.push_back(std::make_pair(0,1)); |
---|
386 | /// arcs.push_back(std::make_pair(0,2)); |
---|
387 | /// arcs.push_back(std::make_pair(1,3)); |
---|
388 | /// arcs.push_back(std::make_pair(1,2)); |
---|
389 | /// arcs.push_back(std::make_pair(3,0)); |
---|
390 | /// CompactDigraph gr; |
---|
391 | /// gr.build(4, arcs.begin(), arcs.end()); |
---|
392 | /// \endcode |
---|
393 | template <typename ArcListIterator> |
---|
394 | void build(int n, ArcListIterator begin, ArcListIterator end) { |
---|
395 | if (built) Parent::clear(); |
---|
396 | CompactDigraphBase::build(n, begin, end); |
---|
397 | notifier(Node()).build(); |
---|
398 | notifier(Arc()).build(); |
---|
399 | } |
---|
400 | |
---|
401 | /// \brief Clear the digraph. |
---|
402 | /// |
---|
403 | /// This function erases all nodes and arcs from the digraph. |
---|
404 | void clear() { |
---|
405 | Parent::clear(); |
---|
406 | } |
---|
407 | |
---|
408 | public: |
---|
409 | |
---|
410 | Node baseNode(const OutArcIt &arc) const { |
---|
411 | return Parent::source(static_cast<const Arc&>(arc)); |
---|
412 | } |
---|
413 | |
---|
414 | Node runningNode(const OutArcIt &arc) const { |
---|
415 | return Parent::target(static_cast<const Arc&>(arc)); |
---|
416 | } |
---|
417 | |
---|
418 | Node baseNode(const InArcIt &arc) const { |
---|
419 | return Parent::target(static_cast<const Arc&>(arc)); |
---|
420 | } |
---|
421 | |
---|
422 | Node runningNode(const InArcIt &arc) const { |
---|
423 | return Parent::source(static_cast<const Arc&>(arc)); |
---|
424 | } |
---|
425 | |
---|
426 | }; |
---|
427 | |
---|
428 | } |
---|
429 | |
---|
430 | #endif |
---|