... | ... |
@@ -10,265 +10,325 @@ |
10 | 10 |
* provided that this copyright notice appears in all copies. For |
11 | 11 |
* precise terms see the accompanying LICENSE file. |
12 | 12 |
* |
13 | 13 |
* This software is provided "AS IS" with no warranty of any kind, |
14 | 14 |
* express or implied, and with no claim as to its suitability for any |
15 | 15 |
* purpose. |
16 | 16 |
* |
17 | 17 |
*/ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_CIRCULATION_H |
20 | 20 |
#define LEMON_CIRCULATION_H |
21 | 21 |
|
22 |
#include <iostream> |
|
23 |
#include <queue> |
|
24 | 22 |
#include <lemon/tolerance.h> |
25 | 23 |
#include <lemon/elevator.h> |
26 | 24 |
|
27 | 25 |
///\ingroup max_flow |
28 | 26 |
///\file |
29 |
///\brief Push- |
|
27 |
///\brief Push-relabel algorithm for finding a feasible circulation. |
|
30 | 28 |
/// |
31 | 29 |
namespace lemon { |
32 | 30 |
|
33 | 31 |
/// \brief Default traits class of Circulation class. |
34 | 32 |
/// |
35 | 33 |
/// Default traits class of Circulation class. |
36 |
/// \param _Graph Digraph type. |
|
37 |
/// \param _CapacityMap Type of capacity map. |
|
38 |
|
|
34 |
/// \tparam _Diraph Digraph type. |
|
35 |
/// \tparam _LCapMap Lower bound capacity map type. |
|
36 |
/// \tparam _UCapMap Upper bound capacity map type. |
|
37 |
/// \tparam _DeltaMap Delta map type. |
|
38 |
template <typename _Diraph, typename _LCapMap, |
|
39 | 39 |
typename _UCapMap, typename _DeltaMap> |
40 | 40 |
struct CirculationDefaultTraits { |
41 | 41 |
|
42 |
/// \brief The digraph type the algorithm runs on. |
|
43 |
typedef _Graph Digraph; |
|
42 |
/// \brief The type of the digraph the algorithm runs on. |
|
43 |
typedef _Diraph Digraph; |
|
44 | 44 |
|
45 | 45 |
/// \brief The type of the map that stores the circulation lower |
46 | 46 |
/// bound. |
47 | 47 |
/// |
48 | 48 |
/// The type of the map that stores the circulation lower bound. |
49 | 49 |
/// It must meet the \ref concepts::ReadMap "ReadMap" concept. |
50 | 50 |
typedef _LCapMap LCapMap; |
51 | 51 |
|
52 | 52 |
/// \brief The type of the map that stores the circulation upper |
53 | 53 |
/// bound. |
54 | 54 |
/// |
55 | 55 |
/// The type of the map that stores the circulation upper bound. |
56 | 56 |
/// It must meet the \ref concepts::ReadMap "ReadMap" concept. |
57 | 57 |
typedef _UCapMap UCapMap; |
58 | 58 |
|
59 |
/// \brief The type of the map that stores the upper bound of |
|
60 |
/// node excess. |
|
59 |
/// \brief The type of the map that stores the lower bound for |
|
60 |
/// the supply of the nodes. |
|
61 | 61 |
/// |
62 |
/// The type of the map that stores the lower bound of node |
|
63 |
/// excess. It must meet the \ref concepts::ReadMap "ReadMap" |
|
62 |
/// The type of the map that stores the lower bound for the supply |
|
63 |
/// of the nodes. It must meet the \ref concepts::ReadMap "ReadMap" |
|
64 | 64 |
/// concept. |
65 | 65 |
typedef _DeltaMap DeltaMap; |
66 | 66 |
|
67 |
/// \brief The type of the |
|
67 |
/// \brief The type of the flow values. |
|
68 | 68 |
typedef typename DeltaMap::Value Value; |
69 | 69 |
|
70 |
/// \brief The |
|
70 |
/// \brief The type of the map that stores the flow values. |
|
71 | 71 |
/// |
72 |
/// The |
|
72 |
/// The type of the map that stores the flow values. |
|
73 | 73 |
/// It must meet the \ref concepts::ReadWriteMap "ReadWriteMap" concept. |
74 | 74 |
typedef typename Digraph::template ArcMap<Value> FlowMap; |
75 | 75 |
|
76 | 76 |
/// \brief Instantiates a FlowMap. |
77 | 77 |
/// |
78 | 78 |
/// This function instantiates a \ref FlowMap. |
79 | 79 |
/// \param digraph The digraph, to which we would like to define |
80 | 80 |
/// the flow map. |
81 | 81 |
static FlowMap* createFlowMap(const Digraph& digraph) { |
82 | 82 |
return new FlowMap(digraph); |
83 | 83 |
} |
84 | 84 |
|
85 |
/// \brief The |
|
85 |
/// \brief The elevator type used by the algorithm. |
|
86 | 86 |
/// |
87 |
/// The elevator type used by |
|
87 |
/// The elevator type used by the algorithm. |
|
88 | 88 |
/// |
89 | 89 |
/// \sa Elevator |
90 | 90 |
/// \sa LinkedElevator |
91 | 91 |
typedef lemon::Elevator<Digraph, typename Digraph::Node> Elevator; |
92 | 92 |
|
93 | 93 |
/// \brief Instantiates an Elevator. |
94 | 94 |
/// |
95 |
/// This function instantiates |
|
95 |
/// This function instantiates an \ref Elevator. |
|
96 | 96 |
/// \param digraph The digraph, to which we would like to define |
97 | 97 |
/// the elevator. |
98 | 98 |
/// \param max_level The maximum level of the elevator. |
99 | 99 |
static Elevator* createElevator(const Digraph& digraph, int max_level) { |
100 | 100 |
return new Elevator(digraph, max_level); |
101 | 101 |
} |
102 | 102 |
|
103 | 103 |
/// \brief The tolerance used by the algorithm |
104 | 104 |
/// |
105 | 105 |
/// The tolerance used by the algorithm to handle inexact computation. |
106 | 106 |
typedef lemon::Tolerance<Value> Tolerance; |
107 | 107 |
|
108 | 108 |
}; |
109 | 109 |
|
110 |
/ |
|
110 |
/** |
|
111 |
\brief Push-relabel algorithm for the network circulation problem. |
|
111 | 112 |
|
112 |
/** |
|
113 | 113 |
\ingroup max_flow |
114 |
This class implements a push-relabel algorithm |
|
115 |
or the Network Circulation Problem. |
|
114 |
This class implements a push-relabel algorithm for the network |
|
115 |
circulation problem. |
|
116 |
It is to find a feasible circulation when lower and upper bounds |
|
117 |
are given for the flow values on the arcs and lower bounds |
|
118 |
are given for the supply values of the nodes. |
|
119 |
|
|
116 | 120 |
The exact formulation of this problem is the following. |
117 |
\f[\sum_{e\in\rho(v)}x(e)-\sum_{e\in\delta(v)}x(e)\leq |
|
118 |
-delta(v)\quad \forall v\in V \f] |
|
119 |
|
|
121 |
Let \f$G=(V,A)\f$ be a digraph, |
|
122 |
\f$lower, upper: A\rightarrow\mathbf{R}^+_0\f$, |
|
123 |
\f$delta: V\rightarrow\mathbf{R}\f$. Find a feasible circulation |
|
124 |
\f$f: A\rightarrow\mathbf{R}^+_0\f$ so that |
|
125 |
\f[ \sum_{a\in\delta_{out}(v)} f(a) - \sum_{a\in\delta_{in}(v)} f(a) |
|
126 |
\geq delta(v) \quad \forall v\in V, \f] |
|
127 |
\f[ lower(a)\leq f(a) \leq upper(a) \quad \forall a\in A. \f] |
|
128 |
\note \f$delta(v)\f$ specifies a lower bound for the supply of node |
|
129 |
\f$v\f$. It can be either positive or negative, however note that |
|
130 |
\f$\sum_{v\in V}delta(v)\f$ should be zero or negative in order to |
|
131 |
have a feasible solution. |
|
132 |
|
|
133 |
\note A special case of this problem is when |
|
134 |
\f$\sum_{v\in V}delta(v) = 0\f$. Then the supply of each node \f$v\f$ |
|
135 |
will be \e equal \e to \f$delta(v)\f$, if a circulation can be found. |
|
136 |
Thus a feasible solution for the |
|
137 |
\ref min_cost_flow "minimum cost flow" problem can be calculated |
|
138 |
in this way. |
|
139 |
|
|
140 |
\tparam _Digraph The type of the digraph the algorithm runs on. |
|
141 |
\tparam _LCapMap The type of the lower bound capacity map. The default |
|
142 |
map type is \ref concepts::Digraph::ArcMap "_Digraph::ArcMap<int>". |
|
143 |
\tparam _UCapMap The type of the upper bound capacity map. The default |
|
144 |
map type is \c _LCapMap. |
|
145 |
\tparam _DeltaMap The type of the map that stores the lower bound |
|
146 |
for the supply of the nodes. The default map type is |
|
147 |
\c _Digraph::ArcMap<_UCapMap::Value>. |
|
120 | 148 |
*/ |
121 |
template<class _Graph, |
|
122 |
class _LCapMap=typename _Graph::template ArcMap<int>, |
|
123 |
class _UCapMap=_LCapMap, |
|
124 |
class _DeltaMap=typename _Graph::template NodeMap< |
|
125 |
typename _UCapMap::Value>, |
|
126 |
class _Traits=CirculationDefaultTraits<_Graph, _LCapMap, |
|
127 |
|
|
149 |
#ifdef DOXYGEN |
|
150 |
template< typename _Digraph, |
|
151 |
typename _LCapMap, |
|
152 |
typename _UCapMap, |
|
153 |
typename _DeltaMap, |
|
154 |
typename _Traits > |
|
155 |
#else |
|
156 |
template< typename _Digraph, |
|
157 |
typename _LCapMap = typename _Digraph::template ArcMap<int>, |
|
158 |
typename _UCapMap = _LCapMap, |
|
159 |
typename _DeltaMap = typename _Digraph:: |
|
160 |
template NodeMap<typename _UCapMap::Value>, |
|
161 |
typename _Traits=CirculationDefaultTraits<_Digraph, _LCapMap, |
|
162 |
_UCapMap, _DeltaMap> > |
|
163 |
#endif |
|
128 | 164 |
class Circulation { |
165 |
public: |
|
129 | 166 |
|
167 |
///The \ref CirculationDefaultTraits "traits class" of the algorithm. |
|
130 | 168 |
typedef _Traits Traits; |
169 |
///The type of the digraph the algorithm runs on. |
|
131 | 170 |
typedef typename Traits::Digraph Digraph; |
132 |
TEMPLATE_DIGRAPH_TYPEDEFS(Digraph); |
|
133 |
|
|
171 |
///The type of the flow values. |
|
134 | 172 |
typedef typename Traits::Value Value; |
135 | 173 |
|
174 |
/// The type of the lower bound capacity map. |
|
136 | 175 |
typedef typename Traits::LCapMap LCapMap; |
176 |
/// The type of the upper bound capacity map. |
|
137 | 177 |
typedef typename Traits::UCapMap UCapMap; |
178 |
/// \brief The type of the map that stores the lower bound for |
|
179 |
/// the supply of the nodes. |
|
138 | 180 |
typedef typename Traits::DeltaMap DeltaMap; |
181 |
///The type of the flow map. |
|
139 | 182 |
typedef typename Traits::FlowMap FlowMap; |
183 |
|
|
184 |
///The type of the elevator. |
|
140 | 185 |
typedef typename Traits::Elevator Elevator; |
186 |
///The type of the tolerance. |
|
141 | 187 |
typedef typename Traits::Tolerance Tolerance; |
142 | 188 |
|
143 |
|
|
189 |
private: |
|
190 |
|
|
191 |
TEMPLATE_DIGRAPH_TYPEDEFS(Digraph); |
|
144 | 192 |
|
145 | 193 |
const Digraph &_g; |
146 | 194 |
int _node_num; |
147 | 195 |
|
148 | 196 |
const LCapMap *_lo; |
149 | 197 |
const UCapMap *_up; |
150 | 198 |
const DeltaMap *_delta; |
151 | 199 |
|
152 | 200 |
FlowMap *_flow; |
153 | 201 |
bool _local_flow; |
154 | 202 |
|
155 | 203 |
Elevator* _level; |
156 | 204 |
bool _local_level; |
157 | 205 |
|
206 |
typedef typename Digraph::template NodeMap<Value> ExcessMap; |
|
158 | 207 |
ExcessMap* _excess; |
159 | 208 |
|
160 | 209 |
Tolerance _tol; |
161 | 210 |
int _el; |
162 | 211 |
|
163 | 212 |
public: |
164 | 213 |
|
165 | 214 |
typedef Circulation Create; |
166 | 215 |
|
167 |
///\name Named |
|
216 |
///\name Named Template Parameters |
|
168 | 217 |
|
169 | 218 |
///@{ |
170 | 219 |
|
171 | 220 |
template <typename _FlowMap> |
172 | 221 |
struct SetFlowMapTraits : public Traits { |
173 | 222 |
typedef _FlowMap FlowMap; |
174 | 223 |
static FlowMap *createFlowMap(const Digraph&) { |
175 | 224 |
LEMON_ASSERT(false, "FlowMap is not initialized"); |
176 | 225 |
return 0; // ignore warnings |
177 | 226 |
} |
178 | 227 |
}; |
179 | 228 |
|
180 | 229 |
/// \brief \ref named-templ-param "Named parameter" for setting |
181 | 230 |
/// FlowMap type |
182 | 231 |
/// |
183 | 232 |
/// \ref named-templ-param "Named parameter" for setting FlowMap |
184 |
/// type |
|
233 |
/// type. |
|
185 | 234 |
template <typename _FlowMap> |
186 | 235 |
struct SetFlowMap |
187 | 236 |
: public Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
188 | 237 |
SetFlowMapTraits<_FlowMap> > { |
189 | 238 |
typedef Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
190 | 239 |
SetFlowMapTraits<_FlowMap> > Create; |
191 | 240 |
}; |
192 | 241 |
|
193 | 242 |
template <typename _Elevator> |
194 | 243 |
struct SetElevatorTraits : public Traits { |
195 | 244 |
typedef _Elevator Elevator; |
196 | 245 |
static Elevator *createElevator(const Digraph&, int) { |
197 | 246 |
LEMON_ASSERT(false, "Elevator is not initialized"); |
198 | 247 |
return 0; // ignore warnings |
199 | 248 |
} |
200 | 249 |
}; |
201 | 250 |
|
202 | 251 |
/// \brief \ref named-templ-param "Named parameter" for setting |
203 | 252 |
/// Elevator type |
204 | 253 |
/// |
205 | 254 |
/// \ref named-templ-param "Named parameter" for setting Elevator |
206 |
/// type |
|
255 |
/// type. If this named parameter is used, then an external |
|
256 |
/// elevator object must be passed to the algorithm using the |
|
257 |
/// \ref elevator(Elevator&) "elevator()" function before calling |
|
258 |
/// \ref run() or \ref init(). |
|
259 |
/// \sa SetStandardElevator |
|
207 | 260 |
template <typename _Elevator> |
208 | 261 |
struct SetElevator |
209 | 262 |
: public Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
210 | 263 |
SetElevatorTraits<_Elevator> > { |
211 | 264 |
typedef Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
212 | 265 |
SetElevatorTraits<_Elevator> > Create; |
213 | 266 |
}; |
214 | 267 |
|
215 | 268 |
template <typename _Elevator> |
216 | 269 |
struct SetStandardElevatorTraits : public Traits { |
217 | 270 |
typedef _Elevator Elevator; |
218 | 271 |
static Elevator *createElevator(const Digraph& digraph, int max_level) { |
219 | 272 |
return new Elevator(digraph, max_level); |
220 | 273 |
} |
221 | 274 |
}; |
222 | 275 |
|
223 | 276 |
/// \brief \ref named-templ-param "Named parameter" for setting |
224 |
/// Elevator type |
|
277 |
/// Elevator type with automatic allocation |
|
225 | 278 |
/// |
226 | 279 |
/// \ref named-templ-param "Named parameter" for setting Elevator |
227 |
/// type. The Elevator should be standard constructor interface, ie. |
|
228 |
/// the digraph and the maximum level should be passed to it. |
|
280 |
/// type with automatic allocation. |
|
281 |
/// The Elevator should have standard constructor interface to be |
|
282 |
/// able to automatically created by the algorithm (i.e. the |
|
283 |
/// digraph and the maximum level should be passed to it). |
|
284 |
/// However an external elevator object could also be passed to the |
|
285 |
/// algorithm with the \ref elevator(Elevator&) "elevator()" function |
|
286 |
/// before calling \ref run() or \ref init(). |
|
287 |
/// \sa SetElevator |
|
229 | 288 |
template <typename _Elevator> |
230 | 289 |
struct SetStandardElevator |
231 | 290 |
: public Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
232 | 291 |
SetStandardElevatorTraits<_Elevator> > { |
233 | 292 |
typedef Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
234 | 293 |
SetStandardElevatorTraits<_Elevator> > Create; |
235 | 294 |
}; |
236 | 295 |
|
237 | 296 |
/// @} |
238 | 297 |
|
239 | 298 |
protected: |
240 | 299 |
|
241 | 300 |
Circulation() {} |
242 | 301 |
|
243 | 302 |
public: |
244 | 303 |
|
245 | 304 |
/// The constructor of the class. |
246 | 305 |
|
247 | 306 |
/// The constructor of the class. |
248 | 307 |
/// \param g The digraph the algorithm runs on. |
249 | 308 |
/// \param lo The lower bound capacity of the arcs. |
250 | 309 |
/// \param up The upper bound capacity of the arcs. |
251 |
/// \param delta The lower bound |
|
310 |
/// \param delta The lower bound for the supply of the nodes. |
|
252 | 311 |
Circulation(const Digraph &g,const LCapMap &lo, |
253 | 312 |
const UCapMap &up,const DeltaMap &delta) |
254 | 313 |
: _g(g), _node_num(), |
255 | 314 |
_lo(&lo),_up(&up),_delta(&delta),_flow(0),_local_flow(false), |
256 | 315 |
_level(0), _local_level(false), _excess(0), _el() {} |
257 | 316 |
|
258 |
/// |
|
317 |
/// Destructor. |
|
259 | 318 |
~Circulation() { |
260 | 319 |
destroyStructures(); |
261 | 320 |
} |
262 | 321 |
|
322 |
|
|
263 | 323 |
private: |
264 | 324 |
|
265 | 325 |
void createStructures() { |
266 | 326 |
_node_num = _el = countNodes(_g); |
267 | 327 |
|
268 | 328 |
if (!_flow) { |
269 | 329 |
_flow = Traits::createFlowMap(_g); |
270 | 330 |
_local_flow = true; |
271 | 331 |
} |
272 | 332 |
if (!_level) { |
273 | 333 |
_level = Traits::createElevator(_g, _node_num); |
274 | 334 |
_local_level = true; |
... | ... |
@@ -286,123 +346,119 @@ |
286 | 346 |
delete _level; |
287 | 347 |
} |
288 | 348 |
if (_excess) { |
289 | 349 |
delete _excess; |
290 | 350 |
} |
291 | 351 |
} |
292 | 352 |
|
293 | 353 |
public: |
294 | 354 |
|
295 | 355 |
/// Sets the lower bound capacity map. |
296 | 356 |
|
297 | 357 |
/// Sets the lower bound capacity map. |
298 |
/// \return |
|
358 |
/// \return <tt>(*this)</tt> |
|
299 | 359 |
Circulation& lowerCapMap(const LCapMap& map) { |
300 | 360 |
_lo = ↦ |
301 | 361 |
return *this; |
302 | 362 |
} |
303 | 363 |
|
304 | 364 |
/// Sets the upper bound capacity map. |
305 | 365 |
|
306 | 366 |
/// Sets the upper bound capacity map. |
307 |
/// \return |
|
367 |
/// \return <tt>(*this)</tt> |
|
308 | 368 |
Circulation& upperCapMap(const LCapMap& map) { |
309 | 369 |
_up = ↦ |
310 | 370 |
return *this; |
311 | 371 |
} |
312 | 372 |
|
313 |
/// Sets the lower bound map |
|
373 |
/// Sets the lower bound map for the supply of the nodes. |
|
314 | 374 |
|
315 |
/// Sets the lower bound map on excess. |
|
316 |
/// \return \c (*this) |
|
375 |
/// Sets the lower bound map for the supply of the nodes. |
|
376 |
/// \return <tt>(*this)</tt> |
|
317 | 377 |
Circulation& deltaMap(const DeltaMap& map) { |
318 | 378 |
_delta = ↦ |
319 | 379 |
return *this; |
320 | 380 |
} |
321 | 381 |
|
382 |
/// \brief Sets the flow map. |
|
383 |
/// |
|
322 | 384 |
/// Sets the flow map. |
323 |
|
|
324 |
/// Sets the flow map. |
|
325 |
/// |
|
385 |
/// If you don't use this function before calling \ref run() or |
|
386 |
/// \ref init(), an instance will be allocated automatically. |
|
387 |
/// The destructor deallocates this automatically allocated map, |
|
388 |
/// of course. |
|
389 |
/// \return <tt>(*this)</tt> |
|
326 | 390 |
Circulation& flowMap(FlowMap& map) { |
327 | 391 |
if (_local_flow) { |
328 | 392 |
delete _flow; |
329 | 393 |
_local_flow = false; |
330 | 394 |
} |
331 | 395 |
_flow = ↦ |
332 | 396 |
return *this; |
333 | 397 |
} |
334 | 398 |
|
335 |
/// Returns the flow map. |
|
336 |
|
|
337 |
/// \ |
|
399 |
/// \brief Sets the elevator used by algorithm. |
|
338 | 400 |
/// |
339 |
const FlowMap& flowMap() { |
|
340 |
return *_flow; |
|
341 |
} |
|
342 |
|
|
343 |
/// Sets the elevator. |
|
344 |
|
|
345 |
/// Sets the elevator. |
|
346 |
/// \return \c (*this) |
|
401 |
/// Sets the elevator used by algorithm. |
|
402 |
/// If you don't use this function before calling \ref run() or |
|
403 |
/// \ref init(), an instance will be allocated automatically. |
|
404 |
/// The destructor deallocates this automatically allocated elevator, |
|
405 |
/// of course. |
|
406 |
/// \return <tt>(*this)</tt> |
|
347 | 407 |
Circulation& elevator(Elevator& elevator) { |
348 | 408 |
if (_local_level) { |
349 | 409 |
delete _level; |
350 | 410 |
_local_level = false; |
351 | 411 |
} |
352 | 412 |
_level = &elevator; |
353 | 413 |
return *this; |
354 | 414 |
} |
355 | 415 |
|
356 |
/// Returns the elevator. |
|
357 |
|
|
358 |
/// \ |
|
416 |
/// \brief Returns a const reference to the elevator. |
|
359 | 417 |
/// |
418 |
/// Returns a const reference to the elevator. |
|
419 |
/// |
|
420 |
/// \pre Either \ref run() or \ref init() must be called before |
|
421 |
/// using this function. |
|
360 | 422 |
const Elevator& elevator() { |
361 | 423 |
return *_level; |
362 | 424 |
} |
363 | 425 |
|
426 |
/// \brief Sets the tolerance used by algorithm. |
|
427 |
/// |
|
364 | 428 |
/// Sets the tolerance used by algorithm. |
365 |
|
|
366 |
/// Sets the tolerance used by algorithm. |
|
367 |
/// |
|
368 | 429 |
Circulation& tolerance(const Tolerance& tolerance) const { |
369 | 430 |
_tol = tolerance; |
370 | 431 |
return *this; |
371 | 432 |
} |
372 | 433 |
|
373 |
/// Returns the tolerance used by algorithm. |
|
374 |
|
|
375 |
/// Returns the tolerance |
|
434 |
/// \brief Returns a const reference to the tolerance. |
|
376 | 435 |
/// |
436 |
/// Returns a const reference to the tolerance. |
|
377 | 437 |
const Tolerance& tolerance() const { |
378 | 438 |
return tolerance; |
379 | 439 |
} |
380 | 440 |
|
381 |
/// \name Execution control |
|
382 |
/// The simplest way to execute the algorithm is to use one of the |
|
383 |
/// member functions called \c run(). |
|
384 |
/// \n |
|
385 |
/// If you need more control on initial solution or execution then |
|
386 |
/// you have to call one \ref init() function and then the start() |
|
387 |
/// |
|
441 |
/// \name Execution Control |
|
442 |
/// The simplest way to execute the algorithm is to call \ref run().\n |
|
443 |
/// If you need more control on the initial solution or the execution, |
|
444 |
/// first you have to call one of the \ref init() functions, then |
|
445 |
/// the \ref start() function. |
|
388 | 446 |
|
389 | 447 |
///@{ |
390 | 448 |
|
391 | 449 |
/// Initializes the internal data structures. |
392 | 450 |
|
393 |
/// Initializes the internal data structures. This function sets |
|
394 |
/// all flow values to the lower bound. |
|
395 |
/// \return This function returns false if the initialization |
|
396 |
/// process found a barrier. |
|
451 |
/// Initializes the internal data structures and sets all flow values |
|
452 |
/// to the lower bound. |
|
397 | 453 |
void init() |
398 | 454 |
{ |
399 | 455 |
createStructures(); |
400 | 456 |
|
401 | 457 |
for(NodeIt n(_g);n!=INVALID;++n) { |
402 | 458 |
_excess->set(n, (*_delta)[n]); |
403 | 459 |
} |
404 | 460 |
|
405 | 461 |
for (ArcIt e(_g);e!=INVALID;++e) { |
406 | 462 |
_flow->set(e, (*_lo)[e]); |
407 | 463 |
_excess->set(_g.target(e), (*_excess)[_g.target(e)] + (*_flow)[e]); |
408 | 464 |
_excess->set(_g.source(e), (*_excess)[_g.source(e)] - (*_flow)[e]); |
... | ... |
@@ -410,28 +466,28 @@ |
410 | 466 |
|
411 | 467 |
// global relabeling tested, but in general case it provides |
412 | 468 |
// worse performance for random digraphs |
413 | 469 |
_level->initStart(); |
414 | 470 |
for(NodeIt n(_g);n!=INVALID;++n) |
415 | 471 |
_level->initAddItem(n); |
416 | 472 |
_level->initFinish(); |
417 | 473 |
for(NodeIt n(_g);n!=INVALID;++n) |
418 | 474 |
if(_tol.positive((*_excess)[n])) |
419 | 475 |
_level->activate(n); |
420 | 476 |
} |
421 | 477 |
|
422 |
/// Initializes the internal data structures. |
|
478 |
/// Initializes the internal data structures using a greedy approach. |
|
423 | 479 |
|
424 |
/// Initializes the internal data structures. This functions uses |
|
425 |
/// greedy approach to construct the initial solution. |
|
480 |
/// Initializes the internal data structures using a greedy approach |
|
481 |
/// to construct the initial solution. |
|
426 | 482 |
void greedyInit() |
427 | 483 |
{ |
428 | 484 |
createStructures(); |
429 | 485 |
|
430 | 486 |
for(NodeIt n(_g);n!=INVALID;++n) { |
431 | 487 |
_excess->set(n, (*_delta)[n]); |
432 | 488 |
} |
433 | 489 |
|
434 | 490 |
for (ArcIt e(_g);e!=INVALID;++e) { |
435 | 491 |
if (!_tol.positive((*_excess)[_g.target(e)] + (*_up)[e])) { |
436 | 492 |
_flow->set(e, (*_up)[e]); |
437 | 493 |
_excess->set(_g.target(e), (*_excess)[_g.target(e)] + (*_up)[e]); |
... | ... |
@@ -448,30 +504,32 @@ |
448 | 504 |
} |
449 | 505 |
} |
450 | 506 |
|
451 | 507 |
_level->initStart(); |
452 | 508 |
for(NodeIt n(_g);n!=INVALID;++n) |
453 | 509 |
_level->initAddItem(n); |
454 | 510 |
_level->initFinish(); |
455 | 511 |
for(NodeIt n(_g);n!=INVALID;++n) |
456 | 512 |
if(_tol.positive((*_excess)[n])) |
457 | 513 |
_level->activate(n); |
458 | 514 |
} |
459 | 515 |
|
460 |
/// |
|
516 |
///Executes the algorithm |
|
461 | 517 |
|
462 |
///This function starts the algorithm. |
|
463 |
///\return This function returns true if it found a feasible circulation. |
|
518 |
///This function executes the algorithm. |
|
519 |
/// |
|
520 |
///\return \c true if a feasible circulation is found. |
|
464 | 521 |
/// |
465 | 522 |
///\sa barrier() |
523 |
///\sa barrierMap() |
|
466 | 524 |
bool start() |
467 | 525 |
{ |
468 | 526 |
|
469 | 527 |
Node act; |
470 | 528 |
Node bact=INVALID; |
471 | 529 |
Node last_activated=INVALID; |
472 | 530 |
while((act=_level->highestActive())!=INVALID) { |
473 | 531 |
int actlevel=(*_level)[act]; |
474 | 532 |
int mlevel=_node_num; |
475 | 533 |
Value exc=(*_excess)[act]; |
476 | 534 |
|
477 | 535 |
for(OutArcIt e(_g,act);e!=INVALID; ++e) { |
... | ... |
@@ -534,112 +592,153 @@ |
534 | 592 |
_level->liftHighestActive(mlevel+1); |
535 | 593 |
if(_level->onLevel(actlevel)==0) { |
536 | 594 |
_el = actlevel; |
537 | 595 |
return false; |
538 | 596 |
} |
539 | 597 |
} |
540 | 598 |
next_l: |
541 | 599 |
; |
542 | 600 |
} |
543 | 601 |
return true; |
544 | 602 |
} |
545 | 603 |
|
546 |
/// Runs the |
|
604 |
/// Runs the algorithm. |
|
547 | 605 |
|
548 |
/// Runs the circulation algorithm. |
|
549 |
/// \note fc.run() is just a shortcut of the following code. |
|
606 |
/// This function runs the algorithm. |
|
607 |
/// |
|
608 |
/// \return \c true if a feasible circulation is found. |
|
609 |
/// |
|
610 |
/// \note Apart from the return value, c.run() is just a shortcut of |
|
611 |
/// the following code. |
|
550 | 612 |
/// \code |
551 |
/// fc.greedyInit(); |
|
552 |
/// return fc.start(); |
|
613 |
/// c.greedyInit(); |
|
614 |
/// c.start(); |
|
553 | 615 |
/// \endcode |
554 | 616 |
bool run() { |
555 | 617 |
greedyInit(); |
556 | 618 |
return start(); |
557 | 619 |
} |
558 | 620 |
|
559 | 621 |
/// @} |
560 | 622 |
|
561 | 623 |
/// \name Query Functions |
562 |
/// The result of the %Circulation algorithm can be obtained using |
|
563 |
/// these functions. |
|
564 |
/// \n |
|
565 |
/// Before the use of these functions, |
|
566 |
/// |
|
624 |
/// The results of the circulation algorithm can be obtained using |
|
625 |
/// these functions.\n |
|
626 |
/// Either \ref run() or \ref start() should be called before |
|
627 |
/// using them. |
|
567 | 628 |
|
568 | 629 |
///@{ |
569 | 630 |
|
631 |
/// \brief Returns the flow on the given arc. |
|
632 |
/// |
|
633 |
/// Returns the flow on the given arc. |
|
634 |
/// |
|
635 |
/// \pre Either \ref run() or \ref init() must be called before |
|
636 |
/// using this function. |
|
637 |
Value flow(const Arc& arc) const { |
|
638 |
return (*_flow)[arc]; |
|
639 |
} |
|
640 |
|
|
641 |
/// \brief Returns a const reference to the flow map. |
|
642 |
/// |
|
643 |
/// Returns a const reference to the arc map storing the found flow. |
|
644 |
/// |
|
645 |
/// \pre Either \ref run() or \ref init() must be called before |
|
646 |
/// using this function. |
|
647 |
const FlowMap& flowMap() { |
|
648 |
return *_flow; |
|
649 |
} |
|
650 |
|
|
570 | 651 |
/** |
571 |
\brief Returns a barrier |
|
572 |
|
|
652 |
\brief Returns \c true if the given node is in a barrier. |
|
653 |
|
|
573 | 654 |
Barrier is a set \e B of nodes for which |
574 |
\f[ \sum_{v\in B}-delta(v)< |
|
575 |
\sum_{e\in\rho(B)}lo(e)-\sum_{e\in\delta(B)}up(e) \f] |
|
576 |
holds. The existence of a set with this property prooves that a feasible |
|
577 |
flow cannot exists. |
|
655 |
|
|
656 |
\f[ \sum_{a\in\delta_{out}(B)} upper(a) - |
|
657 |
\sum_{a\in\delta_{in}(B)} lower(a) < \sum_{v\in B}delta(v) \f] |
|
658 |
|
|
659 |
holds. The existence of a set with this property prooves that a |
|
660 |
feasible circualtion cannot exist. |
|
661 |
|
|
662 |
This function returns \c true if the given node is in the found |
|
663 |
barrier. If a feasible circulation is found, the function |
|
664 |
gives back \c false for every node. |
|
665 |
|
|
666 |
\pre Either \ref run() or \ref init() must be called before |
|
667 |
using this function. |
|
668 |
|
|
669 |
\sa barrierMap() |
|
578 | 670 |
\sa checkBarrier() |
579 |
\sa run() |
|
580 | 671 |
*/ |
581 |
template<class GT> |
|
582 |
void barrierMap(GT &bar) |
|
672 |
bool barrier(const Node& node) |
|
673 |
{ |
|
674 |
return (*_level)[node] >= _el; |
|
675 |
} |
|
676 |
|
|
677 |
/// \brief Gives back a barrier. |
|
678 |
/// |
|
679 |
/// This function sets \c bar to the characteristic vector of the |
|
680 |
/// found barrier. \c bar should be a \ref concepts::WriteMap "writable" |
|
681 |
/// node map with \c bool (or convertible) value type. |
|
682 |
/// |
|
683 |
/// If a feasible circulation is found, the function gives back an |
|
684 |
/// empty set, so \c bar[v] will be \c false for all nodes \c v. |
|
685 |
/// |
|
686 |
/// \note This function calls \ref barrier() for each node, |
|
687 |
/// so it runs in \f$O(n)\f$ time. |
|
688 |
/// |
|
689 |
/// \pre Either \ref run() or \ref init() must be called before |
|
690 |
/// using this function. |
|
691 |
/// |
|
692 |
/// \sa barrier() |
|
693 |
/// \sa checkBarrier() |
|
694 |
template<class BarrierMap> |
|
695 |
void barrierMap(BarrierMap &bar) |
|
583 | 696 |
{ |
584 | 697 |
for(NodeIt n(_g);n!=INVALID;++n) |
585 | 698 |
bar.set(n, (*_level)[n] >= _el); |
586 | 699 |
} |
587 | 700 |
|
588 |
///Returns true if the node is in the barrier |
|
589 |
|
|
590 |
///Returns true if the node is in the barrier |
|
591 |
///\sa barrierMap() |
|
592 |
bool barrier(const Node& node) |
|
593 |
{ |
|
594 |
return (*_level)[node] >= _el; |
|
595 |
} |
|
596 |
|
|
597 |
/// \brief Returns the flow on the arc. |
|
598 |
/// |
|
599 |
/// Sets the \c flowMap to the flow on the arcs. This method can |
|
600 |
/// be called after the second phase of algorithm. |
|
601 |
Value flow(const Arc& arc) const { |
|
602 |
return (*_flow)[arc]; |
|
603 |
} |
|
604 |
|
|
605 | 701 |
/// @} |
606 | 702 |
|
607 | 703 |
/// \name Checker Functions |
608 |
/// The feasibility of the results can be checked using |
|
609 |
/// these functions. |
|
610 |
/// \n |
|
611 |
/// Before the use of these functions, |
|
612 |
/// |
|
704 |
/// The feasibility of the results can be checked using |
|
705 |
/// these functions.\n |
|
706 |
/// Either \ref run() or \ref start() should be called before |
|
707 |
/// using them. |
|
613 | 708 |
|
614 | 709 |
///@{ |
615 | 710 |
|
616 |
///Check if the |
|
711 |
///Check if the found flow is a feasible circulation |
|
712 |
|
|
713 |
///Check if the found flow is a feasible circulation, |
|
714 |
/// |
|
617 | 715 |
bool checkFlow() { |
618 | 716 |
for(ArcIt e(_g);e!=INVALID;++e) |
619 | 717 |
if((*_flow)[e]<(*_lo)[e]||(*_flow)[e]>(*_up)[e]) return false; |
620 | 718 |
for(NodeIt n(_g);n!=INVALID;++n) |
621 | 719 |
{ |
622 | 720 |
Value dif=-(*_delta)[n]; |
623 | 721 |
for(InArcIt e(_g,n);e!=INVALID;++e) dif-=(*_flow)[e]; |
624 | 722 |
for(OutArcIt e(_g,n);e!=INVALID;++e) dif+=(*_flow)[e]; |
625 | 723 |
if(_tol.negative(dif)) return false; |
626 | 724 |
} |
627 | 725 |
return true; |
628 | 726 |
} |
629 | 727 |
|
630 | 728 |
///Check whether or not the last execution provides a barrier |
631 | 729 |
|
632 |
///Check whether or not the last execution provides a barrier |
|
730 |
///Check whether or not the last execution provides a barrier. |
|
633 | 731 |
///\sa barrier() |
732 |
///\sa barrierMap() |
|
634 | 733 |
bool checkBarrier() |
635 | 734 |
{ |
636 | 735 |
Value delta=0; |
637 | 736 |
for(NodeIt n(_g);n!=INVALID;++n) |
638 | 737 |
if(barrier(n)) |
639 | 738 |
delta-=(*_delta)[n]; |
640 | 739 |
for(ArcIt e(_g);e!=INVALID;++e) |
641 | 740 |
{ |
642 | 741 |
Node s=_g.source(e); |
643 | 742 |
Node t=_g.target(e); |
644 | 743 |
if(barrier(s)&&!barrier(t)) delta+=(*_up)[e]; |
645 | 744 |
else if(barrier(t)&&!barrier(s)) delta-=(*_lo)[e]; |
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