| 1 | /* -*- C++ -*- |
| 2 | * |
| 3 | * This file is a part of LEMON, a generic C++ optimization library |
| 4 | * |
| 5 | * Copyright (C) 2003-2010 |
| 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_MAX_CARDINALITY_SEARCH_H |
| 20 | #define LEMON_MAX_CARDINALITY_SEARCH_H |
| 21 | |
| 22 | |
| 23 | /// \ingroup auxalg |
| 24 | /// \file |
| 25 | /// \brief Maximum cardinality search in undirected digraphs. |
| 26 | |
| 27 | #include <lemon/bin_heap.h> |
| 28 | #include <lemon/bucket_heap.h> |
| 29 | |
| 30 | #include <lemon/error.h> |
| 31 | #include <lemon/maps.h> |
| 32 | |
| 33 | #include <functional> |
| 34 | |
| 35 | namespace lemon { |
| 36 | |
| 37 | /// \brief Default traits class of MaxCardinalitySearch class. |
| 38 | /// |
| 39 | /// Default traits class of MaxCardinalitySearch class. |
| 40 | /// \param Digraph Digraph type. |
| 41 | /// \param CapacityMap Type of capacity map. |
| 42 | template <typename GR, typename CAP> |
| 43 | struct MaxCardinalitySearchDefaultTraits { |
| 44 | /// The digraph type the algorithm runs on. |
| 45 | typedef GR Digraph; |
| 46 | |
| 47 | template <typename CM> |
| 48 | struct CapMapSelector { |
| 49 | |
| 50 | typedef CM CapacityMap; |
| 51 | |
| 52 | static CapacityMap *createCapacityMap(const Digraph& g) { |
| 53 | return new CapacityMap(g); |
| 54 | } |
| 55 | }; |
| 56 | |
| 57 | template <typename CM> |
| 58 | struct CapMapSelector<ConstMap<CM, Const<int, 1> > > { |
| 59 | |
| 60 | typedef ConstMap<CM, Const<int, 1> > CapacityMap; |
| 61 | |
| 62 | static CapacityMap *createCapacityMap(const Digraph& g) { |
| 63 | ignore_unused_variable_warning(g); |
| 64 | return new CapacityMap; |
| 65 | } |
| 66 | }; |
| 67 | |
| 68 | /// \brief The type of the map that stores the arc capacities. |
| 69 | /// |
| 70 | /// The type of the map that stores the arc capacities. |
| 71 | /// It must meet the \ref concepts::ReadMap "ReadMap" concept. |
| 72 | typedef typename CapMapSelector<CAP>::CapacityMap CapacityMap; |
| 73 | |
| 74 | /// \brief The type of the capacity of the arcs. |
| 75 | typedef typename CapacityMap::Value Value; |
| 76 | |
| 77 | /// \brief Instantiates a CapacityMap. |
| 78 | /// |
| 79 | /// This function instantiates a \ref CapacityMap. |
| 80 | /// \param digraph is the digraph, to which we would like to define |
| 81 | /// the CapacityMap. |
| 82 | static CapacityMap *createCapacityMap(const Digraph& digraph) { |
| 83 | return CapMapSelector<CapacityMap>::createCapacityMap(digraph); |
| 84 | } |
| 85 | |
| 86 | /// \brief The cross reference type used by heap. |
| 87 | /// |
| 88 | /// The cross reference type used by heap. |
| 89 | /// Usually it is \c Digraph::NodeMap<int>. |
| 90 | typedef typename Digraph::template NodeMap<int> HeapCrossRef; |
| 91 | |
| 92 | /// \brief Instantiates a HeapCrossRef. |
| 93 | /// |
| 94 | /// This function instantiates a \ref HeapCrossRef. |
| 95 | /// \param digraph is the digraph, to which we would like to define the |
| 96 | /// HeapCrossRef. |
| 97 | static HeapCrossRef *createHeapCrossRef(const Digraph &digraph) { |
| 98 | return new HeapCrossRef(digraph); |
| 99 | } |
| 100 | |
| 101 | template <typename CapacityMap> |
| 102 | struct HeapSelector { |
| 103 | template <typename Value, typename Ref> |
| 104 | struct Selector { |
| 105 | typedef BinHeap<Value, Ref, std::greater<Value> > Heap; |
| 106 | }; |
| 107 | }; |
| 108 | |
| 109 | template <typename CapacityKey> |
| 110 | struct HeapSelector<ConstMap<CapacityKey, Const<int, 1> > > { |
| 111 | template <typename Value, typename Ref> |
| 112 | struct Selector { |
| 113 | typedef BucketHeap<Ref, false > Heap; |
| 114 | }; |
| 115 | }; |
| 116 | |
| 117 | /// \brief The heap type used by MaxCardinalitySearch algorithm. |
| 118 | /// |
| 119 | /// The heap type used by MaxCardinalitySearch algorithm. It should |
| 120 | /// maximalize the priorities. The default heap type is |
| 121 | /// the \ref BinHeap, but it is specialized when the |
| 122 | /// CapacityMap is ConstMap<Digraph::Node, Const<int, 1> > |
| 123 | /// to BucketHeap. |
| 124 | /// |
| 125 | /// \sa MaxCardinalitySearch |
| 126 | typedef typename HeapSelector<CapacityMap> |
| 127 | ::template Selector<Value, HeapCrossRef> |
| 128 | ::Heap Heap; |
| 129 | |
| 130 | /// \brief Instantiates a Heap. |
| 131 | /// |
| 132 | /// This function instantiates a \ref Heap. |
| 133 | /// \param crossref The cross reference of the heap. |
| 134 | static Heap *createHeap(HeapCrossRef& crossref) { |
| 135 | return new Heap(crossref); |
| 136 | } |
| 137 | |
| 138 | /// \brief The type of the map that stores whether a node is processed. |
| 139 | /// |
| 140 | /// The type of the map that stores whether a node is processed. |
| 141 | /// It must meet the \ref concepts::WriteMap "WriteMap" concept. |
| 142 | /// By default it is a NullMap. |
| 143 | typedef NullMap<typename Digraph::Node, bool> ProcessedMap; |
| 144 | |
| 145 | /// \brief Instantiates a ProcessedMap. |
| 146 | /// |
| 147 | /// This function instantiates a \ref ProcessedMap. |
| 148 | /// \param digraph is the digraph, to which |
| 149 | /// we would like to define the \ref ProcessedMap |
| 150 | #ifdef DOXYGEN |
| 151 | static ProcessedMap *createProcessedMap(const Digraph &digraph) |
| 152 | #else |
| 153 | static ProcessedMap *createProcessedMap(const Digraph &) |
| 154 | #endif |
| 155 | { |
| 156 | return new ProcessedMap(); |
| 157 | } |
| 158 | |
| 159 | /// \brief The type of the map that stores the cardinalities of the nodes. |
| 160 | /// |
| 161 | /// The type of the map that stores the cardinalities of the nodes. |
| 162 | /// It must meet the \ref concepts::WriteMap "WriteMap" concept. |
| 163 | typedef typename Digraph::template NodeMap<Value> CardinalityMap; |
| 164 | |
| 165 | /// \brief Instantiates a CardinalityMap. |
| 166 | /// |
| 167 | /// This function instantiates a \ref CardinalityMap. |
| 168 | /// \param digraph is the digraph, to which we would like to define the \ref |
| 169 | /// CardinalityMap |
| 170 | static CardinalityMap *createCardinalityMap(const Digraph &digraph) { |
| 171 | return new CardinalityMap(digraph); |
| 172 | } |
| 173 | |
| 174 | |
| 175 | }; |
| 176 | |
| 177 | /// \ingroup search |
| 178 | /// |
| 179 | /// \brief Maximum Cardinality Search algorithm class. |
| 180 | /// |
| 181 | /// This class provides an efficient implementation of Maximum Cardinality |
| 182 | /// Search algorithm. The maximum cardinality search first chooses any |
| 183 | /// node of the digraph. Then every time it chooses one unprocessed node |
| 184 | /// with maximum cardinality, i.e the sum of capacities on out arcs to the nodes |
| 185 | /// which were previusly processed. |
| 186 | /// If there is a cut in the digraph the algorithm should choose |
| 187 | /// again any unprocessed node of the digraph. |
| 188 | |
| 189 | /// The arc capacities are passed to the algorithm using a |
| 190 | /// \ref concepts::ReadMap "ReadMap", so it is easy to change it to any |
| 191 | /// kind of capacity. |
| 192 | /// |
| 193 | /// The type of the capacity is determined by the \ref |
| 194 | /// concepts::ReadMap::Value "Value" of the capacity map. |
| 195 | /// |
| 196 | /// It is also possible to change the underlying priority heap. |
| 197 | /// |
| 198 | /// |
| 199 | /// \param GR The digraph type the algorithm runs on. The value of |
| 200 | /// Digraph is not used directly by the search algorithm, it |
| 201 | /// is only passed to \ref MaxCardinalitySearchDefaultTraits. |
| 202 | /// \param CAP This read-only ArcMap determines the capacities of |
| 203 | /// the arcs. It is read once for each arc, so the map may involve in |
| 204 | /// relatively time consuming process to compute the arc capacity if |
| 205 | /// it is necessary. The default map type is \ref |
| 206 | /// ConstMap "ConstMap<concepts::Digraph::Arc, Const<int,1> >". The value |
| 207 | /// of CapacityMap is not used directly by search algorithm, it is only |
| 208 | /// passed to \ref MaxCardinalitySearchDefaultTraits. |
| 209 | /// \param TR Traits class to set various data types used by the |
| 210 | /// algorithm. The default traits class is |
| 211 | /// \ref MaxCardinalitySearchDefaultTraits |
| 212 | /// "MaxCardinalitySearchDefaultTraits<GR, CAP>". |
| 213 | /// See \ref MaxCardinalitySearchDefaultTraits |
| 214 | /// for the documentation of a MaxCardinalitySearch traits class. |
| 215 | |
| 216 | #ifdef DOXYGEN |
| 217 | template <typename GR, typename CAP, typename TR> |
| 218 | #else |
| 219 | template <typename GR, typename CAP = |
| 220 | ConstMap<typename GR::Arc, Const<int,1> >, |
| 221 | typename TR = |
| 222 | MaxCardinalitySearchDefaultTraits<GR, CAP> > |
| 223 | #endif |
| 224 | class MaxCardinalitySearch { |
| 225 | public: |
| 226 | |
| 227 | typedef TR Traits; |
| 228 | ///The type of the underlying digraph. |
| 229 | typedef typename Traits::Digraph Digraph; |
| 230 | |
| 231 | ///The type of the capacity of the arcs. |
| 232 | typedef typename Traits::CapacityMap::Value Value; |
| 233 | ///The type of the map that stores the arc capacities. |
| 234 | typedef typename Traits::CapacityMap CapacityMap; |
| 235 | ///The type of the map indicating if a node is processed. |
| 236 | typedef typename Traits::ProcessedMap ProcessedMap; |
| 237 | ///The type of the map that stores the cardinalities of the nodes. |
| 238 | typedef typename Traits::CardinalityMap CardinalityMap; |
| 239 | ///The cross reference type used for the current heap. |
| 240 | typedef typename Traits::HeapCrossRef HeapCrossRef; |
| 241 | ///The heap type used by the algorithm. It maximizes the priorities. |
| 242 | typedef typename Traits::Heap Heap; |
| 243 | private: |
| 244 | /// Pointer to the underlying digraph. |
| 245 | const Digraph *_graph; |
| 246 | /// Pointer to the capacity map |
| 247 | const CapacityMap *_capacity; |
| 248 | /// Indicates if \ref _capacity is locally allocated (\c true) or not. |
| 249 | bool local_capacity; |
| 250 | ///Pointer to the map of cardinality. |
| 251 | CardinalityMap *_cardinality; |
| 252 | ///Indicates if \ref _cardinality is locally allocated (\c true) or not. |
| 253 | bool local_cardinality; |
| 254 | ///Pointer to the map of processed status of the nodes. |
| 255 | ProcessedMap *_processed; |
| 256 | ///Indicates if \ref _processed is locally allocated (\c true) or not. |
| 257 | bool local_processed; |
| 258 | ///Pointer to the heap cross references. |
| 259 | HeapCrossRef *_heap_cross_ref; |
| 260 | ///Indicates if \ref _heap_cross_ref is locally allocated (\c true) or not. |
| 261 | bool local_heap_cross_ref; |
| 262 | ///Pointer to the heap. |
| 263 | Heap *_heap; |
| 264 | ///Indicates if \ref _heap is locally allocated (\c true) or not. |
| 265 | bool local_heap; |
| 266 | |
| 267 | public : |
| 268 | |
| 269 | typedef MaxCardinalitySearch Create; |
| 270 | |
| 271 | ///\name Named template parameters |
| 272 | |
| 273 | ///@{ |
| 274 | |
| 275 | template <class T> |
| 276 | struct DefCapacityMapTraits : public Traits { |
| 277 | typedef T CapacityMap; |
| 278 | static CapacityMap *createCapacityMap(const Digraph &) { |
| 279 | LEMON_ASSERT(false,"Uninitialized parameter."); |
| 280 | return 0; |
| 281 | } |
| 282 | }; |
| 283 | /// \brief \ref named-templ-param "Named parameter" for setting |
| 284 | /// CapacityMap type |
| 285 | /// |
| 286 | /// \ref named-templ-param "Named parameter" for setting CapacityMap type |
| 287 | /// |
| 288 | template <class T> |
| 289 | struct SetCapacityMap |
| 290 | : public MaxCardinalitySearch<Digraph, CapacityMap, |
| 291 | DefCapacityMapTraits<T> > { |
| 292 | typedef MaxCardinalitySearch<Digraph, CapacityMap, |
| 293 | DefCapacityMapTraits<T> > Create; |
| 294 | }; |
| 295 | |
| 296 | template <class T> |
| 297 | struct DefCardinalityMapTraits : public Traits { |
| 298 | typedef T CardinalityMap; |
| 299 | static CardinalityMap *createCardinalityMap(const Digraph &) |
| 300 | { |
| 301 | LEMON_ASSERT(false,"Uninitialized parameter."); |
| 302 | return 0; |
| 303 | } |
| 304 | }; |
| 305 | /// \brief \ref named-templ-param "Named parameter" for setting |
| 306 | /// CardinalityMap type |
| 307 | /// |
| 308 | /// \ref named-templ-param "Named parameter" for setting CardinalityMap |
| 309 | /// type |
| 310 | template <class T> |
| 311 | struct SetCardinalityMap |
| 312 | : public MaxCardinalitySearch<Digraph, CapacityMap, |
| 313 | DefCardinalityMapTraits<T> > { |
| 314 | typedef MaxCardinalitySearch<Digraph, CapacityMap, |
| 315 | DefCardinalityMapTraits<T> > Create; |
| 316 | }; |
| 317 | |
| 318 | template <class T> |
| 319 | struct DefProcessedMapTraits : public Traits { |
| 320 | typedef T ProcessedMap; |
| 321 | static ProcessedMap *createProcessedMap(const Digraph &) { |
| 322 | LEMON_ASSERT(false,"Uninitialized parameter."); |
| 323 | return 0; |
| 324 | } |
| 325 | }; |
| 326 | /// \brief \ref named-templ-param "Named parameter" for setting |
| 327 | /// ProcessedMap type |
| 328 | /// |
| 329 | /// \ref named-templ-param "Named parameter" for setting ProcessedMap type |
| 330 | /// |
| 331 | template <class T> |
| 332 | struct SetProcessedMap |
| 333 | : public MaxCardinalitySearch<Digraph, CapacityMap, |
| 334 | DefProcessedMapTraits<T> > { |
| 335 | typedef MaxCardinalitySearch<Digraph, CapacityMap, |
| 336 | DefProcessedMapTraits<T> > Create; |
| 337 | }; |
| 338 | |
| 339 | template <class H, class CR> |
| 340 | struct DefHeapTraits : public Traits { |
| 341 | typedef CR HeapCrossRef; |
| 342 | typedef H Heap; |
| 343 | static HeapCrossRef *createHeapCrossRef(const Digraph &) { |
| 344 | LEMON_ASSERT(false,"Uninitialized parameter."); |
| 345 | return 0; |
| 346 | } |
| 347 | static Heap *createHeap(HeapCrossRef &) { |
| 348 | LEMON_ASSERT(false,"Uninitialized parameter."); |
| 349 | return 0; |
| 350 | } |
| 351 | }; |
| 352 | /// \brief \ref named-templ-param "Named parameter" for setting heap |
| 353 | /// and cross reference type |
| 354 | /// |
| 355 | /// \ref named-templ-param "Named parameter" for setting heap and cross |
| 356 | /// reference type |
| 357 | template <class H, class CR = typename Digraph::template NodeMap<int> > |
| 358 | struct SetHeap |
| 359 | : public MaxCardinalitySearch<Digraph, CapacityMap, |
| 360 | DefHeapTraits<H, CR> > { |
| 361 | typedef MaxCardinalitySearch< Digraph, CapacityMap, |
| 362 | DefHeapTraits<H, CR> > Create; |
| 363 | }; |
| 364 | |
| 365 | template <class H, class CR> |
| 366 | struct DefStandardHeapTraits : public Traits { |
| 367 | typedef CR HeapCrossRef; |
| 368 | typedef H Heap; |
| 369 | static HeapCrossRef *createHeapCrossRef(const Digraph &digraph) { |
| 370 | return new HeapCrossRef(digraph); |
| 371 | } |
| 372 | static Heap *createHeap(HeapCrossRef &crossref) { |
| 373 | return new Heap(crossref); |
| 374 | } |
| 375 | }; |
| 376 | |
| 377 | /// \brief \ref named-templ-param "Named parameter" for setting heap and |
| 378 | /// cross reference type with automatic allocation |
| 379 | /// |
| 380 | /// \ref named-templ-param "Named parameter" for setting heap and cross |
| 381 | /// reference type. It can allocate the heap and the cross reference |
| 382 | /// object if the cross reference's constructor waits for the digraph as |
| 383 | /// parameter and the heap's constructor waits for the cross reference. |
| 384 | template <class H, class CR = typename Digraph::template NodeMap<int> > |
| 385 | struct SetStandardHeap |
| 386 | : public MaxCardinalitySearch<Digraph, CapacityMap, |
| 387 | DefStandardHeapTraits<H, CR> > { |
| 388 | typedef MaxCardinalitySearch<Digraph, CapacityMap, |
| 389 | DefStandardHeapTraits<H, CR> > |
| 390 | Create; |
| 391 | }; |
| 392 | |
| 393 | ///@} |
| 394 | |
| 395 | |
| 396 | protected: |
| 397 | |
| 398 | MaxCardinalitySearch() {} |
| 399 | |
| 400 | public: |
| 401 | |
| 402 | /// \brief Constructor. |
| 403 | /// |
| 404 | ///\param digraph the digraph the algorithm will run on. |
| 405 | ///\param capacity the capacity map used by the algorithm. |
| 406 | ///When no capacity map given, a constant 1 capacity map will |
| 407 | ///be allocated. |
| 408 | #ifdef DOXYGEN |
| 409 | MaxCardinalitySearch(const Digraph& digraph, |
| 410 | const CapacityMap& capacity=0 ) : |
| 411 | #else |
| 412 | MaxCardinalitySearch(const Digraph& digraph, |
| 413 | const CapacityMap& capacity=*static_cast<const CapacityMap*>(0) ) : |
| 414 | #endif |
| 415 | _graph(&digraph), |
| 416 | _capacity(&capacity), local_capacity(false), |
| 417 | _cardinality(0), local_cardinality(false), |
| 418 | _processed(0), local_processed(false), |
| 419 | _heap_cross_ref(0), local_heap_cross_ref(false), |
| 420 | _heap(0), local_heap(false) |
| 421 | { } |
| 422 | |
| 423 | /// \brief Destructor. |
| 424 | ~MaxCardinalitySearch() { |
| 425 | if(local_capacity) delete _capacity; |
| 426 | if(local_cardinality) delete _cardinality; |
| 427 | if(local_processed) delete _processed; |
| 428 | if(local_heap_cross_ref) delete _heap_cross_ref; |
| 429 | if(local_heap) delete _heap; |
| 430 | } |
| 431 | |
| 432 | /// \brief Sets the capacity map. |
| 433 | /// |
| 434 | /// Sets the capacity map. |
| 435 | /// \return <tt> (*this) </tt> |
| 436 | MaxCardinalitySearch &capacityMap(const CapacityMap &m) { |
| 437 | if (local_capacity) { |
| 438 | delete _capacity; |
| 439 | local_capacity=false; |
| 440 | } |
| 441 | _capacity=&m; |
| 442 | return *this; |
| 443 | } |
| 444 | |
| 445 | /// \brief Returns a const reference to the capacity map. |
| 446 | /// |
| 447 | /// Returns a const reference to the capacity map used by |
| 448 | /// the algorithm. |
| 449 | const CapacityMap &capacityMap() const { |
| 450 | return *_capacity; |
| 451 | } |
| 452 | |
| 453 | /// \brief Sets the map storing the cardinalities calculated by the |
| 454 | /// algorithm. |
| 455 | /// |
| 456 | /// Sets the map storing the cardinalities calculated by the algorithm. |
| 457 | /// If you don't use this function before calling \ref run(), |
| 458 | /// it will allocate one. The destuctor deallocates this |
| 459 | /// automatically allocated map, of course. |
| 460 | /// \return <tt> (*this) </tt> |
| 461 | MaxCardinalitySearch &cardinalityMap(CardinalityMap &m) { |
| 462 | if(local_cardinality) { |
| 463 | delete _cardinality; |
| 464 | local_cardinality=false; |
| 465 | } |
| 466 | _cardinality = &m; |
| 467 | return *this; |
| 468 | } |
| 469 | |
| 470 | /// \brief Sets the map storing the processed nodes. |
| 471 | /// |
| 472 | /// Sets the map storing the processed nodes. |
| 473 | /// If you don't use this function before calling \ref run(), |
| 474 | /// it will allocate one. The destuctor deallocates this |
| 475 | /// automatically allocated map, of course. |
| 476 | /// \return <tt> (*this) </tt> |
| 477 | MaxCardinalitySearch &processedMap(ProcessedMap &m) |
| 478 | { |
| 479 | if(local_processed) { |
| 480 | delete _processed; |
| 481 | local_processed=false; |
| 482 | } |
| 483 | _processed = &m; |
| 484 | return *this; |
| 485 | } |
| 486 | |
| 487 | /// \brief Returns a const reference to the cardinality map. |
| 488 | /// |
| 489 | /// Returns a const reference to the cardinality map used by |
| 490 | /// the algorithm. |
| 491 | const ProcessedMap &processedMap() const { |
| 492 | return *_processed; |
| 493 | } |
| 494 | |
| 495 | /// \brief Sets the heap and the cross reference used by algorithm. |
| 496 | /// |
| 497 | /// Sets the heap and the cross reference used by algorithm. |
| 498 | /// If you don't use this function before calling \ref run(), |
| 499 | /// it will allocate one. The destuctor deallocates this |
| 500 | /// automatically allocated map, of course. |
| 501 | /// \return <tt> (*this) </tt> |
| 502 | MaxCardinalitySearch &heap(Heap& hp, HeapCrossRef &cr) { |
| 503 | if(local_heap_cross_ref) { |
| 504 | delete _heap_cross_ref; |
| 505 | local_heap_cross_ref = false; |
| 506 | } |
| 507 | _heap_cross_ref = &cr; |
| 508 | if(local_heap) { |
| 509 | delete _heap; |
| 510 | local_heap = false; |
| 511 | } |
| 512 | _heap = &hp; |
| 513 | return *this; |
| 514 | } |
| 515 | |
| 516 | /// \brief Returns a const reference to the heap. |
| 517 | /// |
| 518 | /// Returns a const reference to the heap used by |
| 519 | /// the algorithm. |
| 520 | const Heap &heap() const { |
| 521 | return *_heap; |
| 522 | } |
| 523 | |
| 524 | /// \brief Returns a const reference to the cross reference. |
| 525 | /// |
| 526 | /// Returns a const reference to the cross reference |
| 527 | /// of the heap. |
| 528 | const HeapCrossRef &heapCrossRef() const { |
| 529 | return *_heap_cross_ref; |
| 530 | } |
| 531 | |
| 532 | private: |
| 533 | |
| 534 | typedef typename Digraph::Node Node; |
| 535 | typedef typename Digraph::NodeIt NodeIt; |
| 536 | typedef typename Digraph::Arc Arc; |
| 537 | typedef typename Digraph::InArcIt InArcIt; |
| 538 | |
| 539 | void create_maps() { |
| 540 | if(!_capacity) { |
| 541 | local_capacity = true; |
| 542 | _capacity = Traits::createCapacityMap(*_graph); |
| 543 | } |
| 544 | if(!_cardinality) { |
| 545 | local_cardinality = true; |
| 546 | _cardinality = Traits::createCardinalityMap(*_graph); |
| 547 | } |
| 548 | if(!_processed) { |
| 549 | local_processed = true; |
| 550 | _processed = Traits::createProcessedMap(*_graph); |
| 551 | } |
| 552 | if (!_heap_cross_ref) { |
| 553 | local_heap_cross_ref = true; |
| 554 | _heap_cross_ref = Traits::createHeapCrossRef(*_graph); |
| 555 | } |
| 556 | if (!_heap) { |
| 557 | local_heap = true; |
| 558 | _heap = Traits::createHeap(*_heap_cross_ref); |
| 559 | } |
| 560 | } |
| 561 | |
| 562 | void finalizeNodeData(Node node, Value capacity) { |
| 563 | _processed->set(node, true); |
| 564 | _cardinality->set(node, capacity); |
| 565 | } |
| 566 | |
| 567 | public: |
| 568 | /// \name Execution control |
| 569 | /// The simplest way to execute the algorithm is to use |
| 570 | /// one of the member functions called \ref run(). |
| 571 | /// \n |
| 572 | /// If you need more control on the execution, |
| 573 | /// first you must call \ref init(), then you can add several source nodes |
| 574 | /// with \ref addSource(). |
| 575 | /// Finally \ref start() will perform the computation. |
| 576 | |
| 577 | ///@{ |
| 578 | |
| 579 | /// \brief Initializes the internal data structures. |
| 580 | /// |
| 581 | /// Initializes the internal data structures, and clears the heap. |
| 582 | void init() { |
| 583 | create_maps(); |
| 584 | _heap->clear(); |
| 585 | for (NodeIt it(*_graph) ; it != INVALID ; ++it) { |
| 586 | _processed->set(it, false); |
| 587 | _heap_cross_ref->set(it, Heap::PRE_HEAP); |
| 588 | } |
| 589 | } |
| 590 | |
| 591 | /// \brief Adds a new source node. |
| 592 | /// |
| 593 | /// Adds a new source node to the priority heap. |
| 594 | /// |
| 595 | /// It checks if the node has not yet been added to the heap. |
| 596 | void addSource(Node source, Value capacity = 0) { |
| 597 | if(_heap->state(source) == Heap::PRE_HEAP) { |
| 598 | _heap->push(source, capacity); |
| 599 | } |
| 600 | } |
| 601 | |
| 602 | /// \brief Processes the next node in the priority heap |
| 603 | /// |
| 604 | /// Processes the next node in the priority heap. |
| 605 | /// |
| 606 | /// \return The processed node. |
| 607 | /// |
| 608 | /// \warning The priority heap must not be empty! |
| 609 | Node processNextNode() { |
| 610 | Node node = _heap->top(); |
| 611 | finalizeNodeData(node, _heap->prio()); |
| 612 | _heap->pop(); |
| 613 | |
| 614 | for (InArcIt it(*_graph, node); it != INVALID; ++it) { |
| 615 | Node source = _graph->source(it); |
| 616 | switch (_heap->state(source)) { |
| 617 | case Heap::PRE_HEAP: |
| 618 | _heap->push(source, (*_capacity)[it]); |
| 619 | break; |
| 620 | case Heap::IN_HEAP: |
| 621 | _heap->decrease(source, (*_heap)[source] + (*_capacity)[it]); |
| 622 | break; |
| 623 | case Heap::POST_HEAP: |
| 624 | break; |
| 625 | } |
| 626 | } |
| 627 | return node; |
| 628 | } |
| 629 | |
| 630 | /// \brief Next node to be processed. |
| 631 | /// |
| 632 | /// Next node to be processed. |
| 633 | /// |
| 634 | /// \return The next node to be processed or INVALID if the |
| 635 | /// priority heap is empty. |
| 636 | Node nextNode() { |
| 637 | return !_heap->empty() ? _heap->top() : INVALID; |
| 638 | } |
| 639 | |
| 640 | /// \brief Returns \c false if there are nodes |
| 641 | /// to be processed in the priority heap |
| 642 | /// |
| 643 | /// Returns \c false if there are nodes |
| 644 | /// to be processed in the priority heap |
| 645 | bool emptyHeap() { return _heap->empty(); } |
| 646 | /// \brief Returns the number of the nodes to be processed |
| 647 | /// in the priority heap |
| 648 | /// |
| 649 | /// Returns the number of the nodes to be processed in the priority heap |
| 650 | int heapSize() { return _heap->size(); } |
| 651 | |
| 652 | /// \brief Executes the algorithm. |
| 653 | /// |
| 654 | /// Executes the algorithm. |
| 655 | /// |
| 656 | ///\pre init() must be called and at least one node should be added |
| 657 | /// with addSource() before using this function. |
| 658 | /// |
| 659 | /// This method runs the Maximum Cardinality Search algorithm from the |
| 660 | /// source node(s). |
| 661 | void start() { |
| 662 | while ( !_heap->empty() ) processNextNode(); |
| 663 | } |
| 664 | |
| 665 | /// \brief Executes the algorithm until \c dest is reached. |
| 666 | /// |
| 667 | /// Executes the algorithm until \c dest is reached. |
| 668 | /// |
| 669 | /// \pre init() must be called and at least one node should be added |
| 670 | /// with addSource() before using this function. |
| 671 | /// |
| 672 | /// This method runs the %MaxCardinalitySearch algorithm from the source |
| 673 | /// nodes. |
| 674 | void start(Node dest) { |
| 675 | while ( !_heap->empty() && _heap->top()!=dest ) processNextNode(); |
| 676 | if ( !_heap->empty() ) finalizeNodeData(_heap->top(), _heap->prio()); |
| 677 | } |
| 678 | |
| 679 | /// \brief Executes the algorithm until a condition is met. |
| 680 | /// |
| 681 | /// Executes the algorithm until a condition is met. |
| 682 | /// |
| 683 | /// \pre init() must be called and at least one node should be added |
| 684 | /// with addSource() before using this function. |
| 685 | /// |
| 686 | /// \param nm must be a bool (or convertible) node map. The algorithm |
| 687 | /// will stop when it reaches a node \c v with <tt>nm[v]==true</tt>. |
| 688 | template <typename NodeBoolMap> |
| 689 | void start(const NodeBoolMap &nm) { |
| 690 | while ( !_heap->empty() && !nm[_heap->top()] ) processNextNode(); |
| 691 | if ( !_heap->empty() ) finalizeNodeData(_heap->top(),_heap->prio()); |
| 692 | } |
| 693 | |
| 694 | /// \brief Runs the maximum cardinality search algorithm from node \c s. |
| 695 | /// |
| 696 | /// This method runs the %MaxCardinalitySearch algorithm from a root |
| 697 | /// node \c s. |
| 698 | /// |
| 699 | ///\note d.run(s) is just a shortcut of the following code. |
| 700 | ///\code |
| 701 | /// d.init(); |
| 702 | /// d.addSource(s); |
| 703 | /// d.start(); |
| 704 | ///\endcode |
| 705 | void run(Node s) { |
| 706 | init(); |
| 707 | addSource(s); |
| 708 | start(); |
| 709 | } |
| 710 | |
| 711 | /// \brief Runs the maximum cardinality search algorithm for the |
| 712 | /// whole digraph. |
| 713 | /// |
| 714 | /// This method runs the %MaxCardinalitySearch algorithm from all |
| 715 | /// unprocessed node of the digraph. |
| 716 | /// |
| 717 | ///\note d.run(s) is just a shortcut of the following code. |
| 718 | ///\code |
| 719 | /// d.init(); |
| 720 | /// for (NodeIt it(digraph); it != INVALID; ++it) { |
| 721 | /// if (!d.reached(it)) { |
| 722 | /// d.addSource(s); |
| 723 | /// d.start(); |
| 724 | /// } |
| 725 | /// } |
| 726 | ///\endcode |
| 727 | void run() { |
| 728 | init(); |
| 729 | for (NodeIt it(*_graph); it != INVALID; ++it) { |
| 730 | if (!reached(it)) { |
| 731 | addSource(it); |
| 732 | start(); |
| 733 | } |
| 734 | } |
| 735 | } |
| 736 | |
| 737 | ///@} |
| 738 | |
| 739 | /// \name Query Functions |
| 740 | /// The results of the maximum cardinality search algorithm can be |
| 741 | /// obtained using these functions. |
| 742 | /// \n |
| 743 | /// Before the use of these functions, either run() or start() must be |
| 744 | /// called. |
| 745 | |
| 746 | ///@{ |
| 747 | |
| 748 | /// \brief The cardinality of a node. |
| 749 | /// |
| 750 | /// Returns the cardinality of a node. |
| 751 | /// \pre \ref run() must be called before using this function. |
| 752 | /// \warning If node \c v in unreachable from the root the return value |
| 753 | /// of this funcion is undefined. |
| 754 | Value cardinality(Node node) const { return (*_cardinality)[node]; } |
| 755 | |
| 756 | /// \brief The current cardinality of a node. |
| 757 | /// |
| 758 | /// Returns the current cardinality of a node. |
| 759 | /// \pre the given node should be reached but not processed |
| 760 | Value currentCardinality(Node node) const { return (*_heap)[node]; } |
| 761 | |
| 762 | /// \brief Returns a reference to the NodeMap of cardinalities. |
| 763 | /// |
| 764 | /// Returns a reference to the NodeMap of cardinalities. \pre \ref run() |
| 765 | /// must be called before using this function. |
| 766 | const CardinalityMap &cardinalityMap() const { return *_cardinality;} |
| 767 | |
| 768 | /// \brief Checks if a node is reachable from the root. |
| 769 | /// |
| 770 | /// Returns \c true if \c v is reachable from the root. |
| 771 | /// \warning The source nodes are initated as unreached. |
| 772 | /// \pre \ref run() must be called before using this function. |
| 773 | bool reached(Node v) { return (*_heap_cross_ref)[v] != Heap::PRE_HEAP; } |
| 774 | |
| 775 | /// \brief Checks if a node is processed. |
| 776 | /// |
| 777 | /// Returns \c true if \c v is processed, i.e. the shortest |
| 778 | /// path to \c v has already found. |
| 779 | /// \pre \ref run() must be called before using this function. |
| 780 | bool processed(Node v) { return (*_heap_cross_ref)[v] == Heap::POST_HEAP; } |
| 781 | |
| 782 | ///@} |
| 783 | }; |
| 784 | |
| 785 | } |
| 786 | |
| 787 | #endif |