[1912] | 1 | /* -*- C++ -*- |
---|
| 2 | * |
---|
[1956] | 3 | * This file is a part of LEMON, a generic C++ optimization library |
---|
| 4 | * |
---|
| 5 | * Copyright (C) 2003-2006 |
---|
| 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
---|
[1912] | 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_FREDMAN_TARJAN_H |
---|
| 20 | #define LEMON_FREDMAN_TARJAN_H |
---|
| 21 | |
---|
| 22 | ///\ingroup spantree |
---|
| 23 | ///\file |
---|
| 24 | ///\brief FredmanTarjan algorithm to compute minimum spanning forest. |
---|
| 25 | |
---|
| 26 | #include <limits> |
---|
| 27 | #include <vector> |
---|
| 28 | |
---|
| 29 | #include <lemon/list_graph.h> |
---|
| 30 | #include <lemon/smart_graph.h> |
---|
| 31 | #include <lemon/fib_heap.h> |
---|
| 32 | #include <lemon/radix_sort.h> |
---|
| 33 | #include <lemon/invalid.h> |
---|
| 34 | #include <lemon/error.h> |
---|
| 35 | #include <lemon/maps.h> |
---|
| 36 | #include <lemon/traits.h> |
---|
| 37 | #include <lemon/graph_utils.h> |
---|
| 38 | |
---|
| 39 | #include <lemon/concept/ugraph.h> |
---|
| 40 | |
---|
| 41 | namespace lemon { |
---|
| 42 | |
---|
| 43 | ///Default traits class of FredmanTarjan class. |
---|
| 44 | |
---|
| 45 | ///Default traits class of FredmanTarjan class. |
---|
| 46 | ///\param GR Graph type. |
---|
| 47 | ///\param LM Type of cost map. |
---|
| 48 | template<class GR, class LM> |
---|
| 49 | struct FredmanTarjanDefaultTraits{ |
---|
| 50 | ///The graph type the algorithm runs on. |
---|
| 51 | typedef GR UGraph; |
---|
| 52 | ///The type of the map that stores the edge costs. |
---|
| 53 | |
---|
| 54 | ///The type of the map that stores the edge costs. |
---|
| 55 | ///It must meet the \ref concept::ReadMap "ReadMap" concept. |
---|
| 56 | typedef LM CostMap; |
---|
| 57 | //The type of the cost of the edges. |
---|
| 58 | typedef typename LM::Value Value; |
---|
| 59 | ///The type of the map that stores whether an edge is in the |
---|
| 60 | ///spanning tree or not. |
---|
| 61 | |
---|
| 62 | ///The type of the map that stores whether an edge is in the |
---|
| 63 | ///spanning tree or not. |
---|
| 64 | ///It must meet the \ref concept::ReadWriteMap "ReadWriteMap" concept. |
---|
| 65 | ///By default it is a BoolEdgeMap. |
---|
| 66 | typedef typename UGraph::template UEdgeMap<bool> TreeMap; |
---|
| 67 | ///Instantiates a TreeMap. |
---|
| 68 | |
---|
| 69 | ///This function instantiates a \ref TreeMap. |
---|
[1946] | 70 | ///\param _graph is the graph, to which |
---|
[1912] | 71 | ///we would like to define the \ref TreeMap |
---|
| 72 | static TreeMap *createTreeMap(const GR &_graph){ |
---|
| 73 | return new TreeMap(_graph); |
---|
| 74 | } |
---|
| 75 | }; |
---|
| 76 | |
---|
| 77 | ///%FredmanTarjan algorithm class to find a minimum spanning tree. |
---|
| 78 | |
---|
| 79 | /// \ingroup spantree |
---|
| 80 | ///This class provides an efficient implementation of %FredmanTarjan algorithm |
---|
| 81 | ///whitch is sometimes a bit quicker than the Prim algorithm on larger graphs. |
---|
| 82 | ///Due to the structure of the algorithm, it has less controll functions than |
---|
| 83 | ///Prim. |
---|
| 84 | /// |
---|
| 85 | ///The running time is O(e*B(e,n)) where e is the number of edges, n is the |
---|
| 86 | ///number of nodes in the graph and B(e,n) is min { i | log^(i) n <= e/n} |
---|
| 87 | ///( log^(i+1) n = log(log^(i)) n ) |
---|
| 88 | /// |
---|
| 89 | ///The edge costs are passed to the algorithm using a |
---|
| 90 | ///\ref concept::ReadMap "ReadMap", |
---|
| 91 | ///so it is easy to change it to any kind of cost. |
---|
| 92 | /// |
---|
| 93 | ///The type of the cost is determined by the |
---|
| 94 | ///\ref concept::ReadMap::Value "Value" of the cost map. |
---|
| 95 | /// |
---|
| 96 | ///\param GR The graph type the algorithm runs on. The default value |
---|
| 97 | ///is \ref ListUGraph. The value of GR is not used directly by |
---|
| 98 | ///FredmanTarjan, it is only passed to \ref FredmanTarjanDefaultTraits. |
---|
| 99 | /// |
---|
| 100 | ///\param LM This read-only UEdgeMap determines the costs of the |
---|
| 101 | ///edges. It is read once for each edge, so the map may involve in |
---|
| 102 | ///relatively time consuming process to compute the edge cost if |
---|
| 103 | ///it is necessary. The default map type is \ref |
---|
| 104 | ///concept::UGraph::UEdgeMap "UGraph::UEdgeMap<int>". The value |
---|
| 105 | ///of LM is not used directly by FredmanTarjan, it is only passed to \ref |
---|
| 106 | ///FredmanTarjanDefaultTraits. |
---|
| 107 | /// |
---|
| 108 | ///\param TR Traits class to set |
---|
| 109 | ///various data types used by the algorithm. The default traits |
---|
| 110 | ///class is \ref FredmanTarjanDefaultTraits |
---|
| 111 | ///"FredmanTarjanDefaultTraits<GR,LM>". See \ref |
---|
| 112 | ///FredmanTarjanDefaultTraits for the documentation of a FredmanTarjan traits |
---|
| 113 | ///class. |
---|
| 114 | /// |
---|
| 115 | ///\author Balazs Attila Mihaly |
---|
| 116 | |
---|
| 117 | #ifdef DOXYGEN |
---|
| 118 | template <typename GR, |
---|
| 119 | typename LM, |
---|
| 120 | typename TR> |
---|
| 121 | #else |
---|
| 122 | template <typename GR=ListUGraph, |
---|
| 123 | typename LM=typename GR::template UEdgeMap<int>, |
---|
| 124 | typename TR=FredmanTarjanDefaultTraits<GR,LM> > |
---|
| 125 | #endif |
---|
| 126 | class FredmanTarjan { |
---|
| 127 | public: |
---|
| 128 | /** |
---|
| 129 | * \brief \ref Exception for uninitialized parameters. |
---|
| 130 | * |
---|
| 131 | * This error represents problems in the initialization |
---|
| 132 | * of the parameters of the algorithms. |
---|
| 133 | */ |
---|
| 134 | class UninitializedParameter : public lemon::UninitializedParameter { |
---|
| 135 | public: |
---|
| 136 | virtual const char* exceptionName() const { |
---|
| 137 | return "lemon::FredmanTarjan::UninitializedParameter"; |
---|
| 138 | } |
---|
| 139 | }; |
---|
| 140 | |
---|
| 141 | typedef GR Graph; |
---|
| 142 | typedef TR Traits; |
---|
| 143 | ///The type of the underlying graph. |
---|
| 144 | typedef typename TR::UGraph UGraph; |
---|
| 145 | ///\e |
---|
| 146 | typedef typename UGraph::Node Node; |
---|
| 147 | ///\e |
---|
| 148 | typedef typename UGraph::NodeIt NodeIt; |
---|
| 149 | ///\e |
---|
| 150 | typedef typename UGraph::UEdge UEdge; |
---|
| 151 | ///\e |
---|
| 152 | typedef typename UGraph::UEdgeIt UEdgeIt; |
---|
| 153 | ///\e |
---|
| 154 | typedef typename UGraph::IncEdgeIt IncEdgeIt; |
---|
| 155 | |
---|
| 156 | ///The type of the cost of the edges. |
---|
| 157 | typedef typename TR::CostMap::Value Value; |
---|
| 158 | ///The type of the map that stores the edge costs. |
---|
| 159 | typedef typename TR::CostMap CostMap; |
---|
| 160 | ///Edges of the spanning tree. |
---|
| 161 | typedef typename TR::TreeMap TreeMap; |
---|
| 162 | private: |
---|
| 163 | ///Pointer to the underlying graph. |
---|
| 164 | const UGraph *graph; |
---|
| 165 | ///Pointer to the cost map |
---|
| 166 | const CostMap *cost; |
---|
| 167 | ///Pointer to the map of tree edges. |
---|
| 168 | TreeMap *_tree; |
---|
| 169 | ///Indicates if \ref _tree is locally allocated (\c true) or not. |
---|
| 170 | bool local_tree; |
---|
| 171 | |
---|
| 172 | ///Creates the maps if necessary. |
---|
| 173 | |
---|
| 174 | void create_maps(){ |
---|
| 175 | if(!_tree){ |
---|
| 176 | local_tree=true; |
---|
| 177 | _tree=Traits::createTreeMap(*graph); |
---|
| 178 | } |
---|
| 179 | } |
---|
| 180 | |
---|
| 181 | public : |
---|
| 182 | |
---|
| 183 | typedef FredmanTarjan Create; |
---|
| 184 | |
---|
| 185 | ///\name Named template parameters |
---|
| 186 | |
---|
| 187 | ///@{ |
---|
| 188 | |
---|
| 189 | template <class TM> |
---|
| 190 | struct DefTreeMapTraits : public Traits { |
---|
| 191 | typedef TM TreeMap; |
---|
| 192 | static TreeMap *createTreeMap(const UGraph &) { |
---|
| 193 | throw UninitializedParameter(); |
---|
| 194 | } |
---|
| 195 | }; |
---|
| 196 | ///\ref named-templ-param "Named parameter" for setting TreeMap |
---|
| 197 | |
---|
| 198 | ///\ref named-templ-param "Named parameter" for setting TreeMap |
---|
| 199 | /// |
---|
| 200 | template <class TM> |
---|
| 201 | struct DefTreeMap |
---|
| 202 | : public FredmanTarjan< UGraph, CostMap, DefTreeMapTraits<TM> > { |
---|
| 203 | typedef FredmanTarjan< UGraph, CostMap, DefTreeMapTraits<TM> > Create; |
---|
| 204 | }; |
---|
| 205 | |
---|
| 206 | ///@} |
---|
| 207 | |
---|
| 208 | |
---|
| 209 | protected: |
---|
| 210 | |
---|
| 211 | FredmanTarjan() {} |
---|
| 212 | |
---|
| 213 | private: |
---|
| 214 | |
---|
| 215 | template<class SrcGraph,class OrigMap,class Heap,class ProcessedMap,class PredMap> |
---|
| 216 | void processNextTree(const SrcGraph& graph,const OrigMap& orig,Heap &heap, |
---|
| 217 | ProcessedMap& processed,PredMap& pred,int& tree_counter,const int limit){ |
---|
| 218 | std::vector<typename SrcGraph::Node> tree_nodes; |
---|
| 219 | int tree_index=tree_counter; |
---|
| 220 | bool stop=false; |
---|
| 221 | while(!heap.empty() && !stop){ |
---|
| 222 | typename SrcGraph::Node v=heap.top(); |
---|
| 223 | heap.pop(); |
---|
| 224 | if(processed[v]!=-1){ |
---|
| 225 | heap.state(v,Heap::PRE_HEAP); |
---|
| 226 | tree_index=processed[v]; |
---|
| 227 | _tree->set(orig[pred[v]],true); |
---|
| 228 | stop=true; |
---|
| 229 | break; |
---|
| 230 | } |
---|
| 231 | tree_nodes.push_back(v); |
---|
| 232 | for(typename SrcGraph::IncEdgeIt e(graph,v);e!=INVALID;++e){ |
---|
| 233 | typename SrcGraph::Node w=graph.oppositeNode(v,e); |
---|
| 234 | switch(heap.state(w)){ |
---|
| 235 | case Heap::PRE_HEAP: |
---|
| 236 | if(heap.size()>=limit){ |
---|
| 237 | stop=true; |
---|
| 238 | } |
---|
| 239 | else{ |
---|
| 240 | heap.push(w,(*cost)[orig[e]]); |
---|
| 241 | pred.set(w,e); |
---|
| 242 | } |
---|
| 243 | break; |
---|
| 244 | case Heap::IN_HEAP: |
---|
| 245 | if ((*cost)[orig[e]]<heap[w]){ |
---|
| 246 | heap.decrease(w,(*cost)[orig[e]]); |
---|
| 247 | pred.set(w,e); |
---|
| 248 | } |
---|
| 249 | break; |
---|
| 250 | case Heap::POST_HEAP: |
---|
| 251 | break; |
---|
| 252 | } |
---|
| 253 | } |
---|
| 254 | } |
---|
| 255 | for(int i=1;i<(int)tree_nodes.size();++i){ |
---|
| 256 | _tree->set(orig[pred[tree_nodes[i]]],true); |
---|
| 257 | processed.set(tree_nodes[i],tree_index); |
---|
| 258 | heap.state(tree_nodes[i], Heap::PRE_HEAP); |
---|
| 259 | } |
---|
| 260 | processed.set(tree_nodes[0],tree_index); |
---|
| 261 | heap.state(tree_nodes[0],Heap::PRE_HEAP); |
---|
| 262 | while (!heap.empty()) { |
---|
| 263 | typename SrcGraph::Node v=heap.top(); |
---|
| 264 | heap.pop(); |
---|
| 265 | heap.state(v,Heap::PRE_HEAP); |
---|
| 266 | } |
---|
| 267 | if(!stop)++tree_counter; |
---|
| 268 | } |
---|
| 269 | |
---|
| 270 | template<class SrcGraph,class OrigMap,class ProcessedMap> |
---|
| 271 | void createTrees(const SrcGraph& graph,const OrigMap& orig, ProcessedMap& processed, |
---|
| 272 | int edgenum,int& tree_counter){ |
---|
| 273 | typedef typename SrcGraph::Node Node; |
---|
| 274 | typedef typename SrcGraph::UEdge UEdge; |
---|
| 275 | typedef typename SrcGraph::NodeIt NodeIt; |
---|
| 276 | typedef typename SrcGraph::template NodeMap<int> HeapCrossRef; |
---|
| 277 | typedef typename SrcGraph::template NodeMap<UEdge> PredMap; |
---|
| 278 | HeapCrossRef crossref(graph,-1); |
---|
| 279 | FibHeap<Node,Value,HeapCrossRef> heap(crossref); |
---|
| 280 | PredMap pred(graph,INVALID); |
---|
| 281 | int rate=2*edgenum/countNodes(graph); |
---|
| 282 | int limit=(rate>std::numeric_limits<int>::digits)?std::numeric_limits<int>::max():(1<<rate); |
---|
| 283 | for(NodeIt i(graph);i!=INVALID;++i){ |
---|
| 284 | if(processed[i]==-1){ |
---|
| 285 | heap.push(i, Value()); |
---|
| 286 | processNextTree(graph,orig,heap,processed,pred,tree_counter,limit); |
---|
| 287 | } |
---|
| 288 | } |
---|
| 289 | } |
---|
| 290 | |
---|
| 291 | template<class SrcGraph,class DestGraph,class SrcOrigMap,class DestOrigMap,class ProcessedMap> |
---|
| 292 | void collect(const SrcGraph& srcgraph,const SrcOrigMap& srcorig,DestGraph& destgraph, |
---|
| 293 | DestOrigMap& destorig,const ProcessedMap& processed,const int tree_counter){ |
---|
| 294 | typedef typename SrcGraph::Node Node; |
---|
| 295 | typedef typename DestGraph::Node DNode; |
---|
| 296 | typedef typename SrcGraph::UEdge UEdge; |
---|
| 297 | typedef typename DestGraph::UEdge DUEdge; |
---|
| 298 | typedef typename SrcGraph::Edge Edge; |
---|
| 299 | typedef typename SrcGraph::EdgeIt EdgeIt; |
---|
| 300 | std::vector<Edge> edges; |
---|
| 301 | std::vector<DNode> nodes(tree_counter, INVALID); |
---|
| 302 | for(EdgeIt i(srcgraph);i!=INVALID;++i){ |
---|
| 303 | if(processed[srcgraph.source(i)]<processed[srcgraph.target(i)]){ |
---|
| 304 | edges.push_back(i); |
---|
| 305 | if(nodes[processed[srcgraph.source(i)]]==INVALID) { |
---|
| 306 | nodes[processed[srcgraph.source(i)]]=destgraph.addNode(); |
---|
| 307 | } |
---|
| 308 | if(nodes[processed[srcgraph.target(i)]]==INVALID) { |
---|
| 309 | nodes[processed[srcgraph.target(i)]]=destgraph.addNode(); |
---|
| 310 | } |
---|
| 311 | } |
---|
| 312 | } |
---|
| 313 | |
---|
| 314 | radixSort(edges.begin(),edges.end(),mapFunctor(composeMap(processed,sourceMap(srcgraph)))); |
---|
| 315 | counterSort(edges.begin(),edges.end(),mapFunctor(composeMap(processed,targetMap(srcgraph)))); |
---|
| 316 | for(int i=0;i!=(int)edges.size();++i){ |
---|
| 317 | int srcproc=processed[srcgraph.source(edges[i])]; |
---|
| 318 | int trgproc=processed[srcgraph.target(edges[i])]; |
---|
| 319 | Value minval=(*cost)[srcorig[edges[i]]]; |
---|
| 320 | UEdge minpos=edges[i]; |
---|
| 321 | while (i+1!=(int)edges.size() && srcproc==processed[srcgraph.source(edges[i+1])] && |
---|
| 322 | trgproc==processed[srcgraph.target(edges[i+1])]) { |
---|
| 323 | if (minval>(*cost)[srcorig[edges[i+1]]]) { |
---|
| 324 | minval=(*cost)[srcorig[edges[i+1]]]; |
---|
| 325 | minpos=edges[i+1]; |
---|
| 326 | } |
---|
| 327 | ++i; |
---|
| 328 | } |
---|
| 329 | destorig[destgraph.addEdge(nodes[srcproc],nodes[trgproc])]=srcorig[minpos]; |
---|
| 330 | } |
---|
| 331 | } |
---|
| 332 | |
---|
| 333 | template<class SrcGraph,class OrigMap> |
---|
| 334 | void phase(const SrcGraph& graph,const OrigMap& orig,int edgenum){ |
---|
| 335 | int tree_counter = 0; |
---|
| 336 | typename SrcGraph::template NodeMap<int> processed(graph,-1); |
---|
| 337 | SmartUGraph destgraph; |
---|
| 338 | SmartUGraph::UEdgeMap<typename OrigMap::Value> destorig(destgraph); |
---|
| 339 | createTrees(graph,orig,processed,edgenum,tree_counter); |
---|
| 340 | collect(graph,orig,destgraph,destorig,processed,tree_counter); |
---|
| 341 | if (countNodes(destgraph)>1) { |
---|
| 342 | phase(destgraph,destorig,edgenum); |
---|
| 343 | } |
---|
| 344 | } |
---|
| 345 | |
---|
| 346 | public: |
---|
| 347 | |
---|
| 348 | ///Constructor. |
---|
| 349 | |
---|
| 350 | ///\param _graph the graph the algorithm will run on. |
---|
| 351 | ///\param _cost the cost map used by the algorithm. |
---|
| 352 | FredmanTarjan(const UGraph& _graph, const CostMap& _cost) : |
---|
| 353 | graph(&_graph), cost(&_cost), |
---|
| 354 | _tree(0), local_tree(false) |
---|
| 355 | { |
---|
| 356 | checkConcept<concept::UGraph, UGraph>(); |
---|
| 357 | } |
---|
| 358 | |
---|
| 359 | ///Destructor. |
---|
| 360 | ~FredmanTarjan(){ |
---|
| 361 | if(local_tree) delete _tree; |
---|
| 362 | } |
---|
| 363 | |
---|
| 364 | ///Sets the cost map. |
---|
| 365 | |
---|
| 366 | ///Sets the cost map. |
---|
| 367 | ///\return <tt> (*this) </tt> |
---|
| 368 | FredmanTarjan &costMap(const CostMap &m){ |
---|
| 369 | cost = &m; |
---|
| 370 | return *this; |
---|
| 371 | } |
---|
| 372 | |
---|
| 373 | ///Sets the map storing the tree edges. |
---|
| 374 | |
---|
| 375 | ///Sets the map storing the tree edges. |
---|
| 376 | ///If you don't use this function before calling \ref run(), |
---|
| 377 | ///it will allocate one. The destuctor deallocates this |
---|
| 378 | ///automatically allocated map, of course. |
---|
| 379 | ///By default this is a BoolEdgeMap. |
---|
| 380 | ///\return <tt> (*this) </tt> |
---|
| 381 | FredmanTarjan &treeMap(TreeMap &m){ |
---|
| 382 | if(local_tree) { |
---|
| 383 | delete _tree; |
---|
| 384 | local_tree=false; |
---|
| 385 | } |
---|
| 386 | _tree = &m; |
---|
| 387 | return *this; |
---|
| 388 | } |
---|
| 389 | |
---|
| 390 | public: |
---|
| 391 | ///\name Execution control |
---|
| 392 | ///The simplest way to execute the algorithm is to use |
---|
| 393 | ///one of the member functions called \c run(...). |
---|
| 394 | |
---|
| 395 | ///@{ |
---|
| 396 | |
---|
| 397 | ///Initializes the internal data structures. |
---|
| 398 | |
---|
| 399 | ///Initializes the internal data structures. |
---|
| 400 | /// |
---|
| 401 | void init(){ |
---|
| 402 | create_maps(); |
---|
| 403 | for(typename Graph::UEdgeIt i(*graph);i!=INVALID;++i){ |
---|
| 404 | _tree->set(i,false); |
---|
| 405 | } |
---|
| 406 | } |
---|
| 407 | |
---|
| 408 | ///Executes the algorithm. |
---|
| 409 | |
---|
| 410 | ///Executes the algorithm. |
---|
| 411 | /// |
---|
| 412 | ///\pre init() must be called and at least one node should be added |
---|
| 413 | ///with addSource() before using this function. |
---|
| 414 | /// |
---|
| 415 | ///This method runs the %FredmanTarjan algorithm from the node(s) |
---|
| 416 | ///in order to compute the |
---|
| 417 | ///minimum spanning tree. |
---|
| 418 | void start(){ |
---|
| 419 | phase(*graph,identityMap<UEdge>(),countEdges(*graph)); |
---|
| 420 | } |
---|
| 421 | |
---|
| 422 | ///Runs %FredmanTarjan algorithm. |
---|
| 423 | |
---|
| 424 | ///This method runs the %FredmanTarjan algorithm |
---|
| 425 | ///in order to compute the minimum spanning forest. |
---|
| 426 | /// |
---|
| 427 | ///\note ft.run() is just a shortcut of the following code. |
---|
| 428 | ///\code |
---|
| 429 | /// ft.init(); |
---|
| 430 | /// ft.start(); |
---|
| 431 | ///\endcode |
---|
| 432 | void run() { |
---|
| 433 | init(); |
---|
| 434 | start(); |
---|
| 435 | } |
---|
| 436 | |
---|
| 437 | ///@} |
---|
| 438 | |
---|
| 439 | ///\name Query Functions |
---|
| 440 | ///The result of the %FredmanTarjan algorithm can be obtained using these |
---|
| 441 | ///functions.\n |
---|
| 442 | ///Before the use of these functions, |
---|
| 443 | ///either run() or start() must be called. |
---|
| 444 | |
---|
| 445 | ///@{ |
---|
| 446 | |
---|
| 447 | ///Returns a reference to the tree edges map. |
---|
| 448 | |
---|
| 449 | ///Returns a reference to the TreeEdgeMap of the edges of the |
---|
| 450 | ///minimum spanning tree. The value of the map is \c true only if the |
---|
| 451 | ///edge is in the minimum spanning tree. |
---|
| 452 | /// |
---|
| 453 | ///\pre \ref run() or \ref start() must be called before using this |
---|
| 454 | ///function. |
---|
| 455 | const TreeMap &treeMap() const { return *_tree;} |
---|
| 456 | |
---|
| 457 | ///Sets the tree edges map. |
---|
| 458 | |
---|
| 459 | ///Sets the TreeMap of the edges of the minimum spanning tree. |
---|
| 460 | ///The map values belonging to the edges of the minimum |
---|
[1953] | 461 | ///spanning tree are set to \c tree_edge_value or \c true by default |
---|
[1912] | 462 | ///while the edge values not belonging to the minimum spanning tree are |
---|
| 463 | ///set to |
---|
[1953] | 464 | ///\c tree_default_value or \c false by default. |
---|
[1912] | 465 | /// |
---|
| 466 | ///\pre \ref run() or \ref start() must be called before using this |
---|
| 467 | ///function. |
---|
| 468 | |
---|
| 469 | template<class TreeMap> |
---|
| 470 | void treeEdges( |
---|
| 471 | TreeMap& tree, |
---|
| 472 | const typename TreeMap::Value& tree_edge_value=true, |
---|
| 473 | const typename TreeMap::Value& tree_default_value=false) const { |
---|
| 474 | for(typename UGraph::UEdgeIt i(*graph);i!=INVALID;++i){ |
---|
| 475 | (*_tree)[i]?tree.set(i,tree_edge_value):tree.set(i,tree_default_value); |
---|
| 476 | } |
---|
| 477 | } |
---|
| 478 | |
---|
| 479 | ///\brief Checks if an edge is in the spanning tree or not. |
---|
| 480 | |
---|
| 481 | ///Checks if an edge is in the spanning tree or not. |
---|
| 482 | ///\param e is the edge that will be checked |
---|
| 483 | ///\return \c true if e is in the spanning tree, \c false otherwise |
---|
| 484 | bool tree(UEdge e){ |
---|
| 485 | return (*_tree)[e]; |
---|
| 486 | } |
---|
| 487 | ///@} |
---|
| 488 | }; |
---|
| 489 | |
---|
| 490 | /// \ingroup spantree |
---|
| 491 | /// |
---|
| 492 | /// \brief Function type interface for FredmanTarjan algorithm. |
---|
| 493 | /// |
---|
| 494 | /// Function type interface for FredmanTarjan algorithm. |
---|
| 495 | /// \param graph the UGraph that the algorithm runs on |
---|
| 496 | /// \param cost the CostMap of the edges |
---|
| 497 | /// \retval tree the EdgeMap that contains whether an edge is in the |
---|
| 498 | /// spanning tree or not |
---|
| 499 | /// |
---|
| 500 | /// \sa Prim |
---|
| 501 | template<class Graph,class CostMap,class TreeMap> |
---|
| 502 | void fredmanTarjan(const Graph& graph, const CostMap& cost,TreeMap& tree){ |
---|
| 503 | typename FredmanTarjan<Graph,CostMap>::template DefTreeMap<TreeMap>:: |
---|
| 504 | Create ft(graph,cost); |
---|
| 505 | ft.treeMap(tree); |
---|
| 506 | ft.run(); |
---|
| 507 | }; |
---|
| 508 | |
---|
| 509 | } //END OF NAMESPACE LEMON |
---|
| 510 | |
---|
| 511 | #endif |
---|