COIN-OR::LEMON - Graph Library

source: lemon-0.x/lemon/graph_utils.h @ 2006:00d59f733817

Last change on this file since 2006:00d59f733817 was 2006:00d59f733817, checked in by Alpar Juttner, 14 years ago

Spellcheck

File size: 49.4 KB
Line 
1/* -*- C++ -*-
2 *
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
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_GRAPH_UTILS_H
20#define LEMON_GRAPH_UTILS_H
21
22#include <iterator>
23#include <vector>
24#include <map>
25#include <cmath>
26
27#include <lemon/bits/invalid.h>
28#include <lemon/bits/utility.h>
29#include <lemon/maps.h>
30#include <lemon/bits/traits.h>
31
32#include <lemon/bits/alteration_notifier.h>
33#include <lemon/bits/default_map.h>
34
35///\ingroup gutils
36///\file
37///\brief Graph utilities.
38///
39///
40
41
42namespace lemon {
43
44  /// \addtogroup gutils
45  /// @{
46
47  ///Creates convenience typedefs for the graph types and iterators
48
49  ///This \c \#define creates convenience typedefs for the following types
50  ///of \c Graph: \c Node,  \c NodeIt, \c Edge, \c EdgeIt, \c InEdgeIt,
51  ///\c OutEdgeIt,  \c BoolNodeMap,  \c IntNodeMap,  \c DoubleNodeMap,
52  ///\c BoolEdgeMap, \c IntEdgeMap,  \c DoubleEdgeMap. 
53  ///\note If \c G it a template parameter, it should be used in this way.
54  ///\code
55  ///  GRAPH_TYPEDEFS(typename G)
56  ///\endcode
57  ///
58  ///\warning There are no typedefs for the graph maps because of the lack of
59  ///template typedefs in C++.
60#define GRAPH_TYPEDEFS(Graph)                           \
61  typedef Graph::     Node      Node;                   \
62    typedef Graph::   NodeIt    NodeIt;                 \
63    typedef Graph::   Edge      Edge;                   \
64    typedef Graph::   EdgeIt    EdgeIt;                 \
65    typedef Graph:: InEdgeIt  InEdgeIt;                 \
66    typedef Graph::OutEdgeIt OutEdgeIt;                 
67//     typedef Graph::template NodeMap<bool> BoolNodeMap;             
68//     typedef Graph::template NodeMap<int> IntNodeMap;       
69//     typedef Graph::template NodeMap<double> DoubleNodeMap; 
70//     typedef Graph::template EdgeMap<bool> BoolEdgeMap;             
71//     typedef Graph::template EdgeMap<int> IntEdgeMap;       
72//     typedef Graph::template EdgeMap<double> DoubleEdgeMap;
73 
74  ///Creates convenience typedefs for the undirected graph types and iterators
75
76  ///This \c \#define creates the same convenience typedefs as defined by
77  ///\ref GRAPH_TYPEDEFS(Graph) and three more, namely it creates
78  ///\c UEdge, \c UEdgeIt, \c IncEdgeIt,
79  ///\c BoolUEdgeMap, \c IntUEdgeMap,  \c DoubleUEdgeMap. 
80  ///
81  ///\note If \c G it a template parameter, it should be used in this way.
82  ///\code
83  ///  UGRAPH_TYPEDEFS(typename G)
84  ///\endcode
85  ///
86  ///\warning There are no typedefs for the graph maps because of the lack of
87  ///template typedefs in C++.
88#define UGRAPH_TYPEDEFS(Graph)                          \
89  GRAPH_TYPEDEFS(Graph)                                         \
90    typedef Graph:: UEdge   UEdge;                      \
91    typedef Graph:: UEdgeIt UEdgeIt;                    \
92    typedef Graph:: IncEdgeIt   IncEdgeIt;                     
93//     typedef Graph::template UEdgeMap<bool> BoolUEdgeMap;     
94//     typedef Graph::template UEdgeMap<int> IntUEdgeMap;
95//     typedef Graph::template UEdgeMap<double> DoubleUEdgeMap;
96 
97
98
99  /// \brief Function to count the items in the graph.
100  ///
101  /// This function counts the items (nodes, edges etc) in the graph.
102  /// The complexity of the function is O(n) because
103  /// it iterates on all of the items.
104
105  template <typename Graph, typename ItemIt>
106  inline int countItems(const Graph& g) {
107    int num = 0;
108    for (ItemIt it(g); it != INVALID; ++it) {
109      ++num;
110    }
111    return num;
112  }
113
114  // Node counting:
115
116  template <typename Graph>
117  inline typename enable_if<typename Graph::NodeNumTag, int>::type
118  _countNodes(const Graph &g) {
119    return g.nodeNum();
120  }
121
122  template <typename Graph>
123  inline int _countNodes(Wrap<Graph> w) {
124    return countItems<Graph, typename Graph::NodeIt>(w.value);
125  }
126
127  /// \brief Function to count the nodes in the graph.
128  ///
129  /// This function counts the nodes in the graph.
130  /// The complexity of the function is O(n) but for some
131  /// graph structures it is specialized to run in O(1).
132  ///
133  /// \todo refer how to specialize it
134
135  template <typename Graph>
136  inline int countNodes(const Graph& g) {
137    return _countNodes<Graph>(g);
138  }
139
140  // Edge counting:
141
142  template <typename Graph>
143  inline typename enable_if<typename Graph::EdgeNumTag, int>::type
144  _countEdges(const Graph &g) {
145    return g.edgeNum();
146  }
147
148  template <typename Graph>
149  inline int _countEdges(Wrap<Graph> w) {
150    return countItems<Graph, typename Graph::EdgeIt>(w.value);
151  }
152
153  /// \brief Function to count the edges in the graph.
154  ///
155  /// This function counts the edges in the graph.
156  /// The complexity of the function is O(e) but for some
157  /// graph structures it is specialized to run in O(1).
158
159  template <typename Graph>
160  inline int countEdges(const Graph& g) {
161    return _countEdges<Graph>(g);
162  }
163
164  // Undirected edge counting:
165
166  template <typename Graph>
167  inline
168  typename enable_if<typename Graph::EdgeNumTag, int>::type
169  _countUEdges(const Graph &g) {
170    return g.uEdgeNum();
171  }
172
173  template <typename Graph>
174  inline int _countUEdges(Wrap<Graph> w) {
175    return countItems<Graph, typename Graph::UEdgeIt>(w.value);
176  }
177
178  /// \brief Function to count the undirected edges in the graph.
179  ///
180  /// This function counts the undirected edges in the graph.
181  /// The complexity of the function is O(e) but for some
182  /// graph structures it is specialized to run in O(1).
183
184  template <typename Graph>
185  inline int countUEdges(const Graph& g) {
186    return _countUEdges<Graph>(g);
187  }
188
189
190
191  template <typename Graph, typename DegIt>
192  inline int countNodeDegree(const Graph& _g, const typename Graph::Node& _n) {
193    int num = 0;
194    for (DegIt it(_g, _n); it != INVALID; ++it) {
195      ++num;
196    }
197    return num;
198  }
199
200  /// \brief Function to count the number of the out-edges from node \c n.
201  ///
202  /// This function counts the number of the out-edges from node \c n
203  /// in the graph. 
204  template <typename Graph>
205  inline int countOutEdges(const Graph& _g,  const typename Graph::Node& _n) {
206    return countNodeDegree<Graph, typename Graph::OutEdgeIt>(_g, _n);
207  }
208
209  /// \brief Function to count the number of the in-edges to node \c n.
210  ///
211  /// This function counts the number of the in-edges to node \c n
212  /// in the graph. 
213  template <typename Graph>
214  inline int countInEdges(const Graph& _g,  const typename Graph::Node& _n) {
215    return countNodeDegree<Graph, typename Graph::InEdgeIt>(_g, _n);
216  }
217
218  /// \brief Function to count the number of the inc-edges to node \c n.
219  ///
220  /// This function counts the number of the inc-edges to node \c n
221  /// in the graph. 
222  template <typename Graph>
223  inline int countIncEdges(const Graph& _g,  const typename Graph::Node& _n) {
224    return countNodeDegree<Graph, typename Graph::IncEdgeIt>(_g, _n);
225  }
226
227
228  template <typename Graph>
229  inline
230  typename enable_if<typename Graph::FindEdgeTag, typename Graph::Edge>::type
231  _findEdge(const Graph &g,
232            typename Graph::Node u, typename Graph::Node v,
233            typename Graph::Edge prev = INVALID) {
234    return g.findEdge(u, v, prev);
235  }
236
237  template <typename Graph>
238  inline typename Graph::Edge
239  _findEdge(Wrap<Graph> w,
240            typename Graph::Node u,
241            typename Graph::Node v,
242            typename Graph::Edge prev = INVALID) {
243    const Graph& g = w.value;
244    if (prev == INVALID) {
245      typename Graph::OutEdgeIt e(g, u);
246      while (e != INVALID && g.target(e) != v) ++e;
247      return e;
248    } else {
249      typename Graph::OutEdgeIt e(g, prev); ++e;
250      while (e != INVALID && g.target(e) != v) ++e;
251      return e;
252    }
253  }
254
255  /// \brief Finds an edge between two nodes of a graph.
256  ///
257  /// Finds an edge from node \c u to node \c v in graph \c g.
258  ///
259  /// If \c prev is \ref INVALID (this is the default value), then
260  /// it finds the first edge from \c u to \c v. Otherwise it looks for
261  /// the next edge from \c u to \c v after \c prev.
262  /// \return The found edge or \ref INVALID if there is no such an edge.
263  ///
264  /// Thus you can iterate through each edge from \c u to \c v as it follows.
265  ///\code
266  /// for(Edge e=findEdge(g,u,v);e!=INVALID;e=findEdge(g,u,v,e)) {
267  ///   ...
268  /// }
269  ///\endcode
270  // /// \todo We may want to use the "GraphBase"
271  // /// interface here...
272  template <typename Graph>
273  inline typename Graph::Edge findEdge(const Graph &g,
274                                       typename Graph::Node u,
275                                       typename Graph::Node v,
276                                       typename Graph::Edge prev = INVALID) {
277    return _findEdge<Graph>(g, u, v, prev);
278  }
279
280  /// \brief Iterator for iterating on edges connected the same nodes.
281  ///
282  /// Iterator for iterating on edges connected the same nodes. It is
283  /// higher level interface for the findEdge() function. You can
284  /// use it the following way:
285  ///\code
286  /// for (ConEdgeIt<Graph> it(g, src, trg); it != INVALID; ++it) {
287  ///   ...
288  /// }
289  ///\endcode
290  ///
291  /// \author Balazs Dezso
292  template <typename _Graph>
293  class ConEdgeIt : public _Graph::Edge {
294  public:
295
296    typedef _Graph Graph;
297    typedef typename Graph::Edge Parent;
298
299    typedef typename Graph::Edge Edge;
300    typedef typename Graph::Node Node;
301
302    /// \brief Constructor.
303    ///
304    /// Construct a new ConEdgeIt iterating on the edges which
305    /// connects the \c u and \c v node.
306    ConEdgeIt(const Graph& g, Node u, Node v) : graph(g) {
307      Parent::operator=(findEdge(graph, u, v));
308    }
309
310    /// \brief Constructor.
311    ///
312    /// Construct a new ConEdgeIt which continues the iterating from
313    /// the \c e edge.
314    ConEdgeIt(const Graph& g, Edge e) : Parent(e), graph(g) {}
315   
316    /// \brief Increment operator.
317    ///
318    /// It increments the iterator and gives back the next edge.
319    ConEdgeIt& operator++() {
320      Parent::operator=(findEdge(graph, graph.source(*this),
321                                 graph.target(*this), *this));
322      return *this;
323    }
324  private:
325    const Graph& graph;
326  };
327
328  template <typename Graph>
329  inline
330  typename enable_if<
331    typename Graph::FindEdgeTag,
332    typename Graph::UEdge>::type
333  _findUEdge(const Graph &g,
334            typename Graph::Node u, typename Graph::Node v,
335            typename Graph::UEdge prev = INVALID) {
336    return g.findUEdge(u, v, prev);
337  }
338
339  template <typename Graph>
340  inline typename Graph::UEdge
341  _findUEdge(Wrap<Graph> w,
342            typename Graph::Node u,
343            typename Graph::Node v,
344            typename Graph::UEdge prev = INVALID) {
345    const Graph& g = w.value;
346    if (prev == INVALID) {
347      typename Graph::OutEdgeIt e(g, u);
348      while (e != INVALID && g.target(e) != v) ++e;
349      return e;
350    } else {
351      typename Graph::OutEdgeIt e(g, g.direct(prev, u)); ++e;
352      while (e != INVALID && g.target(e) != v) ++e;
353      return e;
354    }
355  }
356
357  /// \brief Finds an uedge between two nodes of a graph.
358  ///
359  /// Finds an uedge from node \c u to node \c v in graph \c g.
360  ///
361  /// If \c prev is \ref INVALID (this is the default value), then
362  /// it finds the first edge from \c u to \c v. Otherwise it looks for
363  /// the next edge from \c u to \c v after \c prev.
364  /// \return The found edge or \ref INVALID if there is no such an edge.
365  ///
366  /// Thus you can iterate through each edge from \c u to \c v as it follows.
367  ///\code
368  /// for(UEdge e = findUEdge(g,u,v); e != INVALID;
369  ///     e = findUEdge(g,u,v,e)) {
370  ///   ...
371  /// }
372  ///\endcode
373  // /// \todo We may want to use the "GraphBase"
374  // /// interface here...
375  template <typename Graph>
376  inline typename Graph::UEdge
377  findUEdge(const Graph &g,
378                typename Graph::Node u,
379                typename Graph::Node v,
380                typename Graph::UEdge prev = INVALID) {
381    return _findUEdge<Graph>(g, u, v, prev);
382  }
383
384  /// \brief Iterator for iterating on uedges connected the same nodes.
385  ///
386  /// Iterator for iterating on uedges connected the same nodes. It is
387  /// higher level interface for the findUEdge() function. You can
388  /// use it the following way:
389  ///\code
390  /// for (ConUEdgeIt<Graph> it(g, src, trg); it != INVALID; ++it) {
391  ///   ...
392  /// }
393  ///\endcode
394  ///
395  /// \author Balazs Dezso
396  template <typename _Graph>
397  class ConUEdgeIt : public _Graph::UEdge {
398  public:
399
400    typedef _Graph Graph;
401    typedef typename Graph::UEdge Parent;
402
403    typedef typename Graph::UEdge UEdge;
404    typedef typename Graph::Node Node;
405
406    /// \brief Constructor.
407    ///
408    /// Construct a new ConUEdgeIt iterating on the edges which
409    /// connects the \c u and \c v node.
410    ConUEdgeIt(const Graph& g, Node u, Node v) : graph(g) {
411      Parent::operator=(findUEdge(graph, u, v));
412    }
413
414    /// \brief Constructor.
415    ///
416    /// Construct a new ConUEdgeIt which continues the iterating from
417    /// the \c e edge.
418    ConUEdgeIt(const Graph& g, UEdge e) : Parent(e), graph(g) {}
419   
420    /// \brief Increment operator.
421    ///
422    /// It increments the iterator and gives back the next edge.
423    ConUEdgeIt& operator++() {
424      Parent::operator=(findUEdge(graph, graph.source(*this),
425                                      graph.target(*this), *this));
426      return *this;
427    }
428  private:
429    const Graph& graph;
430  };
431
432  /// \brief Copy a map.
433  ///
434  /// This function copies the \c source map to the \c target map. It uses the
435  /// given iterator to iterate on the data structure and it uses the \c ref
436  /// mapping to convert the source's keys to the target's keys.
437  template <typename Target, typename Source,
438            typename ItemIt, typename Ref>         
439  void copyMap(Target& target, const Source& source,
440               ItemIt it, const Ref& ref) {
441    for (; it != INVALID; ++it) {
442      target[ref[it]] = source[it];
443    }
444  }
445
446  /// \brief Copy the source map to the target map.
447  ///
448  /// Copy the \c source map to the \c target map. It uses the given iterator
449  /// to iterate on the data structure.
450  template <typename Target, typename Source, typename ItemIt>     
451  void copyMap(Target& target, const Source& source, ItemIt it) {
452    for (; it != INVALID; ++it) {
453      target[it] = source[it];
454    }
455  }
456
457  /// \brief Class to copy a graph.
458  ///
459  /// Class to copy a graph to another graph (duplicate a graph). The
460  /// simplest way of using it is through the \c copyGraph() function.
461  template <typename Target, typename Source>
462  class GraphCopy {
463  public:
464    typedef typename Source::Node Node;
465    typedef typename Source::NodeIt NodeIt;
466    typedef typename Source::Edge Edge;
467    typedef typename Source::EdgeIt EdgeIt;
468
469    typedef typename Source::template NodeMap<typename Target::Node>NodeRefMap;
470    typedef typename Source::template EdgeMap<typename Target::Edge>EdgeRefMap;
471
472    /// \brief Constructor for the GraphCopy.
473    ///
474    /// It copies the content of the \c _source graph into the
475    /// \c _target graph. It creates also two references, one beetween
476    /// the two nodeset and one beetween the two edgesets.
477    GraphCopy(Target& _target, const Source& _source)
478      : source(_source), target(_target),
479        nodeRefMap(_source), edgeRefMap(_source) {
480      for (NodeIt it(source); it != INVALID; ++it) {
481        nodeRefMap[it] = target.addNode();
482      }
483      for (EdgeIt it(source); it != INVALID; ++it) {
484        edgeRefMap[it] = target.addEdge(nodeRefMap[source.source(it)],
485                                        nodeRefMap[source.target(it)]);
486      }
487    }
488
489    /// \brief Copies the node references into the given map.
490    ///
491    /// Copies the node references into the given map.
492    template <typename NodeRef>
493    const GraphCopy& nodeRef(NodeRef& map) const {
494      for (NodeIt it(source); it != INVALID; ++it) {
495        map.set(it, nodeRefMap[it]);
496      }
497      return *this;
498    }
499
500    /// \brief Reverse and copies the node references into the given map.
501    ///
502    /// Reverse and copies the node references into the given map.
503    template <typename NodeRef>
504    const GraphCopy& nodeCrossRef(NodeRef& map) const {
505      for (NodeIt it(source); it != INVALID; ++it) {
506        map.set(nodeRefMap[it], it);
507      }
508      return *this;
509    }
510
511    /// \brief Copies the edge references into the given map.
512    ///
513    /// Copies the edge references into the given map.
514    template <typename EdgeRef>
515    const GraphCopy& edgeRef(EdgeRef& map) const {
516      for (EdgeIt it(source); it != INVALID; ++it) {
517        map.set(it, edgeRefMap[it]);
518      }
519      return *this;
520    }
521
522    /// \brief Reverse and copies the edge references into the given map.
523    ///
524    /// Reverse and copies the edge references into the given map.
525    template <typename EdgeRef>
526    const GraphCopy& edgeCrossRef(EdgeRef& map) const {
527      for (EdgeIt it(source); it != INVALID; ++it) {
528        map.set(edgeRefMap[it], it);
529      }
530      return *this;
531    }
532
533    /// \brief Make copy of the given map.
534    ///
535    /// Makes copy of the given map for the newly created graph.
536    /// The new map's key type is the target graph's node type,
537    /// and the copied map's key type is the source graph's node
538    /// type. 
539    template <typename TargetMap, typename SourceMap>
540    const GraphCopy& nodeMap(TargetMap& tMap, const SourceMap& sMap) const {
541      copyMap(tMap, sMap, NodeIt(source), nodeRefMap);
542      return *this;
543    }
544
545    /// \brief Make copy of the given map.
546    ///
547    /// Makes copy of the given map for the newly created graph.
548    /// The new map's key type is the target graph's edge type,
549    /// and the copied map's key type is the source graph's edge
550    /// type. 
551    template <typename TargetMap, typename SourceMap>
552    const GraphCopy& edgeMap(TargetMap& tMap, const SourceMap& sMap) const {
553      copyMap(tMap, sMap, EdgeIt(source), edgeRefMap);
554      return *this;
555    }
556
557    /// \brief Gives back the stored node references.
558    ///
559    /// Gives back the stored node references.
560    const NodeRefMap& nodeRef() const {
561      return nodeRefMap;
562    }
563
564    /// \brief Gives back the stored edge references.
565    ///
566    /// Gives back the stored edge references.
567    const EdgeRefMap& edgeRef() const {
568      return edgeRefMap;
569    }
570
571    void run() const {}
572
573  private:
574   
575    const Source& source;
576    Target& target;
577
578    NodeRefMap nodeRefMap;
579    EdgeRefMap edgeRefMap;
580  };
581
582  /// \brief Copy a graph to another graph.
583  ///
584  /// Copy a graph to another graph.
585  /// The usage of the function:
586  ///
587  ///\code
588  /// copyGraph(trg, src).nodeRef(nr).edgeCrossRef(ecr);
589  ///\endcode
590  ///
591  /// After the copy the \c nr map will contain the mapping from the
592  /// source graph's nodes to the target graph's nodes and the \c ecr will
593  /// contain the mapping from the target graph's edges to the source's
594  /// edges.
595  template <typename Target, typename Source>
596  GraphCopy<Target, Source> copyGraph(Target& target, const Source& source) {
597    return GraphCopy<Target, Source>(target, source);
598  }
599
600  /// \brief Class to copy an undirected graph.
601  ///
602  /// Class to copy an undirected graph to another graph (duplicate a graph).
603  /// The simplest way of using it is through the \c copyUGraph() function.
604  template <typename Target, typename Source>
605  class UGraphCopy {
606  public:
607    typedef typename Source::Node Node;
608    typedef typename Source::NodeIt NodeIt;
609    typedef typename Source::Edge Edge;
610    typedef typename Source::EdgeIt EdgeIt;
611    typedef typename Source::UEdge UEdge;
612    typedef typename Source::UEdgeIt UEdgeIt;
613
614    typedef typename Source::
615    template NodeMap<typename Target::Node> NodeRefMap;
616   
617    typedef typename Source::
618    template UEdgeMap<typename Target::UEdge> UEdgeRefMap;
619
620  private:
621
622    struct EdgeRefMap {
623      EdgeRefMap(UGraphCopy& _gc) : gc(_gc) {}
624      typedef typename Source::Edge Key;
625      typedef typename Target::Edge Value;
626
627      Value operator[](const Key& key) {
628        return gc.target.direct(gc.uEdgeRef[key],
629                                gc.target.direction(key));
630      }
631     
632      UGraphCopy& gc;
633    };
634   
635  public:
636
637    /// \brief Constructor for the UGraphCopy.
638    ///
639    /// It copies the content of the \c _source graph into the
640    /// \c _target graph. It creates also two references, one beetween
641    /// the two nodeset and one beetween the two edgesets.
642    UGraphCopy(Target& _target, const Source& _source)
643      : source(_source), target(_target),
644        nodeRefMap(_source), edgeRefMap(*this), uEdgeRefMap(_source) {
645      for (NodeIt it(source); it != INVALID; ++it) {
646        nodeRefMap[it] = target.addNode();
647      }
648      for (UEdgeIt it(source); it != INVALID; ++it) {
649        uEdgeRefMap[it] = target.addEdge(nodeRefMap[source.source(it)],
650                                        nodeRefMap[source.target(it)]);
651      }
652    }
653
654    /// \brief Copies the node references into the given map.
655    ///
656    /// Copies the node references into the given map.
657    template <typename NodeRef>
658    const UGraphCopy& nodeRef(NodeRef& map) const {
659      for (NodeIt it(source); it != INVALID; ++it) {
660        map.set(it, nodeRefMap[it]);
661      }
662      return *this;
663    }
664
665    /// \brief Reverse and copies the node references into the given map.
666    ///
667    /// Reverse and copies the node references into the given map.
668    template <typename NodeRef>
669    const UGraphCopy& nodeCrossRef(NodeRef& map) const {
670      for (NodeIt it(source); it != INVALID; ++it) {
671        map.set(nodeRefMap[it], it);
672      }
673      return *this;
674    }
675
676    /// \brief Copies the edge references into the given map.
677    ///
678    /// Copies the edge references into the given map.
679    template <typename EdgeRef>
680    const UGraphCopy& edgeRef(EdgeRef& map) const {
681      for (EdgeIt it(source); it != INVALID; ++it) {
682        map.set(edgeRefMap[it], it);
683      }
684      return *this;
685    }
686
687    /// \brief Reverse and copies the undirected edge references into the
688    /// given map.
689    ///
690    /// Reverse and copies the undirected edge references into the given map.
691    template <typename EdgeRef>
692    const UGraphCopy& edgeCrossRef(EdgeRef& map) const {
693      for (EdgeIt it(source); it != INVALID; ++it) {
694        map.set(it, edgeRefMap[it]);
695      }
696      return *this;
697    }
698
699    /// \brief Copies the undirected edge references into the given map.
700    ///
701    /// Copies the undirected edge references into the given map.
702    template <typename EdgeRef>
703    const UGraphCopy& uEdgeRef(EdgeRef& map) const {
704      for (UEdgeIt it(source); it != INVALID; ++it) {
705        map.set(it, uEdgeRefMap[it]);
706      }
707      return *this;
708    }
709
710    /// \brief Reverse and copies the undirected edge references into the
711    /// given map.
712    ///
713    /// Reverse and copies the undirected edge references into the given map.
714    template <typename EdgeRef>
715    const UGraphCopy& uEdgeCrossRef(EdgeRef& map) const {
716      for (UEdgeIt it(source); it != INVALID; ++it) {
717        map.set(uEdgeRefMap[it], it);
718      }
719      return *this;
720    }
721
722    /// \brief Make copy of the given map.
723    ///
724    /// Makes copy of the given map for the newly created graph.
725    /// The new map's key type is the target graph's node type,
726    /// and the copied map's key type is the source graph's node
727    /// type. 
728    template <typename TargetMap, typename SourceMap>
729    const UGraphCopy& nodeMap(TargetMap& tMap,
730                                  const SourceMap& sMap) const {
731      copyMap(tMap, sMap, NodeIt(source), nodeRefMap);
732      return *this;
733    }
734
735    /// \brief Make copy of the given map.
736    ///
737    /// Makes copy of the given map for the newly created graph.
738    /// The new map's key type is the target graph's edge type,
739    /// and the copied map's key type is the source graph's edge
740    /// type. 
741    template <typename TargetMap, typename SourceMap>
742    const UGraphCopy& edgeMap(TargetMap& tMap,
743                                  const SourceMap& sMap) const {
744      copyMap(tMap, sMap, EdgeIt(source), edgeRefMap);
745      return *this;
746    }
747
748    /// \brief Make copy of the given map.
749    ///
750    /// Makes copy of the given map for the newly created graph.
751    /// The new map's key type is the target graph's edge type,
752    /// and the copied map's key type is the source graph's edge
753    /// type. 
754    template <typename TargetMap, typename SourceMap>
755    const UGraphCopy& uEdgeMap(TargetMap& tMap,
756                                  const SourceMap& sMap) const {
757      copyMap(tMap, sMap, UEdgeIt(source), uEdgeRefMap);
758      return *this;
759    }
760
761    /// \brief Gives back the stored node references.
762    ///
763    /// Gives back the stored node references.
764    const NodeRefMap& nodeRef() const {
765      return nodeRefMap;
766    }
767
768    /// \brief Gives back the stored edge references.
769    ///
770    /// Gives back the stored edge references.
771    const EdgeRefMap& edgeRef() const {
772      return edgeRefMap;
773    }
774
775    /// \brief Gives back the stored uedge references.
776    ///
777    /// Gives back the stored uedge references.
778    const UEdgeRefMap& uEdgeRef() const {
779      return uEdgeRefMap;
780    }
781
782    void run() const {}
783
784  private:
785   
786    const Source& source;
787    Target& target;
788
789    NodeRefMap nodeRefMap;
790    EdgeRefMap edgeRefMap;
791    UEdgeRefMap uEdgeRefMap;
792  };
793
794  /// \brief Copy a graph to another graph.
795  ///
796  /// Copy a graph to another graph.
797  /// The usage of the function:
798  ///
799  ///\code
800  /// copyGraph(trg, src).nodeRef(nr).edgeCrossRef(ecr);
801  ///\endcode
802  ///
803  /// After the copy the \c nr map will contain the mapping from the
804  /// source graph's nodes to the target graph's nodes and the \c ecr will
805  /// contain the mapping from the target graph's edges to the source's
806  /// edges.
807  template <typename Target, typename Source>
808  UGraphCopy<Target, Source>
809  copyUGraph(Target& target, const Source& source) {
810    return UGraphCopy<Target, Source>(target, source);
811  }
812
813
814  /// @}
815
816  /// \addtogroup graph_maps
817  /// @{
818
819  /// Provides an immutable and unique id for each item in the graph.
820
821  /// The IdMap class provides a unique and immutable id for each item of the
822  /// same type (e.g. node) in the graph. This id is <ul><li>\b unique:
823  /// different items (nodes) get different ids <li>\b immutable: the id of an
824  /// item (node) does not change (even if you delete other nodes).  </ul>
825  /// Through this map you get access (i.e. can read) the inner id values of
826  /// the items stored in the graph. This map can be inverted with its member
827  /// class \c InverseMap.
828  ///
829  template <typename _Graph, typename _Item>
830  class IdMap {
831  public:
832    typedef _Graph Graph;
833    typedef int Value;
834    typedef _Item Item;
835    typedef _Item Key;
836
837    /// \brief Constructor.
838    ///
839    /// Constructor for creating id map.
840    IdMap(const Graph& _graph) : graph(&_graph) {}
841
842    /// \brief Gives back the \e id of the item.
843    ///
844    /// Gives back the immutable and unique \e id of the map.
845    int operator[](const Item& item) const { return graph->id(item);}
846
847
848  private:
849    const Graph* graph;
850
851  public:
852
853    /// \brief The class represents the inverse of its owner (IdMap).
854    ///
855    /// The class represents the inverse of its owner (IdMap).
856    /// \see inverse()
857    class InverseMap {
858    public:
859
860      /// \brief Constructor.
861      ///
862      /// Constructor for creating an id-to-item map.
863      InverseMap(const Graph& _graph) : graph(&_graph) {}
864
865      /// \brief Constructor.
866      ///
867      /// Constructor for creating an id-to-item map.
868      InverseMap(const IdMap& idMap) : graph(idMap.graph) {}
869
870      /// \brief Gives back the given item from its id.
871      ///
872      /// Gives back the given item from its id.
873      ///
874      Item operator[](int id) const { return graph->fromId(id, Item());}
875    private:
876      const Graph* graph;
877    };
878
879    /// \brief Gives back the inverse of the map.
880    ///
881    /// Gives back the inverse of the IdMap.
882    InverseMap inverse() const { return InverseMap(*graph);}
883
884  };
885
886 
887  /// \brief General invertable graph-map type.
888
889  /// This type provides simple invertable graph-maps.
890  /// The InvertableMap wraps an arbitrary ReadWriteMap
891  /// and if a key is set to a new value then store it
892  /// in the inverse map.
893  ///
894  /// The values of the map can be accessed
895  /// with stl compatible forward iterator.
896  ///
897  /// \param _Graph The graph type.
898  /// \param _Item The item type of the graph.
899  /// \param _Value The value type of the map.
900  ///
901  /// \see IterableValueMap
902#ifndef DOXYGEN
903  /// \param _Map A ReadWriteMap mapping from the item type to integer.
904  template <
905    typename _Graph, typename _Item, typename _Value,
906    typename _Map = DefaultMap<_Graph, _Item, _Value>
907  >
908#else
909  template <typename _Graph, typename _Item, typename _Value>
910#endif
911  class InvertableMap : protected _Map {
912  public:
913
914    /// The key type of InvertableMap (Node, Edge, UEdge).
915    typedef typename _Map::Key Key;
916    /// The value type of the InvertableMap.
917    typedef typename _Map::Value Value;
918
919  private:
920   
921    typedef _Map Map;
922    typedef _Graph Graph;
923
924    typedef std::map<Value, Key> Container;
925    Container invMap;   
926
927  public:
928 
929
930
931    /// \brief Constructor.
932    ///
933    /// Construct a new InvertableMap for the graph.
934    ///
935    InvertableMap(const Graph& graph) : Map(graph) {}
936
937    /// \brief Forward iterator for values.
938    ///
939    /// This iterator is an stl compatible forward
940    /// iterator on the values of the map. The values can
941    /// be accessed in the [beginValue, endValue) range.
942    ///
943    class ValueIterator
944      : public std::iterator<std::forward_iterator_tag, Value> {
945      friend class InvertableMap;
946    private:
947      ValueIterator(typename Container::const_iterator _it)
948        : it(_it) {}
949    public:
950     
951      ValueIterator() {}
952
953      ValueIterator& operator++() { ++it; return *this; }
954      ValueIterator operator++(int) {
955        ValueIterator tmp(*this);
956        operator++();
957        return tmp;
958      }
959
960      const Value& operator*() const { return it->first; }
961      const Value* operator->() const { return &(it->first); }
962
963      bool operator==(ValueIterator jt) const { return it == jt.it; }
964      bool operator!=(ValueIterator jt) const { return it != jt.it; }
965     
966    private:
967      typename Container::const_iterator it;
968    };
969
970    /// \brief Returns an iterator to the first value.
971    ///
972    /// Returns an stl compatible iterator to the
973    /// first value of the map. The values of the
974    /// map can be accessed in the [beginValue, endValue)
975    /// range.
976    ValueIterator beginValue() const {
977      return ValueIterator(invMap.begin());
978    }
979
980    /// \brief Returns an iterator after the last value.
981    ///
982    /// Returns an stl compatible iterator after the
983    /// last value of the map. The values of the
984    /// map can be accessed in the [beginValue, endValue)
985    /// range.
986    ValueIterator endValue() const {
987      return ValueIterator(invMap.end());
988    }
989   
990    /// \brief The setter function of the map.
991    ///
992    /// Sets the mapped value.
993    void set(const Key& key, const Value& val) {
994      Value oldval = Map::operator[](key);
995      typename Container::iterator it = invMap.find(oldval);
996      if (it != invMap.end() && it->second == key) {
997        invMap.erase(it);
998      }     
999      invMap.insert(make_pair(val, key));
1000      Map::set(key, val);
1001    }
1002
1003    /// \brief The getter function of the map.
1004    ///
1005    /// It gives back the value associated with the key.
1006    typename MapTraits<Map>::ConstReturnValue
1007    operator[](const Key& key) const {
1008      return Map::operator[](key);
1009    }
1010
1011  protected:
1012
1013    /// \brief Erase the key from the map.
1014    ///
1015    /// Erase the key to the map. It is called by the
1016    /// \c AlterationNotifier.
1017    virtual void erase(const Key& key) {
1018      Value val = Map::operator[](key);
1019      typename Container::iterator it = invMap.find(val);
1020      if (it != invMap.end() && it->second == key) {
1021        invMap.erase(it);
1022      }
1023      Map::erase(key);
1024    }
1025
1026    /// \brief Erase more keys from the map.
1027    ///
1028    /// Erase more keys from the map. It is called by the
1029    /// \c AlterationNotifier.
1030    virtual void erase(const std::vector<Key>& keys) {
1031      for (int i = 0; i < (int)keys.size(); ++i) {
1032        Value val = Map::operator[](keys[i]);
1033        typename Container::iterator it = invMap.find(val);
1034        if (it != invMap.end() && it->second == keys[i]) {
1035          invMap.erase(it);
1036        }
1037      }
1038      Map::erase(keys);
1039    }
1040
1041    /// \brief Clear the keys from the map and inverse map.
1042    ///
1043    /// Clear the keys from the map and inverse map. It is called by the
1044    /// \c AlterationNotifier.
1045    virtual void clear() {
1046      invMap.clear();
1047      Map::clear();
1048    }
1049
1050  public:
1051
1052    /// \brief The inverse map type.
1053    ///
1054    /// The inverse of this map. The subscript operator of the map
1055    /// gives back always the item what was last assigned to the value.
1056    class InverseMap {
1057    public:
1058      /// \brief Constructor of the InverseMap.
1059      ///
1060      /// Constructor of the InverseMap.
1061      InverseMap(const InvertableMap& _inverted) : inverted(_inverted) {}
1062
1063      /// The value type of the InverseMap.
1064      typedef typename InvertableMap::Key Value;
1065      /// The key type of the InverseMap.
1066      typedef typename InvertableMap::Value Key;
1067
1068      /// \brief Subscript operator.
1069      ///
1070      /// Subscript operator. It gives back always the item
1071      /// what was last assigned to the value.
1072      Value operator[](const Key& key) const {
1073        typename Container::const_iterator it = inverted.invMap.find(key);
1074        return it->second;
1075      }
1076     
1077    private:
1078      const InvertableMap& inverted;
1079    };
1080
1081    /// \brief It gives back the just readeable inverse map.
1082    ///
1083    /// It gives back the just readeable inverse map.
1084    InverseMap inverse() const {
1085      return InverseMap(*this);
1086    }
1087
1088
1089   
1090  };
1091
1092  /// \brief Provides a mutable, continuous and unique descriptor for each
1093  /// item in the graph.
1094  ///
1095  /// The DescriptorMap class provides a unique and continuous (but mutable)
1096  /// descriptor (id) for each item of the same type (e.g. node) in the
1097  /// graph. This id is <ul><li>\b unique: different items (nodes) get
1098  /// different ids <li>\b continuous: the range of the ids is the set of
1099  /// integers between 0 and \c n-1, where \c n is the number of the items of
1100  /// this type (e.g. nodes) (so the id of a node can change if you delete an
1101  /// other node, i.e. this id is mutable).  </ul> This map can be inverted
1102  /// with its member class \c InverseMap.
1103  ///
1104  /// \param _Graph The graph class the \c DescriptorMap belongs to.
1105  /// \param _Item The Item is the Key of the Map. It may be Node, Edge or
1106  /// UEdge.
1107#ifndef DOXYGEN
1108  /// \param _Map A ReadWriteMap mapping from the item type to integer.
1109  template <
1110    typename _Graph, typename _Item,
1111    typename _Map = DefaultMap<_Graph, _Item, int>
1112  >
1113#else
1114  template <typename _Graph, typename _Item>
1115#endif
1116  class DescriptorMap : protected _Map {
1117
1118    typedef _Item Item;
1119    typedef _Map Map;
1120
1121  public:
1122    /// The graph class of DescriptorMap.
1123    typedef _Graph Graph;
1124
1125    /// The key type of DescriptorMap (Node, Edge, UEdge).
1126    typedef typename _Map::Key Key;
1127    /// The value type of DescriptorMap.
1128    typedef typename _Map::Value Value;
1129
1130    /// \brief Constructor.
1131    ///
1132    /// Constructor for descriptor map.
1133    DescriptorMap(const Graph& _graph) : Map(_graph) {
1134      build();
1135    }
1136
1137  protected:
1138
1139    /// \brief Add a new key to the map.
1140    ///
1141    /// Add a new key to the map. It is called by the
1142    /// \c AlterationNotifier.
1143    virtual void add(const Item& item) {
1144      Map::add(item);
1145      Map::set(item, invMap.size());
1146      invMap.push_back(item);
1147    }
1148
1149    /// \brief Add more new keys to the map.
1150    ///
1151    /// Add more new keys to the map. It is called by the
1152    /// \c AlterationNotifier.
1153    virtual void add(const std::vector<Item>& items) {
1154      Map::add(items);
1155      for (int i = 0; i < (int)items.size(); ++i) {
1156        Map::set(items[i], invMap.size());
1157        invMap.push_back(items[i]);
1158      }
1159    }
1160
1161    /// \brief Erase the key from the map.
1162    ///
1163    /// Erase the key from the map. It is called by the
1164    /// \c AlterationNotifier.
1165    virtual void erase(const Item& item) {
1166      Map::set(invMap.back(), Map::operator[](item));
1167      invMap[Map::operator[](item)] = invMap.back();
1168      invMap.pop_back();
1169      Map::erase(item);
1170    }
1171
1172    /// \brief Erase more keys from the map.
1173    ///
1174    /// Erase more keys from the map. It is called by the
1175    /// \c AlterationNotifier.
1176    virtual void erase(const std::vector<Item>& items) {
1177      for (int i = 0; i < (int)items.size(); ++i) {
1178        Map::set(invMap.back(), Map::operator[](items[i]));
1179        invMap[Map::operator[](items[i])] = invMap.back();
1180        invMap.pop_back();
1181      }
1182      Map::erase(items);
1183    }
1184
1185    /// \brief Build the unique map.
1186    ///
1187    /// Build the unique map. It is called by the
1188    /// \c AlterationNotifier.
1189    virtual void build() {
1190      Map::build();
1191      Item it;
1192      const typename Map::Notifier* notifier = Map::getNotifier();
1193      for (notifier->first(it); it != INVALID; notifier->next(it)) {
1194        Map::set(it, invMap.size());
1195        invMap.push_back(it);   
1196      }     
1197    }
1198   
1199    /// \brief Clear the keys from the map.
1200    ///
1201    /// Clear the keys from the map. It is called by the
1202    /// \c AlterationNotifier.
1203    virtual void clear() {
1204      invMap.clear();
1205      Map::clear();
1206    }
1207
1208  public:
1209
1210    /// \brief Returns the maximal value plus one.
1211    ///
1212    /// Returns the maximal value plus one in the map.
1213    unsigned int size() const {
1214      return invMap.size();
1215    }
1216
1217    /// \brief Swaps the position of the two items in the map.
1218    ///
1219    /// Swaps the position of the two items in the map.
1220    void swap(const Item& p, const Item& q) {
1221      int pi = Map::operator[](p);
1222      int qi = Map::operator[](q);
1223      Map::set(p, qi);
1224      invMap[qi] = p;
1225      Map::set(q, pi);
1226      invMap[pi] = q;
1227    }
1228
1229    /// \brief Gives back the \e descriptor of the item.
1230    ///
1231    /// Gives back the mutable and unique \e descriptor of the map.
1232    int operator[](const Item& item) const {
1233      return Map::operator[](item);
1234    }
1235   
1236  private:
1237
1238    typedef std::vector<Item> Container;
1239    Container invMap;
1240
1241  public:
1242    /// \brief The inverse map type of DescriptorMap.
1243    ///
1244    /// The inverse map type of DescriptorMap.
1245    class InverseMap {
1246    public:
1247      /// \brief Constructor of the InverseMap.
1248      ///
1249      /// Constructor of the InverseMap.
1250      InverseMap(const DescriptorMap& _inverted)
1251        : inverted(_inverted) {}
1252
1253
1254      /// The value type of the InverseMap.
1255      typedef typename DescriptorMap::Key Value;
1256      /// The key type of the InverseMap.
1257      typedef typename DescriptorMap::Value Key;
1258
1259      /// \brief Subscript operator.
1260      ///
1261      /// Subscript operator. It gives back the item
1262      /// that the descriptor belongs to currently.
1263      Value operator[](const Key& key) const {
1264        return inverted.invMap[key];
1265      }
1266
1267      /// \brief Size of the map.
1268      ///
1269      /// Returns the size of the map.
1270      unsigned int size() const {
1271        return inverted.invMap.size();
1272      }
1273     
1274    private:
1275      const DescriptorMap& inverted;
1276    };
1277
1278    /// \brief Gives back the inverse of the map.
1279    ///
1280    /// Gives back the inverse of the map.
1281    const InverseMap inverse() const {
1282      return InverseMap(*this);
1283    }
1284  };
1285
1286  /// \brief Returns the source of the given edge.
1287  ///
1288  /// The SourceMap gives back the source Node of the given edge.
1289  /// \author Balazs Dezso
1290  template <typename Graph>
1291  class SourceMap {
1292  public:
1293
1294    typedef typename Graph::Node Value;
1295    typedef typename Graph::Edge Key;
1296
1297    /// \brief Constructor
1298    ///
1299    /// Constructor
1300    /// \param _graph The graph that the map belongs to.
1301    SourceMap(const Graph& _graph) : graph(_graph) {}
1302
1303    /// \brief The subscript operator.
1304    ///
1305    /// The subscript operator.
1306    /// \param edge The edge
1307    /// \return The source of the edge
1308    Value operator[](const Key& edge) const {
1309      return graph.source(edge);
1310    }
1311
1312  private:
1313    const Graph& graph;
1314  };
1315
1316  /// \brief Returns a \ref SourceMap class
1317  ///
1318  /// This function just returns an \ref SourceMap class.
1319  /// \relates SourceMap
1320  template <typename Graph>
1321  inline SourceMap<Graph> sourceMap(const Graph& graph) {
1322    return SourceMap<Graph>(graph);
1323  }
1324
1325  /// \brief Returns the target of the given edge.
1326  ///
1327  /// The TargetMap gives back the target Node of the given edge.
1328  /// \author Balazs Dezso
1329  template <typename Graph>
1330  class TargetMap {
1331  public:
1332
1333    typedef typename Graph::Node Value;
1334    typedef typename Graph::Edge Key;
1335
1336    /// \brief Constructor
1337    ///
1338    /// Constructor
1339    /// \param _graph The graph that the map belongs to.
1340    TargetMap(const Graph& _graph) : graph(_graph) {}
1341
1342    /// \brief The subscript operator.
1343    ///
1344    /// The subscript operator.
1345    /// \param e The edge
1346    /// \return The target of the edge
1347    Value operator[](const Key& e) const {
1348      return graph.target(e);
1349    }
1350
1351  private:
1352    const Graph& graph;
1353  };
1354
1355  /// \brief Returns a \ref TargetMap class
1356  ///
1357  /// This function just returns a \ref TargetMap class.
1358  /// \relates TargetMap
1359  template <typename Graph>
1360  inline TargetMap<Graph> targetMap(const Graph& graph) {
1361    return TargetMap<Graph>(graph);
1362  }
1363
1364  /// \brief Returns the "forward" directed edge view of an undirected edge.
1365  ///
1366  /// Returns the "forward" directed edge view of an undirected edge.
1367  /// \author Balazs Dezso
1368  template <typename Graph>
1369  class ForwardMap {
1370  public:
1371
1372    typedef typename Graph::Edge Value;
1373    typedef typename Graph::UEdge Key;
1374
1375    /// \brief Constructor
1376    ///
1377    /// Constructor
1378    /// \param _graph The graph that the map belongs to.
1379    ForwardMap(const Graph& _graph) : graph(_graph) {}
1380
1381    /// \brief The subscript operator.
1382    ///
1383    /// The subscript operator.
1384    /// \param key An undirected edge
1385    /// \return The "forward" directed edge view of undirected edge
1386    Value operator[](const Key& key) const {
1387      return graph.direct(key, true);
1388    }
1389
1390  private:
1391    const Graph& graph;
1392  };
1393
1394  /// \brief Returns a \ref ForwardMap class
1395  ///
1396  /// This function just returns an \ref ForwardMap class.
1397  /// \relates ForwardMap
1398  template <typename Graph>
1399  inline ForwardMap<Graph> forwardMap(const Graph& graph) {
1400    return ForwardMap<Graph>(graph);
1401  }
1402
1403  /// \brief Returns the "backward" directed edge view of an undirected edge.
1404  ///
1405  /// Returns the "backward" directed edge view of an undirected edge.
1406  /// \author Balazs Dezso
1407  template <typename Graph>
1408  class BackwardMap {
1409  public:
1410
1411    typedef typename Graph::Edge Value;
1412    typedef typename Graph::UEdge Key;
1413
1414    /// \brief Constructor
1415    ///
1416    /// Constructor
1417    /// \param _graph The graph that the map belongs to.
1418    BackwardMap(const Graph& _graph) : graph(_graph) {}
1419
1420    /// \brief The subscript operator.
1421    ///
1422    /// The subscript operator.
1423    /// \param key An undirected edge
1424    /// \return The "backward" directed edge view of undirected edge
1425    Value operator[](const Key& key) const {
1426      return graph.direct(key, false);
1427    }
1428
1429  private:
1430    const Graph& graph;
1431  };
1432
1433  /// \brief Returns a \ref BackwardMap class
1434
1435  /// This function just returns a \ref BackwardMap class.
1436  /// \relates BackwardMap
1437  template <typename Graph>
1438  inline BackwardMap<Graph> backwardMap(const Graph& graph) {
1439    return BackwardMap<Graph>(graph);
1440  }
1441
1442  /// \brief Potential difference map
1443  ///
1444  /// If there is an potential map on the nodes then we
1445  /// can get an edge map as we get the substraction of the
1446  /// values of the target and source.
1447  template <typename Graph, typename NodeMap>
1448  class PotentialDifferenceMap {
1449  public:
1450    typedef typename Graph::Edge Key;
1451    typedef typename NodeMap::Value Value;
1452
1453    /// \brief Constructor
1454    ///
1455    /// Contructor of the map
1456    PotentialDifferenceMap(const Graph& _graph, const NodeMap& _potential)
1457      : graph(_graph), potential(_potential) {}
1458
1459    /// \brief Const subscription operator
1460    ///
1461    /// Const subscription operator
1462    Value operator[](const Key& edge) const {
1463      return potential[graph.target(edge)] - potential[graph.source(edge)];
1464    }
1465
1466  private:
1467    const Graph& graph;
1468    const NodeMap& potential;
1469  };
1470
1471  /// \brief Just returns a PotentialDifferenceMap
1472  ///
1473  /// Just returns a PotentialDifferenceMap
1474  /// \relates PotentialDifferenceMap
1475  template <typename Graph, typename NodeMap>
1476  PotentialDifferenceMap<Graph, NodeMap>
1477  potentialDifferenceMap(const Graph& graph, const NodeMap& potential) {
1478    return PotentialDifferenceMap<Graph, NodeMap>(graph, potential);
1479  }
1480
1481  /// \brief Map of the node in-degrees.
1482  ///
1483  /// This map returns the in-degree of a node. Once it is constructed,
1484  /// the degrees are stored in a standard NodeMap, so each query is done
1485  /// in constant time. On the other hand, the values are updated automatically
1486  /// whenever the graph changes.
1487  ///
1488  /// \warning Besides addNode() and addEdge(), a graph structure may provide
1489  /// alternative ways to modify the graph. The correct behavior of InDegMap
1490  /// is not guarantied if these additional features are used. For example
1491  /// the functions \ref ListGraph::changeSource() "changeSource()",
1492  /// \ref ListGraph::changeTarget() "changeTarget()" and
1493  /// \ref ListGraph::reverseEdge() "reverseEdge()"
1494  /// of \ref ListGraph will \e not update the degree values correctly.
1495  ///
1496  /// \sa OutDegMap
1497
1498  template <typename _Graph>
1499  class InDegMap 
1500    : protected ItemSetTraits<_Graph, typename _Graph::Edge>
1501      ::ItemNotifier::ObserverBase {
1502
1503  public:
1504   
1505    typedef _Graph Graph;
1506    typedef int Value;
1507    typedef typename Graph::Node Key;
1508
1509    typedef typename ItemSetTraits<_Graph, typename _Graph::Edge>
1510    ::ItemNotifier::ObserverBase Parent;
1511
1512  private:
1513
1514    class AutoNodeMap : public DefaultMap<_Graph, Key, int> {
1515    public:
1516
1517      typedef DefaultMap<_Graph, Key, int> Parent;
1518      typedef typename Parent::Graph Graph;
1519
1520      AutoNodeMap(const Graph& graph) : Parent(graph, 0) {}
1521     
1522      virtual void add(const Key& key) {
1523        Parent::add(key);
1524        Parent::set(key, 0);
1525      }
1526
1527      virtual void add(const std::vector<Key>& keys) {
1528        Parent::add(keys);
1529        for (int i = 0; i < (int)keys.size(); ++i) {
1530          Parent::set(keys[i], 0);
1531        }
1532      }
1533    };
1534
1535  public:
1536
1537    /// \brief Constructor.
1538    ///
1539    /// Constructor for creating in-degree map.
1540    InDegMap(const Graph& _graph) : graph(_graph), deg(_graph) {
1541      Parent::attach(graph.getNotifier(typename _Graph::Edge()));
1542     
1543      for(typename _Graph::NodeIt it(graph); it != INVALID; ++it) {
1544        deg[it] = countInEdges(graph, it);
1545      }
1546    }
1547   
1548    /// Gives back the in-degree of a Node.
1549    int operator[](const Key& key) const {
1550      return deg[key];
1551    }
1552
1553  protected:
1554   
1555    typedef typename Graph::Edge Edge;
1556
1557    virtual void add(const Edge& edge) {
1558      ++deg[graph.target(edge)];
1559    }
1560
1561    virtual void add(const std::vector<Edge>& edges) {
1562      for (int i = 0; i < (int)edges.size(); ++i) {
1563        ++deg[graph.target(edges[i])];
1564      }
1565    }
1566
1567    virtual void erase(const Edge& edge) {
1568      --deg[graph.target(edge)];
1569    }
1570
1571    virtual void erase(const std::vector<Edge>& edges) {
1572      for (int i = 0; i < (int)edges.size(); ++i) {
1573        --deg[graph.target(edges[i])];
1574      }
1575    }
1576
1577    virtual void build() {
1578      for(typename _Graph::NodeIt it(graph); it != INVALID; ++it) {
1579        deg[it] = countInEdges(graph, it);
1580      }     
1581    }
1582
1583    virtual void clear() {
1584      for(typename _Graph::NodeIt it(graph); it != INVALID; ++it) {
1585        deg[it] = 0;
1586      }
1587    }
1588  private:
1589   
1590    const _Graph& graph;
1591    AutoNodeMap deg;
1592  };
1593
1594  /// \brief Map of the node out-degrees.
1595  ///
1596  /// This map returns the out-degree of a node. Once it is constructed,
1597  /// the degrees are stored in a standard NodeMap, so each query is done
1598  /// in constant time. On the other hand, the values are updated automatically
1599  /// whenever the graph changes.
1600  ///
1601  /// \warning Besides addNode() and addEdge(), a graph structure may provide
1602  /// alternative ways to modify the graph. The correct behavior of OutDegMap
1603  /// is not guarantied if these additional features are used. For example
1604  /// the functions \ref ListGraph::changeSource() "changeSource()",
1605  /// \ref ListGraph::changeTarget() "changeTarget()" and
1606  /// \ref ListGraph::reverseEdge() "reverseEdge()"
1607  /// of \ref ListGraph will \e not update the degree values correctly.
1608  ///
1609  /// \sa InDegMap
1610
1611  template <typename _Graph>
1612  class OutDegMap 
1613    : protected ItemSetTraits<_Graph, typename _Graph::Edge>
1614      ::ItemNotifier::ObserverBase {
1615
1616  public:
1617
1618    typedef typename ItemSetTraits<_Graph, typename _Graph::Edge>
1619    ::ItemNotifier::ObserverBase Parent;
1620   
1621    typedef _Graph Graph;
1622    typedef int Value;
1623    typedef typename Graph::Node Key;
1624
1625  private:
1626
1627    class AutoNodeMap : public DefaultMap<_Graph, Key, int> {
1628    public:
1629
1630      typedef DefaultMap<_Graph, Key, int> Parent;
1631      typedef typename Parent::Graph Graph;
1632
1633      AutoNodeMap(const Graph& graph) : Parent(graph, 0) {}
1634     
1635      virtual void add(const Key& key) {
1636        Parent::add(key);
1637        Parent::set(key, 0);
1638      }
1639      virtual void add(const std::vector<Key>& keys) {
1640        Parent::add(keys);
1641        for (int i = 0; i < (int)keys.size(); ++i) {
1642          Parent::set(keys[i], 0);
1643        }
1644      }
1645    };
1646
1647  public:
1648
1649    /// \brief Constructor.
1650    ///
1651    /// Constructor for creating out-degree map.
1652    OutDegMap(const Graph& _graph) : graph(_graph), deg(_graph) {
1653      Parent::attach(graph.getNotifier(typename _Graph::Edge()));
1654     
1655      for(typename _Graph::NodeIt it(graph); it != INVALID; ++it) {
1656        deg[it] = countOutEdges(graph, it);
1657      }
1658    }
1659
1660    /// Gives back the out-degree of a Node.
1661    int operator[](const Key& key) const {
1662      return deg[key];
1663    }
1664
1665  protected:
1666   
1667    typedef typename Graph::Edge Edge;
1668
1669    virtual void add(const Edge& edge) {
1670      ++deg[graph.source(edge)];
1671    }
1672
1673    virtual void add(const std::vector<Edge>& edges) {
1674      for (int i = 0; i < (int)edges.size(); ++i) {
1675        ++deg[graph.source(edges[i])];
1676      }
1677    }
1678
1679    virtual void erase(const Edge& edge) {
1680      --deg[graph.source(edge)];
1681    }
1682
1683    virtual void erase(const std::vector<Edge>& edges) {
1684      for (int i = 0; i < (int)edges.size(); ++i) {
1685        --deg[graph.source(edges[i])];
1686      }
1687    }
1688
1689    virtual void build() {
1690      for(typename _Graph::NodeIt it(graph); it != INVALID; ++it) {
1691        deg[it] = countOutEdges(graph, it);
1692      }     
1693    }
1694
1695    virtual void clear() {
1696      for(typename _Graph::NodeIt it(graph); it != INVALID; ++it) {
1697        deg[it] = 0;
1698      }
1699    }
1700  private:
1701   
1702    const _Graph& graph;
1703    AutoNodeMap deg;
1704  };
1705
1706
1707  /// @}
1708
1709} //END OF NAMESPACE LEMON
1710
1711#endif
Note: See TracBrowser for help on using the repository browser.