COIN-OR::LEMON - Graph Library

source: lemon-0.x/lemon/graph_utils.h @ 1946:17eb3eaad9f8

Last change on this file since 1946:17eb3eaad9f8 was 1946:17eb3eaad9f8, checked in by Alpar Juttner, 14 years ago
  • workaround for a Doxygen 1.4.6 bug
  • other doc fixes
File size: 49.6 KB
Line 
1/* -*- C++ -*-
2 * lemon/graph_utils.h - Part of LEMON, a generic C++ optimization library
3 *
4 * Copyright (C) 2006 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Research Group on Combinatorial Optimization, EGRES).
6 *
7 * Permission to use, modify and distribute this software is granted
8 * provided that this copyright notice appears in all copies. For
9 * precise terms see the accompanying LICENSE file.
10 *
11 * This software is provided "AS IS" with no warranty of any kind,
12 * express or implied, and with no claim as to its suitability for any
13 * purpose.
14 *
15 */
16
17#ifndef LEMON_GRAPH_UTILS_H
18#define LEMON_GRAPH_UTILS_H
19
20#include <iterator>
21#include <vector>
22#include <map>
23#include <cmath>
24
25#include <lemon/invalid.h>
26#include <lemon/utility.h>
27#include <lemon/maps.h>
28#include <lemon/traits.h>
29#include <lemon/bits/alteration_notifier.h>
30
31///\ingroup gutils
32///\file
33///\brief Graph utilities.
34///
35///
36
37
38namespace lemon {
39
40  /// \addtogroup gutils
41  /// @{
42
43  ///Creates convenience typedefs for the graph types and iterators
44
45  ///This \c \#define creates convenience typedefs for the following types
46  ///of \c Graph: \c Node,  \c NodeIt, \c Edge, \c EdgeIt, \c InEdgeIt,
47  ///\c OutEdgeIt,  \c BoolNodeMap,  \c IntNodeMap,  \c DoubleNodeMap,
48  ///\c BoolEdgeMap, \c IntEdgeMap,  \c DoubleEdgeMap. 
49  ///\note If \c G it a template parameter, it should be used in this way.
50  ///\code
51  ///  GRAPH_TYPEDEFS(typename G)
52  ///\endcode
53  ///
54  ///\warning There are no typedefs for the graph maps because of the lack of
55  ///template typedefs in C++.
56#define GRAPH_TYPEDEFS(Graph)                           \
57  typedef Graph::     Node      Node;                   \
58    typedef Graph::   NodeIt    NodeIt;                 \
59    typedef Graph::   Edge      Edge;                   \
60    typedef Graph::   EdgeIt    EdgeIt;                 \
61    typedef Graph:: InEdgeIt  InEdgeIt;                 \
62    typedef Graph::OutEdgeIt OutEdgeIt;                 
63//     typedef Graph::template NodeMap<bool> BoolNodeMap;             
64//     typedef Graph::template NodeMap<int> IntNodeMap;       
65//     typedef Graph::template NodeMap<double> DoubleNodeMap; 
66//     typedef Graph::template EdgeMap<bool> BoolEdgeMap;             
67//     typedef Graph::template EdgeMap<int> IntEdgeMap;       
68//     typedef Graph::template EdgeMap<double> DoubleEdgeMap;
69 
70  ///Creates convenience typedefs for the undirected graph types and iterators
71
72  ///This \c \#define creates the same convenience typedefs as defined by
73  ///\ref GRAPH_TYPEDEFS(Graph) and three more, namely it creates
74  ///\c UEdge, \c UEdgeIt, \c IncEdgeIt,
75  ///\c BoolUEdgeMap, \c IntUEdgeMap,  \c DoubleUEdgeMap. 
76  ///
77  ///\note If \c G it a template parameter, it should be used in this way.
78  ///\code
79  ///  UNDIRGRAPH_TYPEDEFS(typename G)
80  ///\endcode
81  ///
82  ///\warning There are no typedefs for the graph maps because of the lack of
83  ///template typedefs in C++.
84#define UNDIRGRAPH_TYPEDEFS(Graph)                              \
85  GRAPH_TYPEDEFS(Graph)                                         \
86    typedef Graph:: UEdge   UEdge;                      \
87    typedef Graph:: UEdgeIt UEdgeIt;                    \
88    typedef Graph:: IncEdgeIt   IncEdgeIt;                     
89//     typedef Graph::template UEdgeMap<bool> BoolUEdgeMap;     
90//     typedef Graph::template UEdgeMap<int> IntUEdgeMap;
91//     typedef Graph::template UEdgeMap<double> DoubleUEdgeMap;
92 
93
94
95  /// \brief Function to count the items in the graph.
96  ///
97  /// This function counts the items (nodes, edges etc) in the graph.
98  /// The complexity of the function is O(n) because
99  /// it iterates on all of the items.
100
101  template <typename Graph, typename ItemIt>
102  inline int countItems(const Graph& g) {
103    int num = 0;
104    for (ItemIt it(g); it != INVALID; ++it) {
105      ++num;
106    }
107    return num;
108  }
109
110  // Node counting:
111
112  template <typename Graph>
113  inline typename enable_if<typename Graph::NodeNumTag, int>::type
114  _countNodes(const Graph &g) {
115    return g.nodeNum();
116  }
117
118  template <typename Graph>
119  inline int _countNodes(Wrap<Graph> w) {
120    return countItems<Graph, typename Graph::NodeIt>(w.value);
121  }
122
123  /// \brief Function to count the nodes in the graph.
124  ///
125  /// This function counts the nodes in the graph.
126  /// The complexity of the function is O(n) but for some
127  /// graph structures it is specialized to run in O(1).
128  ///
129  /// \todo refer how to specialize it
130
131  template <typename Graph>
132  inline int countNodes(const Graph& g) {
133    return _countNodes<Graph>(g);
134  }
135
136  // Edge counting:
137
138  template <typename Graph>
139  inline typename enable_if<typename Graph::EdgeNumTag, int>::type
140  _countEdges(const Graph &g) {
141    return g.edgeNum();
142  }
143
144  template <typename Graph>
145  inline int _countEdges(Wrap<Graph> w) {
146    return countItems<Graph, typename Graph::EdgeIt>(w.value);
147  }
148
149  /// \brief Function to count the edges in the graph.
150  ///
151  /// This function counts the edges in the graph.
152  /// The complexity of the function is O(e) but for some
153  /// graph structures it is specialized to run in O(1).
154
155  template <typename Graph>
156  inline int countEdges(const Graph& g) {
157    return _countEdges<Graph>(g);
158  }
159
160  // Undirected edge counting:
161
162  template <typename Graph>
163  inline
164  typename enable_if<typename Graph::EdgeNumTag, int>::type
165  _countUEdges(const Graph &g) {
166    return g.uEdgeNum();
167  }
168
169  template <typename Graph>
170  inline int _countUEdges(Wrap<Graph> w) {
171    return countItems<Graph, typename Graph::UEdgeIt>(w.value);
172  }
173
174  /// \brief Function to count the undirected edges in the graph.
175  ///
176  /// This function counts the undirected edges in the graph.
177  /// The complexity of the function is O(e) but for some
178  /// graph structures it is specialized to run in O(1).
179
180  template <typename Graph>
181  inline int countUEdges(const Graph& g) {
182    return _countUEdges<Graph>(g);
183  }
184
185
186
187  template <typename Graph, typename DegIt>
188  inline int countNodeDegree(const Graph& _g, const typename Graph::Node& _n) {
189    int num = 0;
190    for (DegIt it(_g, _n); it != INVALID; ++it) {
191      ++num;
192    }
193    return num;
194  }
195
196  /// \brief Function to count the number of the out-edges from node \c n.
197  ///
198  /// This function counts the number of the out-edges from node \c n
199  /// in the graph. 
200  template <typename Graph>
201  inline int countOutEdges(const Graph& _g,  const typename Graph::Node& _n) {
202    return countNodeDegree<Graph, typename Graph::OutEdgeIt>(_g, _n);
203  }
204
205  /// \brief Function to count the number of the in-edges to node \c n.
206  ///
207  /// This function counts the number of the in-edges to node \c n
208  /// in the graph. 
209  template <typename Graph>
210  inline int countInEdges(const Graph& _g,  const typename Graph::Node& _n) {
211    return countNodeDegree<Graph, typename Graph::InEdgeIt>(_g, _n);
212  }
213
214  /// \brief Function to count the number of the inc-edges to node \c n.
215  ///
216  /// This function counts the number of the inc-edges to node \c n
217  /// in the graph. 
218  template <typename Graph>
219  inline int countIncEdges(const Graph& _g,  const typename Graph::Node& _n) {
220    return countNodeDegree<Graph, typename Graph::IncEdgeIt>(_g, _n);
221  }
222
223
224  template <typename Graph>
225  inline
226  typename enable_if<typename Graph::FindEdgeTag, typename Graph::Edge>::type
227  _findEdge(const Graph &g,
228            typename Graph::Node u, typename Graph::Node v,
229            typename Graph::Edge prev = INVALID) {
230    return g.findEdge(u, v, prev);
231  }
232
233  template <typename Graph>
234  inline typename Graph::Edge
235  _findEdge(Wrap<Graph> w,
236            typename Graph::Node u,
237            typename Graph::Node v,
238            typename Graph::Edge prev = INVALID) {
239    const Graph& g = w.value;
240    if (prev == INVALID) {
241      typename Graph::OutEdgeIt e(g, u);
242      while (e != INVALID && g.target(e) != v) ++e;
243      return e;
244    } else {
245      typename Graph::OutEdgeIt e(g, prev); ++e;
246      while (e != INVALID && g.target(e) != v) ++e;
247      return e;
248    }
249  }
250
251  /// \brief Finds an edge between two nodes of a graph.
252  ///
253  /// Finds an edge from node \c u to node \c v in graph \c g.
254  ///
255  /// If \c prev is \ref INVALID (this is the default value), then
256  /// it finds the first edge from \c u to \c v. Otherwise it looks for
257  /// the next edge from \c u to \c v after \c prev.
258  /// \return The found edge or \ref INVALID if there is no such an edge.
259  ///
260  /// Thus you can iterate through each edge from \c u to \c v as it follows.
261  ///\code
262  /// for(Edge e=findEdge(g,u,v);e!=INVALID;e=findEdge(g,u,v,e)) {
263  ///   ...
264  /// }
265  ///\endcode
266  // /// \todo We may want to use the "GraphBase"
267  // /// interface here...
268  template <typename Graph>
269  inline typename Graph::Edge findEdge(const Graph &g,
270                                       typename Graph::Node u,
271                                       typename Graph::Node v,
272                                       typename Graph::Edge prev = INVALID) {
273    return _findEdge<Graph>(g, u, v, prev);
274  }
275
276  /// \brief Iterator for iterating on edges connected the same nodes.
277  ///
278  /// Iterator for iterating on edges connected the same nodes. It is
279  /// higher level interface for the findEdge() function. You can
280  /// use it the following way:
281  ///\code
282  /// for (ConEdgeIt<Graph> it(g, src, trg); it != INVALID; ++it) {
283  ///   ...
284  /// }
285  ///\endcode
286  ///
287  /// \author Balazs Dezso
288  template <typename _Graph>
289  class ConEdgeIt : public _Graph::Edge {
290  public:
291
292    typedef _Graph Graph;
293    typedef typename Graph::Edge Parent;
294
295    typedef typename Graph::Edge Edge;
296    typedef typename Graph::Node Node;
297
298    /// \brief Constructor.
299    ///
300    /// Construct a new ConEdgeIt iterating on the edges which
301    /// connects the \c u and \c v node.
302    ConEdgeIt(const Graph& g, Node u, Node v) : graph(g) {
303      Parent::operator=(findEdge(graph, u, v));
304    }
305
306    /// \brief Constructor.
307    ///
308    /// Construct a new ConEdgeIt which continues the iterating from
309    /// the \c e edge.
310    ConEdgeIt(const Graph& g, Edge e) : Parent(e), graph(g) {}
311   
312    /// \brief Increment operator.
313    ///
314    /// It increments the iterator and gives back the next edge.
315    ConEdgeIt& operator++() {
316      Parent::operator=(findEdge(graph, graph.source(*this),
317                                 graph.target(*this), *this));
318      return *this;
319    }
320  private:
321    const Graph& graph;
322  };
323
324  template <typename Graph>
325  inline
326  typename enable_if<
327    typename Graph::FindEdgeTag,
328    typename Graph::UEdge>::type
329  _findUEdge(const Graph &g,
330            typename Graph::Node u, typename Graph::Node v,
331            typename Graph::UEdge prev = INVALID) {
332    return g.findUEdge(u, v, prev);
333  }
334
335  template <typename Graph>
336  inline typename Graph::UEdge
337  _findUEdge(Wrap<Graph> w,
338            typename Graph::Node u,
339            typename Graph::Node v,
340            typename Graph::UEdge prev = INVALID) {
341    const Graph& g = w.value;
342    if (prev == INVALID) {
343      typename Graph::OutEdgeIt e(g, u);
344      while (e != INVALID && g.target(e) != v) ++e;
345      return e;
346    } else {
347      typename Graph::OutEdgeIt e(g, g.direct(prev, u)); ++e;
348      while (e != INVALID && g.target(e) != v) ++e;
349      return e;
350    }
351  }
352
353  /// \brief Finds an uedge between two nodes of a graph.
354  ///
355  /// Finds an uedge from node \c u to node \c v in graph \c g.
356  ///
357  /// If \c prev is \ref INVALID (this is the default value), then
358  /// it finds the first edge from \c u to \c v. Otherwise it looks for
359  /// the next edge from \c u to \c v after \c prev.
360  /// \return The found edge or \ref INVALID if there is no such an edge.
361  ///
362  /// Thus you can iterate through each edge from \c u to \c v as it follows.
363  ///\code
364  /// for(UEdge e = findUEdge(g,u,v); e != INVALID;
365  ///     e = findUEdge(g,u,v,e)) {
366  ///   ...
367  /// }
368  ///\endcode
369  // /// \todo We may want to use the "GraphBase"
370  // /// interface here...
371  template <typename Graph>
372  inline typename Graph::UEdge
373  findUEdge(const Graph &g,
374                typename Graph::Node u,
375                typename Graph::Node v,
376                typename Graph::UEdge prev = INVALID) {
377    return _findUEdge<Graph>(g, u, v, prev);
378  }
379
380  /// \brief Iterator for iterating on uedges connected the same nodes.
381  ///
382  /// Iterator for iterating on uedges connected the same nodes. It is
383  /// higher level interface for the findUEdge() function. You can
384  /// use it the following way:
385  ///\code
386  /// for (ConUEdgeIt<Graph> it(g, src, trg); it != INVALID; ++it) {
387  ///   ...
388  /// }
389  ///\endcode
390  ///
391  /// \author Balazs Dezso
392  template <typename _Graph>
393  class ConUEdgeIt : public _Graph::UEdge {
394  public:
395
396    typedef _Graph Graph;
397    typedef typename Graph::UEdge Parent;
398
399    typedef typename Graph::UEdge UEdge;
400    typedef typename Graph::Node Node;
401
402    /// \brief Constructor.
403    ///
404    /// Construct a new ConUEdgeIt iterating on the edges which
405    /// connects the \c u and \c v node.
406    ConUEdgeIt(const Graph& g, Node u, Node v) : graph(g) {
407      Parent::operator=(findUEdge(graph, u, v));
408    }
409
410    /// \brief Constructor.
411    ///
412    /// Construct a new ConUEdgeIt which continues the iterating from
413    /// the \c e edge.
414    ConUEdgeIt(const Graph& g, UEdge e) : Parent(e), graph(g) {}
415   
416    /// \brief Increment operator.
417    ///
418    /// It increments the iterator and gives back the next edge.
419    ConUEdgeIt& operator++() {
420      Parent::operator=(findUEdge(graph, graph.source(*this),
421                                      graph.target(*this), *this));
422      return *this;
423    }
424  private:
425    const Graph& graph;
426  };
427
428  /// \brief Copy a map.
429  ///
430  /// This function copies the \c source map to the \c target map. It uses the
431  /// given iterator to iterate on the data structure and it uses the \c ref
432  /// mapping to convert the source's keys to the target's keys.
433  template <typename Target, typename Source,
434            typename ItemIt, typename Ref>         
435  void copyMap(Target& target, const Source& source,
436               ItemIt it, const Ref& ref) {
437    for (; it != INVALID; ++it) {
438      target[ref[it]] = source[it];
439    }
440  }
441
442  /// \brief Copy the source map to the target map.
443  ///
444  /// Copy the \c source map to the \c target map. It uses the given iterator
445  /// to iterate on the data structure.
446  template <typename Target, typename Source, typename ItemIt>     
447  void copyMap(Target& target, const Source& source, ItemIt it) {
448    for (; it != INVALID; ++it) {
449      target[it] = source[it];
450    }
451  }
452
453  /// \brief Class to copy a graph.
454  ///
455  /// Class to copy a graph to an other graph (duplicate a graph). The
456  /// simplest way of using it is through the \c copyGraph() function.
457  template <typename Target, typename Source>
458  class GraphCopy {
459  public:
460    typedef typename Source::Node Node;
461    typedef typename Source::NodeIt NodeIt;
462    typedef typename Source::Edge Edge;
463    typedef typename Source::EdgeIt EdgeIt;
464
465    typedef typename Source::template NodeMap<typename Target::Node>NodeRefMap;
466    typedef typename Source::template EdgeMap<typename Target::Edge>EdgeRefMap;
467
468    /// \brief Constructor for the GraphCopy.
469    ///
470    /// It copies the content of the \c _source graph into the
471    /// \c _target graph. It creates also two references, one beetween
472    /// the two nodeset and one beetween the two edgesets.
473    GraphCopy(Target& _target, const Source& _source)
474      : source(_source), target(_target),
475        nodeRefMap(_source), edgeRefMap(_source) {
476      for (NodeIt it(source); it != INVALID; ++it) {
477        nodeRefMap[it] = target.addNode();
478      }
479      for (EdgeIt it(source); it != INVALID; ++it) {
480        edgeRefMap[it] = target.addEdge(nodeRefMap[source.source(it)],
481                                        nodeRefMap[source.target(it)]);
482      }
483    }
484
485    /// \brief Copies the node references into the given map.
486    ///
487    /// Copies the node references into the given map.
488    template <typename NodeRef>
489    const GraphCopy& nodeRef(NodeRef& map) const {
490      for (NodeIt it(source); it != INVALID; ++it) {
491        map.set(it, nodeRefMap[it]);
492      }
493      return *this;
494    }
495
496    /// \brief Reverse and copies the node references into the given map.
497    ///
498    /// Reverse and copies the node references into the given map.
499    template <typename NodeRef>
500    const GraphCopy& nodeCrossRef(NodeRef& map) const {
501      for (NodeIt it(source); it != INVALID; ++it) {
502        map.set(nodeRefMap[it], it);
503      }
504      return *this;
505    }
506
507    /// \brief Copies the edge references into the given map.
508    ///
509    /// Copies the edge references into the given map.
510    template <typename EdgeRef>
511    const GraphCopy& edgeRef(EdgeRef& map) const {
512      for (EdgeIt it(source); it != INVALID; ++it) {
513        map.set(it, edgeRefMap[it]);
514      }
515      return *this;
516    }
517
518    /// \brief Reverse and copies the edge references into the given map.
519    ///
520    /// Reverse and copies the edge references into the given map.
521    template <typename EdgeRef>
522    const GraphCopy& edgeCrossRef(EdgeRef& map) const {
523      for (EdgeIt it(source); it != INVALID; ++it) {
524        map.set(edgeRefMap[it], it);
525      }
526      return *this;
527    }
528
529    /// \brief Make copy of the given map.
530    ///
531    /// Makes copy of the given map for the newly created graph.
532    /// The new map's key type is the target graph's node type,
533    /// and the copied map's key type is the source graph's node
534    /// type. 
535    template <typename TargetMap, typename SourceMap>
536    const GraphCopy& nodeMap(TargetMap& tMap, const SourceMap& sMap) const {
537      copyMap(tMap, sMap, NodeIt(source), nodeRefMap);
538      return *this;
539    }
540
541    /// \brief Make copy of the given map.
542    ///
543    /// Makes copy of the given map for the newly created graph.
544    /// The new map's key type is the target graph's edge type,
545    /// and the copied map's key type is the source graph's edge
546    /// type. 
547    template <typename TargetMap, typename SourceMap>
548    const GraphCopy& edgeMap(TargetMap& tMap, const SourceMap& sMap) const {
549      copyMap(tMap, sMap, EdgeIt(source), edgeRefMap);
550      return *this;
551    }
552
553    /// \brief Gives back the stored node references.
554    ///
555    /// Gives back the stored node references.
556    const NodeRefMap& nodeRef() const {
557      return nodeRefMap;
558    }
559
560    /// \brief Gives back the stored edge references.
561    ///
562    /// Gives back the stored edge references.
563    const EdgeRefMap& edgeRef() const {
564      return edgeRefMap;
565    }
566
567    void run() {}
568
569  private:
570   
571    const Source& source;
572    Target& target;
573
574    NodeRefMap nodeRefMap;
575    EdgeRefMap edgeRefMap;
576  };
577
578  /// \brief Copy a graph to an other graph.
579  ///
580  /// Copy a graph to an other graph.
581  /// The usage of the function:
582  ///
583  ///\code
584  /// copyGraph(trg, src).nodeRef(nr).edgeCrossRef(ecr);
585  ///\endcode
586  ///
587  /// After the copy the \c nr map will contain the mapping from the
588  /// source graph's nodes to the target graph's nodes and the \c ecr will
589  /// contain the mapping from the target graph's edges to the source's
590  /// edges.
591  template <typename Target, typename Source>
592  GraphCopy<Target, Source> copyGraph(Target& target, const Source& source) {
593    return GraphCopy<Target, Source>(target, source);
594  }
595
596  /// \brief Class to copy an undirected graph.
597  ///
598  /// Class to copy an undirected graph to an other graph (duplicate a graph).
599  /// The simplest way of using it is through the \c copyUGraph() function.
600  template <typename Target, typename Source>
601  class UGraphCopy {
602  public:
603    typedef typename Source::Node Node;
604    typedef typename Source::NodeIt NodeIt;
605    typedef typename Source::Edge Edge;
606    typedef typename Source::EdgeIt EdgeIt;
607    typedef typename Source::UEdge UEdge;
608    typedef typename Source::UEdgeIt UEdgeIt;
609
610    typedef typename Source::
611    template NodeMap<typename Target::Node> NodeRefMap;
612   
613    typedef typename Source::
614    template UEdgeMap<typename Target::UEdge> UEdgeRefMap;
615
616  private:
617
618    struct EdgeRefMap {
619      EdgeRefMap(UGraphCopy& _gc) : gc(_gc) {}
620      typedef typename Source::Edge Key;
621      typedef typename Target::Edge Value;
622
623      Value operator[](const Key& key) {
624        return gc.target.direct(gc.uEdgeRef[key],
625                                gc.target.direction(key));
626      }
627     
628      UGraphCopy& gc;
629    };
630   
631  public:
632
633    /// \brief Constructor for the UGraphCopy.
634    ///
635    /// It copies the content of the \c _source graph into the
636    /// \c _target graph. It creates also two references, one beetween
637    /// the two nodeset and one beetween the two edgesets.
638    UGraphCopy(Target& _target, const Source& _source)
639      : source(_source), target(_target),
640        nodeRefMap(_source), edgeRefMap(*this), uEdgeRefMap(_source) {
641      for (NodeIt it(source); it != INVALID; ++it) {
642        nodeRefMap[it] = target.addNode();
643      }
644      for (UEdgeIt it(source); it != INVALID; ++it) {
645        uEdgeRefMap[it] = target.addEdge(nodeRefMap[source.source(it)],
646                                        nodeRefMap[source.target(it)]);
647      }
648    }
649
650    /// \brief Copies the node references into the given map.
651    ///
652    /// Copies the node references into the given map.
653    template <typename NodeRef>
654    const UGraphCopy& nodeRef(NodeRef& map) const {
655      for (NodeIt it(source); it != INVALID; ++it) {
656        map.set(it, nodeRefMap[it]);
657      }
658      return *this;
659    }
660
661    /// \brief Reverse and copies the node references into the given map.
662    ///
663    /// Reverse and copies the node references into the given map.
664    template <typename NodeRef>
665    const UGraphCopy& nodeCrossRef(NodeRef& map) const {
666      for (NodeIt it(source); it != INVALID; ++it) {
667        map.set(nodeRefMap[it], it);
668      }
669      return *this;
670    }
671
672    /// \brief Copies the edge references into the given map.
673    ///
674    /// Copies the edge references into the given map.
675    template <typename EdgeRef>
676    const UGraphCopy& edgeRef(EdgeRef& map) const {
677      for (EdgeIt it(source); it != INVALID; ++it) {
678        map.set(edgeRefMap[it], it);
679      }
680      return *this;
681    }
682
683    /// \brief Reverse and copies the undirected edge references into the
684    /// given map.
685    ///
686    /// Reverse and copies the undirected edge references into the given map.
687    template <typename EdgeRef>
688    const UGraphCopy& edgeCrossRef(EdgeRef& map) const {
689      for (EdgeIt it(source); it != INVALID; ++it) {
690        map.set(it, edgeRefMap[it]);
691      }
692      return *this;
693    }
694
695    /// \brief Copies the undirected edge references into the given map.
696    ///
697    /// Copies the undirected edge references into the given map.
698    template <typename EdgeRef>
699    const UGraphCopy& uEdgeRef(EdgeRef& map) const {
700      for (UEdgeIt it(source); it != INVALID; ++it) {
701        map.set(it, uEdgeRefMap[it]);
702      }
703      return *this;
704    }
705
706    /// \brief Reverse and copies the undirected edge references into the
707    /// given map.
708    ///
709    /// Reverse and copies the undirected edge references into the given map.
710    template <typename EdgeRef>
711    const UGraphCopy& uEdgeCrossRef(EdgeRef& map) const {
712      for (UEdgeIt it(source); it != INVALID; ++it) {
713        map.set(uEdgeRefMap[it], it);
714      }
715      return *this;
716    }
717
718    /// \brief Make copy of the given map.
719    ///
720    /// Makes copy of the given map for the newly created graph.
721    /// The new map's key type is the target graph's node type,
722    /// and the copied map's key type is the source graph's node
723    /// type. 
724    template <typename TargetMap, typename SourceMap>
725    const UGraphCopy& nodeMap(TargetMap& tMap,
726                                  const SourceMap& sMap) const {
727      copyMap(tMap, sMap, NodeIt(source), nodeRefMap);
728      return *this;
729    }
730
731    /// \brief Make copy of the given map.
732    ///
733    /// Makes copy of the given map for the newly created graph.
734    /// The new map's key type is the target graph's edge type,
735    /// and the copied map's key type is the source graph's edge
736    /// type. 
737    template <typename TargetMap, typename SourceMap>
738    const UGraphCopy& edgeMap(TargetMap& tMap,
739                                  const SourceMap& sMap) const {
740      copyMap(tMap, sMap, EdgeIt(source), edgeRefMap);
741      return *this;
742    }
743
744    /// \brief Make copy of the given map.
745    ///
746    /// Makes copy of the given map for the newly created graph.
747    /// The new map's key type is the target graph's edge type,
748    /// and the copied map's key type is the source graph's edge
749    /// type. 
750    template <typename TargetMap, typename SourceMap>
751    const UGraphCopy& uEdgeMap(TargetMap& tMap,
752                                  const SourceMap& sMap) const {
753      copyMap(tMap, sMap, UEdgeIt(source), uEdgeRefMap);
754      return *this;
755    }
756
757    /// \brief Gives back the stored node references.
758    ///
759    /// Gives back the stored node references.
760    const NodeRefMap& nodeRef() const {
761      return nodeRefMap;
762    }
763
764    /// \brief Gives back the stored edge references.
765    ///
766    /// Gives back the stored edge references.
767    const EdgeRefMap& edgeRef() const {
768      return edgeRefMap;
769    }
770
771    /// \brief Gives back the stored uedge references.
772    ///
773    /// Gives back the stored uedge references.
774    const UEdgeRefMap& uEdgeRef() const {
775      return uEdgeRefMap;
776    }
777
778    void run() {}
779
780  private:
781   
782    const Source& source;
783    Target& target;
784
785    NodeRefMap nodeRefMap;
786    EdgeRefMap edgeRefMap;
787    UEdgeRefMap uEdgeRefMap;
788  };
789
790  /// \brief Copy a graph to an other graph.
791  ///
792  /// Copy a graph to an other graph.
793  /// The usage of the function:
794  ///
795  ///\code
796  /// copyGraph(trg, src).nodeRef(nr).edgeCrossRef(ecr);
797  ///\endcode
798  ///
799  /// After the copy the \c nr map will contain the mapping from the
800  /// source graph's nodes to the target graph's nodes and the \c ecr will
801  /// contain the mapping from the target graph's edges to the source's
802  /// edges.
803  template <typename Target, typename Source>
804  UGraphCopy<Target, Source>
805  copyUGraph(Target& target, const Source& source) {
806    return UGraphCopy<Target, Source>(target, source);
807  }
808
809
810  /// @}
811
812  /// \addtogroup graph_maps
813  /// @{
814
815  /// Provides an immutable and unique id for each item in the graph.
816
817  /// The IdMap class provides a unique and immutable id for each item of the
818  /// same type (e.g. node) in the graph. This id is <ul><li>\b unique:
819  /// different items (nodes) get different ids <li>\b immutable: the id of an
820  /// item (node) does not change (even if you delete other nodes).  </ul>
821  /// Through this map you get access (i.e. can read) the inner id values of
822  /// the items stored in the graph. This map can be inverted with its member
823  /// class \c InverseMap.
824  ///
825  template <typename _Graph, typename _Item>
826  class IdMap {
827  public:
828    typedef _Graph Graph;
829    typedef int Value;
830    typedef _Item Item;
831    typedef _Item Key;
832
833    /// \brief Constructor.
834    ///
835    /// Constructor for creating id map.
836    IdMap(const Graph& _graph) : graph(&_graph) {}
837
838    /// \brief Gives back the \e id of the item.
839    ///
840    /// Gives back the immutable and unique \e id of the map.
841    int operator[](const Item& item) const { return graph->id(item);}
842
843
844  private:
845    const Graph* graph;
846
847  public:
848
849    /// \brief The class represents the inverse of its owner (IdMap).
850    ///
851    /// The class represents the inverse of its owner (IdMap).
852    /// \see inverse()
853    class InverseMap {
854    public:
855
856      /// \brief Constructor.
857      ///
858      /// Constructor for creating an id-to-item map.
859      InverseMap(const Graph& _graph) : graph(&_graph) {}
860
861      /// \brief Constructor.
862      ///
863      /// Constructor for creating an id-to-item map.
864      InverseMap(const IdMap& idMap) : graph(idMap.graph) {}
865
866      /// \brief Gives back the given item from its id.
867      ///
868      /// Gives back the given item from its id.
869      ///
870      Item operator[](int id) const { return graph->fromId(id, Item());}
871    private:
872      const Graph* graph;
873    };
874
875    /// \brief Gives back the inverse of the map.
876    ///
877    /// Gives back the inverse of the IdMap.
878    InverseMap inverse() const { return InverseMap(*graph);}
879
880  };
881
882 
883  /// \brief General invertable graph-map type.
884
885  /// This type provides simple invertable graph-maps.
886  /// The InvertableMap wraps an arbitrary ReadWriteMap
887  /// and if a key is set to a new value then store it
888  /// in the inverse map.
889  ///
890  /// The values of the map can be accessed
891  /// with stl compatible forward iterator.
892  ///
893  /// \param _Graph The graph type.
894  /// \param _Item The item type of the graph.
895  /// \param _Value The value type of the map.
896  ///
897  /// \see IterableValueMap
898#ifndef DOXYGEN
899  /// \param _Map A ReadWriteMap mapping from the item type to integer.
900  template <
901    typename _Graph, typename _Item, typename _Value, typename _Map
902    = typename ItemSetTraits<_Graph, _Item>::template Map<_Value>::Parent
903  >
904#else
905  template <typename _Graph, typename _Item, typename _Value>
906#endif
907  class InvertableMap : protected _Map {
908  public:
909
910    /// The key type of InvertableMap (Node, Edge, UEdge).
911    typedef typename _Map::Key Key;
912    /// The value type of the InvertableMap.
913    typedef typename _Map::Value Value;
914
915  private:
916   
917    typedef _Map Map;
918    typedef _Graph Graph;
919
920    typedef std::map<Value, Key> Container;
921    Container invMap;   
922
923  public:
924 
925
926
927    /// \brief Constructor.
928    ///
929    /// Construct a new InvertableMap for the graph.
930    ///
931    InvertableMap(const Graph& graph) : Map(graph) {}
932
933    /// \brief Forward iterator for values.
934    ///
935    /// This iterator is an stl compatible forward
936    /// iterator on the values of the map. The values can
937    /// be accessed in the [beginValue, endValue) range.
938    ///
939    class ValueIterator
940      : public std::iterator<std::forward_iterator_tag, Value> {
941      friend class InvertableMap;
942    private:
943      ValueIterator(typename Container::const_iterator _it)
944        : it(_it) {}
945    public:
946     
947      ValueIterator() {}
948
949      ValueIterator& operator++() { ++it; return *this; }
950      ValueIterator operator++(int) {
951        ValueIterator tmp(*this);
952        operator++();
953        return tmp;
954      }
955
956      const Value& operator*() const { return it->first; }
957      const Value* operator->() const { return &(it->first); }
958
959      bool operator==(ValueIterator jt) const { return it == jt.it; }
960      bool operator!=(ValueIterator jt) const { return it != jt.it; }
961     
962    private:
963      typename Container::const_iterator it;
964    };
965
966    /// \brief Returns an iterator to the first value.
967    ///
968    /// Returns an stl compatible iterator to the
969    /// first value of the map. The values of the
970    /// map can be accessed in the [beginValue, endValue)
971    /// range.
972    ValueIterator beginValue() const {
973      return ValueIterator(invMap.begin());
974    }
975
976    /// \brief Returns an iterator after the last value.
977    ///
978    /// Returns an stl compatible iterator after the
979    /// last value of the map. The values of the
980    /// map can be accessed in the [beginValue, endValue)
981    /// range.
982    ValueIterator endValue() const {
983      return ValueIterator(invMap.end());
984    }
985   
986    /// \brief The setter function of the map.
987    ///
988    /// Sets the mapped value.
989    void set(const Key& key, const Value& val) {
990      Value oldval = Map::operator[](key);
991      typename Container::iterator it = invMap.find(oldval);
992      if (it != invMap.end() && it->second == key) {
993        invMap.erase(it);
994      }     
995      invMap.insert(make_pair(val, key));
996      Map::set(key, val);
997    }
998
999    /// \brief The getter function of the map.
1000    ///
1001    /// It gives back the value associated with the key.
1002    typename MapTraits<Map>::ConstReturnValue
1003    operator[](const Key& key) const {
1004      return Map::operator[](key);
1005    }
1006
1007  protected:
1008
1009    /// \brief Erase the key from the map.
1010    ///
1011    /// Erase the key to the map. It is called by the
1012    /// \c AlterationNotifier.
1013    virtual void erase(const Key& key) {
1014      Value val = Map::operator[](key);
1015      typename Container::iterator it = invMap.find(val);
1016      if (it != invMap.end() && it->second == key) {
1017        invMap.erase(it);
1018      }
1019      Map::erase(key);
1020    }
1021
1022    /// \brief Erase more keys from the map.
1023    ///
1024    /// Erase more keys from the map. It is called by the
1025    /// \c AlterationNotifier.
1026    virtual void erase(const std::vector<Key>& keys) {
1027      for (int i = 0; i < (int)keys.size(); ++i) {
1028        Value val = Map::operator[](keys[i]);
1029        typename Container::iterator it = invMap.find(val);
1030        if (it != invMap.end() && it->second == keys[i]) {
1031          invMap.erase(it);
1032        }
1033      }
1034      Map::erase(keys);
1035    }
1036
1037    /// \brief Clear the keys from the map and inverse map.
1038    ///
1039    /// Clear the keys from the map and inverse map. It is called by the
1040    /// \c AlterationNotifier.
1041    virtual void clear() {
1042      invMap.clear();
1043      Map::clear();
1044    }
1045
1046  public:
1047
1048    /// \brief The inverse map type.
1049    ///
1050    /// The inverse of this map. The subscript operator of the map
1051    /// gives back always the item what was last assigned to the value.
1052    class InverseMap {
1053    public:
1054      /// \brief Constructor of the InverseMap.
1055      ///
1056      /// Constructor of the InverseMap.
1057      InverseMap(const InvertableMap& _inverted) : inverted(_inverted) {}
1058
1059      /// The value type of the InverseMap.
1060      typedef typename InvertableMap::Key Value;
1061      /// The key type of the InverseMap.
1062      typedef typename InvertableMap::Value Key;
1063
1064      /// \brief Subscript operator.
1065      ///
1066      /// Subscript operator. It gives back always the item
1067      /// what was last assigned to the value.
1068      Value operator[](const Key& key) const {
1069        typename Container::const_iterator it = inverted.invMap.find(key);
1070        return it->second;
1071      }
1072     
1073    private:
1074      const InvertableMap& inverted;
1075    };
1076
1077    /// \brief It gives back the just readeable inverse map.
1078    ///
1079    /// It gives back the just readeable inverse map.
1080    InverseMap inverse() const {
1081      return InverseMap(*this);
1082    }
1083
1084
1085   
1086  };
1087
1088  /// \brief Provides a mutable, continuous and unique descriptor for each
1089  /// item in the graph.
1090  ///
1091  /// The DescriptorMap class provides a unique and continuous (but mutable)
1092  /// descriptor (id) for each item of the same type (e.g. node) in the
1093  /// graph. This id is <ul><li>\b unique: different items (nodes) get
1094  /// different ids <li>\b continuous: the range of the ids is the set of
1095  /// integers between 0 and \c n-1, where \c n is the number of the items of
1096  /// this type (e.g. nodes) (so the id of a node can change if you delete an
1097  /// other node, i.e. this id is mutable).  </ul> This map can be inverted
1098  /// with its member class \c InverseMap.
1099  ///
1100  /// \param _Graph The graph class the \c DescriptorMap belongs to.
1101  /// \param _Item The Item is the Key of the Map. It may be Node, Edge or
1102  /// UEdge.
1103#ifndef DOXYGEN
1104  /// \param _Map A ReadWriteMap mapping from the item type to integer.
1105  template <
1106    typename _Graph, typename _Item, typename _Map
1107    = typename ItemSetTraits<_Graph, _Item>::template Map<int>::Parent
1108  >
1109#else
1110  template <typename _Graph, typename _Item>
1111#endif
1112  class DescriptorMap : protected _Map {
1113
1114    typedef _Item Item;
1115    typedef _Map Map;
1116
1117  public:
1118    /// The graph class of DescriptorMap.
1119    typedef _Graph Graph;
1120
1121    /// The key type of DescriptorMap (Node, Edge, UEdge).
1122    typedef typename _Map::Key Key;
1123    /// The value type of DescriptorMap.
1124    typedef typename _Map::Value Value;
1125
1126    /// \brief Constructor.
1127    ///
1128    /// Constructor for descriptor map.
1129    DescriptorMap(const Graph& _graph) : Map(_graph) {
1130      build();
1131    }
1132
1133  protected:
1134
1135    /// \brief Add a new key to the map.
1136    ///
1137    /// Add a new key to the map. It is called by the
1138    /// \c AlterationNotifier.
1139    virtual void add(const Item& item) {
1140      Map::add(item);
1141      Map::set(item, invMap.size());
1142      invMap.push_back(item);
1143    }
1144
1145    /// \brief Add more new keys to the map.
1146    ///
1147    /// Add more new keys to the map. It is called by the
1148    /// \c AlterationNotifier.
1149    virtual void add(const std::vector<Item>& items) {
1150      Map::add(items);
1151      for (int i = 0; i < (int)items.size(); ++i) {
1152        Map::set(items[i], invMap.size());
1153        invMap.push_back(items[i]);
1154      }
1155    }
1156
1157    /// \brief Erase the key from the map.
1158    ///
1159    /// Erase the key from the map. It is called by the
1160    /// \c AlterationNotifier.
1161    virtual void erase(const Item& item) {
1162      Map::set(invMap.back(), Map::operator[](item));
1163      invMap[Map::operator[](item)] = invMap.back();
1164      invMap.pop_back();
1165      Map::erase(item);
1166    }
1167
1168    /// \brief Erase more keys from the map.
1169    ///
1170    /// Erase more keys from the map. It is called by the
1171    /// \c AlterationNotifier.
1172    virtual void erase(const std::vector<Item>& items) {
1173      for (int i = 0; i < (int)items.size(); ++i) {
1174        Map::set(invMap.back(), Map::operator[](items[i]));
1175        invMap[Map::operator[](items[i])] = invMap.back();
1176        invMap.pop_back();
1177      }
1178      Map::erase(items);
1179    }
1180
1181    /// \brief Build the unique map.
1182    ///
1183    /// Build the unique map. It is called by the
1184    /// \c AlterationNotifier.
1185    virtual void build() {
1186      Map::build();
1187      Item it;
1188      const typename Map::Graph* graph = Map::getGraph();
1189      for (graph->first(it); it != INVALID; graph->next(it)) {
1190        Map::set(it, invMap.size());
1191        invMap.push_back(it);   
1192      }     
1193    }
1194   
1195    /// \brief Clear the keys from the map.
1196    ///
1197    /// Clear the keys from the map. It is called by the
1198    /// \c AlterationNotifier.
1199    virtual void clear() {
1200      invMap.clear();
1201      Map::clear();
1202    }
1203
1204  public:
1205
1206    /// \brief Returns the maximal value plus one.
1207    ///
1208    /// Returns the maximal value plus one in the map.
1209    unsigned int size() const {
1210      return invMap.size();
1211    }
1212
1213    /// \brief Swaps the position of the two items in the map.
1214    ///
1215    /// Swaps the position of the two items in the map.
1216    void swap(const Item& p, const Item& q) {
1217      int pi = Map::operator[](p);
1218      int qi = Map::operator[](q);
1219      Map::set(p, qi);
1220      invMap[qi] = p;
1221      Map::set(q, pi);
1222      invMap[pi] = q;
1223    }
1224
1225    /// \brief Gives back the \e descriptor of the item.
1226    ///
1227    /// Gives back the mutable and unique \e descriptor of the map.
1228    int operator[](const Item& item) const {
1229      return Map::operator[](item);
1230    }
1231   
1232  private:
1233
1234    typedef std::vector<Item> Container;
1235    Container invMap;
1236
1237  public:
1238    /// \brief The inverse map type of DescriptorMap.
1239    ///
1240    /// The inverse map type of DescriptorMap.
1241    class InverseMap {
1242    public:
1243      /// \brief Constructor of the InverseMap.
1244      ///
1245      /// Constructor of the InverseMap.
1246      InverseMap(const DescriptorMap& _inverted)
1247        : inverted(_inverted) {}
1248
1249
1250      /// The value type of the InverseMap.
1251      typedef typename DescriptorMap::Key Value;
1252      /// The key type of the InverseMap.
1253      typedef typename DescriptorMap::Value Key;
1254
1255      /// \brief Subscript operator.
1256      ///
1257      /// Subscript operator. It gives back the item
1258      /// that the descriptor belongs to currently.
1259      Value operator[](const Key& key) const {
1260        return inverted.invMap[key];
1261      }
1262
1263      /// \brief Size of the map.
1264      ///
1265      /// Returns the size of the map.
1266      unsigned int size() const {
1267        return inverted.invMap.size();
1268      }
1269     
1270    private:
1271      const DescriptorMap& inverted;
1272    };
1273
1274    /// \brief Gives back the inverse of the map.
1275    ///
1276    /// Gives back the inverse of the map.
1277    const InverseMap inverse() const {
1278      return InverseMap(*this);
1279    }
1280  };
1281
1282  /// \brief Returns the source of the given edge.
1283  ///
1284  /// The SourceMap gives back the source Node of the given edge.
1285  /// \author Balazs Dezso
1286  template <typename Graph>
1287  class SourceMap {
1288  public:
1289
1290    typedef typename Graph::Node Value;
1291    typedef typename Graph::Edge Key;
1292
1293    /// \brief Constructor
1294    ///
1295    /// Constructor
1296    /// \param _graph The graph that the map belongs to.
1297    SourceMap(const Graph& _graph) : graph(_graph) {}
1298
1299    /// \brief The subscript operator.
1300    ///
1301    /// The subscript operator.
1302    /// \param edge The edge
1303    /// \return The source of the edge
1304    Value operator[](const Key& edge) const {
1305      return graph.source(edge);
1306    }
1307
1308  private:
1309    const Graph& graph;
1310  };
1311
1312  /// \brief Returns a \ref SourceMap class
1313  ///
1314  /// This function just returns an \ref SourceMap class.
1315  /// \relates SourceMap
1316  template <typename Graph>
1317  inline SourceMap<Graph> sourceMap(const Graph& graph) {
1318    return SourceMap<Graph>(graph);
1319  }
1320
1321  /// \brief Returns the target of the given edge.
1322  ///
1323  /// The TargetMap gives back the target Node of the given edge.
1324  /// \author Balazs Dezso
1325  template <typename Graph>
1326  class TargetMap {
1327  public:
1328
1329    typedef typename Graph::Node Value;
1330    typedef typename Graph::Edge Key;
1331
1332    /// \brief Constructor
1333    ///
1334    /// Constructor
1335    /// \param _graph The graph that the map belongs to.
1336    TargetMap(const Graph& _graph) : graph(_graph) {}
1337
1338    /// \brief The subscript operator.
1339    ///
1340    /// The subscript operator.
1341    /// \param e The edge
1342    /// \return The target of the edge
1343    Value operator[](const Key& e) const {
1344      return graph.target(e);
1345    }
1346
1347  private:
1348    const Graph& graph;
1349  };
1350
1351  /// \brief Returns a \ref TargetMap class
1352  ///
1353  /// This function just returns a \ref TargetMap class.
1354  /// \relates TargetMap
1355  template <typename Graph>
1356  inline TargetMap<Graph> targetMap(const Graph& graph) {
1357    return TargetMap<Graph>(graph);
1358  }
1359
1360  /// \brief Returns the "forward" directed edge view of an undirected edge.
1361  ///
1362  /// Returns the "forward" directed edge view of an undirected edge.
1363  /// \author Balazs Dezso
1364  template <typename Graph>
1365  class ForwardMap {
1366  public:
1367
1368    typedef typename Graph::Edge Value;
1369    typedef typename Graph::UEdge Key;
1370
1371    /// \brief Constructor
1372    ///
1373    /// Constructor
1374    /// \param _graph The graph that the map belongs to.
1375    ForwardMap(const Graph& _graph) : graph(_graph) {}
1376
1377    /// \brief The subscript operator.
1378    ///
1379    /// The subscript operator.
1380    /// \param key An undirected edge
1381    /// \return The "forward" directed edge view of undirected edge
1382    Value operator[](const Key& key) const {
1383      return graph.direct(key, true);
1384    }
1385
1386  private:
1387    const Graph& graph;
1388  };
1389
1390  /// \brief Returns a \ref ForwardMap class
1391  ///
1392  /// This function just returns an \ref ForwardMap class.
1393  /// \relates ForwardMap
1394  template <typename Graph>
1395  inline ForwardMap<Graph> forwardMap(const Graph& graph) {
1396    return ForwardMap<Graph>(graph);
1397  }
1398
1399  /// \brief Returns the "backward" directed edge view of an undirected edge.
1400  ///
1401  /// Returns the "backward" directed edge view of an undirected edge.
1402  /// \author Balazs Dezso
1403  template <typename Graph>
1404  class BackwardMap {
1405  public:
1406
1407    typedef typename Graph::Edge Value;
1408    typedef typename Graph::UEdge Key;
1409
1410    /// \brief Constructor
1411    ///
1412    /// Constructor
1413    /// \param _graph The graph that the map belongs to.
1414    BackwardMap(const Graph& _graph) : graph(_graph) {}
1415
1416    /// \brief The subscript operator.
1417    ///
1418    /// The subscript operator.
1419    /// \param key An undirected edge
1420    /// \return The "backward" directed edge view of undirected edge
1421    Value operator[](const Key& key) const {
1422      return graph.direct(key, false);
1423    }
1424
1425  private:
1426    const Graph& graph;
1427  };
1428
1429  /// \brief Returns a \ref BackwardMap class
1430
1431  /// This function just returns a \ref BackwardMap class.
1432  /// \relates BackwardMap
1433  template <typename Graph>
1434  inline BackwardMap<Graph> backwardMap(const Graph& graph) {
1435    return BackwardMap<Graph>(graph);
1436  }
1437
1438  /// \brief Potential difference map
1439  ///
1440  /// If there is an potential map on the nodes then we
1441  /// can get an edge map as we get the substraction of the
1442  /// values of the target and source.
1443  template <typename Graph, typename NodeMap>
1444  class PotentialDifferenceMap {
1445  public:
1446    typedef typename Graph::Edge Key;
1447    typedef typename NodeMap::Value Value;
1448
1449    /// \brief Constructor
1450    ///
1451    /// Contructor of the map
1452    PotentialDifferenceMap(const Graph& _graph, const NodeMap& _potential)
1453      : graph(_graph), potential(_potential) {}
1454
1455    /// \brief Const subscription operator
1456    ///
1457    /// Const subscription operator
1458    Value operator[](const Key& edge) const {
1459      return potential[graph.target(edge)] - potential[graph.source(edge)];
1460    }
1461
1462  private:
1463    const Graph& graph;
1464    const NodeMap& potential;
1465  };
1466
1467  /// \brief Just returns a PotentialDifferenceMap
1468  ///
1469  /// Just returns a PotentialDifferenceMap
1470  /// \relates PotentialDifferenceMap
1471  template <typename Graph, typename NodeMap>
1472  PotentialDifferenceMap<Graph, NodeMap>
1473  potentialDifferenceMap(const Graph& graph, const NodeMap& potential) {
1474    return PotentialDifferenceMap<Graph, NodeMap>(graph, potential);
1475  }
1476
1477  /// \brief Map of the node in-degrees.
1478  ///
1479  /// This map returns the in-degree of a node. Once it is constructed,
1480  /// the degrees are stored in a standard NodeMap, so each query is done
1481  /// in constant time. On the other hand, the values are updated automatically
1482  /// whenever the graph changes.
1483  ///
1484  /// \warning Besides addNode() and addEdge(), a graph structure may provide
1485  /// alternative ways to modify the graph. The correct behavior of InDegMap
1486  /// is not guarantied if these additional features are used. For example
1487  /// the functions \ref ListGraph::changeSource() "changeSource()",
1488  /// \ref ListGraph::changeTarget() "changeTarget()" and
1489  /// \ref ListGraph::reverseEdge() "reverseEdge()"
1490  /// of \ref ListGraph will \e not update the degree values correctly.
1491  ///
1492  /// \sa OutDegMap
1493
1494  template <typename _Graph>
1495  class InDegMap 
1496    : protected AlterationNotifier<typename _Graph::Edge>::ObserverBase {
1497
1498  public:
1499   
1500    typedef _Graph Graph;
1501    typedef int Value;
1502    typedef typename Graph::Node Key;
1503
1504  private:
1505
1506    class AutoNodeMap : public Graph::template NodeMap<int> {
1507    public:
1508
1509      typedef typename Graph::template NodeMap<int> Parent;
1510
1511      typedef typename Parent::Key Key;
1512      typedef typename Parent::Value Value;
1513     
1514      AutoNodeMap(const Graph& graph) : Parent(graph, 0) {}
1515     
1516      virtual void add(const Key& key) {
1517        Parent::add(key);
1518        Parent::set(key, 0);
1519      }
1520
1521      virtual void add(const std::vector<Key>& keys) {
1522        Parent::add(keys);
1523        for (int i = 0; i < (int)keys.size(); ++i) {
1524          Parent::set(keys[i], 0);
1525        }
1526      }
1527    };
1528
1529  public:
1530
1531    /// \brief Constructor.
1532    ///
1533    /// Constructor for creating in-degree map.
1534    InDegMap(const Graph& _graph) : graph(_graph), deg(_graph) {
1535      AlterationNotifier<typename _Graph::Edge>
1536        ::ObserverBase::attach(graph.getNotifier(typename _Graph::Edge()));
1537     
1538      for(typename _Graph::NodeIt it(graph); it != INVALID; ++it) {
1539        deg[it] = countInEdges(graph, it);
1540      }
1541    }
1542
1543    virtual ~InDegMap() {
1544      AlterationNotifier<typename _Graph::Edge>::
1545        ObserverBase::detach();
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 AlterationNotifier<typename _Graph::Edge>::ObserverBase {
1614
1615  public:
1616   
1617    typedef _Graph Graph;
1618    typedef int Value;
1619    typedef typename Graph::Node Key;
1620
1621  private:
1622
1623    class AutoNodeMap : public Graph::template NodeMap<int> {
1624    public:
1625
1626      typedef typename Graph::template NodeMap<int> Parent;
1627
1628      typedef typename Parent::Key Key;
1629      typedef typename Parent::Value Value;
1630     
1631      AutoNodeMap(const Graph& graph) : Parent(graph, 0) {}
1632     
1633      virtual void add(const Key& key) {
1634        Parent::add(key);
1635        Parent::set(key, 0);
1636      }
1637      virtual void add(const std::vector<Key>& keys) {
1638        Parent::add(keys);
1639        for (int i = 0; i < (int)keys.size(); ++i) {
1640          Parent::set(keys[i], 0);
1641        }
1642      }
1643    };
1644
1645  public:
1646
1647    /// \brief Constructor.
1648    ///
1649    /// Constructor for creating out-degree map.
1650    OutDegMap(const Graph& _graph) : graph(_graph), deg(_graph) {
1651      AlterationNotifier<typename _Graph::Edge>
1652        ::ObserverBase::attach(graph.getNotifier(typename _Graph::Edge()));
1653     
1654      for(typename _Graph::NodeIt it(graph); it != INVALID; ++it) {
1655        deg[it] = countOutEdges(graph, it);
1656      }
1657    }
1658
1659    virtual ~OutDegMap() {
1660      AlterationNotifier<typename _Graph::Edge>::
1661        ObserverBase::detach();
1662    }
1663   
1664    /// Gives back the in-degree of a Node.
1665    int operator[](const Key& key) const {
1666      return deg[key];
1667    }
1668
1669  protected:
1670   
1671    typedef typename Graph::Edge Edge;
1672
1673    virtual void add(const Edge& edge) {
1674      ++deg[graph.source(edge)];
1675    }
1676
1677    virtual void add(const std::vector<Edge>& edges) {
1678      for (int i = 0; i < (int)edges.size(); ++i) {
1679        ++deg[graph.source(edges[i])];
1680      }
1681    }
1682
1683    virtual void erase(const Edge& edge) {
1684      --deg[graph.source(edge)];
1685    }
1686
1687    virtual void erase(const std::vector<Edge>& edges) {
1688      for (int i = 0; i < (int)edges.size(); ++i) {
1689        --deg[graph.source(edges[i])];
1690      }
1691    }
1692
1693    virtual void build() {
1694      for(typename _Graph::NodeIt it(graph); it != INVALID; ++it) {
1695        deg[it] = countOutEdges(graph, it);
1696      }     
1697    }
1698
1699    virtual void clear() {
1700      for(typename _Graph::NodeIt it(graph); it != INVALID; ++it) {
1701        deg[it] = 0;
1702      }
1703    }
1704  private:
1705   
1706    const _Graph& graph;
1707    AutoNodeMap deg;
1708  };
1709
1710
1711  /// @}
1712
1713} //END OF NAMESPACE LEMON
1714
1715#endif
Note: See TracBrowser for help on using the repository browser.