lemon/adaptors.h
author Janos Tapolcai <tapolcai@tmit.bme.hu>
Fri, 23 Jan 2009 18:40:41 +0100
changeset 514 2eb5c8ca2c91
parent 464 acfb0f24d178
child 516 dab9e610e37d
permissions -rw-r--r--
Dirty hacking for VS 2005 in lp_base.h (#209)
     1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library.
     4  *
     5  * Copyright (C) 2003-2009
     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_ADAPTORS_H
    20 #define LEMON_ADAPTORS_H
    21 
    22 /// \ingroup graph_adaptors
    23 /// \file
    24 /// \brief Adaptor classes for digraphs and graphs
    25 ///
    26 /// This file contains several useful adaptors for digraphs and graphs.
    27 
    28 #include <lemon/core.h>
    29 #include <lemon/maps.h>
    30 #include <lemon/bits/variant.h>
    31 
    32 #include <lemon/bits/graph_adaptor_extender.h>
    33 #include <lemon/tolerance.h>
    34 
    35 #include <algorithm>
    36 
    37 namespace lemon {
    38 
    39 #ifdef _MSC_VER
    40 #define LEMON_SCOPE_FIX(OUTER, NESTED) OUTER::NESTED
    41 #else
    42 #define LEMON_SCOPE_FIX(OUTER, NESTED) typename OUTER::template NESTED
    43 #endif
    44 
    45   template<typename DGR>
    46   class DigraphAdaptorBase {
    47   public:
    48     typedef DGR Digraph;
    49     typedef DigraphAdaptorBase Adaptor;
    50 
    51   protected:
    52     DGR* _digraph;
    53     DigraphAdaptorBase() : _digraph(0) { }
    54     void initialize(DGR& digraph) { _digraph = &digraph; }
    55 
    56   public:
    57     DigraphAdaptorBase(DGR& digraph) : _digraph(&digraph) { }
    58 
    59     typedef typename DGR::Node Node;
    60     typedef typename DGR::Arc Arc;
    61 
    62     void first(Node& i) const { _digraph->first(i); }
    63     void first(Arc& i) const { _digraph->first(i); }
    64     void firstIn(Arc& i, const Node& n) const { _digraph->firstIn(i, n); }
    65     void firstOut(Arc& i, const Node& n ) const { _digraph->firstOut(i, n); }
    66 
    67     void next(Node& i) const { _digraph->next(i); }
    68     void next(Arc& i) const { _digraph->next(i); }
    69     void nextIn(Arc& i) const { _digraph->nextIn(i); }
    70     void nextOut(Arc& i) const { _digraph->nextOut(i); }
    71 
    72     Node source(const Arc& a) const { return _digraph->source(a); }
    73     Node target(const Arc& a) const { return _digraph->target(a); }
    74 
    75     typedef NodeNumTagIndicator<DGR> NodeNumTag;
    76     int nodeNum() const { return _digraph->nodeNum(); }
    77 
    78     typedef ArcNumTagIndicator<DGR> ArcNumTag;
    79     int arcNum() const { return _digraph->arcNum(); }
    80 
    81     typedef FindArcTagIndicator<DGR> FindArcTag;
    82     Arc findArc(const Node& u, const Node& v, const Arc& prev = INVALID) const {
    83       return _digraph->findArc(u, v, prev);
    84     }
    85 
    86     Node addNode() { return _digraph->addNode(); }
    87     Arc addArc(const Node& u, const Node& v) { return _digraph->addArc(u, v); }
    88 
    89     void erase(const Node& n) { _digraph->erase(n); }
    90     void erase(const Arc& a) { _digraph->erase(a); }
    91 
    92     void clear() { _digraph->clear(); }
    93 
    94     int id(const Node& n) const { return _digraph->id(n); }
    95     int id(const Arc& a) const { return _digraph->id(a); }
    96 
    97     Node nodeFromId(int ix) const { return _digraph->nodeFromId(ix); }
    98     Arc arcFromId(int ix) const { return _digraph->arcFromId(ix); }
    99 
   100     int maxNodeId() const { return _digraph->maxNodeId(); }
   101     int maxArcId() const { return _digraph->maxArcId(); }
   102 
   103     typedef typename ItemSetTraits<DGR, Node>::ItemNotifier NodeNotifier;
   104     NodeNotifier& notifier(Node) const { return _digraph->notifier(Node()); }
   105 
   106     typedef typename ItemSetTraits<DGR, Arc>::ItemNotifier ArcNotifier;
   107     ArcNotifier& notifier(Arc) const { return _digraph->notifier(Arc()); }
   108 
   109     template <typename V>
   110     class NodeMap : public DGR::template NodeMap<V> {
   111     public:
   112 
   113       typedef typename DGR::template NodeMap<V> Parent;
   114 
   115       explicit NodeMap(const Adaptor& adaptor)
   116         : Parent(*adaptor._digraph) {}
   117 
   118       NodeMap(const Adaptor& adaptor, const V& value)
   119         : Parent(*adaptor._digraph, value) { }
   120 
   121     private:
   122       NodeMap& operator=(const NodeMap& cmap) {
   123         return operator=<NodeMap>(cmap);
   124       }
   125 
   126       template <typename CMap>
   127       NodeMap& operator=(const CMap& cmap) {
   128         Parent::operator=(cmap);
   129         return *this;
   130       }
   131 
   132     };
   133 
   134     template <typename V>
   135     class ArcMap : public DGR::template ArcMap<V> {
   136     public:
   137 
   138       typedef typename DGR::template ArcMap<V> Parent;
   139 
   140       explicit ArcMap(const DigraphAdaptorBase<DGR>& adaptor)
   141         : Parent(*adaptor._digraph) {}
   142 
   143       ArcMap(const DigraphAdaptorBase<DGR>& adaptor, const V& value)
   144         : Parent(*adaptor._digraph, value) {}
   145 
   146     private:
   147       ArcMap& operator=(const ArcMap& cmap) {
   148         return operator=<ArcMap>(cmap);
   149       }
   150 
   151       template <typename CMap>
   152       ArcMap& operator=(const CMap& cmap) {
   153         Parent::operator=(cmap);
   154         return *this;
   155       }
   156 
   157     };
   158 
   159   };
   160 
   161   template<typename GR>
   162   class GraphAdaptorBase {
   163   public:
   164     typedef GR Graph;
   165 
   166   protected:
   167     GR* _graph;
   168 
   169     GraphAdaptorBase() : _graph(0) {}
   170 
   171     void initialize(GR& graph) { _graph = &graph; }
   172 
   173   public:
   174     GraphAdaptorBase(GR& graph) : _graph(&graph) {}
   175 
   176     typedef typename GR::Node Node;
   177     typedef typename GR::Arc Arc;
   178     typedef typename GR::Edge Edge;
   179 
   180     void first(Node& i) const { _graph->first(i); }
   181     void first(Arc& i) const { _graph->first(i); }
   182     void first(Edge& i) const { _graph->first(i); }
   183     void firstIn(Arc& i, const Node& n) const { _graph->firstIn(i, n); }
   184     void firstOut(Arc& i, const Node& n ) const { _graph->firstOut(i, n); }
   185     void firstInc(Edge &i, bool &d, const Node &n) const {
   186       _graph->firstInc(i, d, n);
   187     }
   188 
   189     void next(Node& i) const { _graph->next(i); }
   190     void next(Arc& i) const { _graph->next(i); }
   191     void next(Edge& i) const { _graph->next(i); }
   192     void nextIn(Arc& i) const { _graph->nextIn(i); }
   193     void nextOut(Arc& i) const { _graph->nextOut(i); }
   194     void nextInc(Edge &i, bool &d) const { _graph->nextInc(i, d); }
   195 
   196     Node u(const Edge& e) const { return _graph->u(e); }
   197     Node v(const Edge& e) const { return _graph->v(e); }
   198 
   199     Node source(const Arc& a) const { return _graph->source(a); }
   200     Node target(const Arc& a) const { return _graph->target(a); }
   201 
   202     typedef NodeNumTagIndicator<Graph> NodeNumTag;
   203     int nodeNum() const { return _graph->nodeNum(); }
   204 
   205     typedef ArcNumTagIndicator<Graph> ArcNumTag;
   206     int arcNum() const { return _graph->arcNum(); }
   207 
   208     typedef EdgeNumTagIndicator<Graph> EdgeNumTag;
   209     int edgeNum() const { return _graph->edgeNum(); }
   210 
   211     typedef FindArcTagIndicator<Graph> FindArcTag;
   212     Arc findArc(const Node& u, const Node& v,
   213                 const Arc& prev = INVALID) const {
   214       return _graph->findArc(u, v, prev);
   215     }
   216 
   217     typedef FindEdgeTagIndicator<Graph> FindEdgeTag;
   218     Edge findEdge(const Node& u, const Node& v,
   219                   const Edge& prev = INVALID) const {
   220       return _graph->findEdge(u, v, prev);
   221     }
   222 
   223     Node addNode() { return _graph->addNode(); }
   224     Edge addEdge(const Node& u, const Node& v) { return _graph->addEdge(u, v); }
   225 
   226     void erase(const Node& i) { _graph->erase(i); }
   227     void erase(const Edge& i) { _graph->erase(i); }
   228 
   229     void clear() { _graph->clear(); }
   230 
   231     bool direction(const Arc& a) const { return _graph->direction(a); }
   232     Arc direct(const Edge& e, bool d) const { return _graph->direct(e, d); }
   233 
   234     int id(const Node& v) const { return _graph->id(v); }
   235     int id(const Arc& a) const { return _graph->id(a); }
   236     int id(const Edge& e) const { return _graph->id(e); }
   237 
   238     Node nodeFromId(int ix) const { return _graph->nodeFromId(ix); }
   239     Arc arcFromId(int ix) const { return _graph->arcFromId(ix); }
   240     Edge edgeFromId(int ix) const { return _graph->edgeFromId(ix); }
   241 
   242     int maxNodeId() const { return _graph->maxNodeId(); }
   243     int maxArcId() const { return _graph->maxArcId(); }
   244     int maxEdgeId() const { return _graph->maxEdgeId(); }
   245 
   246     typedef typename ItemSetTraits<GR, Node>::ItemNotifier NodeNotifier;
   247     NodeNotifier& notifier(Node) const { return _graph->notifier(Node()); }
   248 
   249     typedef typename ItemSetTraits<GR, Arc>::ItemNotifier ArcNotifier;
   250     ArcNotifier& notifier(Arc) const { return _graph->notifier(Arc()); }
   251 
   252     typedef typename ItemSetTraits<GR, Edge>::ItemNotifier EdgeNotifier;
   253     EdgeNotifier& notifier(Edge) const { return _graph->notifier(Edge()); }
   254 
   255     template <typename V>
   256     class NodeMap : public GR::template NodeMap<V> {
   257     public:
   258       typedef typename GR::template NodeMap<V> Parent;
   259       explicit NodeMap(const GraphAdaptorBase<GR>& adapter)
   260         : Parent(*adapter._graph) {}
   261       NodeMap(const GraphAdaptorBase<GR>& adapter, const V& value)
   262         : Parent(*adapter._graph, value) {}
   263 
   264     private:
   265       NodeMap& operator=(const NodeMap& cmap) {
   266         return operator=<NodeMap>(cmap);
   267       }
   268 
   269       template <typename CMap>
   270       NodeMap& operator=(const CMap& cmap) {
   271         Parent::operator=(cmap);
   272         return *this;
   273       }
   274 
   275     };
   276 
   277     template <typename V>
   278     class ArcMap : public GR::template ArcMap<V> {
   279     public:
   280       typedef typename GR::template ArcMap<V> Parent;
   281       explicit ArcMap(const GraphAdaptorBase<GR>& adapter)
   282         : Parent(*adapter._graph) {}
   283       ArcMap(const GraphAdaptorBase<GR>& adapter, const V& value)
   284         : Parent(*adapter._graph, value) {}
   285 
   286     private:
   287       ArcMap& operator=(const ArcMap& cmap) {
   288         return operator=<ArcMap>(cmap);
   289       }
   290 
   291       template <typename CMap>
   292       ArcMap& operator=(const CMap& cmap) {
   293         Parent::operator=(cmap);
   294         return *this;
   295       }
   296     };
   297 
   298     template <typename V>
   299     class EdgeMap : public GR::template EdgeMap<V> {
   300     public:
   301       typedef typename GR::template EdgeMap<V> Parent;
   302       explicit EdgeMap(const GraphAdaptorBase<GR>& adapter)
   303         : Parent(*adapter._graph) {}
   304       EdgeMap(const GraphAdaptorBase<GR>& adapter, const V& value)
   305         : Parent(*adapter._graph, value) {}
   306 
   307     private:
   308       EdgeMap& operator=(const EdgeMap& cmap) {
   309         return operator=<EdgeMap>(cmap);
   310       }
   311 
   312       template <typename CMap>
   313       EdgeMap& operator=(const CMap& cmap) {
   314         Parent::operator=(cmap);
   315         return *this;
   316       }
   317     };
   318 
   319   };
   320 
   321   template <typename DGR>
   322   class ReverseDigraphBase : public DigraphAdaptorBase<DGR> {
   323   public:
   324     typedef DGR Digraph;
   325     typedef DigraphAdaptorBase<DGR> Parent;
   326   protected:
   327     ReverseDigraphBase() : Parent() { }
   328   public:
   329     typedef typename Parent::Node Node;
   330     typedef typename Parent::Arc Arc;
   331 
   332     void firstIn(Arc& a, const Node& n) const { Parent::firstOut(a, n); }
   333     void firstOut(Arc& a, const Node& n ) const { Parent::firstIn(a, n); }
   334 
   335     void nextIn(Arc& a) const { Parent::nextOut(a); }
   336     void nextOut(Arc& a) const { Parent::nextIn(a); }
   337 
   338     Node source(const Arc& a) const { return Parent::target(a); }
   339     Node target(const Arc& a) const { return Parent::source(a); }
   340 
   341     Arc addArc(const Node& u, const Node& v) { return Parent::addArc(v, u); }
   342 
   343     typedef FindArcTagIndicator<DGR> FindArcTag;
   344     Arc findArc(const Node& u, const Node& v,
   345                 const Arc& prev = INVALID) const {
   346       return Parent::findArc(v, u, prev);
   347     }
   348 
   349   };
   350 
   351   /// \ingroup graph_adaptors
   352   ///
   353   /// \brief Adaptor class for reversing the orientation of the arcs in
   354   /// a digraph.
   355   ///
   356   /// ReverseDigraph can be used for reversing the arcs in a digraph.
   357   /// It conforms to the \ref concepts::Digraph "Digraph" concept.
   358   ///
   359   /// The adapted digraph can also be modified through this adaptor
   360   /// by adding or removing nodes or arcs, unless the \c GR template
   361   /// parameter is set to be \c const.
   362   ///
   363   /// \tparam DGR The type of the adapted digraph.
   364   /// It must conform to the \ref concepts::Digraph "Digraph" concept.
   365   /// It can also be specified to be \c const.
   366   ///
   367   /// \note The \c Node and \c Arc types of this adaptor and the adapted
   368   /// digraph are convertible to each other.
   369   template<typename DGR>
   370 #ifdef DOXYGEN
   371   class ReverseDigraph {
   372 #else
   373   class ReverseDigraph :
   374     public DigraphAdaptorExtender<ReverseDigraphBase<DGR> > {
   375 #endif
   376   public:
   377     /// The type of the adapted digraph.
   378     typedef DGR Digraph;
   379     typedef DigraphAdaptorExtender<ReverseDigraphBase<DGR> > Parent;
   380   protected:
   381     ReverseDigraph() { }
   382   public:
   383 
   384     /// \brief Constructor
   385     ///
   386     /// Creates a reverse digraph adaptor for the given digraph.
   387     explicit ReverseDigraph(DGR& digraph) {
   388       Parent::initialize(digraph);
   389     }
   390   };
   391 
   392   /// \brief Returns a read-only ReverseDigraph adaptor
   393   ///
   394   /// This function just returns a read-only \ref ReverseDigraph adaptor.
   395   /// \ingroup graph_adaptors
   396   /// \relates ReverseDigraph
   397   template<typename DGR>
   398   ReverseDigraph<const DGR> reverseDigraph(const DGR& digraph) {
   399     return ReverseDigraph<const DGR>(digraph);
   400   }
   401 
   402 
   403   template <typename DGR, typename NF, typename AF, bool ch = true>
   404   class SubDigraphBase : public DigraphAdaptorBase<DGR> {
   405   public:
   406     typedef DGR Digraph;
   407     typedef NF NodeFilterMap;
   408     typedef AF ArcFilterMap;
   409 
   410     typedef SubDigraphBase Adaptor;
   411     typedef DigraphAdaptorBase<DGR> Parent;
   412   protected:
   413     NF* _node_filter;
   414     AF* _arc_filter;
   415     SubDigraphBase()
   416       : Parent(), _node_filter(0), _arc_filter(0) { }
   417 
   418     void initialize(DGR& digraph, NF& node_filter, AF& arc_filter) {
   419       Parent::initialize(digraph);
   420       _node_filter = &node_filter;
   421       _arc_filter = &arc_filter;      
   422     }
   423 
   424   public:
   425 
   426     typedef typename Parent::Node Node;
   427     typedef typename Parent::Arc Arc;
   428 
   429     void first(Node& i) const {
   430       Parent::first(i);
   431       while (i != INVALID && !(*_node_filter)[i]) Parent::next(i);
   432     }
   433 
   434     void first(Arc& i) const {
   435       Parent::first(i);
   436       while (i != INVALID && (!(*_arc_filter)[i]
   437                               || !(*_node_filter)[Parent::source(i)]
   438                               || !(*_node_filter)[Parent::target(i)]))
   439         Parent::next(i);
   440     }
   441 
   442     void firstIn(Arc& i, const Node& n) const {
   443       Parent::firstIn(i, n);
   444       while (i != INVALID && (!(*_arc_filter)[i]
   445                               || !(*_node_filter)[Parent::source(i)]))
   446         Parent::nextIn(i);
   447     }
   448 
   449     void firstOut(Arc& i, const Node& n) const {
   450       Parent::firstOut(i, n);
   451       while (i != INVALID && (!(*_arc_filter)[i]
   452                               || !(*_node_filter)[Parent::target(i)]))
   453         Parent::nextOut(i);
   454     }
   455 
   456     void next(Node& i) const {
   457       Parent::next(i);
   458       while (i != INVALID && !(*_node_filter)[i]) Parent::next(i);
   459     }
   460 
   461     void next(Arc& i) const {
   462       Parent::next(i);
   463       while (i != INVALID && (!(*_arc_filter)[i]
   464                               || !(*_node_filter)[Parent::source(i)]
   465                               || !(*_node_filter)[Parent::target(i)]))
   466         Parent::next(i);
   467     }
   468 
   469     void nextIn(Arc& i) const {
   470       Parent::nextIn(i);
   471       while (i != INVALID && (!(*_arc_filter)[i]
   472                               || !(*_node_filter)[Parent::source(i)]))
   473         Parent::nextIn(i);
   474     }
   475 
   476     void nextOut(Arc& i) const {
   477       Parent::nextOut(i);
   478       while (i != INVALID && (!(*_arc_filter)[i]
   479                               || !(*_node_filter)[Parent::target(i)]))
   480         Parent::nextOut(i);
   481     }
   482 
   483     void status(const Node& n, bool v) const { _node_filter->set(n, v); }
   484     void status(const Arc& a, bool v) const { _arc_filter->set(a, v); }
   485 
   486     bool status(const Node& n) const { return (*_node_filter)[n]; }
   487     bool status(const Arc& a) const { return (*_arc_filter)[a]; }
   488 
   489     typedef False NodeNumTag;
   490     typedef False ArcNumTag;
   491 
   492     typedef FindArcTagIndicator<DGR> FindArcTag;
   493     Arc findArc(const Node& source, const Node& target,
   494                 const Arc& prev = INVALID) const {
   495       if (!(*_node_filter)[source] || !(*_node_filter)[target]) {
   496         return INVALID;
   497       }
   498       Arc arc = Parent::findArc(source, target, prev);
   499       while (arc != INVALID && !(*_arc_filter)[arc]) {
   500         arc = Parent::findArc(source, target, arc);
   501       }
   502       return arc;
   503     }
   504 
   505   public:
   506 
   507     template <typename V>
   508     class NodeMap 
   509       : public SubMapExtender<SubDigraphBase<DGR, NF, AF, ch>, 
   510 	      LEMON_SCOPE_FIX(DigraphAdaptorBase<DGR>, NodeMap<V>)> {
   511     public:
   512       typedef V Value;
   513       typedef SubMapExtender<SubDigraphBase<DGR, NF, AF, ch>,
   514 	    LEMON_SCOPE_FIX(DigraphAdaptorBase<DGR>, NodeMap<V>)> Parent;
   515 
   516       NodeMap(const SubDigraphBase<DGR, NF, AF, ch>& adaptor)
   517         : Parent(adaptor) {}
   518       NodeMap(const SubDigraphBase<DGR, NF, AF, ch>& adaptor, const V& value)
   519         : Parent(adaptor, value) {}
   520 
   521     private:
   522       NodeMap& operator=(const NodeMap& cmap) {
   523         return operator=<NodeMap>(cmap);
   524       }
   525 
   526       template <typename CMap>
   527       NodeMap& operator=(const CMap& cmap) {
   528         Parent::operator=(cmap);
   529         return *this;
   530       }
   531     };
   532 
   533     template <typename V>
   534     class ArcMap 
   535       : public SubMapExtender<SubDigraphBase<DGR, NF, AF, ch>,
   536 	      LEMON_SCOPE_FIX(DigraphAdaptorBase<DGR>, ArcMap<V>)> {
   537     public:
   538       typedef V Value;
   539       typedef SubMapExtender<SubDigraphBase<DGR, NF, AF, ch>,
   540         LEMON_SCOPE_FIX(DigraphAdaptorBase<DGR>, ArcMap<V>)> Parent;
   541 
   542       ArcMap(const SubDigraphBase<DGR, NF, AF, ch>& adaptor)
   543         : Parent(adaptor) {}
   544       ArcMap(const SubDigraphBase<DGR, NF, AF, ch>& adaptor, const V& value)
   545         : Parent(adaptor, value) {}
   546 
   547     private:
   548       ArcMap& operator=(const ArcMap& cmap) {
   549         return operator=<ArcMap>(cmap);
   550       }
   551 
   552       template <typename CMap>
   553       ArcMap& operator=(const CMap& cmap) {
   554         Parent::operator=(cmap);
   555         return *this;
   556       }
   557     };
   558 
   559   };
   560 
   561   template <typename DGR, typename NF, typename AF>
   562   class SubDigraphBase<DGR, NF, AF, false>
   563     : public DigraphAdaptorBase<DGR> {
   564   public:
   565     typedef DGR Digraph;
   566     typedef NF NodeFilterMap;
   567     typedef AF ArcFilterMap;
   568 
   569     typedef SubDigraphBase Adaptor;
   570     typedef DigraphAdaptorBase<Digraph> Parent;
   571   protected:
   572     NF* _node_filter;
   573     AF* _arc_filter;
   574     SubDigraphBase()
   575       : Parent(), _node_filter(0), _arc_filter(0) { }
   576 
   577     void initialize(DGR& digraph, NF& node_filter, AF& arc_filter) {
   578       Parent::initialize(digraph);
   579       _node_filter = &node_filter;
   580       _arc_filter = &arc_filter;      
   581     }
   582 
   583   public:
   584 
   585     typedef typename Parent::Node Node;
   586     typedef typename Parent::Arc Arc;
   587 
   588     void first(Node& i) const {
   589       Parent::first(i);
   590       while (i!=INVALID && !(*_node_filter)[i]) Parent::next(i);
   591     }
   592 
   593     void first(Arc& i) const {
   594       Parent::first(i);
   595       while (i!=INVALID && !(*_arc_filter)[i]) Parent::next(i);
   596     }
   597 
   598     void firstIn(Arc& i, const Node& n) const {
   599       Parent::firstIn(i, n);
   600       while (i!=INVALID && !(*_arc_filter)[i]) Parent::nextIn(i);
   601     }
   602 
   603     void firstOut(Arc& i, const Node& n) const {
   604       Parent::firstOut(i, n);
   605       while (i!=INVALID && !(*_arc_filter)[i]) Parent::nextOut(i);
   606     }
   607 
   608     void next(Node& i) const {
   609       Parent::next(i);
   610       while (i!=INVALID && !(*_node_filter)[i]) Parent::next(i);
   611     }
   612     void next(Arc& i) const {
   613       Parent::next(i);
   614       while (i!=INVALID && !(*_arc_filter)[i]) Parent::next(i);
   615     }
   616     void nextIn(Arc& i) const {
   617       Parent::nextIn(i);
   618       while (i!=INVALID && !(*_arc_filter)[i]) Parent::nextIn(i);
   619     }
   620 
   621     void nextOut(Arc& i) const {
   622       Parent::nextOut(i);
   623       while (i!=INVALID && !(*_arc_filter)[i]) Parent::nextOut(i);
   624     }
   625 
   626     void status(const Node& n, bool v) const { _node_filter->set(n, v); }
   627     void status(const Arc& a, bool v) const { _arc_filter->set(a, v); }
   628 
   629     bool status(const Node& n) const { return (*_node_filter)[n]; }
   630     bool status(const Arc& a) const { return (*_arc_filter)[a]; }
   631 
   632     typedef False NodeNumTag;
   633     typedef False ArcNumTag;
   634 
   635     typedef FindArcTagIndicator<DGR> FindArcTag;
   636     Arc findArc(const Node& source, const Node& target,
   637                 const Arc& prev = INVALID) const {
   638       if (!(*_node_filter)[source] || !(*_node_filter)[target]) {
   639         return INVALID;
   640       }
   641       Arc arc = Parent::findArc(source, target, prev);
   642       while (arc != INVALID && !(*_arc_filter)[arc]) {
   643         arc = Parent::findArc(source, target, arc);
   644       }
   645       return arc;
   646     }
   647 
   648     template <typename V>
   649     class NodeMap 
   650       : public SubMapExtender<SubDigraphBase<DGR, NF, AF, false>,
   651           LEMON_SCOPE_FIX(DigraphAdaptorBase<DGR>, NodeMap<V>)> {
   652     public:
   653       typedef V Value;
   654       typedef SubMapExtender<SubDigraphBase<DGR, NF, AF, false>, 
   655         LEMON_SCOPE_FIX(DigraphAdaptorBase<DGR>, NodeMap<V>)> Parent;
   656 
   657       NodeMap(const SubDigraphBase<DGR, NF, AF, false>& adaptor)
   658         : Parent(adaptor) {}
   659       NodeMap(const SubDigraphBase<DGR, NF, AF, false>& adaptor, const V& value)
   660         : Parent(adaptor, value) {}
   661 
   662     private:
   663       NodeMap& operator=(const NodeMap& cmap) {
   664         return operator=<NodeMap>(cmap);
   665       }
   666 
   667       template <typename CMap>
   668       NodeMap& operator=(const CMap& cmap) {
   669         Parent::operator=(cmap);
   670         return *this;
   671       }
   672     };
   673 
   674     template <typename V>
   675     class ArcMap 
   676       : public SubMapExtender<SubDigraphBase<DGR, NF, AF, false>,
   677           LEMON_SCOPE_FIX(DigraphAdaptorBase<DGR>, ArcMap<V>)> {
   678     public:
   679       typedef V Value;
   680       typedef SubMapExtender<SubDigraphBase<DGR, NF, AF, false>,
   681           LEMON_SCOPE_FIX(DigraphAdaptorBase<DGR>, ArcMap<V>)> Parent;
   682 
   683       ArcMap(const SubDigraphBase<DGR, NF, AF, false>& adaptor)
   684         : Parent(adaptor) {}
   685       ArcMap(const SubDigraphBase<DGR, NF, AF, false>& adaptor, const V& value)
   686         : Parent(adaptor, value) {}
   687 
   688     private:
   689       ArcMap& operator=(const ArcMap& cmap) {
   690         return operator=<ArcMap>(cmap);
   691       }
   692 
   693       template <typename CMap>
   694       ArcMap& operator=(const CMap& cmap) {
   695         Parent::operator=(cmap);
   696         return *this;
   697       }
   698     };
   699 
   700   };
   701 
   702   /// \ingroup graph_adaptors
   703   ///
   704   /// \brief Adaptor class for hiding nodes and arcs in a digraph
   705   ///
   706   /// SubDigraph can be used for hiding nodes and arcs in a digraph.
   707   /// A \c bool node map and a \c bool arc map must be specified, which
   708   /// define the filters for nodes and arcs.
   709   /// Only the nodes and arcs with \c true filter value are
   710   /// shown in the subdigraph. The arcs that are incident to hidden
   711   /// nodes are also filtered out.
   712   /// This adaptor conforms to the \ref concepts::Digraph "Digraph" concept.
   713   ///
   714   /// The adapted digraph can also be modified through this adaptor
   715   /// by adding or removing nodes or arcs, unless the \c GR template
   716   /// parameter is set to be \c const.
   717   ///
   718   /// \tparam DGR The type of the adapted digraph.
   719   /// It must conform to the \ref concepts::Digraph "Digraph" concept.
   720   /// It can also be specified to be \c const.
   721   /// \tparam NF The type of the node filter map.
   722   /// It must be a \c bool (or convertible) node map of the
   723   /// adapted digraph. The default type is
   724   /// \ref concepts::Digraph::NodeMap "DGR::NodeMap<bool>".
   725   /// \tparam AF The type of the arc filter map.
   726   /// It must be \c bool (or convertible) arc map of the
   727   /// adapted digraph. The default type is
   728   /// \ref concepts::Digraph::ArcMap "DGR::ArcMap<bool>".
   729   ///
   730   /// \note The \c Node and \c Arc types of this adaptor and the adapted
   731   /// digraph are convertible to each other.
   732   ///
   733   /// \see FilterNodes
   734   /// \see FilterArcs
   735 #ifdef DOXYGEN
   736   template<typename DGR, typename NF, typename AF>
   737   class SubDigraph {
   738 #else
   739   template<typename DGR,
   740            typename NF = typename DGR::template NodeMap<bool>,
   741            typename AF = typename DGR::template ArcMap<bool> >
   742   class SubDigraph :
   743     public DigraphAdaptorExtender<SubDigraphBase<DGR, NF, AF, true> > {
   744 #endif
   745   public:
   746     /// The type of the adapted digraph.
   747     typedef DGR Digraph;
   748     /// The type of the node filter map.
   749     typedef NF NodeFilterMap;
   750     /// The type of the arc filter map.
   751     typedef AF ArcFilterMap;
   752 
   753     typedef DigraphAdaptorExtender<SubDigraphBase<DGR, NF, AF, true> >
   754       Parent;
   755 
   756     typedef typename Parent::Node Node;
   757     typedef typename Parent::Arc Arc;
   758 
   759   protected:
   760     SubDigraph() { }
   761   public:
   762 
   763     /// \brief Constructor
   764     ///
   765     /// Creates a subdigraph for the given digraph with the
   766     /// given node and arc filter maps.
   767     SubDigraph(DGR& digraph, NF& node_filter, AF& arc_filter) {
   768       Parent::initialize(digraph, node_filter, arc_filter);
   769     }
   770 
   771     /// \brief Sets the status of the given node
   772     ///
   773     /// This function sets the status of the given node.
   774     /// It is done by simply setting the assigned value of \c n
   775     /// to \c v in the node filter map.
   776     void status(const Node& n, bool v) const { Parent::status(n, v); }
   777 
   778     /// \brief Sets the status of the given arc
   779     ///
   780     /// This function sets the status of the given arc.
   781     /// It is done by simply setting the assigned value of \c a
   782     /// to \c v in the arc filter map.
   783     void status(const Arc& a, bool v) const { Parent::status(a, v); }
   784 
   785     /// \brief Returns the status of the given node
   786     ///
   787     /// This function returns the status of the given node.
   788     /// It is \c true if the given node is enabled (i.e. not hidden).
   789     bool status(const Node& n) const { return Parent::status(n); }
   790 
   791     /// \brief Returns the status of the given arc
   792     ///
   793     /// This function returns the status of the given arc.
   794     /// It is \c true if the given arc is enabled (i.e. not hidden).
   795     bool status(const Arc& a) const { return Parent::status(a); }
   796 
   797     /// \brief Disables the given node
   798     ///
   799     /// This function disables the given node in the subdigraph,
   800     /// so the iteration jumps over it.
   801     /// It is the same as \ref status() "status(n, false)".
   802     void disable(const Node& n) const { Parent::status(n, false); }
   803 
   804     /// \brief Disables the given arc
   805     ///
   806     /// This function disables the given arc in the subdigraph,
   807     /// so the iteration jumps over it.
   808     /// It is the same as \ref status() "status(a, false)".
   809     void disable(const Arc& a) const { Parent::status(a, false); }
   810 
   811     /// \brief Enables the given node
   812     ///
   813     /// This function enables the given node in the subdigraph.
   814     /// It is the same as \ref status() "status(n, true)".
   815     void enable(const Node& n) const { Parent::status(n, true); }
   816 
   817     /// \brief Enables the given arc
   818     ///
   819     /// This function enables the given arc in the subdigraph.
   820     /// It is the same as \ref status() "status(a, true)".
   821     void enable(const Arc& a) const { Parent::status(a, true); }
   822 
   823   };
   824 
   825   /// \brief Returns a read-only SubDigraph adaptor
   826   ///
   827   /// This function just returns a read-only \ref SubDigraph adaptor.
   828   /// \ingroup graph_adaptors
   829   /// \relates SubDigraph
   830   template<typename DGR, typename NF, typename AF>
   831   SubDigraph<const DGR, NF, AF>
   832   subDigraph(const DGR& digraph,
   833              NF& node_filter, AF& arc_filter) {
   834     return SubDigraph<const DGR, NF, AF>
   835       (digraph, node_filter, arc_filter);
   836   }
   837 
   838   template<typename DGR, typename NF, typename AF>
   839   SubDigraph<const DGR, const NF, AF>
   840   subDigraph(const DGR& digraph,
   841              const NF& node_filter, AF& arc_filter) {
   842     return SubDigraph<const DGR, const NF, AF>
   843       (digraph, node_filter, arc_filter);
   844   }
   845 
   846   template<typename DGR, typename NF, typename AF>
   847   SubDigraph<const DGR, NF, const AF>
   848   subDigraph(const DGR& digraph,
   849              NF& node_filter, const AF& arc_filter) {
   850     return SubDigraph<const DGR, NF, const AF>
   851       (digraph, node_filter, arc_filter);
   852   }
   853 
   854   template<typename DGR, typename NF, typename AF>
   855   SubDigraph<const DGR, const NF, const AF>
   856   subDigraph(const DGR& digraph,
   857              const NF& node_filter, const AF& arc_filter) {
   858     return SubDigraph<const DGR, const NF, const AF>
   859       (digraph, node_filter, arc_filter);
   860   }
   861 
   862 
   863   template <typename GR, typename NF, typename EF, bool ch = true>
   864   class SubGraphBase : public GraphAdaptorBase<GR> {
   865   public:
   866     typedef GR Graph;
   867     typedef NF NodeFilterMap;
   868     typedef EF EdgeFilterMap;
   869 
   870     typedef SubGraphBase Adaptor;
   871     typedef GraphAdaptorBase<GR> Parent;
   872   protected:
   873 
   874     NF* _node_filter;
   875     EF* _edge_filter;
   876 
   877     SubGraphBase()
   878       : Parent(), _node_filter(0), _edge_filter(0) { }
   879 
   880     void initialize(GR& graph, NF& node_filter, EF& edge_filter) {
   881       Parent::initialize(graph);
   882       _node_filter = &node_filter;
   883       _edge_filter = &edge_filter;
   884     }
   885 
   886   public:
   887 
   888     typedef typename Parent::Node Node;
   889     typedef typename Parent::Arc Arc;
   890     typedef typename Parent::Edge Edge;
   891 
   892     void first(Node& i) const {
   893       Parent::first(i);
   894       while (i!=INVALID && !(*_node_filter)[i]) Parent::next(i);
   895     }
   896 
   897     void first(Arc& i) const {
   898       Parent::first(i);
   899       while (i!=INVALID && (!(*_edge_filter)[i]
   900                             || !(*_node_filter)[Parent::source(i)]
   901                             || !(*_node_filter)[Parent::target(i)]))
   902         Parent::next(i);
   903     }
   904 
   905     void first(Edge& i) const {
   906       Parent::first(i);
   907       while (i!=INVALID && (!(*_edge_filter)[i]
   908                             || !(*_node_filter)[Parent::u(i)]
   909                             || !(*_node_filter)[Parent::v(i)]))
   910         Parent::next(i);
   911     }
   912 
   913     void firstIn(Arc& i, const Node& n) const {
   914       Parent::firstIn(i, n);
   915       while (i!=INVALID && (!(*_edge_filter)[i]
   916                             || !(*_node_filter)[Parent::source(i)]))
   917         Parent::nextIn(i);
   918     }
   919 
   920     void firstOut(Arc& i, const Node& n) const {
   921       Parent::firstOut(i, n);
   922       while (i!=INVALID && (!(*_edge_filter)[i]
   923                             || !(*_node_filter)[Parent::target(i)]))
   924         Parent::nextOut(i);
   925     }
   926 
   927     void firstInc(Edge& i, bool& d, const Node& n) const {
   928       Parent::firstInc(i, d, n);
   929       while (i!=INVALID && (!(*_edge_filter)[i]
   930                             || !(*_node_filter)[Parent::u(i)]
   931                             || !(*_node_filter)[Parent::v(i)]))
   932         Parent::nextInc(i, d);
   933     }
   934 
   935     void next(Node& i) const {
   936       Parent::next(i);
   937       while (i!=INVALID && !(*_node_filter)[i]) Parent::next(i);
   938     }
   939 
   940     void next(Arc& i) const {
   941       Parent::next(i);
   942       while (i!=INVALID && (!(*_edge_filter)[i]
   943                             || !(*_node_filter)[Parent::source(i)]
   944                             || !(*_node_filter)[Parent::target(i)]))
   945         Parent::next(i);
   946     }
   947 
   948     void next(Edge& i) const {
   949       Parent::next(i);
   950       while (i!=INVALID && (!(*_edge_filter)[i]
   951                             || !(*_node_filter)[Parent::u(i)]
   952                             || !(*_node_filter)[Parent::v(i)]))
   953         Parent::next(i);
   954     }
   955 
   956     void nextIn(Arc& i) const {
   957       Parent::nextIn(i);
   958       while (i!=INVALID && (!(*_edge_filter)[i]
   959                             || !(*_node_filter)[Parent::source(i)]))
   960         Parent::nextIn(i);
   961     }
   962 
   963     void nextOut(Arc& i) const {
   964       Parent::nextOut(i);
   965       while (i!=INVALID && (!(*_edge_filter)[i]
   966                             || !(*_node_filter)[Parent::target(i)]))
   967         Parent::nextOut(i);
   968     }
   969 
   970     void nextInc(Edge& i, bool& d) const {
   971       Parent::nextInc(i, d);
   972       while (i!=INVALID && (!(*_edge_filter)[i]
   973                             || !(*_node_filter)[Parent::u(i)]
   974                             || !(*_node_filter)[Parent::v(i)]))
   975         Parent::nextInc(i, d);
   976     }
   977 
   978     void status(const Node& n, bool v) const { _node_filter->set(n, v); }
   979     void status(const Edge& e, bool v) const { _edge_filter->set(e, v); }
   980 
   981     bool status(const Node& n) const { return (*_node_filter)[n]; }
   982     bool status(const Edge& e) const { return (*_edge_filter)[e]; }
   983 
   984     typedef False NodeNumTag;
   985     typedef False ArcNumTag;
   986     typedef False EdgeNumTag;
   987 
   988     typedef FindArcTagIndicator<Graph> FindArcTag;
   989     Arc findArc(const Node& u, const Node& v,
   990                 const Arc& prev = INVALID) const {
   991       if (!(*_node_filter)[u] || !(*_node_filter)[v]) {
   992         return INVALID;
   993       }
   994       Arc arc = Parent::findArc(u, v, prev);
   995       while (arc != INVALID && !(*_edge_filter)[arc]) {
   996         arc = Parent::findArc(u, v, arc);
   997       }
   998       return arc;
   999     }
  1000 
  1001     typedef FindEdgeTagIndicator<Graph> FindEdgeTag;
  1002     Edge findEdge(const Node& u, const Node& v,
  1003                   const Edge& prev = INVALID) const {
  1004       if (!(*_node_filter)[u] || !(*_node_filter)[v]) {
  1005         return INVALID;
  1006       }
  1007       Edge edge = Parent::findEdge(u, v, prev);
  1008       while (edge != INVALID && !(*_edge_filter)[edge]) {
  1009         edge = Parent::findEdge(u, v, edge);
  1010       }
  1011       return edge;
  1012     }
  1013 
  1014     template <typename V>
  1015     class NodeMap 
  1016       : public SubMapExtender<SubGraphBase<GR, NF, EF, ch>,
  1017           LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, NodeMap<V>)> {
  1018     public:
  1019       typedef V Value;
  1020       typedef SubMapExtender<SubGraphBase<GR, NF, EF, ch>, 
  1021         LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, NodeMap<V>)> Parent;
  1022 
  1023       NodeMap(const SubGraphBase<GR, NF, EF, ch>& adaptor)
  1024         : Parent(adaptor) {}
  1025       NodeMap(const SubGraphBase<GR, NF, EF, ch>& adaptor, const V& value)
  1026         : Parent(adaptor, value) {}
  1027 
  1028     private:
  1029       NodeMap& operator=(const NodeMap& cmap) {
  1030         return operator=<NodeMap>(cmap);
  1031       }
  1032 
  1033       template <typename CMap>
  1034       NodeMap& operator=(const CMap& cmap) {
  1035         Parent::operator=(cmap);
  1036         return *this;
  1037       }
  1038     };
  1039 
  1040     template <typename V>
  1041     class ArcMap 
  1042       : public SubMapExtender<SubGraphBase<GR, NF, EF, ch>,
  1043           LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, ArcMap<V>)> {
  1044     public:
  1045       typedef V Value;
  1046       typedef SubMapExtender<SubGraphBase<GR, NF, EF, ch>, 
  1047         LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, ArcMap<V>)> Parent;
  1048 
  1049       ArcMap(const SubGraphBase<GR, NF, EF, ch>& adaptor)
  1050         : Parent(adaptor) {}
  1051       ArcMap(const SubGraphBase<GR, NF, EF, ch>& adaptor, const V& value)
  1052         : Parent(adaptor, value) {}
  1053 
  1054     private:
  1055       ArcMap& operator=(const ArcMap& cmap) {
  1056         return operator=<ArcMap>(cmap);
  1057       }
  1058 
  1059       template <typename CMap>
  1060       ArcMap& operator=(const CMap& cmap) {
  1061         Parent::operator=(cmap);
  1062         return *this;
  1063       }
  1064     };
  1065 
  1066     template <typename V>
  1067     class EdgeMap 
  1068       : public SubMapExtender<SubGraphBase<GR, NF, EF, ch>,
  1069         LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, EdgeMap<V>)> {
  1070     public:
  1071       typedef V Value;
  1072       typedef SubMapExtender<SubGraphBase<GR, NF, EF, ch>, 
  1073         LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, EdgeMap<V>)> Parent;
  1074 
  1075       EdgeMap(const SubGraphBase<GR, NF, EF, ch>& adaptor)
  1076         : Parent(adaptor) {}
  1077 
  1078       EdgeMap(const SubGraphBase<GR, NF, EF, ch>& adaptor, const V& value)
  1079         : Parent(adaptor, value) {}
  1080 
  1081     private:
  1082       EdgeMap& operator=(const EdgeMap& cmap) {
  1083         return operator=<EdgeMap>(cmap);
  1084       }
  1085 
  1086       template <typename CMap>
  1087       EdgeMap& operator=(const CMap& cmap) {
  1088         Parent::operator=(cmap);
  1089         return *this;
  1090       }
  1091     };
  1092 
  1093   };
  1094 
  1095   template <typename GR, typename NF, typename EF>
  1096   class SubGraphBase<GR, NF, EF, false>
  1097     : public GraphAdaptorBase<GR> {
  1098   public:
  1099     typedef GR Graph;
  1100     typedef NF NodeFilterMap;
  1101     typedef EF EdgeFilterMap;
  1102 
  1103     typedef SubGraphBase Adaptor;
  1104     typedef GraphAdaptorBase<GR> Parent;
  1105   protected:
  1106     NF* _node_filter;
  1107     EF* _edge_filter;
  1108     SubGraphBase() 
  1109 	  : Parent(), _node_filter(0), _edge_filter(0) { }
  1110 
  1111     void initialize(GR& graph, NF& node_filter, EF& edge_filter) {
  1112       Parent::initialize(graph);
  1113       _node_filter = &node_filter;
  1114       _edge_filter = &edge_filter;
  1115     }
  1116 
  1117   public:
  1118 
  1119     typedef typename Parent::Node Node;
  1120     typedef typename Parent::Arc Arc;
  1121     typedef typename Parent::Edge Edge;
  1122 
  1123     void first(Node& i) const {
  1124       Parent::first(i);
  1125       while (i!=INVALID && !(*_node_filter)[i]) Parent::next(i);
  1126     }
  1127 
  1128     void first(Arc& i) const {
  1129       Parent::first(i);
  1130       while (i!=INVALID && !(*_edge_filter)[i]) Parent::next(i);
  1131     }
  1132 
  1133     void first(Edge& i) const {
  1134       Parent::first(i);
  1135       while (i!=INVALID && !(*_edge_filter)[i]) Parent::next(i);
  1136     }
  1137 
  1138     void firstIn(Arc& i, const Node& n) const {
  1139       Parent::firstIn(i, n);
  1140       while (i!=INVALID && !(*_edge_filter)[i]) Parent::nextIn(i);
  1141     }
  1142 
  1143     void firstOut(Arc& i, const Node& n) const {
  1144       Parent::firstOut(i, n);
  1145       while (i!=INVALID && !(*_edge_filter)[i]) Parent::nextOut(i);
  1146     }
  1147 
  1148     void firstInc(Edge& i, bool& d, const Node& n) const {
  1149       Parent::firstInc(i, d, n);
  1150       while (i!=INVALID && !(*_edge_filter)[i]) Parent::nextInc(i, d);
  1151     }
  1152 
  1153     void next(Node& i) const {
  1154       Parent::next(i);
  1155       while (i!=INVALID && !(*_node_filter)[i]) Parent::next(i);
  1156     }
  1157     void next(Arc& i) const {
  1158       Parent::next(i);
  1159       while (i!=INVALID && !(*_edge_filter)[i]) Parent::next(i);
  1160     }
  1161     void next(Edge& i) const {
  1162       Parent::next(i);
  1163       while (i!=INVALID && !(*_edge_filter)[i]) Parent::next(i);
  1164     }
  1165     void nextIn(Arc& i) const {
  1166       Parent::nextIn(i);
  1167       while (i!=INVALID && !(*_edge_filter)[i]) Parent::nextIn(i);
  1168     }
  1169 
  1170     void nextOut(Arc& i) const {
  1171       Parent::nextOut(i);
  1172       while (i!=INVALID && !(*_edge_filter)[i]) Parent::nextOut(i);
  1173     }
  1174     void nextInc(Edge& i, bool& d) const {
  1175       Parent::nextInc(i, d);
  1176       while (i!=INVALID && !(*_edge_filter)[i]) Parent::nextInc(i, d);
  1177     }
  1178 
  1179     void status(const Node& n, bool v) const { _node_filter->set(n, v); }
  1180     void status(const Edge& e, bool v) const { _edge_filter->set(e, v); }
  1181 
  1182     bool status(const Node& n) const { return (*_node_filter)[n]; }
  1183     bool status(const Edge& e) const { return (*_edge_filter)[e]; }
  1184 
  1185     typedef False NodeNumTag;
  1186     typedef False ArcNumTag;
  1187     typedef False EdgeNumTag;
  1188 
  1189     typedef FindArcTagIndicator<Graph> FindArcTag;
  1190     Arc findArc(const Node& u, const Node& v,
  1191                 const Arc& prev = INVALID) const {
  1192       Arc arc = Parent::findArc(u, v, prev);
  1193       while (arc != INVALID && !(*_edge_filter)[arc]) {
  1194         arc = Parent::findArc(u, v, arc);
  1195       }
  1196       return arc;
  1197     }
  1198 
  1199     typedef FindEdgeTagIndicator<Graph> FindEdgeTag;
  1200     Edge findEdge(const Node& u, const Node& v,
  1201                   const Edge& prev = INVALID) const {
  1202       Edge edge = Parent::findEdge(u, v, prev);
  1203       while (edge != INVALID && !(*_edge_filter)[edge]) {
  1204         edge = Parent::findEdge(u, v, edge);
  1205       }
  1206       return edge;
  1207     }
  1208 
  1209     template <typename V>
  1210     class NodeMap 
  1211       : public SubMapExtender<SubGraphBase<GR, NF, EF, false>,
  1212           LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, NodeMap<V>)> {
  1213     public:
  1214       typedef V Value;
  1215       typedef SubMapExtender<SubGraphBase<GR, NF, EF, false>, 
  1216         LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, NodeMap<V>)> Parent;
  1217 
  1218       NodeMap(const SubGraphBase<GR, NF, EF, false>& adaptor)
  1219         : Parent(adaptor) {}
  1220       NodeMap(const SubGraphBase<GR, NF, EF, false>& adaptor, const V& value)
  1221         : Parent(adaptor, value) {}
  1222 
  1223     private:
  1224       NodeMap& operator=(const NodeMap& cmap) {
  1225         return operator=<NodeMap>(cmap);
  1226       }
  1227 
  1228       template <typename CMap>
  1229       NodeMap& operator=(const CMap& cmap) {
  1230         Parent::operator=(cmap);
  1231         return *this;
  1232       }
  1233     };
  1234 
  1235     template <typename V>
  1236     class ArcMap 
  1237       : public SubMapExtender<SubGraphBase<GR, NF, EF, false>,
  1238           LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, ArcMap<V>)> {
  1239     public:
  1240       typedef V Value;
  1241       typedef SubMapExtender<SubGraphBase<GR, NF, EF, false>, 
  1242         LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, ArcMap<V>)> Parent;
  1243 
  1244       ArcMap(const SubGraphBase<GR, NF, EF, false>& adaptor)
  1245         : Parent(adaptor) {}
  1246       ArcMap(const SubGraphBase<GR, NF, EF, false>& adaptor, const V& value)
  1247         : Parent(adaptor, value) {}
  1248 
  1249     private:
  1250       ArcMap& operator=(const ArcMap& cmap) {
  1251         return operator=<ArcMap>(cmap);
  1252       }
  1253 
  1254       template <typename CMap>
  1255       ArcMap& operator=(const CMap& cmap) {
  1256         Parent::operator=(cmap);
  1257         return *this;
  1258       }
  1259     };
  1260 
  1261     template <typename V>
  1262     class EdgeMap 
  1263       : public SubMapExtender<SubGraphBase<GR, NF, EF, false>,
  1264         LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, EdgeMap<V>)> {
  1265     public:
  1266       typedef V Value;
  1267       typedef SubMapExtender<SubGraphBase<GR, NF, EF, false>, 
  1268 		  LEMON_SCOPE_FIX(GraphAdaptorBase<GR>, EdgeMap<V>)> Parent;
  1269 
  1270       EdgeMap(const SubGraphBase<GR, NF, EF, false>& adaptor)
  1271         : Parent(adaptor) {}
  1272 
  1273       EdgeMap(const SubGraphBase<GR, NF, EF, false>& adaptor, const V& value)
  1274         : Parent(adaptor, value) {}
  1275 
  1276     private:
  1277       EdgeMap& operator=(const EdgeMap& cmap) {
  1278         return operator=<EdgeMap>(cmap);
  1279       }
  1280 
  1281       template <typename CMap>
  1282       EdgeMap& operator=(const CMap& cmap) {
  1283         Parent::operator=(cmap);
  1284         return *this;
  1285       }
  1286     };
  1287 
  1288   };
  1289 
  1290   /// \ingroup graph_adaptors
  1291   ///
  1292   /// \brief Adaptor class for hiding nodes and edges in an undirected
  1293   /// graph.
  1294   ///
  1295   /// SubGraph can be used for hiding nodes and edges in a graph.
  1296   /// A \c bool node map and a \c bool edge map must be specified, which
  1297   /// define the filters for nodes and edges.
  1298   /// Only the nodes and edges with \c true filter value are
  1299   /// shown in the subgraph. The edges that are incident to hidden
  1300   /// nodes are also filtered out.
  1301   /// This adaptor conforms to the \ref concepts::Graph "Graph" concept.
  1302   ///
  1303   /// The adapted graph can also be modified through this adaptor
  1304   /// by adding or removing nodes or edges, unless the \c GR template
  1305   /// parameter is set to be \c const.
  1306   ///
  1307   /// \tparam GR The type of the adapted graph.
  1308   /// It must conform to the \ref concepts::Graph "Graph" concept.
  1309   /// It can also be specified to be \c const.
  1310   /// \tparam NF The type of the node filter map.
  1311   /// It must be a \c bool (or convertible) node map of the
  1312   /// adapted graph. The default type is
  1313   /// \ref concepts::Graph::NodeMap "GR::NodeMap<bool>".
  1314   /// \tparam EF The type of the edge filter map.
  1315   /// It must be a \c bool (or convertible) edge map of the
  1316   /// adapted graph. The default type is
  1317   /// \ref concepts::Graph::EdgeMap "GR::EdgeMap<bool>".
  1318   ///
  1319   /// \note The \c Node, \c Edge and \c Arc types of this adaptor and the
  1320   /// adapted graph are convertible to each other.
  1321   ///
  1322   /// \see FilterNodes
  1323   /// \see FilterEdges
  1324 #ifdef DOXYGEN
  1325   template<typename GR, typename NF, typename EF>
  1326   class SubGraph {
  1327 #else
  1328   template<typename GR,
  1329            typename NF = typename GR::template NodeMap<bool>,
  1330            typename EF = typename GR::template EdgeMap<bool> >
  1331   class SubGraph :
  1332     public GraphAdaptorExtender<SubGraphBase<GR, NF, EF, true> > {
  1333 #endif
  1334   public:
  1335     /// The type of the adapted graph.
  1336     typedef GR Graph;
  1337     /// The type of the node filter map.
  1338     typedef NF NodeFilterMap;
  1339     /// The type of the edge filter map.
  1340     typedef EF EdgeFilterMap;
  1341 
  1342     typedef GraphAdaptorExtender<SubGraphBase<GR, NF, EF, true> >
  1343       Parent;
  1344 
  1345     typedef typename Parent::Node Node;
  1346     typedef typename Parent::Edge Edge;
  1347 
  1348   protected:
  1349     SubGraph() { }
  1350   public:
  1351 
  1352     /// \brief Constructor
  1353     ///
  1354     /// Creates a subgraph for the given graph with the given node
  1355     /// and edge filter maps.
  1356     SubGraph(GR& graph, NF& node_filter, EF& edge_filter) {
  1357       initialize(graph, node_filter, edge_filter);
  1358     }
  1359 
  1360     /// \brief Sets the status of the given node
  1361     ///
  1362     /// This function sets the status of the given node.
  1363     /// It is done by simply setting the assigned value of \c n
  1364     /// to \c v in the node filter map.
  1365     void status(const Node& n, bool v) const { Parent::status(n, v); }
  1366 
  1367     /// \brief Sets the status of the given edge
  1368     ///
  1369     /// This function sets the status of the given edge.
  1370     /// It is done by simply setting the assigned value of \c e
  1371     /// to \c v in the edge filter map.
  1372     void status(const Edge& e, bool v) const { Parent::status(e, v); }
  1373 
  1374     /// \brief Returns the status of the given node
  1375     ///
  1376     /// This function returns the status of the given node.
  1377     /// It is \c true if the given node is enabled (i.e. not hidden).
  1378     bool status(const Node& n) const { return Parent::status(n); }
  1379 
  1380     /// \brief Returns the status of the given edge
  1381     ///
  1382     /// This function returns the status of the given edge.
  1383     /// It is \c true if the given edge is enabled (i.e. not hidden).
  1384     bool status(const Edge& e) const { return Parent::status(e); }
  1385 
  1386     /// \brief Disables the given node
  1387     ///
  1388     /// This function disables the given node in the subdigraph,
  1389     /// so the iteration jumps over it.
  1390     /// It is the same as \ref status() "status(n, false)".
  1391     void disable(const Node& n) const { Parent::status(n, false); }
  1392 
  1393     /// \brief Disables the given edge
  1394     ///
  1395     /// This function disables the given edge in the subgraph,
  1396     /// so the iteration jumps over it.
  1397     /// It is the same as \ref status() "status(e, false)".
  1398     void disable(const Edge& e) const { Parent::status(e, false); }
  1399 
  1400     /// \brief Enables the given node
  1401     ///
  1402     /// This function enables the given node in the subdigraph.
  1403     /// It is the same as \ref status() "status(n, true)".
  1404     void enable(const Node& n) const { Parent::status(n, true); }
  1405 
  1406     /// \brief Enables the given edge
  1407     ///
  1408     /// This function enables the given edge in the subgraph.
  1409     /// It is the same as \ref status() "status(e, true)".
  1410     void enable(const Edge& e) const { Parent::status(e, true); }
  1411 
  1412   };
  1413 
  1414   /// \brief Returns a read-only SubGraph adaptor
  1415   ///
  1416   /// This function just returns a read-only \ref SubGraph adaptor.
  1417   /// \ingroup graph_adaptors
  1418   /// \relates SubGraph
  1419   template<typename GR, typename NF, typename EF>
  1420   SubGraph<const GR, NF, EF>
  1421   subGraph(const GR& graph, NF& node_filter, EF& edge_filter) {
  1422     return SubGraph<const GR, NF, EF>
  1423       (graph, node_filter, edge_filter);
  1424   }
  1425 
  1426   template<typename GR, typename NF, typename EF>
  1427   SubGraph<const GR, const NF, EF>
  1428   subGraph(const GR& graph, const NF& node_filter, EF& edge_filter) {
  1429     return SubGraph<const GR, const NF, EF>
  1430       (graph, node_filter, edge_filter);
  1431   }
  1432 
  1433   template<typename GR, typename NF, typename EF>
  1434   SubGraph<const GR, NF, const EF>
  1435   subGraph(const GR& graph, NF& node_filter, const EF& edge_filter) {
  1436     return SubGraph<const GR, NF, const EF>
  1437       (graph, node_filter, edge_filter);
  1438   }
  1439 
  1440   template<typename GR, typename NF, typename EF>
  1441   SubGraph<const GR, const NF, const EF>
  1442   subGraph(const GR& graph, const NF& node_filter, const EF& edge_filter) {
  1443     return SubGraph<const GR, const NF, const EF>
  1444       (graph, node_filter, edge_filter);
  1445   }
  1446 
  1447 
  1448   /// \ingroup graph_adaptors
  1449   ///
  1450   /// \brief Adaptor class for hiding nodes in a digraph or a graph.
  1451   ///
  1452   /// FilterNodes adaptor can be used for hiding nodes in a digraph or a
  1453   /// graph. A \c bool node map must be specified, which defines the filter
  1454   /// for the nodes. Only the nodes with \c true filter value and the
  1455   /// arcs/edges incident to nodes both with \c true filter value are shown
  1456   /// in the subgraph. This adaptor conforms to the \ref concepts::Digraph
  1457   /// "Digraph" concept or the \ref concepts::Graph "Graph" concept
  1458   /// depending on the \c GR template parameter.
  1459   ///
  1460   /// The adapted (di)graph can also be modified through this adaptor
  1461   /// by adding or removing nodes or arcs/edges, unless the \c GR template
  1462   /// parameter is set to be \c const.
  1463   ///
  1464   /// \tparam GR The type of the adapted digraph or graph.
  1465   /// It must conform to the \ref concepts::Digraph "Digraph" concept
  1466   /// or the \ref concepts::Graph "Graph" concept.
  1467   /// It can also be specified to be \c const.
  1468   /// \tparam NF The type of the node filter map.
  1469   /// It must be a \c bool (or convertible) node map of the
  1470   /// adapted (di)graph. The default type is
  1471   /// \ref concepts::Graph::NodeMap "GR::NodeMap<bool>".
  1472   ///
  1473   /// \note The \c Node and <tt>Arc/Edge</tt> types of this adaptor and the
  1474   /// adapted (di)graph are convertible to each other.
  1475 #ifdef DOXYGEN
  1476   template<typename GR, typename NF>
  1477   class FilterNodes {
  1478 #else
  1479   template<typename GR,
  1480            typename NF = typename GR::template NodeMap<bool>,
  1481            typename Enable = void>
  1482   class FilterNodes :
  1483     public DigraphAdaptorExtender<
  1484       SubDigraphBase<GR, NF, ConstMap<typename GR::Arc, Const<bool, true> >,
  1485                      true> > {
  1486 #endif
  1487   public:
  1488 
  1489     typedef GR Digraph;
  1490     typedef NF NodeFilterMap;
  1491 
  1492     typedef DigraphAdaptorExtender<
  1493       SubDigraphBase<GR, NF, ConstMap<typename GR::Arc, Const<bool, true> >, 
  1494                      true> > Parent;
  1495 
  1496     typedef typename Parent::Node Node;
  1497 
  1498   protected:
  1499     ConstMap<typename Digraph::Arc, Const<bool, true> > const_true_map;
  1500 
  1501     FilterNodes() : const_true_map() {}
  1502 
  1503   public:
  1504 
  1505     /// \brief Constructor
  1506     ///
  1507     /// Creates a subgraph for the given digraph or graph with the
  1508     /// given node filter map.
  1509     FilterNodes(GR& graph, NF& node_filter) 
  1510       : Parent(), const_true_map()
  1511     {
  1512       Parent::initialize(graph, node_filter, const_true_map);
  1513     }
  1514 
  1515     /// \brief Sets the status of the given node
  1516     ///
  1517     /// This function sets the status of the given node.
  1518     /// It is done by simply setting the assigned value of \c n
  1519     /// to \c v in the node filter map.
  1520     void status(const Node& n, bool v) const { Parent::status(n, v); }
  1521 
  1522     /// \brief Returns the status of the given node
  1523     ///
  1524     /// This function returns the status of the given node.
  1525     /// It is \c true if the given node is enabled (i.e. not hidden).
  1526     bool status(const Node& n) const { return Parent::status(n); }
  1527 
  1528     /// \brief Disables the given node
  1529     ///
  1530     /// This function disables the given node, so the iteration
  1531     /// jumps over it.
  1532     /// It is the same as \ref status() "status(n, false)".
  1533     void disable(const Node& n) const { Parent::status(n, false); }
  1534 
  1535     /// \brief Enables the given node
  1536     ///
  1537     /// This function enables the given node.
  1538     /// It is the same as \ref status() "status(n, true)".
  1539     void enable(const Node& n) const { Parent::status(n, true); }
  1540 
  1541   };
  1542 
  1543   template<typename GR, typename NF>
  1544   class FilterNodes<GR, NF,
  1545                     typename enable_if<UndirectedTagIndicator<GR> >::type> :
  1546     public GraphAdaptorExtender<
  1547       SubGraphBase<GR, NF, ConstMap<typename GR::Edge, Const<bool, true> >, 
  1548                    true> > {
  1549 
  1550   public:
  1551     typedef GR Graph;
  1552     typedef NF NodeFilterMap;
  1553     typedef GraphAdaptorExtender<
  1554       SubGraphBase<GR, NF, ConstMap<typename GR::Edge, Const<bool, true> >, 
  1555                    true> > Parent;
  1556 
  1557     typedef typename Parent::Node Node;
  1558   protected:
  1559     ConstMap<typename GR::Edge, Const<bool, true> > const_true_map;
  1560 
  1561     FilterNodes() : const_true_map() {}
  1562 
  1563   public:
  1564 
  1565     FilterNodes(GR& graph, NodeFilterMap& node_filter) :
  1566       Parent(), const_true_map() {
  1567       Parent::initialize(graph, node_filter, const_true_map);
  1568     }
  1569 
  1570     void status(const Node& n, bool v) const { Parent::status(n, v); }
  1571     bool status(const Node& n) const { return Parent::status(n); }
  1572     void disable(const Node& n) const { Parent::status(n, false); }
  1573     void enable(const Node& n) const { Parent::status(n, true); }
  1574 
  1575   };
  1576 
  1577 
  1578   /// \brief Returns a read-only FilterNodes adaptor
  1579   ///
  1580   /// This function just returns a read-only \ref FilterNodes adaptor.
  1581   /// \ingroup graph_adaptors
  1582   /// \relates FilterNodes
  1583   template<typename GR, typename NF>
  1584   FilterNodes<const GR, NF>
  1585   filterNodes(const GR& graph, NF& node_filter) {
  1586     return FilterNodes<const GR, NF>(graph, node_filter);
  1587   }
  1588 
  1589   template<typename GR, typename NF>
  1590   FilterNodes<const GR, const NF>
  1591   filterNodes(const GR& graph, const NF& node_filter) {
  1592     return FilterNodes<const GR, const NF>(graph, node_filter);
  1593   }
  1594 
  1595   /// \ingroup graph_adaptors
  1596   ///
  1597   /// \brief Adaptor class for hiding arcs in a digraph.
  1598   ///
  1599   /// FilterArcs adaptor can be used for hiding arcs in a digraph.
  1600   /// A \c bool arc map must be specified, which defines the filter for
  1601   /// the arcs. Only the arcs with \c true filter value are shown in the
  1602   /// subdigraph. This adaptor conforms to the \ref concepts::Digraph
  1603   /// "Digraph" concept.
  1604   ///
  1605   /// The adapted digraph can also be modified through this adaptor
  1606   /// by adding or removing nodes or arcs, unless the \c GR template
  1607   /// parameter is set to be \c const.
  1608   ///
  1609   /// \tparam DGR The type of the adapted digraph.
  1610   /// It must conform to the \ref concepts::Digraph "Digraph" concept.
  1611   /// It can also be specified to be \c const.
  1612   /// \tparam AF The type of the arc filter map.
  1613   /// It must be a \c bool (or convertible) arc map of the
  1614   /// adapted digraph. The default type is
  1615   /// \ref concepts::Digraph::ArcMap "DGR::ArcMap<bool>".
  1616   ///
  1617   /// \note The \c Node and \c Arc types of this adaptor and the adapted
  1618   /// digraph are convertible to each other.
  1619 #ifdef DOXYGEN
  1620   template<typename DGR,
  1621            typename AF>
  1622   class FilterArcs {
  1623 #else
  1624   template<typename DGR,
  1625            typename AF = typename DGR::template ArcMap<bool> >
  1626   class FilterArcs :
  1627     public DigraphAdaptorExtender<
  1628       SubDigraphBase<DGR, ConstMap<typename DGR::Node, Const<bool, true> >,
  1629                      AF, false> > {
  1630 #endif
  1631   public:
  1632     /// The type of the adapted digraph.
  1633     typedef DGR Digraph;
  1634     /// The type of the arc filter map.
  1635     typedef AF ArcFilterMap;
  1636 
  1637     typedef DigraphAdaptorExtender<
  1638       SubDigraphBase<DGR, ConstMap<typename DGR::Node, Const<bool, true> >, 
  1639                      AF, false> > Parent;
  1640 
  1641     typedef typename Parent::Arc Arc;
  1642 
  1643   protected:
  1644     ConstMap<typename DGR::Node, Const<bool, true> > const_true_map;
  1645 
  1646     FilterArcs() : const_true_map() {}
  1647 
  1648   public:
  1649 
  1650     /// \brief Constructor
  1651     ///
  1652     /// Creates a subdigraph for the given digraph with the given arc
  1653     /// filter map.
  1654     FilterArcs(DGR& digraph, ArcFilterMap& arc_filter)
  1655       : Parent(), const_true_map() {
  1656       Parent::initialize(digraph, const_true_map, arc_filter);
  1657     }
  1658 
  1659     /// \brief Sets the status of the given arc
  1660     ///
  1661     /// This function sets the status of the given arc.
  1662     /// It is done by simply setting the assigned value of \c a
  1663     /// to \c v in the arc filter map.
  1664     void status(const Arc& a, bool v) const { Parent::status(a, v); }
  1665 
  1666     /// \brief Returns the status of the given arc
  1667     ///
  1668     /// This function returns the status of the given arc.
  1669     /// It is \c true if the given arc is enabled (i.e. not hidden).
  1670     bool status(const Arc& a) const { return Parent::status(a); }
  1671 
  1672     /// \brief Disables the given arc
  1673     ///
  1674     /// This function disables the given arc in the subdigraph,
  1675     /// so the iteration jumps over it.
  1676     /// It is the same as \ref status() "status(a, false)".
  1677     void disable(const Arc& a) const { Parent::status(a, false); }
  1678 
  1679     /// \brief Enables the given arc
  1680     ///
  1681     /// This function enables the given arc in the subdigraph.
  1682     /// It is the same as \ref status() "status(a, true)".
  1683     void enable(const Arc& a) const { Parent::status(a, true); }
  1684 
  1685   };
  1686 
  1687   /// \brief Returns a read-only FilterArcs adaptor
  1688   ///
  1689   /// This function just returns a read-only \ref FilterArcs adaptor.
  1690   /// \ingroup graph_adaptors
  1691   /// \relates FilterArcs
  1692   template<typename DGR, typename AF>
  1693   FilterArcs<const DGR, AF>
  1694   filterArcs(const DGR& digraph, AF& arc_filter) {
  1695     return FilterArcs<const DGR, AF>(digraph, arc_filter);
  1696   }
  1697 
  1698   template<typename DGR, typename AF>
  1699   FilterArcs<const DGR, const AF>
  1700   filterArcs(const DGR& digraph, const AF& arc_filter) {
  1701     return FilterArcs<const DGR, const AF>(digraph, arc_filter);
  1702   }
  1703 
  1704   /// \ingroup graph_adaptors
  1705   ///
  1706   /// \brief Adaptor class for hiding edges in a graph.
  1707   ///
  1708   /// FilterEdges adaptor can be used for hiding edges in a graph.
  1709   /// A \c bool edge map must be specified, which defines the filter for
  1710   /// the edges. Only the edges with \c true filter value are shown in the
  1711   /// subgraph. This adaptor conforms to the \ref concepts::Graph
  1712   /// "Graph" concept.
  1713   ///
  1714   /// The adapted graph can also be modified through this adaptor
  1715   /// by adding or removing nodes or edges, unless the \c GR template
  1716   /// parameter is set to be \c const.
  1717   ///
  1718   /// \tparam GR The type of the adapted graph.
  1719   /// It must conform to the \ref concepts::Graph "Graph" concept.
  1720   /// It can also be specified to be \c const.
  1721   /// \tparam EF The type of the edge filter map.
  1722   /// It must be a \c bool (or convertible) edge map of the
  1723   /// adapted graph. The default type is
  1724   /// \ref concepts::Graph::EdgeMap "GR::EdgeMap<bool>".
  1725   ///
  1726   /// \note The \c Node, \c Edge and \c Arc types of this adaptor and the
  1727   /// adapted graph are convertible to each other.
  1728 #ifdef DOXYGEN
  1729   template<typename GR,
  1730            typename EF>
  1731   class FilterEdges {
  1732 #else
  1733   template<typename GR,
  1734            typename EF = typename GR::template EdgeMap<bool> >
  1735   class FilterEdges :
  1736     public GraphAdaptorExtender<
  1737       SubGraphBase<GR, ConstMap<typename GR::Node, Const<bool, true> >, 
  1738                    EF, false> > {
  1739 #endif
  1740   public:
  1741     /// The type of the adapted graph.
  1742     typedef GR Graph;
  1743     /// The type of the edge filter map.
  1744     typedef EF EdgeFilterMap;
  1745 
  1746     typedef GraphAdaptorExtender<
  1747       SubGraphBase<GR, ConstMap<typename GR::Node, Const<bool, true > >, 
  1748                    EF, false> > Parent;
  1749 
  1750     typedef typename Parent::Edge Edge;
  1751 
  1752   protected:
  1753     ConstMap<typename GR::Node, Const<bool, true> > const_true_map;
  1754 
  1755     FilterEdges() : const_true_map(true) {
  1756       Parent::setNodeFilterMap(const_true_map);
  1757     }
  1758 
  1759   public:
  1760 
  1761     /// \brief Constructor
  1762     ///
  1763     /// Creates a subgraph for the given graph with the given edge
  1764     /// filter map.
  1765     FilterEdges(GR& graph, EF& edge_filter) 
  1766       : Parent(), const_true_map() {
  1767       Parent::initialize(graph, const_true_map, edge_filter);
  1768     }
  1769 
  1770     /// \brief Sets the status of the given edge
  1771     ///
  1772     /// This function sets the status of the given edge.
  1773     /// It is done by simply setting the assigned value of \c e
  1774     /// to \c v in the edge filter map.
  1775     void status(const Edge& e, bool v) const { Parent::status(e, v); }
  1776 
  1777     /// \brief Returns the status of the given edge
  1778     ///
  1779     /// This function returns the status of the given edge.
  1780     /// It is \c true if the given edge is enabled (i.e. not hidden).
  1781     bool status(const Edge& e) const { return Parent::status(e); }
  1782 
  1783     /// \brief Disables the given edge
  1784     ///
  1785     /// This function disables the given edge in the subgraph,
  1786     /// so the iteration jumps over it.
  1787     /// It is the same as \ref status() "status(e, false)".
  1788     void disable(const Edge& e) const { Parent::status(e, false); }
  1789 
  1790     /// \brief Enables the given edge
  1791     ///
  1792     /// This function enables the given edge in the subgraph.
  1793     /// It is the same as \ref status() "status(e, true)".
  1794     void enable(const Edge& e) const { Parent::status(e, true); }
  1795 
  1796   };
  1797 
  1798   /// \brief Returns a read-only FilterEdges adaptor
  1799   ///
  1800   /// This function just returns a read-only \ref FilterEdges adaptor.
  1801   /// \ingroup graph_adaptors
  1802   /// \relates FilterEdges
  1803   template<typename GR, typename EF>
  1804   FilterEdges<const GR, EF>
  1805   filterEdges(const GR& graph, EF& edge_filter) {
  1806     return FilterEdges<const GR, EF>(graph, edge_filter);
  1807   }
  1808 
  1809   template<typename GR, typename EF>
  1810   FilterEdges<const GR, const EF>
  1811   filterEdges(const GR& graph, const EF& edge_filter) {
  1812     return FilterEdges<const GR, const EF>(graph, edge_filter);
  1813   }
  1814 
  1815 
  1816   template <typename DGR>
  1817   class UndirectorBase {
  1818   public:
  1819     typedef DGR Digraph;
  1820     typedef UndirectorBase Adaptor;
  1821 
  1822     typedef True UndirectedTag;
  1823 
  1824     typedef typename Digraph::Arc Edge;
  1825     typedef typename Digraph::Node Node;
  1826 
  1827     class Arc : public Edge {
  1828       friend class UndirectorBase;
  1829     protected:
  1830       bool _forward;
  1831 
  1832       Arc(const Edge& edge, bool forward) :
  1833         Edge(edge), _forward(forward) {}
  1834 
  1835     public:
  1836       Arc() {}
  1837 
  1838       Arc(Invalid) : Edge(INVALID), _forward(true) {}
  1839 
  1840       bool operator==(const Arc &other) const {
  1841         return _forward == other._forward &&
  1842           static_cast<const Edge&>(*this) == static_cast<const Edge&>(other);
  1843       }
  1844       bool operator!=(const Arc &other) const {
  1845         return _forward != other._forward ||
  1846           static_cast<const Edge&>(*this) != static_cast<const Edge&>(other);
  1847       }
  1848       bool operator<(const Arc &other) const {
  1849         return _forward < other._forward ||
  1850           (_forward == other._forward &&
  1851            static_cast<const Edge&>(*this) < static_cast<const Edge&>(other));
  1852       }
  1853     };
  1854 
  1855     void first(Node& n) const {
  1856       _digraph->first(n);
  1857     }
  1858 
  1859     void next(Node& n) const {
  1860       _digraph->next(n);
  1861     }
  1862 
  1863     void first(Arc& a) const {
  1864       _digraph->first(a);
  1865       a._forward = true;
  1866     }
  1867 
  1868     void next(Arc& a) const {
  1869       if (a._forward) {
  1870         a._forward = false;
  1871       } else {
  1872         _digraph->next(a);
  1873         a._forward = true;
  1874       }
  1875     }
  1876 
  1877     void first(Edge& e) const {
  1878       _digraph->first(e);
  1879     }
  1880 
  1881     void next(Edge& e) const {
  1882       _digraph->next(e);
  1883     }
  1884 
  1885     void firstOut(Arc& a, const Node& n) const {
  1886       _digraph->firstIn(a, n);
  1887       if( static_cast<const Edge&>(a) != INVALID ) {
  1888         a._forward = false;
  1889       } else {
  1890         _digraph->firstOut(a, n);
  1891         a._forward = true;
  1892       }
  1893     }
  1894     void nextOut(Arc &a) const {
  1895       if (!a._forward) {
  1896         Node n = _digraph->target(a);
  1897         _digraph->nextIn(a);
  1898         if (static_cast<const Edge&>(a) == INVALID ) {
  1899           _digraph->firstOut(a, n);
  1900           a._forward = true;
  1901         }
  1902       }
  1903       else {
  1904         _digraph->nextOut(a);
  1905       }
  1906     }
  1907 
  1908     void firstIn(Arc &a, const Node &n) const {
  1909       _digraph->firstOut(a, n);
  1910       if (static_cast<const Edge&>(a) != INVALID ) {
  1911         a._forward = false;
  1912       } else {
  1913         _digraph->firstIn(a, n);
  1914         a._forward = true;
  1915       }
  1916     }
  1917     void nextIn(Arc &a) const {
  1918       if (!a._forward) {
  1919         Node n = _digraph->source(a);
  1920         _digraph->nextOut(a);
  1921         if( static_cast<const Edge&>(a) == INVALID ) {
  1922           _digraph->firstIn(a, n);
  1923           a._forward = true;
  1924         }
  1925       }
  1926       else {
  1927         _digraph->nextIn(a);
  1928       }
  1929     }
  1930 
  1931     void firstInc(Edge &e, bool &d, const Node &n) const {
  1932       d = true;
  1933       _digraph->firstOut(e, n);
  1934       if (e != INVALID) return;
  1935       d = false;
  1936       _digraph->firstIn(e, n);
  1937     }
  1938 
  1939     void nextInc(Edge &e, bool &d) const {
  1940       if (d) {
  1941         Node s = _digraph->source(e);
  1942         _digraph->nextOut(e);
  1943         if (e != INVALID) return;
  1944         d = false;
  1945         _digraph->firstIn(e, s);
  1946       } else {
  1947         _digraph->nextIn(e);
  1948       }
  1949     }
  1950 
  1951     Node u(const Edge& e) const {
  1952       return _digraph->source(e);
  1953     }
  1954 
  1955     Node v(const Edge& e) const {
  1956       return _digraph->target(e);
  1957     }
  1958 
  1959     Node source(const Arc &a) const {
  1960       return a._forward ? _digraph->source(a) : _digraph->target(a);
  1961     }
  1962 
  1963     Node target(const Arc &a) const {
  1964       return a._forward ? _digraph->target(a) : _digraph->source(a);
  1965     }
  1966 
  1967     static Arc direct(const Edge &e, bool d) {
  1968       return Arc(e, d);
  1969     }
  1970     Arc direct(const Edge &e, const Node& n) const {
  1971       return Arc(e, _digraph->source(e) == n);
  1972     }
  1973 
  1974     static bool direction(const Arc &a) { return a._forward; }
  1975 
  1976     Node nodeFromId(int ix) const { return _digraph->nodeFromId(ix); }
  1977     Arc arcFromId(int ix) const {
  1978       return direct(_digraph->arcFromId(ix >> 1), bool(ix & 1));
  1979     }
  1980     Edge edgeFromId(int ix) const { return _digraph->arcFromId(ix); }
  1981 
  1982     int id(const Node &n) const { return _digraph->id(n); }
  1983     int id(const Arc &a) const {
  1984       return  (_digraph->id(a) << 1) | (a._forward ? 1 : 0);
  1985     }
  1986     int id(const Edge &e) const { return _digraph->id(e); }
  1987 
  1988     int maxNodeId() const { return _digraph->maxNodeId(); }
  1989     int maxArcId() const { return (_digraph->maxArcId() << 1) | 1; }
  1990     int maxEdgeId() const { return _digraph->maxArcId(); }
  1991 
  1992     Node addNode() { return _digraph->addNode(); }
  1993     Edge addEdge(const Node& u, const Node& v) {
  1994       return _digraph->addArc(u, v);
  1995     }
  1996 
  1997     void erase(const Node& i) { _digraph->erase(i); }
  1998     void erase(const Edge& i) { _digraph->erase(i); }
  1999 
  2000     void clear() { _digraph->clear(); }
  2001 
  2002     typedef NodeNumTagIndicator<Digraph> NodeNumTag;
  2003     int nodeNum() const { return _digraph->nodeNum(); }
  2004 
  2005     typedef ArcNumTagIndicator<Digraph> ArcNumTag;
  2006     int arcNum() const { return 2 * _digraph->arcNum(); }
  2007 
  2008     typedef ArcNumTag EdgeNumTag;
  2009     int edgeNum() const { return _digraph->arcNum(); }
  2010 
  2011     typedef FindArcTagIndicator<Digraph> FindArcTag;
  2012     Arc findArc(Node s, Node t, Arc p = INVALID) const {
  2013       if (p == INVALID) {
  2014         Edge arc = _digraph->findArc(s, t);
  2015         if (arc != INVALID) return direct(arc, true);
  2016         arc = _digraph->findArc(t, s);
  2017         if (arc != INVALID) return direct(arc, false);
  2018       } else if (direction(p)) {
  2019         Edge arc = _digraph->findArc(s, t, p);
  2020         if (arc != INVALID) return direct(arc, true);
  2021         arc = _digraph->findArc(t, s);
  2022         if (arc != INVALID) return direct(arc, false);
  2023       } else {
  2024         Edge arc = _digraph->findArc(t, s, p);
  2025         if (arc != INVALID) return direct(arc, false);
  2026       }
  2027       return INVALID;
  2028     }
  2029 
  2030     typedef FindArcTag FindEdgeTag;
  2031     Edge findEdge(Node s, Node t, Edge p = INVALID) const {
  2032       if (s != t) {
  2033         if (p == INVALID) {
  2034           Edge arc = _digraph->findArc(s, t);
  2035           if (arc != INVALID) return arc;
  2036           arc = _digraph->findArc(t, s);
  2037           if (arc != INVALID) return arc;
  2038         } else if (_digraph->source(p) == s) {
  2039           Edge arc = _digraph->findArc(s, t, p);
  2040           if (arc != INVALID) return arc;
  2041           arc = _digraph->findArc(t, s);
  2042           if (arc != INVALID) return arc;
  2043         } else {
  2044           Edge arc = _digraph->findArc(t, s, p);
  2045           if (arc != INVALID) return arc;
  2046         }
  2047       } else {
  2048         return _digraph->findArc(s, t, p);
  2049       }
  2050       return INVALID;
  2051     }
  2052 
  2053   private:
  2054 
  2055     template <typename V>
  2056     class ArcMapBase {
  2057     private:
  2058 
  2059       typedef typename DGR::template ArcMap<V> MapImpl;
  2060 
  2061     public:
  2062 
  2063       typedef typename MapTraits<MapImpl>::ReferenceMapTag ReferenceMapTag;
  2064 
  2065       typedef V Value;
  2066       typedef Arc Key;
  2067       typedef typename MapTraits<MapImpl>::ConstReturnValue ConstReturnValue;
  2068       typedef typename MapTraits<MapImpl>::ReturnValue ReturnValue;
  2069       typedef typename MapTraits<MapImpl>::ConstReturnValue ConstReference;
  2070       typedef typename MapTraits<MapImpl>::ReturnValue Reference;
  2071 
  2072       ArcMapBase(const UndirectorBase<DGR>& adaptor) :
  2073         _forward(*adaptor._digraph), _backward(*adaptor._digraph) {}
  2074 
  2075       ArcMapBase(const UndirectorBase<DGR>& adaptor, const V& value)
  2076         : _forward(*adaptor._digraph, value), 
  2077           _backward(*adaptor._digraph, value) {}
  2078 
  2079       void set(const Arc& a, const V& value) {
  2080         if (direction(a)) {
  2081           _forward.set(a, value);
  2082         } else {
  2083           _backward.set(a, value);
  2084         }
  2085       }
  2086 
  2087       ConstReturnValue operator[](const Arc& a) const {
  2088         if (direction(a)) {
  2089           return _forward[a];
  2090         } else {
  2091           return _backward[a];
  2092         }
  2093       }
  2094 
  2095       ReturnValue operator[](const Arc& a) {
  2096         if (direction(a)) {
  2097           return _forward[a];
  2098         } else {
  2099           return _backward[a];
  2100         }
  2101       }
  2102 
  2103     protected:
  2104 
  2105       MapImpl _forward, _backward;
  2106 
  2107     };
  2108 
  2109   public:
  2110 
  2111     template <typename V>
  2112     class NodeMap : public DGR::template NodeMap<V> {
  2113     public:
  2114 
  2115       typedef V Value;
  2116       typedef typename DGR::template NodeMap<Value> Parent;
  2117 
  2118       explicit NodeMap(const UndirectorBase<DGR>& adaptor)
  2119         : Parent(*adaptor._digraph) {}
  2120 
  2121       NodeMap(const UndirectorBase<DGR>& adaptor, const V& value)
  2122         : Parent(*adaptor._digraph, value) { }
  2123 
  2124     private:
  2125       NodeMap& operator=(const NodeMap& cmap) {
  2126         return operator=<NodeMap>(cmap);
  2127       }
  2128 
  2129       template <typename CMap>
  2130       NodeMap& operator=(const CMap& cmap) {
  2131         Parent::operator=(cmap);
  2132         return *this;
  2133       }
  2134 
  2135     };
  2136 
  2137     template <typename V>
  2138     class ArcMap
  2139       : public SubMapExtender<UndirectorBase<DGR>, ArcMapBase<V> >
  2140     {
  2141     public:
  2142       typedef V Value;
  2143       typedef SubMapExtender<Adaptor, ArcMapBase<V> > Parent;
  2144 
  2145       explicit ArcMap(const UndirectorBase<DGR>& adaptor)
  2146         : Parent(adaptor) {}
  2147 
  2148       ArcMap(const UndirectorBase<DGR>& adaptor, const V& value)
  2149         : Parent(adaptor, value) {}
  2150 
  2151     private:
  2152       ArcMap& operator=(const ArcMap& cmap) {
  2153         return operator=<ArcMap>(cmap);
  2154       }
  2155 
  2156       template <typename CMap>
  2157       ArcMap& operator=(const CMap& cmap) {
  2158         Parent::operator=(cmap);
  2159         return *this;
  2160       }
  2161     };
  2162 
  2163     template <typename V>
  2164     class EdgeMap : public Digraph::template ArcMap<V> {
  2165     public:
  2166 
  2167       typedef V Value;
  2168       typedef typename Digraph::template ArcMap<V> Parent;
  2169 
  2170       explicit EdgeMap(const UndirectorBase<DGR>& adaptor)
  2171         : Parent(*adaptor._digraph) {}
  2172 
  2173       EdgeMap(const UndirectorBase<DGR>& adaptor, const V& value)
  2174         : Parent(*adaptor._digraph, value) {}
  2175 
  2176     private:
  2177       EdgeMap& operator=(const EdgeMap& cmap) {
  2178         return operator=<EdgeMap>(cmap);
  2179       }
  2180 
  2181       template <typename CMap>
  2182       EdgeMap& operator=(const CMap& cmap) {
  2183         Parent::operator=(cmap);
  2184         return *this;
  2185       }
  2186 
  2187     };
  2188 
  2189     typedef typename ItemSetTraits<DGR, Node>::ItemNotifier NodeNotifier;
  2190     NodeNotifier& notifier(Node) const { return _digraph->notifier(Node()); }
  2191 
  2192     typedef typename ItemSetTraits<DGR, Edge>::ItemNotifier EdgeNotifier;
  2193     EdgeNotifier& notifier(Edge) const { return _digraph->notifier(Edge()); }
  2194 
  2195   protected:
  2196 
  2197     UndirectorBase() : _digraph(0) {}
  2198 
  2199     DGR* _digraph;
  2200 
  2201     void initialize(DGR& digraph) {
  2202       _digraph = &digraph;
  2203     }
  2204 
  2205   };
  2206 
  2207   /// \ingroup graph_adaptors
  2208   ///
  2209   /// \brief Adaptor class for viewing a digraph as an undirected graph.
  2210   ///
  2211   /// Undirector adaptor can be used for viewing a digraph as an undirected
  2212   /// graph. All arcs of the underlying digraph are showed in the
  2213   /// adaptor as an edge (and also as a pair of arcs, of course).
  2214   /// This adaptor conforms to the \ref concepts::Graph "Graph" concept.
  2215   ///
  2216   /// The adapted digraph can also be modified through this adaptor
  2217   /// by adding or removing nodes or edges, unless the \c GR template
  2218   /// parameter is set to be \c const.
  2219   ///
  2220   /// \tparam DGR The type of the adapted digraph.
  2221   /// It must conform to the \ref concepts::Digraph "Digraph" concept.
  2222   /// It can also be specified to be \c const.
  2223   ///
  2224   /// \note The \c Node type of this adaptor and the adapted digraph are
  2225   /// convertible to each other, moreover the \c Edge type of the adaptor
  2226   /// and the \c Arc type of the adapted digraph are also convertible to
  2227   /// each other.
  2228   /// (Thus the \c Arc type of the adaptor is convertible to the \c Arc type
  2229   /// of the adapted digraph.)
  2230   template<typename DGR>
  2231 #ifdef DOXYGEN
  2232   class Undirector {
  2233 #else
  2234   class Undirector :
  2235     public GraphAdaptorExtender<UndirectorBase<DGR> > {
  2236 #endif
  2237   public:
  2238     /// The type of the adapted digraph.
  2239     typedef DGR Digraph;
  2240     typedef GraphAdaptorExtender<UndirectorBase<DGR> > Parent;
  2241   protected:
  2242     Undirector() { }
  2243   public:
  2244 
  2245     /// \brief Constructor
  2246     ///
  2247     /// Creates an undirected graph from the given digraph.
  2248     Undirector(DGR& digraph) {
  2249       initialize(digraph);
  2250     }
  2251 
  2252     /// \brief Arc map combined from two original arc maps
  2253     ///
  2254     /// This map adaptor class adapts two arc maps of the underlying
  2255     /// digraph to get an arc map of the undirected graph.
  2256     /// Its value type is inherited from the first arc map type
  2257     /// (\c %ForwardMap).
  2258     template <typename ForwardMap, typename BackwardMap>
  2259     class CombinedArcMap {
  2260     public:
  2261 
  2262       /// The key type of the map
  2263       typedef typename Parent::Arc Key;
  2264       /// The value type of the map
  2265       typedef typename ForwardMap::Value Value;
  2266 
  2267       typedef typename MapTraits<ForwardMap>::ReferenceMapTag ReferenceMapTag;
  2268 
  2269       typedef typename MapTraits<ForwardMap>::ReturnValue ReturnValue;
  2270       typedef typename MapTraits<ForwardMap>::ConstReturnValue ConstReturnValue;
  2271       typedef typename MapTraits<ForwardMap>::ReturnValue Reference;
  2272       typedef typename MapTraits<ForwardMap>::ConstReturnValue ConstReference;
  2273 
  2274       /// Constructor
  2275       CombinedArcMap(ForwardMap& forward, BackwardMap& backward)
  2276         : _forward(&forward), _backward(&backward) {}
  2277 
  2278       /// Sets the value associated with the given key.
  2279       void set(const Key& e, const Value& a) {
  2280         if (Parent::direction(e)) {
  2281           _forward->set(e, a);
  2282         } else {
  2283           _backward->set(e, a);
  2284         }
  2285       }
  2286 
  2287       /// Returns the value associated with the given key.
  2288       ConstReturnValue operator[](const Key& e) const {
  2289         if (Parent::direction(e)) {
  2290           return (*_forward)[e];
  2291         } else {
  2292           return (*_backward)[e];
  2293         }
  2294       }
  2295 
  2296       /// Returns a reference to the value associated with the given key.
  2297       ReturnValue operator[](const Key& e) {
  2298         if (Parent::direction(e)) {
  2299           return (*_forward)[e];
  2300         } else {
  2301           return (*_backward)[e];
  2302         }
  2303       }
  2304 
  2305     protected:
  2306 
  2307       ForwardMap* _forward;
  2308       BackwardMap* _backward;
  2309 
  2310     };
  2311 
  2312     /// \brief Returns a combined arc map
  2313     ///
  2314     /// This function just returns a combined arc map.
  2315     template <typename ForwardMap, typename BackwardMap>
  2316     static CombinedArcMap<ForwardMap, BackwardMap>
  2317     combinedArcMap(ForwardMap& forward, BackwardMap& backward) {
  2318       return CombinedArcMap<ForwardMap, BackwardMap>(forward, backward);
  2319     }
  2320 
  2321     template <typename ForwardMap, typename BackwardMap>
  2322     static CombinedArcMap<const ForwardMap, BackwardMap>
  2323     combinedArcMap(const ForwardMap& forward, BackwardMap& backward) {
  2324       return CombinedArcMap<const ForwardMap,
  2325         BackwardMap>(forward, backward);
  2326     }
  2327 
  2328     template <typename ForwardMap, typename BackwardMap>
  2329     static CombinedArcMap<ForwardMap, const BackwardMap>
  2330     combinedArcMap(ForwardMap& forward, const BackwardMap& backward) {
  2331       return CombinedArcMap<ForwardMap,
  2332         const BackwardMap>(forward, backward);
  2333     }
  2334 
  2335     template <typename ForwardMap, typename BackwardMap>
  2336     static CombinedArcMap<const ForwardMap, const BackwardMap>
  2337     combinedArcMap(const ForwardMap& forward, const BackwardMap& backward) {
  2338       return CombinedArcMap<const ForwardMap,
  2339         const BackwardMap>(forward, backward);
  2340     }
  2341 
  2342   };
  2343 
  2344   /// \brief Returns a read-only Undirector adaptor
  2345   ///
  2346   /// This function just returns a read-only \ref Undirector adaptor.
  2347   /// \ingroup graph_adaptors
  2348   /// \relates Undirector
  2349   template<typename DGR>
  2350   Undirector<const DGR> undirector(const DGR& digraph) {
  2351     return Undirector<const DGR>(digraph);
  2352   }
  2353 
  2354 
  2355   template <typename GR, typename DM>
  2356   class OrienterBase {
  2357   public:
  2358 
  2359     typedef GR Graph;
  2360     typedef DM DirectionMap;
  2361 
  2362     typedef typename GR::Node Node;
  2363     typedef typename GR::Edge Arc;
  2364 
  2365     void reverseArc(const Arc& arc) {
  2366       _direction->set(arc, !(*_direction)[arc]);
  2367     }
  2368 
  2369     void first(Node& i) const { _graph->first(i); }
  2370     void first(Arc& i) const { _graph->first(i); }
  2371     void firstIn(Arc& i, const Node& n) const {
  2372       bool d = true;
  2373       _graph->firstInc(i, d, n);
  2374       while (i != INVALID && d == (*_direction)[i]) _graph->nextInc(i, d);
  2375     }
  2376     void firstOut(Arc& i, const Node& n ) const {
  2377       bool d = true;
  2378       _graph->firstInc(i, d, n);
  2379       while (i != INVALID && d != (*_direction)[i]) _graph->nextInc(i, d);
  2380     }
  2381 
  2382     void next(Node& i) const { _graph->next(i); }
  2383     void next(Arc& i) const { _graph->next(i); }
  2384     void nextIn(Arc& i) const {
  2385       bool d = !(*_direction)[i];
  2386       _graph->nextInc(i, d);
  2387       while (i != INVALID && d == (*_direction)[i]) _graph->nextInc(i, d);
  2388     }
  2389     void nextOut(Arc& i) const {
  2390       bool d = (*_direction)[i];
  2391       _graph->nextInc(i, d);
  2392       while (i != INVALID && d != (*_direction)[i]) _graph->nextInc(i, d);
  2393     }
  2394 
  2395     Node source(const Arc& e) const {
  2396       return (*_direction)[e] ? _graph->u(e) : _graph->v(e);
  2397     }
  2398     Node target(const Arc& e) const {
  2399       return (*_direction)[e] ? _graph->v(e) : _graph->u(e);
  2400     }
  2401 
  2402     typedef NodeNumTagIndicator<Graph> NodeNumTag;
  2403     int nodeNum() const { return _graph->nodeNum(); }
  2404 
  2405     typedef EdgeNumTagIndicator<Graph> ArcNumTag;
  2406     int arcNum() const { return _graph->edgeNum(); }
  2407 
  2408     typedef FindEdgeTagIndicator<Graph> FindArcTag;
  2409     Arc findArc(const Node& u, const Node& v,
  2410                 const Arc& prev = INVALID) const {
  2411       Arc arc = _graph->findEdge(u, v, prev);
  2412       while (arc != INVALID && source(arc) != u) {
  2413         arc = _graph->findEdge(u, v, arc);
  2414       }
  2415       return arc;
  2416     }
  2417 
  2418     Node addNode() {
  2419       return Node(_graph->addNode());
  2420     }
  2421 
  2422     Arc addArc(const Node& u, const Node& v) {
  2423       Arc arc = _graph->addEdge(u, v);
  2424       _direction->set(arc, _graph->u(arc) == u);
  2425       return arc;
  2426     }
  2427 
  2428     void erase(const Node& i) { _graph->erase(i); }
  2429     void erase(const Arc& i) { _graph->erase(i); }
  2430 
  2431     void clear() { _graph->clear(); }
  2432 
  2433     int id(const Node& v) const { return _graph->id(v); }
  2434     int id(const Arc& e) const { return _graph->id(e); }
  2435 
  2436     Node nodeFromId(int idx) const { return _graph->nodeFromId(idx); }
  2437     Arc arcFromId(int idx) const { return _graph->edgeFromId(idx); }
  2438 
  2439     int maxNodeId() const { return _graph->maxNodeId(); }
  2440     int maxArcId() const { return _graph->maxEdgeId(); }
  2441 
  2442     typedef typename ItemSetTraits<GR, Node>::ItemNotifier NodeNotifier;
  2443     NodeNotifier& notifier(Node) const { return _graph->notifier(Node()); }
  2444 
  2445     typedef typename ItemSetTraits<GR, Arc>::ItemNotifier ArcNotifier;
  2446     ArcNotifier& notifier(Arc) const { return _graph->notifier(Arc()); }
  2447 
  2448     template <typename V>
  2449     class NodeMap : public GR::template NodeMap<V> {
  2450     public:
  2451 
  2452       typedef typename GR::template NodeMap<V> Parent;
  2453 
  2454       explicit NodeMap(const OrienterBase<GR, DM>& adapter)
  2455         : Parent(*adapter._graph) {}
  2456 
  2457       NodeMap(const OrienterBase<GR, DM>& adapter, const V& value)
  2458         : Parent(*adapter._graph, value) {}
  2459 
  2460     private:
  2461       NodeMap& operator=(const NodeMap& cmap) {
  2462         return operator=<NodeMap>(cmap);
  2463       }
  2464 
  2465       template <typename CMap>
  2466       NodeMap& operator=(const CMap& cmap) {
  2467         Parent::operator=(cmap);
  2468         return *this;
  2469       }
  2470 
  2471     };
  2472 
  2473     template <typename V>
  2474     class ArcMap : public GR::template EdgeMap<V> {
  2475     public:
  2476 
  2477       typedef typename Graph::template EdgeMap<V> Parent;
  2478 
  2479       explicit ArcMap(const OrienterBase<GR, DM>& adapter)
  2480         : Parent(*adapter._graph) { }
  2481 
  2482       ArcMap(const OrienterBase<GR, DM>& adapter, const V& value)
  2483         : Parent(*adapter._graph, value) { }
  2484 
  2485     private:
  2486       ArcMap& operator=(const ArcMap& cmap) {
  2487         return operator=<ArcMap>(cmap);
  2488       }
  2489 
  2490       template <typename CMap>
  2491       ArcMap& operator=(const CMap& cmap) {
  2492         Parent::operator=(cmap);
  2493         return *this;
  2494       }
  2495     };
  2496 
  2497 
  2498 
  2499   protected:
  2500     Graph* _graph;
  2501     DM* _direction;
  2502 
  2503     void initialize(GR& graph, DM& direction) {
  2504       _graph = &graph;
  2505       _direction = &direction;
  2506     }
  2507 
  2508   };
  2509 
  2510   /// \ingroup graph_adaptors
  2511   ///
  2512   /// \brief Adaptor class for orienting the edges of a graph to get a digraph
  2513   ///
  2514   /// Orienter adaptor can be used for orienting the edges of a graph to
  2515   /// get a digraph. A \c bool edge map of the underlying graph must be
  2516   /// specified, which define the direction of the arcs in the adaptor.
  2517   /// The arcs can be easily reversed by the \c reverseArc() member function
  2518   /// of the adaptor.
  2519   /// This class conforms to the \ref concepts::Digraph "Digraph" concept.
  2520   ///
  2521   /// The adapted graph can also be modified through this adaptor
  2522   /// by adding or removing nodes or arcs, unless the \c GR template
  2523   /// parameter is set to be \c const.
  2524   ///
  2525   /// \tparam GR The type of the adapted graph.
  2526   /// It must conform to the \ref concepts::Graph "Graph" concept.
  2527   /// It can also be specified to be \c const.
  2528   /// \tparam DM The type of the direction map.
  2529   /// It must be a \c bool (or convertible) edge map of the
  2530   /// adapted graph. The default type is
  2531   /// \ref concepts::Graph::EdgeMap "GR::EdgeMap<bool>".
  2532   ///
  2533   /// \note The \c Node type of this adaptor and the adapted graph are
  2534   /// convertible to each other, moreover the \c Arc type of the adaptor
  2535   /// and the \c Edge type of the adapted graph are also convertible to
  2536   /// each other.
  2537 #ifdef DOXYGEN
  2538   template<typename GR,
  2539            typename DM>
  2540   class Orienter {
  2541 #else
  2542   template<typename GR,
  2543            typename DM = typename GR::template EdgeMap<bool> >
  2544   class Orienter :
  2545     public DigraphAdaptorExtender<OrienterBase<GR, DM> > {
  2546 #endif
  2547   public:
  2548 
  2549     /// The type of the adapted graph.
  2550     typedef GR Graph;
  2551     /// The type of the direction edge map.
  2552     typedef DM DirectionMap;
  2553 
  2554     typedef DigraphAdaptorExtender<OrienterBase<GR, DM> > Parent;
  2555     typedef typename Parent::Arc Arc;
  2556   protected:
  2557     Orienter() { }
  2558   public:
  2559 
  2560     /// \brief Constructor
  2561     ///
  2562     /// Constructor of the adaptor.
  2563     Orienter(GR& graph, DM& direction) {
  2564       Parent::initialize(graph, direction);
  2565     }
  2566 
  2567     /// \brief Reverses the given arc
  2568     ///
  2569     /// This function reverses the given arc.
  2570     /// It is done by simply negate the assigned value of \c a
  2571     /// in the direction map.
  2572     void reverseArc(const Arc& a) {
  2573       Parent::reverseArc(a);
  2574     }
  2575   };
  2576 
  2577   /// \brief Returns a read-only Orienter adaptor
  2578   ///
  2579   /// This function just returns a read-only \ref Orienter adaptor.
  2580   /// \ingroup graph_adaptors
  2581   /// \relates Orienter
  2582   template<typename GR, typename DM>
  2583   Orienter<const GR, DM>
  2584   orienter(const GR& graph, DM& direction) {
  2585     return Orienter<const GR, DM>(graph, direction);
  2586   }
  2587 
  2588   template<typename GR, typename DM>
  2589   Orienter<const GR, const DM>
  2590   orienter(const GR& graph, const DM& direction) {
  2591     return Orienter<const GR, const DM>(graph, direction);
  2592   }
  2593 
  2594   namespace _adaptor_bits {
  2595 
  2596     template <typename DGR, typename CM, typename FM, typename TL>
  2597     class ResForwardFilter {
  2598     public:
  2599 
  2600       typedef typename DGR::Arc Key;
  2601       typedef bool Value;
  2602 
  2603     private:
  2604 
  2605       const CM* _capacity;
  2606       const FM* _flow;
  2607       TL _tolerance;
  2608 
  2609     public:
  2610 
  2611       ResForwardFilter(const CM& capacity, const FM& flow,
  2612                        const TL& tolerance = TL())
  2613         : _capacity(&capacity), _flow(&flow), _tolerance(tolerance) { }
  2614 
  2615       bool operator[](const typename DGR::Arc& a) const {
  2616         return _tolerance.positive((*_capacity)[a] - (*_flow)[a]);
  2617       }
  2618     };
  2619 
  2620     template<typename DGR,typename CM, typename FM, typename TL>
  2621     class ResBackwardFilter {
  2622     public:
  2623 
  2624       typedef typename DGR::Arc Key;
  2625       typedef bool Value;
  2626 
  2627     private:
  2628 
  2629       const CM* _capacity;
  2630       const FM* _flow;
  2631       TL _tolerance;
  2632 
  2633     public:
  2634 
  2635       ResBackwardFilter(const CM& capacity, const FM& flow,
  2636                         const TL& tolerance = TL())
  2637         : _capacity(&capacity), _flow(&flow), _tolerance(tolerance) { }
  2638 
  2639       bool operator[](const typename DGR::Arc& a) const {
  2640         return _tolerance.positive((*_flow)[a]);
  2641       }
  2642     };
  2643 
  2644   }
  2645 
  2646   /// \ingroup graph_adaptors
  2647   ///
  2648   /// \brief Adaptor class for composing the residual digraph for directed
  2649   /// flow and circulation problems.
  2650   ///
  2651   /// ResidualDigraph can be used for composing the \e residual digraph
  2652   /// for directed flow and circulation problems. Let \f$ G=(V, A) \f$
  2653   /// be a directed graph and let \f$ F \f$ be a number type.
  2654   /// Let \f$ flow, cap: A\to F \f$ be functions on the arcs.
  2655   /// This adaptor implements a digraph structure with node set \f$ V \f$
  2656   /// and arc set \f$ A_{forward}\cup A_{backward} \f$,
  2657   /// where \f$ A_{forward}=\{uv : uv\in A, flow(uv)<cap(uv)\} \f$ and
  2658   /// \f$ A_{backward}=\{vu : uv\in A, flow(uv)>0\} \f$, i.e. the so
  2659   /// called residual digraph.
  2660   /// When the union \f$ A_{forward}\cup A_{backward} \f$ is taken,
  2661   /// multiplicities are counted, i.e. the adaptor has exactly
  2662   /// \f$ |A_{forward}| + |A_{backward}|\f$ arcs (it may have parallel
  2663   /// arcs).
  2664   /// This class conforms to the \ref concepts::Digraph "Digraph" concept.
  2665   ///
  2666   /// \tparam DGR The type of the adapted digraph.
  2667   /// It must conform to the \ref concepts::Digraph "Digraph" concept.
  2668   /// It is implicitly \c const.
  2669   /// \tparam CM The type of the capacity map.
  2670   /// It must be an arc map of some numerical type, which defines
  2671   /// the capacities in the flow problem. It is implicitly \c const.
  2672   /// The default type is
  2673   /// \ref concepts::Digraph::ArcMap "GR::ArcMap<int>".
  2674   /// \tparam FM The type of the flow map.
  2675   /// It must be an arc map of some numerical type, which defines
  2676   /// the flow values in the flow problem. The default type is \c CM.
  2677   /// \tparam TL The tolerance type for handling inexact computation.
  2678   /// The default tolerance type depends on the value type of the
  2679   /// capacity map.
  2680   ///
  2681   /// \note This adaptor is implemented using Undirector and FilterArcs
  2682   /// adaptors.
  2683   ///
  2684   /// \note The \c Node type of this adaptor and the adapted digraph are
  2685   /// convertible to each other, moreover the \c Arc type of the adaptor
  2686   /// is convertible to the \c Arc type of the adapted digraph.
  2687 #ifdef DOXYGEN
  2688   template<typename DGR, typename CM, typename FM, typename TL>
  2689   class ResidualDigraph
  2690 #else
  2691   template<typename DGR,
  2692            typename CM = typename DGR::template ArcMap<int>,
  2693            typename FM = CM,
  2694            typename TL = Tolerance<typename CM::Value> >
  2695   class ResidualDigraph 
  2696     : public SubDigraph<
  2697         Undirector<const DGR>,
  2698         ConstMap<typename DGR::Node, Const<bool, true> >,
  2699         typename Undirector<const DGR>::template CombinedArcMap<
  2700           _adaptor_bits::ResForwardFilter<const DGR, CM, FM, TL>,
  2701           _adaptor_bits::ResBackwardFilter<const DGR, CM, FM, TL> > >
  2702 #endif
  2703   {
  2704   public:
  2705 
  2706     /// The type of the underlying digraph.
  2707     typedef DGR Digraph;
  2708     /// The type of the capacity map.
  2709     typedef CM CapacityMap;
  2710     /// The type of the flow map.
  2711     typedef FM FlowMap;
  2712     /// The tolerance type.
  2713     typedef TL Tolerance;
  2714 
  2715     typedef typename CapacityMap::Value Value;
  2716     typedef ResidualDigraph Adaptor;
  2717 
  2718   protected:
  2719 
  2720     typedef Undirector<const Digraph> Undirected;
  2721 
  2722     typedef ConstMap<typename DGR::Node, Const<bool, true> > NodeFilter;
  2723 
  2724     typedef _adaptor_bits::ResForwardFilter<const DGR, CM,
  2725                                             FM, TL> ForwardFilter;
  2726 
  2727     typedef _adaptor_bits::ResBackwardFilter<const DGR, CM,
  2728                                              FM, TL> BackwardFilter;
  2729 
  2730     typedef typename Undirected::
  2731       template CombinedArcMap<ForwardFilter, BackwardFilter> ArcFilter;
  2732 
  2733     typedef SubDigraph<Undirected, NodeFilter, ArcFilter> Parent;
  2734 
  2735     const CapacityMap* _capacity;
  2736     FlowMap* _flow;
  2737 
  2738     Undirected _graph;
  2739     NodeFilter _node_filter;
  2740     ForwardFilter _forward_filter;
  2741     BackwardFilter _backward_filter;
  2742     ArcFilter _arc_filter;
  2743 
  2744   public:
  2745 
  2746     /// \brief Constructor
  2747     ///
  2748     /// Constructor of the residual digraph adaptor. The parameters are the
  2749     /// digraph, the capacity map, the flow map, and a tolerance object.
  2750     ResidualDigraph(const DGR& digraph, const CM& capacity,
  2751                     FM& flow, const TL& tolerance = Tolerance())
  2752       : Parent(), _capacity(&capacity), _flow(&flow), 
  2753         _graph(digraph), _node_filter(),
  2754         _forward_filter(capacity, flow, tolerance),
  2755         _backward_filter(capacity, flow, tolerance),
  2756         _arc_filter(_forward_filter, _backward_filter)
  2757     {
  2758       Parent::initialize(_graph, _node_filter, _arc_filter);
  2759     }
  2760 
  2761     typedef typename Parent::Arc Arc;
  2762 
  2763     /// \brief Returns the residual capacity of the given arc.
  2764     ///
  2765     /// Returns the residual capacity of the given arc.
  2766     Value residualCapacity(const Arc& a) const {
  2767       if (Undirected::direction(a)) {
  2768         return (*_capacity)[a] - (*_flow)[a];
  2769       } else {
  2770         return (*_flow)[a];
  2771       }
  2772     }
  2773 
  2774     /// \brief Augments on the given arc in the residual digraph.
  2775     ///
  2776     /// Augments on the given arc in the residual digraph. It increases
  2777     /// or decreases the flow value on the original arc according to the
  2778     /// direction of the residual arc.
  2779     void augment(const Arc& a, const Value& v) const {
  2780       if (Undirected::direction(a)) {
  2781         _flow->set(a, (*_flow)[a] + v);
  2782       } else {
  2783         _flow->set(a, (*_flow)[a] - v);
  2784       }
  2785     }
  2786 
  2787     /// \brief Returns \c true if the given residual arc is a forward arc.
  2788     ///
  2789     /// Returns \c true if the given residual arc has the same orientation
  2790     /// as the original arc, i.e. it is a so called forward arc.
  2791     static bool forward(const Arc& a) {
  2792       return Undirected::direction(a);
  2793     }
  2794 
  2795     /// \brief Returns \c true if the given residual arc is a backward arc.
  2796     ///
  2797     /// Returns \c true if the given residual arc has the opposite orientation
  2798     /// than the original arc, i.e. it is a so called backward arc.
  2799     static bool backward(const Arc& a) {
  2800       return !Undirected::direction(a);
  2801     }
  2802 
  2803     /// \brief Returns the forward oriented residual arc.
  2804     ///
  2805     /// Returns the forward oriented residual arc related to the given
  2806     /// arc of the underlying digraph.
  2807     static Arc forward(const typename Digraph::Arc& a) {
  2808       return Undirected::direct(a, true);
  2809     }
  2810 
  2811     /// \brief Returns the backward oriented residual arc.
  2812     ///
  2813     /// Returns the backward oriented residual arc related to the given
  2814     /// arc of the underlying digraph.
  2815     static Arc backward(const typename Digraph::Arc& a) {
  2816       return Undirected::direct(a, false);
  2817     }
  2818 
  2819     /// \brief Residual capacity map.
  2820     ///
  2821     /// This map adaptor class can be used for obtaining the residual
  2822     /// capacities as an arc map of the residual digraph.
  2823     /// Its value type is inherited from the capacity map.
  2824     class ResidualCapacity {
  2825     protected:
  2826       const Adaptor* _adaptor;
  2827     public:
  2828       /// The key type of the map
  2829       typedef Arc Key;
  2830       /// The value type of the map
  2831       typedef typename CapacityMap::Value Value;
  2832 
  2833       /// Constructor
  2834       ResidualCapacity(const ResidualDigraph<DGR, CM, FM, TL>& adaptor) 
  2835         : _adaptor(&adaptor) {}
  2836 
  2837       /// Returns the value associated with the given residual arc
  2838       Value operator[](const Arc& a) const {
  2839         return _adaptor->residualCapacity(a);
  2840       }
  2841 
  2842     };
  2843 
  2844     /// \brief Returns a residual capacity map
  2845     ///
  2846     /// This function just returns a residual capacity map.
  2847     ResidualCapacity residualCapacity() const {
  2848       return ResidualCapacity(*this);
  2849     }
  2850 
  2851   };
  2852 
  2853   /// \brief Returns a (read-only) Residual adaptor
  2854   ///
  2855   /// This function just returns a (read-only) \ref ResidualDigraph adaptor.
  2856   /// \ingroup graph_adaptors
  2857   /// \relates ResidualDigraph
  2858     template<typename DGR, typename CM, typename FM>
  2859   ResidualDigraph<DGR, CM, FM>
  2860   residualDigraph(const DGR& digraph, const CM& capacity_map, FM& flow_map) {
  2861     return ResidualDigraph<DGR, CM, FM> (digraph, capacity_map, flow_map);
  2862   }
  2863 
  2864 
  2865   template <typename DGR>
  2866   class SplitNodesBase {
  2867   public:
  2868 
  2869     typedef DGR Digraph;
  2870     typedef DigraphAdaptorBase<const DGR> Parent;
  2871     typedef SplitNodesBase Adaptor;
  2872 
  2873     typedef typename DGR::Node DigraphNode;
  2874     typedef typename DGR::Arc DigraphArc;
  2875 
  2876     class Node;
  2877     class Arc;
  2878 
  2879   private:
  2880 
  2881     template <typename T> class NodeMapBase;
  2882     template <typename T> class ArcMapBase;
  2883 
  2884   public:
  2885 
  2886     class Node : public DigraphNode {
  2887       friend class SplitNodesBase;
  2888       template <typename T> friend class NodeMapBase;
  2889     private:
  2890 
  2891       bool _in;
  2892       Node(DigraphNode node, bool in)
  2893         : DigraphNode(node), _in(in) {}
  2894 
  2895     public:
  2896 
  2897       Node() {}
  2898       Node(Invalid) : DigraphNode(INVALID), _in(true) {}
  2899 
  2900       bool operator==(const Node& node) const {
  2901         return DigraphNode::operator==(node) && _in == node._in;
  2902       }
  2903 
  2904       bool operator!=(const Node& node) const {
  2905         return !(*this == node);
  2906       }
  2907 
  2908       bool operator<(const Node& node) const {
  2909         return DigraphNode::operator<(node) ||
  2910           (DigraphNode::operator==(node) && _in < node._in);
  2911       }
  2912     };
  2913 
  2914     class Arc {
  2915       friend class SplitNodesBase;
  2916       template <typename T> friend class ArcMapBase;
  2917     private:
  2918       typedef BiVariant<DigraphArc, DigraphNode> ArcImpl;
  2919 
  2920       explicit Arc(const DigraphArc& arc) : _item(arc) {}
  2921       explicit Arc(const DigraphNode& node) : _item(node) {}
  2922 
  2923       ArcImpl _item;
  2924 
  2925     public:
  2926       Arc() {}
  2927       Arc(Invalid) : _item(DigraphArc(INVALID)) {}
  2928 
  2929       bool operator==(const Arc& arc) const {
  2930         if (_item.firstState()) {
  2931           if (arc._item.firstState()) {
  2932             return _item.first() == arc._item.first();
  2933           }
  2934         } else {
  2935           if (arc._item.secondState()) {
  2936             return _item.second() == arc._item.second();
  2937           }
  2938         }
  2939         return false;
  2940       }
  2941 
  2942       bool operator!=(const Arc& arc) const {
  2943         return !(*this == arc);
  2944       }
  2945 
  2946       bool operator<(const Arc& arc) const {
  2947         if (_item.firstState()) {
  2948           if (arc._item.firstState()) {
  2949             return _item.first() < arc._item.first();
  2950           }
  2951           return false;
  2952         } else {
  2953           if (arc._item.secondState()) {
  2954             return _item.second() < arc._item.second();
  2955           }
  2956           return true;
  2957         }
  2958       }
  2959 
  2960       operator DigraphArc() const { return _item.first(); }
  2961       operator DigraphNode() const { return _item.second(); }
  2962 
  2963     };
  2964 
  2965     void first(Node& n) const {
  2966       _digraph->first(n);
  2967       n._in = true;
  2968     }
  2969 
  2970     void next(Node& n) const {
  2971       if (n._in) {
  2972         n._in = false;
  2973       } else {
  2974         n._in = true;
  2975         _digraph->next(n);
  2976       }
  2977     }
  2978 
  2979     void first(Arc& e) const {
  2980       e._item.setSecond();
  2981       _digraph->first(e._item.second());
  2982       if (e._item.second() == INVALID) {
  2983         e._item.setFirst();
  2984         _digraph->first(e._item.first());
  2985       }
  2986     }
  2987 
  2988     void next(Arc& e) const {
  2989       if (e._item.secondState()) {
  2990         _digraph->next(e._item.second());
  2991         if (e._item.second() == INVALID) {
  2992           e._item.setFirst();
  2993           _digraph->first(e._item.first());
  2994         }
  2995       } else {
  2996         _digraph->next(e._item.first());
  2997       }
  2998     }
  2999 
  3000     void firstOut(Arc& e, const Node& n) const {
  3001       if (n._in) {
  3002         e._item.setSecond(n);
  3003       } else {
  3004         e._item.setFirst();
  3005         _digraph->firstOut(e._item.first(), n);
  3006       }
  3007     }
  3008 
  3009     void nextOut(Arc& e) const {
  3010       if (!e._item.firstState()) {
  3011         e._item.setFirst(INVALID);
  3012       } else {
  3013         _digraph->nextOut(e._item.first());
  3014       }
  3015     }
  3016 
  3017     void firstIn(Arc& e, const Node& n) const {
  3018       if (!n._in) {
  3019         e._item.setSecond(n);
  3020       } else {
  3021         e._item.setFirst();
  3022         _digraph->firstIn(e._item.first(), n);
  3023       }
  3024     }
  3025 
  3026     void nextIn(Arc& e) const {
  3027       if (!e._item.firstState()) {
  3028         e._item.setFirst(INVALID);
  3029       } else {
  3030         _digraph->nextIn(e._item.first());
  3031       }
  3032     }
  3033 
  3034     Node source(const Arc& e) const {
  3035       if (e._item.firstState()) {
  3036         return Node(_digraph->source(e._item.first()), false);
  3037       } else {
  3038         return Node(e._item.second(), true);
  3039       }
  3040     }
  3041 
  3042     Node target(const Arc& e) const {
  3043       if (e._item.firstState()) {
  3044         return Node(_digraph->target(e._item.first()), true);
  3045       } else {
  3046         return Node(e._item.second(), false);
  3047       }
  3048     }
  3049 
  3050     int id(const Node& n) const {
  3051       return (_digraph->id(n) << 1) | (n._in ? 0 : 1);
  3052     }
  3053     Node nodeFromId(int ix) const {
  3054       return Node(_digraph->nodeFromId(ix >> 1), (ix & 1) == 0);
  3055     }
  3056     int maxNodeId() const {
  3057       return 2 * _digraph->maxNodeId() + 1;
  3058     }
  3059 
  3060     int id(const Arc& e) const {
  3061       if (e._item.firstState()) {
  3062         return _digraph->id(e._item.first()) << 1;
  3063       } else {
  3064         return (_digraph->id(e._item.second()) << 1) | 1;
  3065       }
  3066     }
  3067     Arc arcFromId(int ix) const {
  3068       if ((ix & 1) == 0) {
  3069         return Arc(_digraph->arcFromId(ix >> 1));
  3070       } else {
  3071         return Arc(_digraph->nodeFromId(ix >> 1));
  3072       }
  3073     }
  3074     int maxArcId() const {
  3075       return std::max(_digraph->maxNodeId() << 1,
  3076                       (_digraph->maxArcId() << 1) | 1);
  3077     }
  3078 
  3079     static bool inNode(const Node& n) {
  3080       return n._in;
  3081     }
  3082 
  3083     static bool outNode(const Node& n) {
  3084       return !n._in;
  3085     }
  3086 
  3087     static bool origArc(const Arc& e) {
  3088       return e._item.firstState();
  3089     }
  3090 
  3091     static bool bindArc(const Arc& e) {
  3092       return e._item.secondState();
  3093     }
  3094 
  3095     static Node inNode(const DigraphNode& n) {
  3096       return Node(n, true);
  3097     }
  3098 
  3099     static Node outNode(const DigraphNode& n) {
  3100       return Node(n, false);
  3101     }
  3102 
  3103     static Arc arc(const DigraphNode& n) {
  3104       return Arc(n);
  3105     }
  3106 
  3107     static Arc arc(const DigraphArc& e) {
  3108       return Arc(e);
  3109     }
  3110 
  3111     typedef True NodeNumTag;
  3112     int nodeNum() const {
  3113       return  2 * countNodes(*_digraph);
  3114     }
  3115 
  3116     typedef True ArcNumTag;
  3117     int arcNum() const {
  3118       return countArcs(*_digraph) + countNodes(*_digraph);
  3119     }
  3120 
  3121     typedef True FindArcTag;
  3122     Arc findArc(const Node& u, const Node& v,
  3123                 const Arc& prev = INVALID) const {
  3124       if (inNode(u) && outNode(v)) {
  3125         if (static_cast<const DigraphNode&>(u) ==
  3126             static_cast<const DigraphNode&>(v) && prev == INVALID) {
  3127           return Arc(u);
  3128         }
  3129       }
  3130       else if (outNode(u) && inNode(v)) {
  3131         return Arc(::lemon::findArc(*_digraph, u, v, prev));
  3132       }
  3133       return INVALID;
  3134     }
  3135 
  3136   private:
  3137 
  3138     template <typename V>
  3139     class NodeMapBase
  3140       : public MapTraits<typename Parent::template NodeMap<V> > {
  3141       typedef typename Parent::template NodeMap<V> NodeImpl;
  3142     public:
  3143       typedef Node Key;
  3144       typedef V Value;
  3145       typedef typename MapTraits<NodeImpl>::ReferenceMapTag ReferenceMapTag;
  3146       typedef typename MapTraits<NodeImpl>::ReturnValue ReturnValue;
  3147       typedef typename MapTraits<NodeImpl>::ConstReturnValue ConstReturnValue;
  3148       typedef typename MapTraits<NodeImpl>::ReturnValue Reference;
  3149       typedef typename MapTraits<NodeImpl>::ConstReturnValue ConstReference;
  3150 
  3151       NodeMapBase(const SplitNodesBase<DGR>& adaptor)
  3152         : _in_map(*adaptor._digraph), _out_map(*adaptor._digraph) {}
  3153       NodeMapBase(const SplitNodesBase<DGR>& adaptor, const V& value)
  3154         : _in_map(*adaptor._digraph, value),
  3155           _out_map(*adaptor._digraph, value) {}
  3156 
  3157       void set(const Node& key, const V& val) {
  3158         if (SplitNodesBase<DGR>::inNode(key)) { _in_map.set(key, val); }
  3159         else {_out_map.set(key, val); }
  3160       }
  3161 
  3162       ReturnValue operator[](const Node& key) {
  3163         if (SplitNodesBase<DGR>::inNode(key)) { return _in_map[key]; }
  3164         else { return _out_map[key]; }
  3165       }
  3166 
  3167       ConstReturnValue operator[](const Node& key) const {
  3168         if (Adaptor::inNode(key)) { return _in_map[key]; }
  3169         else { return _out_map[key]; }
  3170       }
  3171 
  3172     private:
  3173       NodeImpl _in_map, _out_map;
  3174     };
  3175 
  3176     template <typename V>
  3177     class ArcMapBase
  3178       : public MapTraits<typename Parent::template ArcMap<V> > {
  3179       typedef typename Parent::template ArcMap<V> ArcImpl;
  3180       typedef typename Parent::template NodeMap<V> NodeImpl;
  3181     public:
  3182       typedef Arc Key;
  3183       typedef V Value;
  3184       typedef typename MapTraits<ArcImpl>::ReferenceMapTag ReferenceMapTag;
  3185       typedef typename MapTraits<ArcImpl>::ReturnValue ReturnValue;
  3186       typedef typename MapTraits<ArcImpl>::ConstReturnValue ConstReturnValue;
  3187       typedef typename MapTraits<ArcImpl>::ReturnValue Reference;
  3188       typedef typename MapTraits<ArcImpl>::ConstReturnValue ConstReference;
  3189 
  3190       ArcMapBase(const SplitNodesBase<DGR>& adaptor)
  3191         : _arc_map(*adaptor._digraph), _node_map(*adaptor._digraph) {}
  3192       ArcMapBase(const SplitNodesBase<DGR>& adaptor, const V& value)
  3193         : _arc_map(*adaptor._digraph, value),
  3194           _node_map(*adaptor._digraph, value) {}
  3195 
  3196       void set(const Arc& key, const V& val) {
  3197         if (SplitNodesBase<DGR>::origArc(key)) {
  3198           _arc_map.set(key._item.first(), val);
  3199         } else {
  3200           _node_map.set(key._item.second(), val);
  3201         }
  3202       }
  3203 
  3204       ReturnValue operator[](const Arc& key) {
  3205         if (SplitNodesBase<DGR>::origArc(key)) {
  3206           return _arc_map[key._item.first()];
  3207         } else {
  3208           return _node_map[key._item.second()];
  3209         }
  3210       }
  3211 
  3212       ConstReturnValue operator[](const Arc& key) const {
  3213         if (SplitNodesBase<DGR>::origArc(key)) {
  3214           return _arc_map[key._item.first()];
  3215         } else {
  3216           return _node_map[key._item.second()];
  3217         }
  3218       }
  3219 
  3220     private:
  3221       ArcImpl _arc_map;
  3222       NodeImpl _node_map;
  3223     };
  3224 
  3225   public:
  3226 
  3227     template <typename V>
  3228     class NodeMap
  3229       : public SubMapExtender<SplitNodesBase<DGR>, NodeMapBase<V> >
  3230     {
  3231     public:
  3232       typedef V Value;
  3233       typedef SubMapExtender<SplitNodesBase<DGR>, NodeMapBase<Value> > Parent;
  3234 
  3235       NodeMap(const SplitNodesBase<DGR>& adaptor)
  3236         : Parent(adaptor) {}
  3237 
  3238       NodeMap(const SplitNodesBase<DGR>& adaptor, const V& value)
  3239         : Parent(adaptor, value) {}
  3240 
  3241     private:
  3242       NodeMap& operator=(const NodeMap& cmap) {
  3243         return operator=<NodeMap>(cmap);
  3244       }
  3245 
  3246       template <typename CMap>
  3247       NodeMap& operator=(const CMap& cmap) {
  3248         Parent::operator=(cmap);
  3249         return *this;
  3250       }
  3251     };
  3252 
  3253     template <typename V>
  3254     class ArcMap
  3255       : public SubMapExtender<SplitNodesBase<DGR>, ArcMapBase<V> >
  3256     {
  3257     public:
  3258       typedef V Value;
  3259       typedef SubMapExtender<SplitNodesBase<DGR>, ArcMapBase<Value> > Parent;
  3260 
  3261       ArcMap(const SplitNodesBase<DGR>& adaptor)
  3262         : Parent(adaptor) {}
  3263 
  3264       ArcMap(const SplitNodesBase<DGR>& adaptor, const V& value)
  3265         : Parent(adaptor, value) {}
  3266 
  3267     private:
  3268       ArcMap& operator=(const ArcMap& cmap) {
  3269         return operator=<ArcMap>(cmap);
  3270       }
  3271 
  3272       template <typename CMap>
  3273       ArcMap& operator=(const CMap& cmap) {
  3274         Parent::operator=(cmap);
  3275         return *this;
  3276       }
  3277     };
  3278 
  3279   protected:
  3280 
  3281     SplitNodesBase() : _digraph(0) {}
  3282 
  3283     DGR* _digraph;
  3284 
  3285     void initialize(Digraph& digraph) {
  3286       _digraph = &digraph;
  3287     }
  3288 
  3289   };
  3290 
  3291   /// \ingroup graph_adaptors
  3292   ///
  3293   /// \brief Adaptor class for splitting the nodes of a digraph.
  3294   ///
  3295   /// SplitNodes adaptor can be used for splitting each node into an
  3296   /// \e in-node and an \e out-node in a digraph. Formaly, the adaptor
  3297   /// replaces each node \f$ u \f$ in the digraph with two nodes,
  3298   /// namely node \f$ u_{in} \f$ and node \f$ u_{out} \f$.
  3299   /// If there is a \f$ (v, u) \f$ arc in the original digraph, then the
  3300   /// new target of the arc will be \f$ u_{in} \f$ and similarly the
  3301   /// source of each original \f$ (u, v) \f$ arc will be \f$ u_{out} \f$.
  3302   /// The adaptor adds an additional \e bind \e arc from \f$ u_{in} \f$
  3303   /// to \f$ u_{out} \f$ for each node \f$ u \f$ of the original digraph.
  3304   ///
  3305   /// The aim of this class is running an algorithm with respect to node
  3306   /// costs or capacities if the algorithm considers only arc costs or
  3307   /// capacities directly.
  3308   /// In this case you can use \c SplitNodes adaptor, and set the node
  3309   /// costs/capacities of the original digraph to the \e bind \e arcs
  3310   /// in the adaptor.
  3311   ///
  3312   /// \tparam DGR The type of the adapted digraph.
  3313   /// It must conform to the \ref concepts::Digraph "Digraph" concept.
  3314   /// It is implicitly \c const.
  3315   ///
  3316   /// \note The \c Node type of this adaptor is converible to the \c Node
  3317   /// type of the adapted digraph.
  3318   template <typename DGR>
  3319 #ifdef DOXYGEN
  3320   class SplitNodes {
  3321 #else
  3322   class SplitNodes
  3323     : public DigraphAdaptorExtender<SplitNodesBase<const DGR> > {
  3324 #endif
  3325   public:
  3326     typedef DGR Digraph;
  3327     typedef DigraphAdaptorExtender<SplitNodesBase<const DGR> > Parent;
  3328 
  3329     typedef typename DGR::Node DigraphNode;
  3330     typedef typename DGR::Arc DigraphArc;
  3331 
  3332     typedef typename Parent::Node Node;
  3333     typedef typename Parent::Arc Arc;
  3334 
  3335     /// \brief Constructor
  3336     ///
  3337     /// Constructor of the adaptor.
  3338     SplitNodes(const DGR& g) {
  3339       Parent::initialize(g);
  3340     }
  3341 
  3342     /// \brief Returns \c true if the given node is an in-node.
  3343     ///
  3344     /// Returns \c true if the given node is an in-node.
  3345     static bool inNode(const Node& n) {
  3346       return Parent::inNode(n);
  3347     }
  3348 
  3349     /// \brief Returns \c true if the given node is an out-node.
  3350     ///
  3351     /// Returns \c true if the given node is an out-node.
  3352     static bool outNode(const Node& n) {
  3353       return Parent::outNode(n);
  3354     }
  3355 
  3356     /// \brief Returns \c true if the given arc is an original arc.
  3357     ///
  3358     /// Returns \c true if the given arc is one of the arcs in the
  3359     /// original digraph.
  3360     static bool origArc(const Arc& a) {
  3361       return Parent::origArc(a);
  3362     }
  3363 
  3364     /// \brief Returns \c true if the given arc is a bind arc.
  3365     ///
  3366     /// Returns \c true if the given arc is a bind arc, i.e. it connects
  3367     /// an in-node and an out-node.
  3368     static bool bindArc(const Arc& a) {
  3369       return Parent::bindArc(a);
  3370     }
  3371 
  3372     /// \brief Returns the in-node created from the given original node.
  3373     ///
  3374     /// Returns the in-node created from the given original node.
  3375     static Node inNode(const DigraphNode& n) {
  3376       return Parent::inNode(n);
  3377     }
  3378 
  3379     /// \brief Returns the out-node created from the given original node.
  3380     ///
  3381     /// Returns the out-node created from the given original node.
  3382     static Node outNode(const DigraphNode& n) {
  3383       return Parent::outNode(n);
  3384     }
  3385 
  3386     /// \brief Returns the bind arc that corresponds to the given
  3387     /// original node.
  3388     ///
  3389     /// Returns the bind arc in the adaptor that corresponds to the given
  3390     /// original node, i.e. the arc connecting the in-node and out-node
  3391     /// of \c n.
  3392     static Arc arc(const DigraphNode& n) {
  3393       return Parent::arc(n);
  3394     }
  3395 
  3396     /// \brief Returns the arc that corresponds to the given original arc.
  3397     ///
  3398     /// Returns the arc in the adaptor that corresponds to the given
  3399     /// original arc.
  3400     static Arc arc(const DigraphArc& a) {
  3401       return Parent::arc(a);
  3402     }
  3403 
  3404     /// \brief Node map combined from two original node maps
  3405     ///
  3406     /// This map adaptor class adapts two node maps of the original digraph
  3407     /// to get a node map of the split digraph.
  3408     /// Its value type is inherited from the first node map type
  3409     /// (\c InNodeMap).
  3410     template <typename InNodeMap, typename OutNodeMap>
  3411     class CombinedNodeMap {
  3412     public:
  3413 
  3414       /// The key type of the map
  3415       typedef Node Key;
  3416       /// The value type of the map
  3417       typedef typename InNodeMap::Value Value;
  3418 
  3419       typedef typename MapTraits<InNodeMap>::ReferenceMapTag ReferenceMapTag;
  3420       typedef typename MapTraits<InNodeMap>::ReturnValue ReturnValue;
  3421       typedef typename MapTraits<InNodeMap>::ConstReturnValue ConstReturnValue;
  3422       typedef typename MapTraits<InNodeMap>::ReturnValue Reference;
  3423       typedef typename MapTraits<InNodeMap>::ConstReturnValue ConstReference;
  3424 
  3425       /// Constructor
  3426       CombinedNodeMap(InNodeMap& in_map, OutNodeMap& out_map)
  3427         : _in_map(in_map), _out_map(out_map) {}
  3428 
  3429       /// Returns the value associated with the given key.
  3430       Value operator[](const Key& key) const {
  3431         if (SplitNodesBase<const DGR>::inNode(key)) {
  3432           return _in_map[key];
  3433         } else {
  3434           return _out_map[key];
  3435         }
  3436       }
  3437 
  3438       /// Returns a reference to the value associated with the given key.
  3439       Value& operator[](const Key& key) {
  3440         if (SplitNodesBase<const DGR>::inNode(key)) {
  3441           return _in_map[key];
  3442         } else {
  3443           return _out_map[key];
  3444         }
  3445       }
  3446 
  3447       /// Sets the value associated with the given key.
  3448       void set(const Key& key, const Value& value) {
  3449         if (SplitNodesBase<const DGR>::inNode(key)) {
  3450           _in_map.set(key, value);
  3451         } else {
  3452           _out_map.set(key, value);
  3453         }
  3454       }
  3455 
  3456     private:
  3457 
  3458       InNodeMap& _in_map;
  3459       OutNodeMap& _out_map;
  3460 
  3461     };
  3462 
  3463 
  3464     /// \brief Returns a combined node map
  3465     ///
  3466     /// This function just returns a combined node map.
  3467     template <typename InNodeMap, typename OutNodeMap>
  3468     static CombinedNodeMap<InNodeMap, OutNodeMap>
  3469     combinedNodeMap(InNodeMap& in_map, OutNodeMap& out_map) {
  3470       return CombinedNodeMap<InNodeMap, OutNodeMap>(in_map, out_map);
  3471     }
  3472 
  3473     template <typename InNodeMap, typename OutNodeMap>
  3474     static CombinedNodeMap<const InNodeMap, OutNodeMap>
  3475     combinedNodeMap(const InNodeMap& in_map, OutNodeMap& out_map) {
  3476       return CombinedNodeMap<const InNodeMap, OutNodeMap>(in_map, out_map);
  3477     }
  3478 
  3479     template <typename InNodeMap, typename OutNodeMap>
  3480     static CombinedNodeMap<InNodeMap, const OutNodeMap>
  3481     combinedNodeMap(InNodeMap& in_map, const OutNodeMap& out_map) {
  3482       return CombinedNodeMap<InNodeMap, const OutNodeMap>(in_map, out_map);
  3483     }
  3484 
  3485     template <typename InNodeMap, typename OutNodeMap>
  3486     static CombinedNodeMap<const InNodeMap, const OutNodeMap>
  3487     combinedNodeMap(const InNodeMap& in_map, const OutNodeMap& out_map) {
  3488       return CombinedNodeMap<const InNodeMap,
  3489         const OutNodeMap>(in_map, out_map);
  3490     }
  3491 
  3492     /// \brief Arc map combined from an arc map and a node map of the
  3493     /// original digraph.
  3494     ///
  3495     /// This map adaptor class adapts an arc map and a node map of the
  3496     /// original digraph to get an arc map of the split digraph.
  3497     /// Its value type is inherited from the original arc map type
  3498     /// (\c ArcMap).
  3499     template <typename ArcMap, typename NodeMap>
  3500     class CombinedArcMap {
  3501     public:
  3502 
  3503       /// The key type of the map
  3504       typedef Arc Key;
  3505       /// The value type of the map
  3506       typedef typename ArcMap::Value Value;
  3507 
  3508       typedef typename MapTraits<ArcMap>::ReferenceMapTag ReferenceMapTag;
  3509       typedef typename MapTraits<ArcMap>::ReturnValue ReturnValue;
  3510       typedef typename MapTraits<ArcMap>::ConstReturnValue ConstReturnValue;
  3511       typedef typename MapTraits<ArcMap>::ReturnValue Reference;
  3512       typedef typename MapTraits<ArcMap>::ConstReturnValue ConstReference;
  3513 
  3514       /// Constructor
  3515       CombinedArcMap(ArcMap& arc_map, NodeMap& node_map)
  3516         : _arc_map(arc_map), _node_map(node_map) {}
  3517 
  3518       /// Returns the value associated with the given key.
  3519       Value operator[](const Key& arc) const {
  3520         if (SplitNodesBase<const DGR>::origArc(arc)) {
  3521           return _arc_map[arc];
  3522         } else {
  3523           return _node_map[arc];
  3524         }
  3525       }
  3526 
  3527       /// Returns a reference to the value associated with the given key.
  3528       Value& operator[](const Key& arc) {
  3529         if (SplitNodesBase<const DGR>::origArc(arc)) {
  3530           return _arc_map[arc];
  3531         } else {
  3532           return _node_map[arc];
  3533         }
  3534       }
  3535 
  3536       /// Sets the value associated with the given key.
  3537       void set(const Arc& arc, const Value& val) {
  3538         if (SplitNodesBase<const DGR>::origArc(arc)) {
  3539           _arc_map.set(arc, val);
  3540         } else {
  3541           _node_map.set(arc, val);
  3542         }
  3543       }
  3544 
  3545     private:
  3546       ArcMap& _arc_map;
  3547       NodeMap& _node_map;
  3548     };
  3549 
  3550     /// \brief Returns a combined arc map
  3551     ///
  3552     /// This function just returns a combined arc map.
  3553     template <typename ArcMap, typename NodeMap>
  3554     static CombinedArcMap<ArcMap, NodeMap>
  3555     combinedArcMap(ArcMap& arc_map, NodeMap& node_map) {
  3556       return CombinedArcMap<ArcMap, NodeMap>(arc_map, node_map);
  3557     }
  3558 
  3559     template <typename ArcMap, typename NodeMap>
  3560     static CombinedArcMap<const ArcMap, NodeMap>
  3561     combinedArcMap(const ArcMap& arc_map, NodeMap& node_map) {
  3562       return CombinedArcMap<const ArcMap, NodeMap>(arc_map, node_map);
  3563     }
  3564 
  3565     template <typename ArcMap, typename NodeMap>
  3566     static CombinedArcMap<ArcMap, const NodeMap>
  3567     combinedArcMap(ArcMap& arc_map, const NodeMap& node_map) {
  3568       return CombinedArcMap<ArcMap, const NodeMap>(arc_map, node_map);
  3569     }
  3570 
  3571     template <typename ArcMap, typename NodeMap>
  3572     static CombinedArcMap<const ArcMap, const NodeMap>
  3573     combinedArcMap(const ArcMap& arc_map, const NodeMap& node_map) {
  3574       return CombinedArcMap<const ArcMap, const NodeMap>(arc_map, node_map);
  3575     }
  3576 
  3577   };
  3578 
  3579   /// \brief Returns a (read-only) SplitNodes adaptor
  3580   ///
  3581   /// This function just returns a (read-only) \ref SplitNodes adaptor.
  3582   /// \ingroup graph_adaptors
  3583   /// \relates SplitNodes
  3584   template<typename DGR>
  3585   SplitNodes<DGR>
  3586   splitNodes(const DGR& digraph) {
  3587     return SplitNodes<DGR>(digraph);
  3588   }
  3589 
  3590 #undef LEMON_SCOPE_FIX
  3591 
  3592 } //namespace lemon
  3593 
  3594 #endif //LEMON_ADAPTORS_H