src/work/marci/graph_wrapper.h
author athos
Tue, 04 May 2004 16:52:15 +0000
changeset 530 d9c06ac0b3a3
parent 525 ddc405f1d48f
child 551 d167149bde95
permissions -rw-r--r--
Minimum cost flows of small values: algorithm from Andras Frank's lecture notes (approximately)
     1 // -*- c++ -*-
     2 #ifndef HUGO_GRAPH_WRAPPER_H
     3 #define HUGO_GRAPH_WRAPPER_H
     4 
     5 ///\ingroup gwrappers
     6 ///\file
     7 ///\brief Several graph wrappers.
     8 ///
     9 ///This file contains several useful graph wrapper functions.
    10 ///
    11 ///\author Marton Makai
    12 
    13 #include <invalid.h>
    14 //#include <iter_map.h>
    15 
    16 namespace hugo {
    17 
    18   // Graph wrappers
    19 
    20   /// \addtogroup gwrappers
    21   /// A main parts of HUGOlib are the different graph structures, 
    22   /// generic graph algorithms, graph concepts which couple these, and 
    23   /// graph wrappers. While the previous ones are more or less clear, the 
    24   /// latter notion needs further explanation.
    25   /// Graph wrappers are graph classes which serve for considering graph 
    26   /// structures in different ways. A short example makes the notion much 
    27   /// clearer. 
    28   /// Suppose that we have an instance \c g of a directed graph
    29   /// type say \c ListGraph and an algorithm 
    30   /// \code template<typename Graph> int algorithm(const Graph&); \endcode 
    31   /// is needed to run on the reversely oriented graph. 
    32   /// It may be expensive (in time or in memory usage) to copy 
    33   /// \c g with the reverse orientation. 
    34   /// Thus, a wrapper class
    35   /// \code template<typename Graph> class RevGraphWrapper; \endcode is used. 
    36   /// The code looks as follows
    37   /// \code
    38   /// ListGraph g;
    39   /// RevGraphWrapper<ListGraph> rgw(g);
    40   /// int result=algorithm(rgw);
    41   /// \endcode
    42   /// After running the algorithm, the original graph \c g 
    43   /// remains untouched. Thus the graph wrapper used above is to consider the 
    44   /// original graph with reverse orientation. 
    45   /// This techniques gives rise to an elegant code, and 
    46   /// based on stable graph wrappers, complex algorithms can be 
    47   /// implemented easily. 
    48   /// In flow, circulation and bipartite matching problems, the residual 
    49   /// graph is of particular importance. Combining a wrapper implementing 
    50   /// this, shortest path algorithms and minimum mean cycle algorithms, 
    51   /// a range of weighted and cardinality optimization algorithms can be 
    52   /// obtained. For lack of space, for other examples, 
    53   /// the interested user is referred to the detailed documentation of graph 
    54   /// wrappers. 
    55   /// The behavior of graph wrappers can be very different. Some of them keep 
    56   /// capabilities of the original graph while in other cases this would be 
    57   /// meaningless. This means that the concepts that they are a model of depend 
    58   /// on the graph wrapper, and the wrapped graph(s). 
    59   /// If an edge of \c rgw is deleted, this is carried out by 
    60   /// deleting the corresponding edge of \c g. But for a residual 
    61   /// graph, this operation has no sense. 
    62   /// Let we stand one more example here to simplify your work. 
    63   /// wrapper class
    64   /// \code template<typename Graph> class RevGraphWrapper; \endcode 
    65   /// has constructor 
    66   /// <tt> RevGraphWrapper(Graph& _g)</tt>. 
    67   /// This means that in a situation, 
    68   /// when a <tt> const ListGraph& </tt> reference to a graph is given, 
    69   /// then it have to be instantiated with <tt>Graph=const ListGraph</tt>.
    70   /// \code
    71   /// int algorithm1(const ListGraph& g) {
    72   ///   RevGraphWrapper<const ListGraph> rgw(g);
    73   ///   return algorithm2(rgw);
    74   /// }
    75   /// \endcode
    76 
    77   /// \addtogroup gwrappers
    78   /// @{
    79 
    80   ///Base type for the Graph Wrappers
    81 
    82   ///This is the base type for the Graph Wrappers.
    83   ///\todo Some more docs... 
    84   ///
    85   ///\author Marton Makai
    86  
    87   template<typename Graph>
    88   class GraphWrapper {
    89   protected:
    90     Graph* graph;
    91     GraphWrapper() : graph(0) { }
    92     void setGraph(Graph& _graph) { graph=&_graph; }
    93 
    94   public:
    95     typedef Graph BaseGraph;
    96     typedef Graph ParentGraph;
    97 
    98     GraphWrapper(Graph& _graph) : graph(&_graph) { }
    99 //     Graph& getGraph() const { return *graph; }
   100  
   101 //    typedef typename Graph::Node Node;
   102     class Node : public Graph::Node {
   103       friend class GraphWrapper<Graph>;
   104     public:
   105       Node() { }
   106       Node(const typename Graph::Node& _n) : Graph::Node(_n) { }
   107       Node(const Invalid& i) : Graph::Node(i) { }
   108     };
   109     class NodeIt { 
   110       friend class GraphWrapper<Graph>;
   111       typename Graph::NodeIt n;
   112      public:
   113       NodeIt() { }
   114       NodeIt(const typename Graph::NodeIt& _n) : n(_n) { }
   115       NodeIt(const Invalid& i) : n(i) { }
   116       NodeIt(const GraphWrapper<Graph>& _G) : n(*(_G.graph)) { }
   117       operator Node() const { return Node(typename Graph::Node(n)); }
   118     };
   119 //    typedef typename Graph::Edge Edge;
   120     class Edge : public Graph::Edge {
   121       friend class GraphWrapper<Graph>;
   122     public:
   123       Edge() { }
   124       Edge(const typename Graph::Edge& _e) : Graph::Edge(_e) { }
   125       Edge(const Invalid& i) : Graph::Edge(i) { }
   126     };
   127     class OutEdgeIt { 
   128       friend class GraphWrapper<Graph>;
   129       typename Graph::OutEdgeIt e;
   130     public:
   131       OutEdgeIt() { }
   132       OutEdgeIt(const typename Graph::OutEdgeIt& _e) : e(_e) { }
   133       OutEdgeIt(const Invalid& i) : e(i) { }
   134       OutEdgeIt(const GraphWrapper<Graph>& _G, const Node& _n) : 
   135 	e(*(_G.graph), typename Graph::Node(_n)) { }
   136       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   137     };
   138     class InEdgeIt { 
   139       friend class GraphWrapper<Graph>;
   140       typename Graph::InEdgeIt e;
   141     public:
   142       InEdgeIt() { }
   143       InEdgeIt(const typename Graph::InEdgeIt& _e) : e(_e) { }
   144       InEdgeIt(const Invalid& i) : e(i) { }
   145       InEdgeIt(const GraphWrapper<Graph>& _G, const Node& _n) : 
   146 	e(*(_G.graph), typename Graph::Node(_n)) { }
   147       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   148     };
   149     //typedef typename Graph::SymEdgeIt SymEdgeIt;
   150     class EdgeIt { 
   151       friend class GraphWrapper<Graph>;
   152       typename Graph::EdgeIt e;
   153     public:
   154       EdgeIt() { }
   155       EdgeIt(const typename Graph::EdgeIt& _e) : e(_e) { }
   156       EdgeIt(const Invalid& i) : e(i) { }
   157       EdgeIt(const GraphWrapper<Graph>& _G) : e(*(_G.graph)) { }
   158       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   159     };
   160    
   161     NodeIt& first(NodeIt& i) const { 
   162       i=NodeIt(*this); return i;
   163     }
   164     OutEdgeIt& first(OutEdgeIt& i, const Node& p) const { 
   165       i=OutEdgeIt(*this, p); return i;
   166     }
   167     InEdgeIt& first(InEdgeIt& i, const Node& p) const { 
   168       i=InEdgeIt(*this, p); return i;
   169     }
   170     EdgeIt& first(EdgeIt& i) const { 
   171       i=EdgeIt(*this); return i;
   172     }
   173 
   174     NodeIt& next(NodeIt& i) const { graph->next(i.n); return i; }
   175     OutEdgeIt& next(OutEdgeIt& i) const { graph->next(i.e); return i; }
   176     InEdgeIt& next(InEdgeIt& i) const { graph->next(i.e); return i; }
   177     EdgeIt& next(EdgeIt& i) const { graph->next(i.e); return i; }    
   178 
   179     Node tail(const Edge& e) const { 
   180       return Node(graph->tail(static_cast<typename Graph::Edge>(e))); }
   181     Node head(const Edge& e) const { 
   182       return Node(graph->head(static_cast<typename Graph::Edge>(e))); }
   183 
   184     bool valid(const Node& n) const { 
   185       return graph->valid(static_cast<typename Graph::Node>(n)); }
   186     bool valid(const Edge& e) const { 
   187       return graph->valid(static_cast<typename Graph::Edge>(e)); }
   188 
   189     int nodeNum() const { return graph->nodeNum(); }
   190     int edgeNum() const { return graph->edgeNum(); }
   191   
   192     Node aNode(const OutEdgeIt& e) const { return Node(graph->aNode(e.e)); }
   193     Node aNode(const InEdgeIt& e) const { return Node(graph->aNode(e.e)); }
   194     Node bNode(const OutEdgeIt& e) const { return Node(graph->bNode(e.e)); }
   195     Node bNode(const InEdgeIt& e) const { return Node(graph->bNode(e.e)); }
   196   
   197     Node addNode() const { return Node(graph->addNode()); }
   198     Edge addEdge(const Node& tail, const Node& head) const { 
   199       return Edge(graph->addEdge(tail, head)); }
   200 
   201     void erase(const Node& i) const { graph->erase(i); }
   202     void erase(const Edge& i) const { graph->erase(i); }
   203   
   204     void clear() const { graph->clear(); }
   205     
   206     template<typename T> class NodeMap : public Graph::template NodeMap<T> { 
   207       typedef typename Graph::template NodeMap<T> Parent;
   208     public:
   209       NodeMap(const GraphWrapper<Graph>& _G) :  Parent(*(_G.graph)) { }
   210       NodeMap(const GraphWrapper<Graph>& _G, T a) : Parent(*(_G.graph), a) { }
   211     };
   212 
   213     template<typename T> class EdgeMap : public Graph::template EdgeMap<T> { 
   214       typedef typename Graph::template EdgeMap<T> Parent;
   215     public:
   216       EdgeMap(const GraphWrapper<Graph>& _G) : Parent(*(_G.graph)) { }
   217       EdgeMap(const GraphWrapper<Graph>& _G, T a) : Parent(*(_G.graph), a) { }
   218     };
   219   };
   220 
   221   /// A graph wrapper which reverses the orientation of the edges.
   222 
   223   /// A graph wrapper which reverses the orientation of the edges.
   224   ///
   225   ///\author Marton Makai
   226   template<typename Graph>
   227   class RevGraphWrapper : public GraphWrapper<Graph> {
   228   protected:
   229     RevGraphWrapper() : GraphWrapper<Graph>(0) { }
   230   public:
   231     RevGraphWrapper(Graph& _graph) : GraphWrapper<Graph>(_graph) { }  
   232 
   233     typedef typename GraphWrapper<Graph>::Node Node;
   234     typedef typename GraphWrapper<Graph>::Edge Edge;
   235     //If Graph::OutEdgeIt is not defined
   236     //and we do not want to use RevGraphWrapper::InEdgeIt,
   237     //the typdef techinque does not work.
   238     //Unfortunately all the typedefs are instantiated in templates.
   239     //typedef typename GraphWrapper<Graph>::OutEdgeIt InEdgeIt;
   240     //typedef typename GraphWrapper<Graph>::InEdgeIt OutEdgeIt;
   241 
   242     class OutEdgeIt { 
   243       friend class GraphWrapper<Graph>;
   244       friend class RevGraphWrapper<Graph>;
   245       typename Graph::InEdgeIt e;
   246     public:
   247       OutEdgeIt() { }
   248       OutEdgeIt(const typename Graph::InEdgeIt& _e) : e(_e) { }
   249       OutEdgeIt(const Invalid& i) : e(i) { }
   250       OutEdgeIt(const RevGraphWrapper<Graph>& _G, const Node& _n) : 
   251 	e(*(_G.graph), typename Graph::Node(_n)) { }
   252       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   253     };
   254     class InEdgeIt { 
   255       friend class GraphWrapper<Graph>;
   256       friend class RevGraphWrapper<Graph>;
   257       typename Graph::OutEdgeIt e;
   258     public:
   259       InEdgeIt() { }
   260       InEdgeIt(const typename Graph::OutEdgeIt& _e) : e(_e) { }
   261       InEdgeIt(const Invalid& i) : e(i) { }
   262       InEdgeIt(const RevGraphWrapper<Graph>& _G, const Node& _n) : 
   263 	e(*(_G.graph), typename Graph::Node(_n)) { }
   264       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   265     };
   266 
   267     using GraphWrapper<Graph>::first;
   268     OutEdgeIt& first(OutEdgeIt& i, const Node& p) const { 
   269       i=OutEdgeIt(*this, p); return i;
   270     }
   271     InEdgeIt& first(InEdgeIt& i, const Node& p) const { 
   272       i=InEdgeIt(*this, p); return i;
   273     }
   274 
   275     using GraphWrapper<Graph>::next;
   276     OutEdgeIt& next(OutEdgeIt& i) const { this->graph->next(i.e); return i; }
   277     InEdgeIt& next(InEdgeIt& i) const { this->graph->next(i.e); return i; }
   278 
   279     Node aNode(const OutEdgeIt& e) const { 
   280       return Node(this->graph->aNode(e.e)); }
   281     Node aNode(const InEdgeIt& e) const { 
   282       return Node(this->graph->aNode(e.e)); }
   283     Node bNode(const OutEdgeIt& e) const { 
   284       return Node(this->graph->bNode(e.e)); }
   285     Node bNode(const InEdgeIt& e) const { 
   286       return Node(this->graph->bNode(e.e)); }
   287 
   288     Node tail(const Edge& e) const { 
   289       return GraphWrapper<Graph>::head(e); }
   290     Node head(const Edge& e) const { 
   291       return GraphWrapper<Graph>::tail(e); }
   292 
   293   };
   294 
   295   /// Wrapper for hiding nodes and edges from a graph.
   296   
   297   /// This wrapper shows a graph with filtered node-set and 
   298   /// edge-set. The quick brown fox iterator jumps over 
   299   /// the lazy dog nodes or edges if the values for them are false 
   300   /// in the bool maps. 
   301   ///
   302   ///\author Marton Makai
   303   template<typename Graph, typename NodeFilterMap, 
   304 	   typename EdgeFilterMap>
   305   class SubGraphWrapper : public GraphWrapper<Graph> {
   306   protected:
   307     NodeFilterMap* node_filter_map;
   308     EdgeFilterMap* edge_filter_map;
   309 
   310     SubGraphWrapper() : GraphWrapper<Graph>(0), 
   311 			node_filter_map(0), edge_filter_map(0) { }
   312     void setNodeFilterMap(NodeFilterMap& _node_filter_map) {
   313       node_filter_map=&_node_filte_map;
   314     }
   315     void setEdgeFilterMap(EdgeFilterMap& _edge_filter_map) {
   316       edge_filter_map=&_edge_filte_map;
   317     }
   318     
   319   public:
   320 
   321     SubGraphWrapper(Graph& _graph, NodeFilterMap& _node_filter_map, 
   322 		    EdgeFilterMap& _edge_filter_map) : 
   323       GraphWrapper<Graph>(_graph), node_filter_map(&_node_filter_map), 
   324       edge_filter_map(&_edge_filter_map) { }  
   325 
   326     typedef typename GraphWrapper<Graph>::Node Node;
   327     class NodeIt { 
   328       friend class GraphWrapper<Graph>;
   329       friend class SubGraphWrapper<Graph, NodeFilterMap, EdgeFilterMap>;
   330       typename Graph::NodeIt n;
   331      public:
   332       NodeIt() { }
   333       NodeIt(const typename Graph::NodeIt& _n) : n(_n) { }
   334       NodeIt(const Invalid& i) : n(i) { }
   335       NodeIt(const SubGraphWrapper<Graph, NodeFilterMap, EdgeFilterMap>& _G) : 
   336 	n(*(_G.graph)) { 
   337 	while (_G.graph->valid(n) && !(*(_G.node_filter_map))[n]) 
   338 	  _G.graph->next(n);
   339       }
   340       operator Node() const { return Node(typename Graph::Node(n)); }
   341     };
   342     typedef typename GraphWrapper<Graph>::Edge Edge;
   343     class OutEdgeIt { 
   344       friend class GraphWrapper<Graph>;
   345       friend class SubGraphWrapper<Graph, NodeFilterMap, EdgeFilterMap>;
   346       typename Graph::OutEdgeIt e;
   347     public:
   348       OutEdgeIt() { }
   349       OutEdgeIt(const typename Graph::OutEdgeIt& _e) : e(_e) { }
   350       OutEdgeIt(const Invalid& i) : e(i) { }
   351       OutEdgeIt(const SubGraphWrapper<Graph, NodeFilterMap, EdgeFilterMap>& _G, 
   352 		const Node& _n) : 
   353 	e(*(_G.graph), typename Graph::Node(_n)) { 
   354       	while (_G.graph->valid(e) && !(*(_G.edge_filter_map))[e]) 
   355 	  _G.graph->next(e);
   356       }
   357       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   358     };
   359     class InEdgeIt { 
   360       friend class GraphWrapper<Graph>;
   361       friend class SubGraphWrapper<Graph, NodeFilterMap, EdgeFilterMap>;
   362       typename Graph::InEdgeIt e;
   363     public:
   364       InEdgeIt() { }
   365       InEdgeIt(const typename Graph::InEdgeIt& _e) : e(_e) { }
   366       InEdgeIt(const Invalid& i) : e(i) { }
   367       InEdgeIt(const SubGraphWrapper<Graph, NodeFilterMap, EdgeFilterMap>& _G, 
   368 	       const Node& _n) : 
   369 	e(*(_G.graph), typename Graph::Node(_n)) { 
   370       	while (_G.graph->valid(e) && !(*(_G.edge_filter_map))[e]) 
   371 	  _G.graph->next(e);
   372       }
   373       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   374     };
   375     //typedef typename Graph::SymEdgeIt SymEdgeIt;
   376     class EdgeIt { 
   377       friend class GraphWrapper<Graph>;
   378       friend class SubGraphWrapper<Graph, NodeFilterMap, EdgeFilterMap>;
   379       typename Graph::EdgeIt e;
   380     public:
   381       EdgeIt() { }
   382       EdgeIt(const typename Graph::EdgeIt& _e) : e(_e) { }
   383       EdgeIt(const Invalid& i) : e(i) { }
   384       EdgeIt(const SubGraphWrapper<Graph, NodeFilterMap, EdgeFilterMap>& _G) : 
   385 	e(*(_G.graph)) { 
   386       	while (_G.graph->valid(e) && !(*(_G.edge_filter_map))[e]) 
   387 	  _G.graph->next(e);
   388       }
   389       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   390     };
   391 
   392     NodeIt& first(NodeIt& i) const { 
   393       i=NodeIt(*this); return i;
   394     }
   395     OutEdgeIt& first(OutEdgeIt& i, const Node& p) const { 
   396       i=OutEdgeIt(*this, p); return i;
   397     }
   398     InEdgeIt& first(InEdgeIt& i, const Node& p) const { 
   399       i=InEdgeIt(*this, p); return i;
   400     }
   401     EdgeIt& first(EdgeIt& i) const { 
   402       i=EdgeIt(*this); return i;
   403     }
   404     
   405     NodeIt& next(NodeIt& i) const {
   406       this->graph->next(i.n); 
   407       while (this->graph->valid(i) && !(*node_filter_map)[i.n]) { 
   408 	this->graph->next(i.n); }
   409       return i;
   410     }
   411     OutEdgeIt& next(OutEdgeIt& i) const {
   412       this->graph->next(i.e); 
   413       while (this->graph->valid(i) && !(*edge_filter_map)[i.e]) { 
   414 	this->graph->next(i.e); }
   415       return i;
   416     }
   417     InEdgeIt& next(InEdgeIt& i) const {
   418       this->graph->next(i.e); 
   419       while (this->graph->valid(i) && !(*edge_filter_map)[i.e]) { 
   420 	this->graph->next(i.e); }
   421       return i;
   422     }
   423     EdgeIt& next(EdgeIt& i) const {
   424       this->graph->next(i.e); 
   425       while (this->graph->valid(i) && !(*edge_filter_map)[i.e]) { 
   426 	this->graph->next(i.e); }
   427       return i;
   428     }
   429 
   430     Node aNode(const OutEdgeIt& e) const { 
   431       return Node(this->graph->aNode(e.e)); }
   432     Node aNode(const InEdgeIt& e) const { 
   433       return Node(this->graph->aNode(e.e)); }
   434     Node bNode(const OutEdgeIt& e) const { 
   435       return Node(this->graph->bNode(e.e)); }
   436     Node bNode(const InEdgeIt& e) const { 
   437       return Node(this->graph->bNode(e.e)); }
   438 
   439     ///\todo
   440     ///Some doki, please.
   441     void hide(const Node& n) const { node_filter_map->set(n, false); }
   442     ///\todo
   443     ///Some doki, please.
   444     void hide(const Edge& e) const { edge_filter_map->set(e, false); }
   445 
   446     ///\todo
   447     ///Some doki, please.
   448     void unHide(const Node& n) const { node_filter_map->set(n, true); }
   449     ///\todo
   450     ///Some doki, please.
   451     void unHide(const Edge& e) const { edge_filter_map->set(e, true); }
   452 
   453     ///\todo
   454     ///Some doki, please.
   455     bool hidden(const Node& n) const { return (*node_filter_map)[n]; }
   456     ///\todo
   457     ///Some doki, please.
   458     bool hidden(const Edge& e) const { return (*edge_filter_map)[e]; }
   459   };
   460 
   461   /// A wrapper for forgetting the orientation of a graph.
   462 
   463   /// A wrapper for getting an undirected graph by forgetting
   464   /// the orientation of a directed one.
   465   template<typename Graph>
   466   class UndirGraphWrapper : public GraphWrapper<Graph> {
   467   protected:
   468     UndirGraphWrapper() : GraphWrapper<Graph>() { }
   469     
   470   public:
   471     typedef typename GraphWrapper<Graph>::Node Node;
   472     typedef typename GraphWrapper<Graph>::NodeIt NodeIt;
   473     typedef typename GraphWrapper<Graph>::Edge Edge;
   474     typedef typename GraphWrapper<Graph>::EdgeIt EdgeIt;
   475 
   476     UndirGraphWrapper(Graph& _graph) : GraphWrapper<Graph>(_graph) { }  
   477 
   478     class OutEdgeIt {
   479       friend class UndirGraphWrapper<Graph>;
   480       bool out_or_in; //true iff out
   481       typename Graph::OutEdgeIt out;
   482       typename Graph::InEdgeIt in;
   483     public:
   484       OutEdgeIt() { }
   485       OutEdgeIt(const Invalid& i) : Edge(i) { }
   486       OutEdgeIt(const UndirGraphWrapper<Graph>& _G, const Node& _n) {
   487 	out_or_in=true; _G.graph->first(out, _n);
   488 	if (!(_G.graph->valid(out))) { out_or_in=false; _G.graph->first(in, _n);	}
   489       } 
   490       operator Edge() const { 
   491 	if (out_or_in) return Edge(out); else return Edge(in); 
   492       }
   493     };
   494 
   495 //FIXME InEdgeIt
   496     typedef OutEdgeIt InEdgeIt; 
   497 
   498     using GraphWrapper<Graph>::first;
   499 //     NodeIt& first(NodeIt& i) const { 
   500 //       i=NodeIt(*this); return i;
   501 //     }
   502     OutEdgeIt& first(OutEdgeIt& i, const Node& p) const { 
   503       i=OutEdgeIt(*this, p); return i;
   504     }
   505 //FIXME
   506 //     InEdgeIt& first(InEdgeIt& i, const Node& p) const { 
   507 //       i=InEdgeIt(*this, p); return i;
   508 //     }
   509 //     EdgeIt& first(EdgeIt& i) const { 
   510 //       i=EdgeIt(*this); return i;
   511 //     }
   512 
   513     using GraphWrapper<Graph>::next;
   514 //     NodeIt& next(NodeIt& n) const {
   515 //       GraphWrapper<Graph>::next(n);
   516 //       return n;
   517 //     }
   518     OutEdgeIt& next(OutEdgeIt& e) const {
   519       if (e.out_or_in) {
   520 	typename Graph::Node n=this->graph->tail(e.out);
   521 	this->graph->next(e.out);
   522 	if (!this->graph->valid(e.out)) { 
   523 	  e.out_or_in=false; this->graph->first(e.in, n); }
   524       } else {
   525 	this->graph->next(e.in);
   526       }
   527       return e;
   528     }
   529     //FIXME InEdgeIt
   530 //     EdgeIt& next(EdgeIt& e) const {
   531 //       GraphWrapper<Graph>::next(n);
   532 // //      graph->next(e.e);
   533 //       return e;
   534 //     }
   535 
   536     Node aNode(const OutEdgeIt& e) const { 
   537       if (e.out_or_in) return this->graph->tail(e); else 
   538 	return this->graph->head(e); }
   539     Node bNode(const OutEdgeIt& e) const { 
   540       if (e.out_or_in) return this->graph->head(e); else 
   541 	return this->graph->tail(e); }
   542   };
   543   
   544 
   545 
   546   /// An undirected graph template
   547   template<typename Graph>
   548   class UndirGraph : public UndirGraphWrapper<Graph> {
   549     typedef UndirGraphWrapper<Graph> Parent;
   550   protected:
   551     Graph gr;
   552   public:
   553     UndirGraph() : UndirGraphWrapper<Graph>() { 
   554       Parent::setGraph(gr); 
   555     }
   556   };
   557 
   558   
   559 
   560   /// A wrapper for composing the residual graph for directed flow and circulation problems.
   561 
   562   /// A wrapper for composing the residual graph for directed flow and circulation problems.
   563   template<typename Graph, typename Number, 
   564 	   typename CapacityMap, typename FlowMap>
   565   class ResGraphWrapper : public GraphWrapper<Graph> {
   566   protected:
   567     const CapacityMap* capacity;
   568     FlowMap* flow;
   569 
   570     ResGraphWrapper() : GraphWrapper<Graph>(0), 
   571 			capacity(0), flow(0) { }
   572     void setCapacityMap(const CapacityMap& _capacity_map) {
   573       capacity_map=&_capacity_map;
   574     }
   575     void setFlowMap(FlowMap& _flow) {
   576       flow=&_flow;
   577     }
   578 
   579   public:
   580 
   581     ResGraphWrapper(Graph& _graph, const CapacityMap& _capacity, 
   582 		    FlowMap& _flow) : 
   583       GraphWrapper<Graph>(_graph), capacity(&_capacity), flow(&_flow) { }
   584 
   585     class Edge; 
   586     class OutEdgeIt; 
   587     friend class Edge; 
   588     friend class OutEdgeIt; 
   589 
   590     typedef typename GraphWrapper<Graph>::Node Node;
   591     typedef typename GraphWrapper<Graph>::NodeIt NodeIt;
   592     class Edge : public Graph::Edge {
   593       friend class ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>;
   594     protected:
   595       bool forward; //true, iff forward
   596 //      typename Graph::Edge e;
   597     public:
   598       Edge() { }
   599       Edge(const typename Graph::Edge& _e, bool _forward) : 
   600 	Graph::Edge(_e), forward(_forward) { }
   601       Edge(const Invalid& i) : Graph::Edge(i), forward(false) { }
   602 //the unique invalid iterator
   603       friend bool operator==(const Edge& u, const Edge& v) { 
   604 	return (v.forward==u.forward && 
   605 		static_cast<typename Graph::Edge>(u)==
   606 		static_cast<typename Graph::Edge>(v));
   607       } 
   608       friend bool operator!=(const Edge& u, const Edge& v) { 
   609 	return (v.forward!=u.forward || 
   610 		static_cast<typename Graph::Edge>(u)!=
   611 		static_cast<typename Graph::Edge>(v));
   612       } 
   613     };
   614 
   615     class OutEdgeIt {
   616       friend class ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>;
   617     protected:
   618       typename Graph::OutEdgeIt out;
   619       typename Graph::InEdgeIt in;
   620       bool forward;
   621     public:
   622       OutEdgeIt() { }
   623       //FIXME
   624 //      OutEdgeIt(const Edge& e) : Edge(e) { }
   625       OutEdgeIt(const Invalid& i) : out(i), in(i), forward(false) { }
   626 //the unique invalid iterator
   627       OutEdgeIt(const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>& resG, Node v) { 
   628 	forward=true;
   629 	resG.graph->first(out, v);
   630 	while( resG.graph->valid(out) && !(resG.resCap(*this)>0) ) { resG.graph->next(out); }
   631 	if (!resG.graph->valid(out)) {
   632 	  forward=false;
   633 	  resG.graph->first(in, v);
   634 	  while( resG.graph->valid(in) && !(resG.resCap(*this)>0) ) { resG.graph->next(in); }
   635 	}
   636       }
   637       operator Edge() const { 
   638 //	Edge e;
   639 //	e.forward=this->forward;
   640 //	if (this->forward) e=out; else e=in;
   641 //	return e;
   642 	if (this->forward) 
   643 	  return Edge(out, this->forward); 
   644 	else 
   645 	  return Edge(in, this->forward);
   646       }
   647     };
   648 
   649     class InEdgeIt {
   650       friend class ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>;
   651     protected:
   652       typename Graph::OutEdgeIt out;
   653       typename Graph::InEdgeIt in;
   654       bool forward;
   655     public:
   656       InEdgeIt() { }
   657       //FIXME
   658 //      OutEdgeIt(const Edge& e) : Edge(e) { }
   659       InEdgeIt(const Invalid& i) : out(i), in(i), forward(false) { }
   660 //the unique invalid iterator
   661       InEdgeIt(const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>& resG, Node v) { 
   662 	forward=true;
   663 	resG.graph->first(in, v);
   664 	while( resG.graph->valid(in) && !(resG.resCap(*this)>0) ) { resG.graph->next(in); }
   665 	if (!resG.graph->valid(in)) {
   666 	  forward=false;
   667 	  resG.graph->first(out, v);
   668 	  while( resG.graph->valid(out) && !(resG.resCap(*this)>0) ) { resG.graph->next(out); }
   669 	}
   670       }
   671       operator Edge() const { 
   672 //	Edge e;
   673 //	e.forward=this->forward;
   674 //	if (this->forward) e=out; else e=in;
   675 //	return e;
   676 	if (this->forward) 
   677 	  return Edge(in, this->forward); 
   678 	else 
   679 	  return Edge(out, this->forward);
   680       }
   681     };
   682 
   683     class EdgeIt {
   684       friend class ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>;
   685     protected:
   686       typename Graph::EdgeIt e;
   687       bool forward;
   688     public:
   689       EdgeIt() { }
   690       EdgeIt(const Invalid& i) : e(i), forward(false) { }
   691       EdgeIt(const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>& resG) { 
   692 	forward=true;
   693 	resG.graph->first(e);
   694 	while (resG.graph->valid(e) && !(resG.resCap(*this)>0)) resG.graph->next(e);
   695 	if (!resG.graph->valid(e)) {
   696 	  forward=false;
   697 	  resG.graph->first(e);
   698 	  while (resG.graph->valid(e) && !(resG.resCap(*this)>0)) resG.graph->next(e);
   699 	}
   700       }
   701       operator Edge() const { 
   702 	return Edge(e, this->forward);
   703       }
   704     };
   705 
   706     using GraphWrapper<Graph>::first;
   707 //     NodeIt& first(NodeIt& i) const { 
   708 //       i=NodeIt(*this); return i;
   709 //     }
   710     OutEdgeIt& first(OutEdgeIt& i, const Node& p) const { 
   711       i=OutEdgeIt(*this, p); return i;
   712     }
   713 //    FIXME not tested
   714     InEdgeIt& first(InEdgeIt& i, const Node& p) const { 
   715       i=InEdgeIt(*this, p); return i;
   716     }
   717     EdgeIt& first(EdgeIt& i) const { 
   718       i=EdgeIt(*this); return i;
   719     }
   720   
   721     using GraphWrapper<Graph>::next;
   722 //    NodeIt& next(NodeIt& n) const { GraphWrapper<Graph>::next(n); return n; }
   723     OutEdgeIt& next(OutEdgeIt& e) const { 
   724       if (e.forward) {
   725 	Node v=this->graph->aNode(e.out);
   726 	this->graph->next(e.out);
   727 	while( this->graph->valid(e.out) && !(resCap(e)>0) ) { 
   728 	  this->graph->next(e.out); }
   729 	if (!this->graph->valid(e.out)) {
   730 	  e.forward=false;
   731 	  this->graph->first(e.in, v); 
   732 	  while( this->graph->valid(e.in) && !(resCap(e)>0) ) { 
   733 	    this->graph->next(e.in); }
   734 	}
   735       } else {
   736 	this->graph->next(e.in);
   737 	while( this->graph->valid(e.in) && !(resCap(e)>0) ) { 
   738 	  this->graph->next(e.in); } 
   739       }
   740       return e;
   741     }
   742 //     FIXME Not tested
   743     InEdgeIt& next(InEdgeIt& e) const { 
   744       if (e.forward) {
   745 	Node v=this->graph->aNode(e.in);
   746 	this->graph->next(e.in);
   747 	while( this->graph->valid(e.in) && !(resCap(e)>0) ) { 
   748 	  this->graph->next(e.in); }
   749 	if (!this->graph->valid(e.in)) {
   750 	  e.forward=false;
   751 	  this->graph->first(e.out, v); 
   752 	  while( this->graph->valid(e.out) && !(resCap(e)>0) ) { 
   753 	    this->graph->next(e.out); }
   754 	}
   755       } else {
   756 	this->graph->next(e.out);
   757 	while( this->graph->valid(e.out) && !(resCap(e)>0) ) { 
   758 	  this->graph->next(e.out); } 
   759       }
   760       return e;
   761     }
   762     EdgeIt& next(EdgeIt& e) const {
   763       if (e.forward) {
   764 	this->graph->next(e.e);
   765 	while( this->graph->valid(e.e) && !(resCap(e)>0) ) { 
   766 	  this->graph->next(e.e); }
   767 	if (!this->graph->valid(e.e)) {
   768 	  e.forward=false;
   769 	  this->graph->first(e.e); 
   770 	  while( this->graph->valid(e.e) && !(resCap(e)>0) ) { 
   771 	    this->graph->next(e.e); }
   772 	}
   773       } else {
   774 	this->graph->next(e.e);
   775 	while( this->graph->valid(e.e) && !(resCap(e)>0) ) { 
   776 	  this->graph->next(e.e); } 
   777       }
   778       return e;
   779     }
   780 
   781     Node tail(Edge e) const { 
   782       return ((e.forward) ? this->graph->tail(e) : this->graph->head(e)); }
   783     Node head(Edge e) const { 
   784       return ((e.forward) ? this->graph->head(e) : this->graph->tail(e)); }
   785 
   786     Node aNode(OutEdgeIt e) const { 
   787       return ((e.forward) ? this->graph->aNode(e.out) : 
   788 	      this->graph->aNode(e.in)); }
   789     Node bNode(OutEdgeIt e) const { 
   790       return ((e.forward) ? this->graph->bNode(e.out) : 
   791 	      this->graph->bNode(e.in)); }
   792 
   793     Node aNode(InEdgeIt e) const { 
   794       return ((e.forward) ? this->graph->aNode(e.in) : 
   795 	      this->graph->aNode(e.out)); }
   796     Node bNode(InEdgeIt e) const { 
   797       return ((e.forward) ? this->graph->bNode(e.in) : 
   798 	      this->graph->bNode(e.out)); }
   799 
   800 //    int nodeNum() const { return graph->nodeNum(); }
   801     //FIXME
   802     void edgeNum() const { }
   803     //int edgeNum() const { return graph->edgeNum(); }
   804 
   805 
   806 //    int id(Node v) const { return graph->id(v); }
   807 
   808     bool valid(Node n) const { return GraphWrapper<Graph>::valid(n); }
   809     bool valid(Edge e) const { 
   810       return this->graph->valid(e);
   811 	//return e.forward ? graph->valid(e.out) : graph->valid(e.in); 
   812     }
   813 
   814     bool forward(const Edge& e) const { return e.forward; }
   815     bool backward(const Edge& e) const { return !e.forward; }
   816 
   817     void augment(const Edge& e, Number a) const {
   818       if (e.forward)  
   819 // 	flow->set(e.out, flow->get(e.out)+a);
   820 	flow->set(e, (*flow)[e]+a);
   821       else  
   822 // 	flow->set(e.in, flow->get(e.in)-a);
   823 	flow->set(e, (*flow)[e]-a);
   824     }
   825 
   826     Number resCap(const Edge& e) const { 
   827       if (e.forward) 
   828 //	return (capacity->get(e.out)-flow->get(e.out)); 
   829 	return ((*capacity)[e]-(*flow)[e]); 
   830       else 
   831 //	return (flow->get(e.in)); 
   832 	return ((*flow)[e]); 
   833     }
   834 
   835 //     Number resCap(typename Graph::OutEdgeIt out) const { 
   836 // //      return (capacity->get(out)-flow->get(out)); 
   837 //       return ((*capacity)[out]-(*flow)[out]); 
   838 //     }
   839     
   840 //     Number resCap(typename Graph::InEdgeIt in) const { 
   841 // //      return (flow->get(in)); 
   842 //       return ((*flow)[in]); 
   843 //     }
   844 
   845     template <typename T>
   846     class EdgeMap {
   847       typename Graph::template EdgeMap<T> forward_map, backward_map; 
   848     public:
   849       EdgeMap(const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>& _G) : forward_map(*(_G.graph)), backward_map(*(_G.graph)) { }
   850       EdgeMap(const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>& _G, T a) : forward_map(*(_G.graph), a), backward_map(*(_G.graph), a) { }
   851       void set(Edge e, T a) { 
   852 	if (e.forward) 
   853 	  forward_map.set(e.out, a); 
   854 	else 
   855 	  backward_map.set(e.in, a); 
   856       }
   857       T operator[](Edge e) const { 
   858 	if (e.forward) 
   859 	  return forward_map[e.out]; 
   860 	else 
   861 	  return backward_map[e.in]; 
   862       }
   863 //       T get(Edge e) const { 
   864 // 	if (e.out_or_in) 
   865 // 	  return forward_map.get(e.out); 
   866 // 	else 
   867 // 	  return backward_map.get(e.in); 
   868 //       }
   869     };
   870   };
   871 
   872   /// ErasingFirstGraphWrapper for blocking flows.
   873 
   874   /// ErasingFirstGraphWrapper for blocking flows.
   875   ///
   876   ///\author Marton Makai
   877   template<typename Graph, typename FirstOutEdgesMap>
   878   class ErasingFirstGraphWrapper : public GraphWrapper<Graph> {
   879   protected:
   880     FirstOutEdgesMap* first_out_edges;
   881   public:
   882     ErasingFirstGraphWrapper(Graph& _graph, 
   883 			     FirstOutEdgesMap& _first_out_edges) : 
   884       GraphWrapper<Graph>(_graph), first_out_edges(&_first_out_edges) { }  
   885 
   886     typedef typename GraphWrapper<Graph>::Node Node;
   887 //     class NodeIt { 
   888 //       friend class GraphWrapper<Graph>;
   889 //       friend class ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>;
   890 //       typename Graph::NodeIt n;
   891 //      public:
   892 //       NodeIt() { }
   893 //       NodeIt(const typename Graph::NodeIt& _n) : n(_n) { }
   894 //       NodeIt(const Invalid& i) : n(i) { }
   895 //       NodeIt(const ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>& _G) : 
   896 // 	n(*(_G.graph)) { }
   897 //       operator Node() const { return Node(typename Graph::Node(n)); }
   898 //     };
   899     typedef typename GraphWrapper<Graph>::Edge Edge;
   900     class OutEdgeIt { 
   901       friend class GraphWrapper<Graph>;
   902       friend class ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>;
   903 //      typedef typename Graph::OutEdgeIt GraphOutEdgeIt;
   904       typename Graph::OutEdgeIt e;
   905     public:
   906       OutEdgeIt() { }
   907       OutEdgeIt(const typename Graph::OutEdgeIt& _e) : e(_e) { }
   908       OutEdgeIt(const Invalid& i) : e(i) { }
   909       OutEdgeIt(const ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>& _G, 
   910 		const Node& _n) : 
   911 	e((*_G.first_out_edges)[_n]) { }
   912       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   913     };
   914     class InEdgeIt { 
   915       friend class GraphWrapper<Graph>;
   916       friend class ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>;
   917 //      typedef typename Graph::InEdgeIt GraphInEdgeIt;
   918       typename Graph::InEdgeIt e;
   919     public:
   920       InEdgeIt() { }
   921       InEdgeIt(const typename Graph::InEdgeIt& _e) : e(_e) { }
   922       InEdgeIt(const Invalid& i) : e(i) { }
   923       InEdgeIt(const ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>& _G, 
   924 	       const Node& _n) : 
   925 	e(*(_G.graph), typename Graph::Node(_n)) { }
   926       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   927     };
   928     //typedef typename Graph::SymEdgeIt SymEdgeIt;
   929     class EdgeIt { 
   930       friend class GraphWrapper<Graph>;
   931       friend class ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>;
   932 //      typedef typename Graph::EdgeIt GraphEdgeIt;
   933       typename Graph::EdgeIt e;
   934     public:
   935       EdgeIt() { }
   936       EdgeIt(const typename Graph::EdgeIt& _e) : e(_e) { }
   937       EdgeIt(const Invalid& i) : e(i) { }
   938       EdgeIt(const ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>& _G) : 
   939 	e(*(_G.graph)) { }
   940       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   941     };
   942 
   943     using GraphWrapper<Graph>::first;
   944 //     NodeIt& first(NodeIt& i) const { 
   945 //       i=NodeIt(*this); return i;
   946 //     }
   947     OutEdgeIt& first(OutEdgeIt& i, const Node& p) const { 
   948       i=OutEdgeIt(*this, p); return i;
   949     }
   950     InEdgeIt& first(InEdgeIt& i, const Node& p) const { 
   951       i=InEdgeIt(*this, p); return i;
   952     }
   953     EdgeIt& first(EdgeIt& i) const { 
   954       i=EdgeIt(*this); return i;
   955     }
   956 
   957     using GraphWrapper<Graph>::next;
   958 //    NodeIt& next(NodeIt& i) const { graph->next(i.n); return i; }
   959     OutEdgeIt& next(OutEdgeIt& i) const { this->graph->next(i.e); return i; }
   960     InEdgeIt& next(InEdgeIt& i) const { this->graph->next(i.e); return i; }
   961     EdgeIt& next(EdgeIt& i) const { this->graph->next(i.e); return i; }    
   962     
   963     Node aNode(const OutEdgeIt& e) const { 
   964       return Node(this->graph->aNode(e.e)); }
   965     Node aNode(const InEdgeIt& e) const { 
   966       return Node(this->graph->aNode(e.e)); }
   967     Node bNode(const OutEdgeIt& e) const { 
   968       return Node(this->graph->bNode(e.e)); }
   969     Node bNode(const InEdgeIt& e) const { 
   970       return Node(this->graph->bNode(e.e)); }
   971 
   972     void erase(const OutEdgeIt& e) const {
   973       OutEdgeIt f=e;
   974       this->next(f);
   975       first_out_edges->set(this->tail(e), f.e);
   976     }
   977   };
   978 
   979   ///@}
   980 
   981 } //namespace hugo
   982 
   983 
   984 #endif //HUGO_GRAPH_WRAPPER_H
   985