src/hugo/graph_wrapper.h
author alpar
Fri, 07 May 2004 06:35:02 +0000
changeset 566 14355e502338
parent 561 a10e6f1769e2
child 569 3b6afd33c221
permissions -rw-r--r--
Exit with correct return value
     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 <hugo/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_filter_map;
   314     }
   315     void setEdgeFilterMap(EdgeFilterMap& _edge_filter_map) {
   316       edge_filter_map=&_edge_filter_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     /// This function hides \c n in the graph, i.e. the iteration 
   440     /// jumps over it. This is done by simply setting the value of \c n  
   441     /// to be false in the corresponding node-map.
   442     void hide(const Node& n) const { node_filter_map->set(n, false); }
   443 
   444     /// This function hides \c e in the graph, i.e. the iteration 
   445     /// jumps over it. This is done by simply setting the value of \c e  
   446     /// to be false in the corresponding edge-map.
   447     void hide(const Edge& e) const { edge_filter_map->set(e, false); }
   448 
   449     /// The value of \c n is set to be true in the node-map which stores 
   450     /// hide information. If \c n was hidden previuosly, then it is shown 
   451     /// again
   452      void unHide(const Node& n) const { node_filter_map->set(n, true); }
   453 
   454     /// The value of \c e is set to be true in the edge-map which stores 
   455     /// hide information. If \c e was hidden previuosly, then it is shown 
   456     /// again
   457     void unHide(const Edge& e) const { edge_filter_map->set(e, true); }
   458 
   459     /// Returns true if \c n is hidden.
   460     bool hidden(const Node& n) const { return !(*node_filter_map)[n]; }
   461 
   462     /// Returns true if \c n is hidden.
   463     bool hidden(const Edge& e) const { return !(*edge_filter_map)[e]; }
   464   };
   465 
   466   /// A wrapper for forgetting the orientation of a graph.
   467 
   468   /// A wrapper for getting an undirected graph by forgetting
   469   /// the orientation of a directed one.
   470   template<typename Graph>
   471   class UndirGraphWrapper : public GraphWrapper<Graph> {
   472   protected:
   473     UndirGraphWrapper() : GraphWrapper<Graph>() { }
   474     
   475   public:
   476     typedef typename GraphWrapper<Graph>::Node Node;
   477     typedef typename GraphWrapper<Graph>::NodeIt NodeIt;
   478     typedef typename GraphWrapper<Graph>::Edge Edge;
   479     typedef typename GraphWrapper<Graph>::EdgeIt EdgeIt;
   480 
   481     UndirGraphWrapper(Graph& _graph) : GraphWrapper<Graph>(_graph) { }  
   482 
   483     class OutEdgeIt {
   484       friend class UndirGraphWrapper<Graph>;
   485       bool out_or_in; //true iff out
   486       typename Graph::OutEdgeIt out;
   487       typename Graph::InEdgeIt in;
   488     public:
   489       OutEdgeIt() { }
   490       OutEdgeIt(const Invalid& i) : Edge(i) { }
   491       OutEdgeIt(const UndirGraphWrapper<Graph>& _G, const Node& _n) {
   492 	out_or_in=true; _G.graph->first(out, _n);
   493 	if (!(_G.graph->valid(out))) { out_or_in=false; _G.graph->first(in, _n);	}
   494       } 
   495       operator Edge() const { 
   496 	if (out_or_in) return Edge(out); else return Edge(in); 
   497       }
   498     };
   499 
   500 //FIXME InEdgeIt
   501     typedef OutEdgeIt InEdgeIt; 
   502 
   503     using GraphWrapper<Graph>::first;
   504 //     NodeIt& first(NodeIt& i) const { 
   505 //       i=NodeIt(*this); return i;
   506 //     }
   507     OutEdgeIt& first(OutEdgeIt& i, const Node& p) const { 
   508       i=OutEdgeIt(*this, p); return i;
   509     }
   510 //FIXME
   511 //     InEdgeIt& first(InEdgeIt& i, const Node& p) const { 
   512 //       i=InEdgeIt(*this, p); return i;
   513 //     }
   514 //     EdgeIt& first(EdgeIt& i) const { 
   515 //       i=EdgeIt(*this); return i;
   516 //     }
   517 
   518     using GraphWrapper<Graph>::next;
   519 //     NodeIt& next(NodeIt& n) const {
   520 //       GraphWrapper<Graph>::next(n);
   521 //       return n;
   522 //     }
   523     OutEdgeIt& next(OutEdgeIt& e) const {
   524       if (e.out_or_in) {
   525 	typename Graph::Node n=this->graph->tail(e.out);
   526 	this->graph->next(e.out);
   527 	if (!this->graph->valid(e.out)) { 
   528 	  e.out_or_in=false; this->graph->first(e.in, n); }
   529       } else {
   530 	this->graph->next(e.in);
   531       }
   532       return e;
   533     }
   534     //FIXME InEdgeIt
   535 //     EdgeIt& next(EdgeIt& e) const {
   536 //       GraphWrapper<Graph>::next(n);
   537 // //      graph->next(e.e);
   538 //       return e;
   539 //     }
   540 
   541     Node aNode(const OutEdgeIt& e) const { 
   542       if (e.out_or_in) return this->graph->tail(e); else 
   543 	return this->graph->head(e); }
   544     Node bNode(const OutEdgeIt& e) const { 
   545       if (e.out_or_in) return this->graph->head(e); else 
   546 	return this->graph->tail(e); }
   547   };
   548   
   549 
   550 
   551   /// An undirected graph template
   552   template<typename Graph>
   553   class UndirGraph : public UndirGraphWrapper<Graph> {
   554     typedef UndirGraphWrapper<Graph> Parent;
   555   protected:
   556     Graph gr;
   557   public:
   558     UndirGraph() : UndirGraphWrapper<Graph>() { 
   559       Parent::setGraph(gr); 
   560     }
   561   };
   562 
   563   
   564 
   565   /// A wrapper for composing the residual graph for directed flow and circulation problems.
   566 
   567   /// A wrapper for composing the residual graph for directed flow and circulation problems.
   568   template<typename Graph, typename Number, 
   569 	   typename CapacityMap, typename FlowMap>
   570   class ResGraphWrapper : public GraphWrapper<Graph> {
   571   protected:
   572     const CapacityMap* capacity;
   573     FlowMap* flow;
   574 
   575     ResGraphWrapper() : GraphWrapper<Graph>(0), 
   576 			capacity(0), flow(0) { }
   577     void setCapacityMap(const CapacityMap& _capacity) {
   578       capacity=&_capacity;
   579     }
   580     void setFlowMap(FlowMap& _flow) {
   581       flow=&_flow;
   582     }
   583 
   584   public:
   585 
   586     ResGraphWrapper(Graph& _graph, const CapacityMap& _capacity, 
   587 		    FlowMap& _flow) : 
   588       GraphWrapper<Graph>(_graph), capacity(&_capacity), flow(&_flow) { }
   589 
   590     class Edge; 
   591     class OutEdgeIt; 
   592     friend class Edge; 
   593     friend class OutEdgeIt; 
   594 
   595     typedef typename GraphWrapper<Graph>::Node Node;
   596     typedef typename GraphWrapper<Graph>::NodeIt NodeIt;
   597     class Edge : public Graph::Edge {
   598       friend class ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>;
   599     protected:
   600       bool backward; //true, iff backward
   601 //      typename Graph::Edge e;
   602     public:
   603       Edge() { }
   604       Edge(const typename Graph::Edge& _e, bool _backward) : 
   605 	Graph::Edge(_e), backward(_backward) { }
   606       Edge(const Invalid& i) : Graph::Edge(i), backward(true) { }
   607 //the unique invalid iterator
   608       friend bool operator==(const Edge& u, const Edge& v) { 
   609 	return (v.backward==u.backward && 
   610 		static_cast<typename Graph::Edge>(u)==
   611 		static_cast<typename Graph::Edge>(v));
   612       } 
   613       friend bool operator!=(const Edge& u, const Edge& v) { 
   614 	return (v.backward!=u.backward || 
   615 		static_cast<typename Graph::Edge>(u)!=
   616 		static_cast<typename Graph::Edge>(v));
   617       } 
   618     };
   619 
   620     class OutEdgeIt {
   621       friend class ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>;
   622     protected:
   623       typename Graph::OutEdgeIt out;
   624       typename Graph::InEdgeIt in;
   625       bool backward;
   626     public:
   627       OutEdgeIt() { }
   628       //FIXME
   629 //      OutEdgeIt(const Edge& e) : Edge(e) { }
   630       OutEdgeIt(const Invalid& i) : out(i), in(i), backward(true) { }
   631 //the unique invalid iterator
   632       OutEdgeIt(const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>& resG, Node v) { 
   633 	backward=false;
   634 	resG.graph->first(out, v);
   635 	while( resG.graph->valid(out) && !(resG.resCap(*this)>0) ) { resG.graph->next(out); }
   636 	if (!resG.graph->valid(out)) {
   637 	  backward=true;
   638 	  resG.graph->first(in, v);
   639 	  while( resG.graph->valid(in) && !(resG.resCap(*this)>0) ) { resG.graph->next(in); }
   640 	}
   641       }
   642       operator Edge() const { 
   643 //	Edge e;
   644 //	e.forward=this->forward;
   645 //	if (this->forward) e=out; else e=in;
   646 //	return e;
   647 	if (this->backward) 
   648 	  return Edge(in, this->backward); 
   649 	else 
   650 	  return Edge(out, this->backward);
   651       }
   652     };
   653 
   654     class InEdgeIt {
   655       friend class ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>;
   656     protected:
   657       typename Graph::OutEdgeIt out;
   658       typename Graph::InEdgeIt in;
   659       bool backward;
   660     public:
   661       InEdgeIt() { }
   662       //FIXME
   663 //      OutEdgeIt(const Edge& e) : Edge(e) { }
   664       InEdgeIt(const Invalid& i) : out(i), in(i), backward(true) { }
   665 //the unique invalid iterator
   666       InEdgeIt(const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>& resG, Node v) { 
   667 	backward=false;
   668 	resG.graph->first(in, v);
   669 	while( resG.graph->valid(in) && !(resG.resCap(*this)>0) ) { resG.graph->next(in); }
   670 	if (!resG.graph->valid(in)) {
   671 	  backward=true;
   672 	  resG.graph->first(out, v);
   673 	  while( resG.graph->valid(out) && !(resG.resCap(*this)>0) ) { resG.graph->next(out); }
   674 	}
   675       }
   676       operator Edge() const { 
   677 //	Edge e;
   678 //	e.forward=this->forward;
   679 //	if (this->forward) e=out; else e=in;
   680 //	return e;
   681 	if (this->backward) 
   682 	  return Edge(out, this->backward); 
   683 	else 
   684 	  return Edge(in, this->backward);
   685       }
   686     };
   687 
   688     class EdgeIt {
   689       friend class ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>;
   690     protected:
   691       typename Graph::EdgeIt e;
   692       bool backward;
   693     public:
   694       EdgeIt() { }
   695       EdgeIt(const Invalid& i) : e(i), backward(true) { }
   696       EdgeIt(const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>& resG) { 
   697 	backward=false;
   698 	resG.graph->first(e);
   699 	while (resG.graph->valid(e) && !(resG.resCap(*this)>0)) resG.graph->next(e);
   700 	if (!resG.graph->valid(e)) {
   701 	  backward=true;
   702 	  resG.graph->first(e);
   703 	  while (resG.graph->valid(e) && !(resG.resCap(*this)>0)) resG.graph->next(e);
   704 	}
   705       }
   706       operator Edge() const { 
   707 	return Edge(e, this->backward);
   708       }
   709     };
   710 
   711     using GraphWrapper<Graph>::first;
   712 //     NodeIt& first(NodeIt& i) const { 
   713 //       i=NodeIt(*this); return i;
   714 //     }
   715     OutEdgeIt& first(OutEdgeIt& i, const Node& p) const { 
   716       i=OutEdgeIt(*this, p); return i;
   717     }
   718 //    FIXME not tested
   719     InEdgeIt& first(InEdgeIt& i, const Node& p) const { 
   720       i=InEdgeIt(*this, p); return i;
   721     }
   722     EdgeIt& first(EdgeIt& i) const { 
   723       i=EdgeIt(*this); return i;
   724     }
   725   
   726     using GraphWrapper<Graph>::next;
   727 //    NodeIt& next(NodeIt& n) const { GraphWrapper<Graph>::next(n); return n; }
   728     OutEdgeIt& next(OutEdgeIt& e) const { 
   729       if (!e.backward) {
   730 	Node v=this->graph->aNode(e.out);
   731 	this->graph->next(e.out);
   732 	while( this->graph->valid(e.out) && !(resCap(e)>0) ) { 
   733 	  this->graph->next(e.out); }
   734 	if (!this->graph->valid(e.out)) {
   735 	  e.backward=true;
   736 	  this->graph->first(e.in, v); 
   737 	  while( this->graph->valid(e.in) && !(resCap(e)>0) ) { 
   738 	    this->graph->next(e.in); }
   739 	}
   740       } else {
   741 	this->graph->next(e.in);
   742 	while( this->graph->valid(e.in) && !(resCap(e)>0) ) { 
   743 	  this->graph->next(e.in); } 
   744       }
   745       return e;
   746     }
   747 //     FIXME Not tested
   748     InEdgeIt& next(InEdgeIt& e) const { 
   749       if (!e.backward) {
   750 	Node v=this->graph->aNode(e.in);
   751 	this->graph->next(e.in);
   752 	while( this->graph->valid(e.in) && !(resCap(e)>0) ) { 
   753 	  this->graph->next(e.in); }
   754 	if (!this->graph->valid(e.in)) {
   755 	  e.backward=true;
   756 	  this->graph->first(e.out, v); 
   757 	  while( this->graph->valid(e.out) && !(resCap(e)>0) ) { 
   758 	    this->graph->next(e.out); }
   759 	}
   760       } else {
   761 	this->graph->next(e.out);
   762 	while( this->graph->valid(e.out) && !(resCap(e)>0) ) { 
   763 	  this->graph->next(e.out); } 
   764       }
   765       return e;
   766     }
   767     EdgeIt& next(EdgeIt& e) const {
   768       if (!e.backward) {
   769 	this->graph->next(e.e);
   770 	while( this->graph->valid(e.e) && !(resCap(e)>0) ) { 
   771 	  this->graph->next(e.e); }
   772 	if (!this->graph->valid(e.e)) {
   773 	  e.backward=true;
   774 	  this->graph->first(e.e); 
   775 	  while( this->graph->valid(e.e) && !(resCap(e)>0) ) { 
   776 	    this->graph->next(e.e); }
   777 	}
   778       } else {
   779 	this->graph->next(e.e);
   780 	while( this->graph->valid(e.e) && !(resCap(e)>0) ) { 
   781 	  this->graph->next(e.e); } 
   782       }
   783       return e;
   784     }
   785 
   786     Node tail(Edge e) const { 
   787       return ((!e.backward) ? this->graph->tail(e) : this->graph->head(e)); }
   788     Node head(Edge e) const { 
   789       return ((!e.backward) ? this->graph->head(e) : this->graph->tail(e)); }
   790 
   791     Node aNode(OutEdgeIt e) const { 
   792       return ((!e.backward) ? this->graph->aNode(e.out) : 
   793 	      this->graph->aNode(e.in)); }
   794     Node bNode(OutEdgeIt e) const { 
   795       return ((!e.backward) ? this->graph->bNode(e.out) : 
   796 	      this->graph->bNode(e.in)); }
   797 
   798     Node aNode(InEdgeIt e) const { 
   799       return ((!e.backward) ? this->graph->aNode(e.in) : 
   800 	      this->graph->aNode(e.out)); }
   801     Node bNode(InEdgeIt e) const { 
   802       return ((!e.backward) ? this->graph->bNode(e.in) : 
   803 	      this->graph->bNode(e.out)); }
   804 
   805 //    int nodeNum() const { return graph->nodeNum(); }
   806     //FIXME
   807     void edgeNum() const { }
   808     //int edgeNum() const { return graph->edgeNum(); }
   809 
   810 
   811 //    int id(Node v) const { return graph->id(v); }
   812 
   813     bool valid(Node n) const { return GraphWrapper<Graph>::valid(n); }
   814     bool valid(Edge e) const { 
   815       return this->graph->valid(e);
   816 	//return e.forward ? graph->valid(e.out) : graph->valid(e.in); 
   817     }
   818 
   819     bool forward(const Edge& e) const { return !e.backward; }
   820     bool backward(const Edge& e) const { return e.backward; }
   821 
   822     void augment(const Edge& e, Number a) const {
   823       if (!e.backward)  
   824 // 	flow->set(e.out, flow->get(e.out)+a);
   825 	flow->set(e, (*flow)[e]+a);
   826       else  
   827 // 	flow->set(e.in, flow->get(e.in)-a);
   828 	flow->set(e, (*flow)[e]-a);
   829     }
   830 
   831     Number resCap(const Edge& e) const { 
   832       if (!e.backward) 
   833 //	return (capacity->get(e.out)-flow->get(e.out)); 
   834 	return ((*capacity)[e]-(*flow)[e]); 
   835       else 
   836 //	return (flow->get(e.in)); 
   837 	return ((*flow)[e]); 
   838     }
   839 
   840 //     Number resCap(typename Graph::OutEdgeIt out) const { 
   841 // //      return (capacity->get(out)-flow->get(out)); 
   842 //       return ((*capacity)[out]-(*flow)[out]); 
   843 //     }
   844     
   845 //     Number resCap(typename Graph::InEdgeIt in) const { 
   846 // //      return (flow->get(in)); 
   847 //       return ((*flow)[in]); 
   848 //     }
   849 
   850     template <typename T>
   851     class EdgeMap {
   852       typename Graph::template EdgeMap<T> forward_map, backward_map; 
   853     public:
   854       EdgeMap(const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>& _G) : forward_map(*(_G.graph)), backward_map(*(_G.graph)) { }
   855       EdgeMap(const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>& _G, T a) : forward_map(*(_G.graph), a), backward_map(*(_G.graph), a) { }
   856       void set(Edge e, T a) { 
   857 	if (!e.backward) 
   858 	  forward_map.set(e.out, a); 
   859 	else 
   860 	  backward_map.set(e.in, a); 
   861       }
   862       T operator[](Edge e) const { 
   863 	if (!e.backward) 
   864 	  return forward_map[e.out]; 
   865 	else 
   866 	  return backward_map[e.in]; 
   867       }
   868 //       T get(Edge e) const { 
   869 // 	if (e.out_or_in) 
   870 // 	  return forward_map.get(e.out); 
   871 // 	else 
   872 // 	  return backward_map.get(e.in); 
   873 //       }
   874     };
   875   };
   876 
   877   /// ErasingFirstGraphWrapper for blocking flows.
   878 
   879   /// ErasingFirstGraphWrapper for blocking flows.
   880   ///
   881   ///\author Marton Makai
   882   template<typename Graph, typename FirstOutEdgesMap>
   883   class ErasingFirstGraphWrapper : public GraphWrapper<Graph> {
   884   protected:
   885     FirstOutEdgesMap* first_out_edges;
   886   public:
   887     ErasingFirstGraphWrapper(Graph& _graph, 
   888 			     FirstOutEdgesMap& _first_out_edges) : 
   889       GraphWrapper<Graph>(_graph), first_out_edges(&_first_out_edges) { }  
   890 
   891     typedef typename GraphWrapper<Graph>::Node Node;
   892 //     class NodeIt { 
   893 //       friend class GraphWrapper<Graph>;
   894 //       friend class ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>;
   895 //       typename Graph::NodeIt n;
   896 //      public:
   897 //       NodeIt() { }
   898 //       NodeIt(const typename Graph::NodeIt& _n) : n(_n) { }
   899 //       NodeIt(const Invalid& i) : n(i) { }
   900 //       NodeIt(const ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>& _G) : 
   901 // 	n(*(_G.graph)) { }
   902 //       operator Node() const { return Node(typename Graph::Node(n)); }
   903 //     };
   904     typedef typename GraphWrapper<Graph>::Edge Edge;
   905     class OutEdgeIt { 
   906       friend class GraphWrapper<Graph>;
   907       friend class ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>;
   908 //      typedef typename Graph::OutEdgeIt GraphOutEdgeIt;
   909       typename Graph::OutEdgeIt e;
   910     public:
   911       OutEdgeIt() { }
   912       OutEdgeIt(const typename Graph::OutEdgeIt& _e) : e(_e) { }
   913       OutEdgeIt(const Invalid& i) : e(i) { }
   914       OutEdgeIt(const ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>& _G, 
   915 		const Node& _n) : 
   916 	e((*_G.first_out_edges)[_n]) { }
   917       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   918     };
   919     class InEdgeIt { 
   920       friend class GraphWrapper<Graph>;
   921       friend class ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>;
   922 //      typedef typename Graph::InEdgeIt GraphInEdgeIt;
   923       typename Graph::InEdgeIt e;
   924     public:
   925       InEdgeIt() { }
   926       InEdgeIt(const typename Graph::InEdgeIt& _e) : e(_e) { }
   927       InEdgeIt(const Invalid& i) : e(i) { }
   928       InEdgeIt(const ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>& _G, 
   929 	       const Node& _n) : 
   930 	e(*(_G.graph), typename Graph::Node(_n)) { }
   931       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   932     };
   933     //typedef typename Graph::SymEdgeIt SymEdgeIt;
   934     class EdgeIt { 
   935       friend class GraphWrapper<Graph>;
   936       friend class ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>;
   937 //      typedef typename Graph::EdgeIt GraphEdgeIt;
   938       typename Graph::EdgeIt e;
   939     public:
   940       EdgeIt() { }
   941       EdgeIt(const typename Graph::EdgeIt& _e) : e(_e) { }
   942       EdgeIt(const Invalid& i) : e(i) { }
   943       EdgeIt(const ErasingFirstGraphWrapper<Graph, FirstOutEdgesMap>& _G) : 
   944 	e(*(_G.graph)) { }
   945       operator Edge() const { return Edge(typename Graph::Edge(e)); }
   946     };
   947 
   948     using GraphWrapper<Graph>::first;
   949 //     NodeIt& first(NodeIt& i) const { 
   950 //       i=NodeIt(*this); return i;
   951 //     }
   952     OutEdgeIt& first(OutEdgeIt& i, const Node& p) const { 
   953       i=OutEdgeIt(*this, p); return i;
   954     }
   955     InEdgeIt& first(InEdgeIt& i, const Node& p) const { 
   956       i=InEdgeIt(*this, p); return i;
   957     }
   958     EdgeIt& first(EdgeIt& i) const { 
   959       i=EdgeIt(*this); return i;
   960     }
   961 
   962     using GraphWrapper<Graph>::next;
   963 //    NodeIt& next(NodeIt& i) const { graph->next(i.n); return i; }
   964     OutEdgeIt& next(OutEdgeIt& i) const { this->graph->next(i.e); return i; }
   965     InEdgeIt& next(InEdgeIt& i) const { this->graph->next(i.e); return i; }
   966     EdgeIt& next(EdgeIt& i) const { this->graph->next(i.e); return i; }    
   967     
   968     Node aNode(const OutEdgeIt& e) const { 
   969       return Node(this->graph->aNode(e.e)); }
   970     Node aNode(const InEdgeIt& e) const { 
   971       return Node(this->graph->aNode(e.e)); }
   972     Node bNode(const OutEdgeIt& e) const { 
   973       return Node(this->graph->bNode(e.e)); }
   974     Node bNode(const InEdgeIt& e) const { 
   975       return Node(this->graph->bNode(e.e)); }
   976 
   977     void erase(const OutEdgeIt& e) const {
   978       OutEdgeIt f=e;
   979       this->next(f);
   980       first_out_edges->set(this->tail(e), f.e);
   981     }
   982   };
   983 
   984   ///@}
   985 
   986 } //namespace hugo
   987 
   988 
   989 #endif //HUGO_GRAPH_WRAPPER_H
   990