/* -*- C++ -*-

  *

  * This file is a part of LEMON, a generic C++ optimization library

  *

  * Copyright (C) 2003-2008

  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Research Group on Combinatorial Optimization, EGRES).

  *

  * Permission to use, modify and distribute this software is granted

  * provided that this copyright notice appears in all copies. For

  * precise terms see the accompanying LICENSE file.

  *

  * This software is provided "AS IS" with no warranty of any kind,

  * express or implied, and with no claim as to its suitability for any

  * purpose.

  *

  */

 #ifndef LEMON_BITS_GRAPH_EXTENDER_H

 #define LEMON_BITS_GRAPH_EXTENDER_H

 #include <lemon/bits/invalid.h>

 #include <lemon/bits/utility.h>

 #include <lemon/error.h>

 #include <lemon/bits/map_extender.h>

 #include <lemon/bits/default_map.h>

 #include <lemon/concept_check.h>

 #include <lemon/concepts/maps.h>

 ///\ingroup graphbits

 ///\file

 ///\brief Extenders for the graph types

 namespace lemon {

   /// \ingroup graphbits

   ///

   /// \brief Extender for the Graphs

   template <typename Base>

   class GraphExtender : public Base {

   public:

     typedef Base Parent;

     typedef GraphExtender Graph;

     // Base extensions

     typedef typename Parent::Node Node;

     typedef typename Parent::Edge Edge;

     int maxId(Node) const {

       return Parent::maxNodeId();

     }

     int maxId(Edge) const {

       return Parent::maxEdgeId();

     }

     Node fromId(int id, Node) const {

       return Parent::nodeFromId(id);

     }

     Edge fromId(int id, Edge) const {

       return Parent::edgeFromId(id);

     }

     Node oppositeNode(const Node &n, const Edge &e) const {

       if (n == Parent::source(e))

 	return Parent::target(e);

       else if(n==Parent::target(e))

 	return Parent::source(e);

       else

 	return INVALID;

     }

     // Alterable extension

     typedef AlterationNotifier<GraphExtender, Node> NodeNotifier;

     typedef AlterationNotifier<GraphExtender, Edge> EdgeNotifier;

   protected:

     mutable NodeNotifier node_notifier;

     mutable EdgeNotifier edge_notifier;

   public:

     NodeNotifier& notifier(Node) const {

       return node_notifier;

     }

     EdgeNotifier& notifier(Edge) const {

       return edge_notifier;

     }

     class NodeIt : public Node { 

       const Graph* graph;

     public:

       NodeIt() {}

       NodeIt(Invalid i) : Node(i) { }

       explicit NodeIt(const Graph& _graph) : graph(&_graph) {

 	_graph.first(static_cast<Node&>(*this));

       }

       NodeIt(const Graph& _graph, const Node& node) 

 	: Node(node), graph(&_graph) {}

       NodeIt& operator++() { 

 	graph->next(*this);

 	return *this; 

       }

     };

     class EdgeIt : public Edge { 

       const Graph* graph;

     public:

       EdgeIt() { }

       EdgeIt(Invalid i) : Edge(i) { }

       explicit EdgeIt(const Graph& _graph) : graph(&_graph) {

 	_graph.first(static_cast<Edge&>(*this));

       }

       EdgeIt(const Graph& _graph, const Edge& e) : 

 	Edge(e), graph(&_graph) { }

       EdgeIt& operator++() { 

 	graph->next(*this);

 	return *this; 

       }

     };

     class OutEdgeIt : public Edge { 

       const Graph* graph;

     public:

       OutEdgeIt() { }

       OutEdgeIt(Invalid i) : Edge(i) { }

       OutEdgeIt(const Graph& _graph, const Node& node) 

 	: graph(&_graph) {

 	_graph.firstOut(*this, node);

       }

       OutEdgeIt(const Graph& _graph, const Edge& edge) 

 	: Edge(edge), graph(&_graph) {}

       OutEdgeIt& operator++() { 

 	graph->nextOut(*this);

 	return *this; 

       }

     };

     class InEdgeIt : public Edge { 

       const Graph* graph;

     public:

       InEdgeIt() { }

       InEdgeIt(Invalid i) : Edge(i) { }

       InEdgeIt(const Graph& _graph, const Node& node) 

 	: graph(&_graph) {

 	_graph.firstIn(*this, node);

       }

       InEdgeIt(const Graph& _graph, const Edge& edge) : 

 	Edge(edge), graph(&_graph) {}

       InEdgeIt& operator++() { 

 	graph->nextIn(*this);

 	return *this; 

       }

     };

     /// \brief Base node of the iterator

     ///

     /// Returns the base node (i.e. the source in this case) of the iterator

     Node baseNode(const OutEdgeIt &e) const {

       return Parent::source(e);

     }

     /// \brief Running node of the iterator

     ///

     /// Returns the running node (i.e. the target in this case) of the

     /// iterator

     Node runningNode(const OutEdgeIt &e) const {

       return Parent::target(e);

     }

     /// \brief Base node of the iterator

     ///

     /// Returns the base node (i.e. the target in this case) of the iterator

     Node baseNode(const InEdgeIt &e) const {

       return Parent::target(e);

     }

     /// \brief Running node of the iterator

     ///

     /// Returns the running node (i.e. the source in this case) of the

     /// iterator

     Node runningNode(const InEdgeIt &e) const {

       return Parent::source(e);

     }

     template <typename _Value>

     class NodeMap 

       : public MapExtender<DefaultMap<Graph, Node, _Value> > {

     public:

       typedef GraphExtender Graph;

       typedef MapExtender<DefaultMap<Graph, Node, _Value> > Parent;

       explicit NodeMap(const Graph& graph) 

 	: Parent(graph) {}

       NodeMap(const Graph& graph, const _Value& value) 

 	: Parent(graph, value) {}

       NodeMap& operator=(const NodeMap& cmap) {

 	return operator=<NodeMap>(cmap);

       }

       template <typename CMap>

       NodeMap& operator=(const CMap& cmap) {

         Parent::operator=(cmap);

 	return *this;

       }

     };

     template <typename _Value>

     class EdgeMap 

       : public MapExtender<DefaultMap<Graph, Edge, _Value> > {

     public:

       typedef GraphExtender Graph;

       typedef MapExtender<DefaultMap<Graph, Edge, _Value> > Parent;

       explicit EdgeMap(const Graph& graph) 

 	: Parent(graph) {}

       EdgeMap(const Graph& graph, const _Value& value) 

 	: Parent(graph, value) {}

       EdgeMap& operator=(const EdgeMap& cmap) {

 	return operator=<EdgeMap>(cmap);

       }

       template <typename CMap>

       EdgeMap& operator=(const CMap& cmap) {

         Parent::operator=(cmap);

 	return *this;

       }

     };

     Node addNode() {

       Node node = Parent::addNode();

       notifier(Node()).add(node);

       return node;

     }

     Edge addEdge(const Node& from, const Node& to) {

       Edge edge = Parent::addEdge(from, to);

       notifier(Edge()).add(edge);

       return edge;

     }

     void clear() {

       notifier(Edge()).clear();

       notifier(Node()).clear();

       Parent::clear();

     }

     template <typename Graph, typename NodeRefMap, typename EdgeRefMap>

     void build(const Graph& graph, NodeRefMap& nodeRef, EdgeRefMap& edgeRef) {

       Parent::build(graph, nodeRef, edgeRef);

       notifier(Node()).build();

       notifier(Edge()).build();

     }

     void erase(const Node& node) {

       Edge edge;

       Parent::firstOut(edge, node);

       while (edge != INVALID ) {

 	erase(edge);

 	Parent::firstOut(edge, node);

       } 

       Parent::firstIn(edge, node);

       while (edge != INVALID ) {

 	erase(edge);

 	Parent::firstIn(edge, node);

       }

       notifier(Node()).erase(node);

       Parent::erase(node);

     }

     void erase(const Edge& edge) {

       notifier(Edge()).erase(edge);

       Parent::erase(edge);

     }

     GraphExtender() {

       node_notifier.setContainer(*this);

       edge_notifier.setContainer(*this);

     } 

     ~GraphExtender() {

       edge_notifier.clear();

       node_notifier.clear();

     }

   };

   /// \ingroup graphbits

   ///

   /// \brief Extender for the UGraphs

   template <typename Base> 

   class UGraphExtender : public Base {

   public:

     typedef Base Parent;

     typedef UGraphExtender Graph;

     typedef True UndirectedTag;

     typedef typename Parent::Node Node;

     typedef typename Parent::Edge Edge;

     typedef typename Parent::UEdge UEdge;

     // UGraph extension    

     int maxId(Node) const {

       return Parent::maxNodeId();

     }

     int maxId(Edge) const {

       return Parent::maxEdgeId();

     }

     int maxId(UEdge) const {

       return Parent::maxUEdgeId();

     }

     Node fromId(int id, Node) const {

       return Parent::nodeFromId(id);

     }

     Edge fromId(int id, Edge) const {

       return Parent::edgeFromId(id);

     }

     UEdge fromId(int id, UEdge) const {

       return Parent::uEdgeFromId(id);

     }

     Node oppositeNode(const Node &n, const UEdge &e) const {

       if( n == Parent::source(e))

 	return Parent::target(e);

       else if( n == Parent::target(e))

 	return Parent::source(e);

       else

 	return INVALID;

     }

     Edge oppositeEdge(const Edge &e) const {

       return Parent::direct(e, !Parent::direction(e));

     }

     using Parent::direct;

     Edge direct(const UEdge &ue, const Node &s) const {

       return Parent::direct(ue, Parent::source(ue) == s);

     }

     // Alterable extension

     typedef AlterationNotifier<UGraphExtender, Node> NodeNotifier;

     typedef AlterationNotifier<UGraphExtender, Edge> EdgeNotifier;

     typedef AlterationNotifier<UGraphExtender, UEdge> UEdgeNotifier;

   protected:

     mutable NodeNotifier node_notifier;

     mutable EdgeNotifier edge_notifier;

     mutable UEdgeNotifier uedge_notifier;

   public:

     NodeNotifier& notifier(Node) const {

       return node_notifier;

     }

     EdgeNotifier& notifier(Edge) const {

       return edge_notifier;

     }

     UEdgeNotifier& notifier(UEdge) const {

       return uedge_notifier;

     }

     class NodeIt : public Node { 

       const Graph* graph;

     public:

       NodeIt() {}

       NodeIt(Invalid i) : Node(i) { }

       explicit NodeIt(const Graph& _graph) : graph(&_graph) {

 	_graph.first(static_cast<Node&>(*this));

       }

       NodeIt(const Graph& _graph, const Node& node) 

 	: Node(node), graph(&_graph) {}

       NodeIt& operator++() { 

 	graph->next(*this);

 	return *this; 

       }

     };

     class EdgeIt : public Edge { 

       const Graph* graph;

     public:

       EdgeIt() { }

       EdgeIt(Invalid i) : Edge(i) { }

       explicit EdgeIt(const Graph& _graph) : graph(&_graph) {

 	_graph.first(static_cast<Edge&>(*this));

       }

       EdgeIt(const Graph& _graph, const Edge& e) : 

 	Edge(e), graph(&_graph) { }

       EdgeIt& operator++() { 

 	graph->next(*this);

 	return *this; 

       }

     };

     class OutEdgeIt : public Edge { 

       const Graph* graph;

     public:

       OutEdgeIt() { }

       OutEdgeIt(Invalid i) : Edge(i) { }

       OutEdgeIt(const Graph& _graph, const Node& node) 

 	: graph(&_graph) {

 	_graph.firstOut(*this, node);

       }

       OutEdgeIt(const Graph& _graph, const Edge& edge) 

 	: Edge(edge), graph(&_graph) {}

       OutEdgeIt& operator++() { 

 	graph->nextOut(*this);

 	return *this; 

       }

     };

     class InEdgeIt : public Edge { 

       const Graph* graph;

     public:

       InEdgeIt() { }

       InEdgeIt(Invalid i) : Edge(i) { }

       InEdgeIt(const Graph& _graph, const Node& node) 

 	: graph(&_graph) {

 	_graph.firstIn(*this, node);

       }

       InEdgeIt(const Graph& _graph, const Edge& edge) : 

 	Edge(edge), graph(&_graph) {}

       InEdgeIt& operator++() { 

 	graph->nextIn(*this);

 	return *this; 

       }

     };

     class UEdgeIt : public Parent::UEdge { 

       const Graph* graph;

     public:

       UEdgeIt() { }

       UEdgeIt(Invalid i) : UEdge(i) { }

       explicit UEdgeIt(const Graph& _graph) : graph(&_graph) {

 	_graph.first(static_cast<UEdge&>(*this));

       }

       UEdgeIt(const Graph& _graph, const UEdge& e) : 

 	UEdge(e), graph(&_graph) { }

       UEdgeIt& operator++() { 

 	graph->next(*this);

 	return *this; 

       }

     };

     class IncEdgeIt : public Parent::UEdge {

       friend class UGraphExtender;

       const Graph* graph;

       bool direction;

     public:

       IncEdgeIt() { }

       IncEdgeIt(Invalid i) : UEdge(i), direction(false) { }

       IncEdgeIt(const Graph& _graph, const Node &n) : graph(&_graph) {

 	_graph.firstInc(*this, direction, n);

       }

       IncEdgeIt(const Graph& _graph, const UEdge &ue, const Node &n)

 	: graph(&_graph), UEdge(ue) {

 	direction = (_graph.source(ue) == n);

       }

       IncEdgeIt& operator++() {

 	graph->nextInc(*this, direction);

 	return *this; 

       }

     };

     /// \brief Base node of the iterator

     ///

     /// Returns the base node (ie. the source in this case) of the iterator

     Node baseNode(const OutEdgeIt &e) const {

       return Parent::source(static_cast<const Edge&>(e));

     }

     /// \brief Running node of the iterator

     ///

     /// Returns the running node (ie. the target in this case) of the

     /// iterator

     Node runningNode(const OutEdgeIt &e) const {

       return Parent::target(static_cast<const Edge&>(e));

     }

     /// \brief Base node of the iterator

     ///

     /// Returns the base node (ie. the target in this case) of the iterator

     Node baseNode(const InEdgeIt &e) const {

       return Parent::target(static_cast<const Edge&>(e));

     }

     /// \brief Running node of the iterator

     ///

     /// Returns the running node (ie. the source in this case) of the

     /// iterator

     Node runningNode(const InEdgeIt &e) const {

       return Parent::source(static_cast<const Edge&>(e));

     }

     /// Base node of the iterator

     ///

     /// Returns the base node of the iterator

     Node baseNode(const IncEdgeIt &e) const {

       return e.direction ? source(e) : target(e);

     }

     /// Running node of the iterator

     ///

     /// Returns the running node of the iterator

     Node runningNode(const IncEdgeIt &e) const {

       return e.direction ? target(e) : source(e);

     }

     // Mappable extension

     template <typename _Value>

     class NodeMap 

       : public MapExtender<DefaultMap<Graph, Node, _Value> > {

     public:

       typedef UGraphExtender Graph;

       typedef MapExtender<DefaultMap<Graph, Node, _Value> > Parent;

       NodeMap(const Graph& graph) 

 	: Parent(graph) {}

       NodeMap(const Graph& graph, const _Value& value) 

 	: Parent(graph, value) {}

       NodeMap& operator=(const NodeMap& cmap) {

 	return operator=<NodeMap>(cmap);

       }

       template <typename CMap>

       NodeMap& operator=(const CMap& cmap) {

         Parent::operator=(cmap);

 	return *this;

       }

     };

     template <typename _Value>

     class EdgeMap 

       : public MapExtender<DefaultMap<Graph, Edge, _Value> > {

     public:

       typedef UGraphExtender Graph;

       typedef MapExtender<DefaultMap<Graph, Edge, _Value> > Parent;

       EdgeMap(const Graph& graph) 

 	: Parent(graph) {}

       EdgeMap(const Graph& graph, const _Value& value) 

 	: Parent(graph, value) {}

       EdgeMap& operator=(const EdgeMap& cmap) {

 	return operator=<EdgeMap>(cmap);

       }

       template <typename CMap>

       EdgeMap& operator=(const CMap& cmap) {

         Parent::operator=(cmap);

 	return *this;

       }

     };

     template <typename _Value>

     class UEdgeMap 

       : public MapExtender<DefaultMap<Graph, UEdge, _Value> > {

     public:

       typedef UGraphExtender Graph;

       typedef MapExtender<DefaultMap<Graph, UEdge, _Value> > Parent;

       UEdgeMap(const Graph& graph) 

 	: Parent(graph) {}

       UEdgeMap(const Graph& graph, const _Value& value) 

 	: Parent(graph, value) {}

       UEdgeMap& operator=(const UEdgeMap& cmap) {

 	return operator=<UEdgeMap>(cmap);

       }

       template <typename CMap>

       UEdgeMap& operator=(const CMap& cmap) {

         Parent::operator=(cmap);

 	return *this;

       }

     };

     // Alteration extension

     Node addNode() {

       Node node = Parent::addNode();

       notifier(Node()).add(node);

       return node;

     }

     UEdge addEdge(const Node& from, const Node& to) {

       UEdge uedge = Parent::addEdge(from, to);

       notifier(UEdge()).add(uedge);

       std::vector<Edge> ev;

       ev.push_back(Parent::direct(uedge, true));

       ev.push_back(Parent::direct(uedge, false));      

       notifier(Edge()).add(ev);

       return uedge;

     }

     void clear() {

       notifier(Edge()).clear();

       notifier(UEdge()).clear();

       notifier(Node()).clear();

       Parent::clear();

     }

     template <typename Graph, typename NodeRefMap, typename UEdgeRefMap>

     void build(const Graph& graph, NodeRefMap& nodeRef, 

                UEdgeRefMap& uEdgeRef) {

       Parent::build(graph, nodeRef, uEdgeRef);

       notifier(Node()).build();

       notifier(UEdge()).build();

       notifier(Edge()).build();

     }

     void erase(const Node& node) {

       Edge edge;

       Parent::firstOut(edge, node);

       while (edge != INVALID ) {

 	erase(edge);

 	Parent::firstOut(edge, node);

       } 

       Parent::firstIn(edge, node);

       while (edge != INVALID ) {

 	erase(edge);

 	Parent::firstIn(edge, node);

       }

       notifier(Node()).erase(node);

       Parent::erase(node);

     }

     void erase(const UEdge& uedge) {

       std::vector<Edge> ev;

       ev.push_back(Parent::direct(uedge, true));

       ev.push_back(Parent::direct(uedge, false));      

       notifier(Edge()).erase(ev);

       notifier(UEdge()).erase(uedge);

       Parent::erase(uedge);

     }

     UGraphExtender() {

       node_notifier.setContainer(*this); 

       edge_notifier.setContainer(*this);

       uedge_notifier.setContainer(*this);

     } 

     ~UGraphExtender() {

       uedge_notifier.clear();

       edge_notifier.clear();

       node_notifier.clear(); 

     } 

   };

   /// \ingroup graphbits

   ///

   /// \brief Extender for the BpUGraphs

   template <typename Base>

   class BpUGraphExtender : public Base {

   public:

     typedef Base Parent;

     typedef BpUGraphExtender Graph;

     typedef True UndirectedTag;

     typedef typename Parent::Node Node;

     typedef typename Parent::ANode ANode;

     typedef typename Parent::BNode BNode;

     typedef typename Parent::Edge Edge;

     typedef typename Parent::UEdge UEdge;

     Node oppositeNode(const Node& node, const UEdge& edge) const {

       return Parent::aNode(edge) == node ? 

 	Parent::bNode(edge) : Parent::aNode(edge);

     }

     using Parent::direct;

     Edge direct(const UEdge& edge, const Node& node) const {

       return Parent::direct(edge, node == Parent::source(edge));

     }

     Edge oppositeEdge(const Edge& edge) const {

       return direct(edge, !Parent::direction(edge));

     }

     int maxId(Node) const {

       return Parent::maxNodeId();

     }

     int maxId(BNode) const {

       return Parent::maxBNodeId();

     }

     int maxId(ANode) const {

       return Parent::maxANodeId();

     }

     int maxId(Edge) const {

       return Parent::maxEdgeId();

     }

     int maxId(UEdge) const {

       return Parent::maxUEdgeId();

     }

     Node fromId(int id, Node) const {

       return Parent::nodeFromId(id);

     }

     ANode fromId(int id, ANode) const {

       return Parent::nodeFromANodeId(id);

     }

     BNode fromId(int id, BNode) const {

       return Parent::nodeFromBNodeId(id);

     }

     Edge fromId(int id, Edge) const {

       return Parent::edgeFromId(id);

     }

     UEdge fromId(int id, UEdge) const {

       return Parent::uEdgeFromId(id);

     }  

     typedef AlterationNotifier<BpUGraphExtender, ANode> ANodeNotifier;

     typedef AlterationNotifier<BpUGraphExtender, BNode> BNodeNotifier;

     typedef AlterationNotifier<BpUGraphExtender, Node> NodeNotifier;

     typedef AlterationNotifier<BpUGraphExtender, Edge> EdgeNotifier;

     typedef AlterationNotifier<BpUGraphExtender, UEdge> UEdgeNotifier;

   protected:

     mutable ANodeNotifier anode_notifier;

     mutable BNodeNotifier bnode_notifier;

     mutable NodeNotifier node_notifier;

     mutable EdgeNotifier edge_notifier;

     mutable UEdgeNotifier uedge_notifier;

   public:

     NodeNotifier& notifier(Node) const {

       return node_notifier;

     }

     ANodeNotifier& notifier(ANode) const {

       return anode_notifier;

     }

     BNodeNotifier& notifier(BNode) const {

       return bnode_notifier;

     }

     EdgeNotifier& notifier(Edge) const {

       return edge_notifier;

     }

     UEdgeNotifier& notifier(UEdge) const {

       return uedge_notifier;

     }

     class NodeIt : public Node { 

       const Graph* graph;

     public:

       NodeIt() { }

       NodeIt(Invalid i) : Node(INVALID) { }

       explicit NodeIt(const Graph& _graph) : graph(&_graph) {

 	graph->first(static_cast<Node&>(*this));

       }

       NodeIt(const Graph& _graph, const Node& node) 

 	: Node(node), graph(&_graph) { }

       NodeIt& operator++() { 

 	graph->next(*this);

 	return *this; 

       }

     };

     class ANodeIt : public Node { 

       friend class BpUGraphExtender;

       const Graph* graph;

     public:

       ANodeIt() { }

       ANodeIt(Invalid i) : Node(INVALID) { }

       explicit ANodeIt(const Graph& _graph) : graph(&_graph) {

 	graph->firstANode(static_cast<Node&>(*this));

       }

       ANodeIt(const Graph& _graph, const Node& node) 

 	: Node(node), graph(&_graph) {}

       ANodeIt& operator++() { 

 	graph->nextANode(*this);

 	return *this; 

       }

     };

     class BNodeIt : public Node { 

       friend class BpUGraphExtender;

       const Graph* graph;

     public:

       BNodeIt() { }

       BNodeIt(Invalid i) : Node(INVALID) { }

       explicit BNodeIt(const Graph& _graph) : graph(&_graph) {

 	graph->firstBNode(static_cast<Node&>(*this));

       }

       BNodeIt(const Graph& _graph, const Node& node) 

 	: Node(node), graph(&_graph) {}

       BNodeIt& operator++() { 

 	graph->nextBNode(*this);

 	return *this; 

       }

     };

     class EdgeIt : public Edge { 

       friend class BpUGraphExtender;

       const Graph* graph;

     public:

       EdgeIt() { }

       EdgeIt(Invalid i) : Edge(INVALID) { }

       explicit EdgeIt(const Graph& _graph) : graph(&_graph) {

 	graph->first(static_cast<Edge&>(*this));

       }

       EdgeIt(const Graph& _graph, const Edge& edge) 

 	: Edge(edge), graph(&_graph) { }

       EdgeIt& operator++() { 

 	graph->next(*this);

 	return *this; 

       }

     };

     class UEdgeIt : public UEdge { 

       friend class BpUGraphExtender;

       const Graph* graph;

     public:

       UEdgeIt() { }

       UEdgeIt(Invalid i) : UEdge(INVALID) { }

       explicit UEdgeIt(const Graph& _graph) : graph(&_graph) {

 	graph->first(static_cast<UEdge&>(*this));

       }

       UEdgeIt(const Graph& _graph, const UEdge& edge) 

 	: UEdge(edge), graph(&_graph) { }

       UEdgeIt& operator++() { 

 	graph->next(*this);

 	return *this; 

       }

     };

     class OutEdgeIt : public Edge { 

       friend class BpUGraphExtender;

       const Graph* graph;

     public:

       OutEdgeIt() { }

       OutEdgeIt(Invalid i) : Edge(i) { }

       OutEdgeIt(const Graph& _graph, const Node& node) 

 	: graph(&_graph) {

 	graph->firstOut(*this, node);

       }

       OutEdgeIt(const Graph& _graph, const Edge& edge) 

 	: Edge(edge), graph(&_graph) {}

       OutEdgeIt& operator++() { 

 	graph->nextOut(*this);

 	return *this; 

       }

     };

     class InEdgeIt : public Edge { 

       friend class BpUGraphExtender;

       const Graph* graph;

     public:

       InEdgeIt() { }

       InEdgeIt(Invalid i) : Edge(i) { }

       InEdgeIt(const Graph& _graph, const Node& node) 

 	: graph(&_graph) {

 	graph->firstIn(*this, node);

       }

       InEdgeIt(const Graph& _graph, const Edge& edge) : 

 	Edge(edge), graph(&_graph) {}

       InEdgeIt& operator++() { 

 	graph->nextIn(*this);

 	return *this; 

       }

     };

     /// \brief Base node of the iterator

     ///

     /// Returns the base node (ie. the source in this case) of the iterator

     Node baseNode(const OutEdgeIt &e) const {

       return Parent::source(static_cast<const Edge&>(e));

     }

     /// \brief Running node of the iterator

     ///

     /// Returns the running node (ie. the target in this case) of the

     /// iterator

     Node runningNode(const OutEdgeIt &e) const {

       return Parent::target(static_cast<const Edge&>(e));

     }

     /// \brief Base node of the iterator

     ///

     /// Returns the base node (ie. the target in this case) of the iterator

     Node baseNode(const InEdgeIt &e) const {

       return Parent::target(static_cast<const Edge&>(e));

     }

     /// \brief Running node of the iterator

     ///

     /// Returns the running node (ie. the source in this case) of the

     /// iterator

     Node runningNode(const InEdgeIt &e) const {

       return Parent::source(static_cast<const Edge&>(e));

     }

     class IncEdgeIt : public Parent::UEdge { 

       friend class BpUGraphExtender;

       const Graph* graph;

       bool direction;

     public:

       IncEdgeIt() { }

       IncEdgeIt(Invalid i) : UEdge(i), direction(true) { }

       IncEdgeIt(const Graph& _graph, const Node &n) : graph(&_graph) {

 	graph->firstInc(*this, direction, n);

       }

       IncEdgeIt(const Graph& _graph, const UEdge &ue, const Node &n)

 	: graph(&_graph), UEdge(ue) {

 	direction = (graph->source(ue) == n);

       }

       IncEdgeIt& operator++() {

 	graph->nextInc(*this, direction);

 	return *this; 

       }

     };

     /// Base node of the iterator

     ///

     /// Returns the base node of the iterator

     Node baseNode(const IncEdgeIt &e) const {

       return e.direction ? source(e) : target(e);

     }

     /// Running node of the iterator

     ///

     /// Returns the running node of the iterator

     Node runningNode(const IncEdgeIt &e) const {

       return e.direction ? target(e) : source(e);

     }

     template <typename _Value>

     class ANodeMap 

       : public MapExtender<DefaultMap<Graph, ANode, _Value> > {

     public:

       typedef BpUGraphExtender Graph;

       typedef MapExtender<DefaultMap<Graph, ANode, _Value> > Parent;

       ANodeMap(const Graph& graph) 

 	: Parent(graph) {}

       ANodeMap(const Graph& graph, const _Value& value) 

 	: Parent(graph, value) {}

       ANodeMap& operator=(const ANodeMap& cmap) {

 	return operator=<ANodeMap>(cmap);

       }

       template <typename CMap>

       ANodeMap& operator=(const CMap& cmap) {

         Parent::operator=(cmap);

 	return *this;

       }

     };

     template <typename _Value>

     class BNodeMap 

       : public MapExtender<DefaultMap<Graph, BNode, _Value> > {

     public:

       typedef BpUGraphExtender Graph;

       typedef MapExtender<DefaultMap<Graph, BNode, _Value> > Parent;

       BNodeMap(const Graph& graph) 

 	: Parent(graph) {}

       BNodeMap(const Graph& graph, const _Value& value) 

 	: Parent(graph, value) {}

       BNodeMap& operator=(const BNodeMap& cmap) {

 	return operator=<BNodeMap>(cmap);

       }

       template <typename CMap>

       BNodeMap& operator=(const CMap& cmap) {

         Parent::operator=(cmap);

 	return *this;

       }

     };

   public:

     template <typename _Value>

     class NodeMap {

     public:

       typedef BpUGraphExtender Graph;

       typedef Node Key;

       typedef _Value Value;

       /// The reference type of the map;

       typedef typename ANodeMap<_Value>::Reference Reference;

       /// The const reference type of the map;

       typedef typename ANodeMap<_Value>::ConstReference ConstReference;

       typedef True ReferenceMapTag;

       NodeMap(const Graph& _graph) 

 	: graph(_graph), aNodeMap(_graph), bNodeMap(_graph) {}

       NodeMap(const Graph& _graph, const _Value& _value) 

 	: graph(_graph), aNodeMap(_graph, _value), bNodeMap(_graph, _value) {}

       NodeMap& operator=(const NodeMap& cmap) {

 	return operator=<NodeMap>(cmap);

       }

       template <typename CMap>

       NodeMap& operator=(const CMap& cmap) {

 	checkConcept<concepts::ReadMap<Node, _Value>, CMap>();

         aNodeMap = cmap;

         bNodeMap = cmap;

         return *this;

       }

       ConstReference operator[](const Key& node) const {

 	if (Parent::aNode(node)) {

 	  return aNodeMap[node];

 	} else {

 	  return bNodeMap[node];

 	}

       } 

       Reference operator[](const Key& node) {

 	if (Parent::aNode(node)) {

 	  return aNodeMap[node];

 	} else {

 	  return bNodeMap[node];

 	}

       }

       void set(const Key& node, const Value& value) {

 	if (Parent::aNode(node)) {

 	  aNodeMap.set(node, value);

 	} else {

 	  bNodeMap.set(node, value);

 	}

       }

       class MapIt : public NodeIt {

       public:

         typedef NodeIt Parent;

         explicit MapIt(NodeMap& _map) 

           : Parent(_map.graph), map(_map) {}

         typename MapTraits<NodeMap>::ConstReturnValue operator*() const {

           return map[*this];

         }

         typename MapTraits<NodeMap>::ReturnValue operator*() {

           return map[*this];

         }

         void set(const Value& value) {

           map.set(*this, value);

         }

       private:

         NodeMap& map;

       };

       class ConstMapIt : public NodeIt {

       public:

         typedef NodeIt Parent;

         explicit ConstMapIt(const NodeMap& _map) 

           : Parent(_map.graph), map(_map) {}

         typename MapTraits<NodeMap>::ConstReturnValue operator*() const {

           return map[*this];

         }

       private:

         const NodeMap& map;

       };

       class ItemIt : public NodeIt {

       public:

         typedef NodeIt Parent;

         explicit ItemIt(const NodeMap& _map)

           : Parent(_map.graph) {}

       };

     private:

       const Graph& graph;

       ANodeMap<_Value> aNodeMap;

       BNodeMap<_Value> bNodeMap;

     };

     template <typename _Value>

     class EdgeMap 

       : public MapExtender<DefaultMap<Graph, Edge, _Value> > {

     public:

       typedef BpUGraphExtender Graph;

       typedef MapExtender<DefaultMap<Graph, Edge, _Value> > Parent;

       EdgeMap(const Graph& graph) 

 	: Parent(graph) {}

       EdgeMap(const Graph& graph, const _Value& value) 

 	: Parent(graph, value) {}

       EdgeMap& operator=(const EdgeMap& cmap) {

 	return operator=<EdgeMap>(cmap);

       }

       template <typename CMap>

       EdgeMap& operator=(const CMap& cmap) {

         Parent::operator=(cmap);

 	return *this;

       }

     };

     template <typename _Value>

     class UEdgeMap 

       : public MapExtender<DefaultMap<Graph, UEdge, _Value> > {

     public:

       typedef BpUGraphExtender Graph;

       typedef MapExtender<DefaultMap<Graph, UEdge, _Value> > Parent;

       UEdgeMap(const Graph& graph) 

 	: Parent(graph) {}

       UEdgeMap(const Graph& graph, const _Value& value) 

 	: Parent(graph, value) {}

       UEdgeMap& operator=(const UEdgeMap& cmap) {

 	return operator=<UEdgeMap>(cmap);

       }

       template <typename CMap>

       UEdgeMap& operator=(const CMap& cmap) {

         Parent::operator=(cmap);

 	return *this;

       }

     };

     Node addANode() {

       Node node = Parent::addANode();

       notifier(ANode()).add(node);

       notifier(Node()).add(node);

       return node;

     }

     Node addBNode() {

       Node node = Parent::addBNode();

       notifier(BNode()).add(node);

       notifier(Node()).add(node);

       return node;

     }

     UEdge addEdge(const Node& s, const Node& t) {

       UEdge uedge = Parent::addEdge(s, t);

       notifier(UEdge()).add(uedge);

       std::vector<Edge> ev;

       ev.push_back(Parent::direct(uedge, true));

       ev.push_back(Parent::direct(uedge, false));

       notifier(Edge()).add(ev);

       return uedge;

     }

     void clear() {

       notifier(Edge()).clear();

       notifier(UEdge()).clear();

       notifier(Node()).clear();

       notifier(BNode()).clear();

       notifier(ANode()).clear();

       Parent::clear();

     }

     template <typename Graph, typename ANodeRefMap, 

               typename BNodeRefMap, typename UEdgeRefMap>

     void build(const Graph& graph, ANodeRefMap& aNodeRef, 

                BNodeRefMap& bNodeRef, UEdgeRefMap& uEdgeRef) {

       Parent::build(graph, aNodeRef, bNodeRef, uEdgeRef);

       notifier(ANode()).build();

       notifier(BNode()).build();

       notifier(Node()).build();

       notifier(UEdge()).build();

       notifier(Edge()).build();

     }

     void erase(const Node& node) {

       UEdge uedge;

       if (Parent::aNode(node)) {

         Parent::firstFromANode(uedge, node);

         while (uedge != INVALID) {

           erase(uedge);

           Parent::firstFromANode(uedge, node);

         }

         notifier(ANode()).erase(node);

       } else {

         Parent::firstFromBNode(uedge, node);

         while (uedge != INVALID) {

           erase(uedge);

           Parent::firstFromBNode(uedge, node);

         }

         notifier(BNode()).erase(node);

       }

       notifier(Node()).erase(node);

       Parent::erase(node);

     }

     void erase(const UEdge& uedge) {

       std::vector<Edge> ev;

       ev.push_back(Parent::direct(uedge, true));

       ev.push_back(Parent::direct(uedge, false));

       notifier(Edge()).erase(ev);

       notifier(UEdge()).erase(uedge);

       Parent::erase(uedge);

     }

     BpUGraphExtender() {

       anode_notifier.setContainer(*this); 

       bnode_notifier.setContainer(*this); 

       node_notifier.setContainer(*this); 

       edge_notifier.setContainer(*this); 

       uedge_notifier.setContainer(*this);

     } 

     ~BpUGraphExtender() {

       uedge_notifier.clear();

       edge_notifier.clear(); 

       node_notifier.clear(); 

       anode_notifier.clear(); 

       bnode_notifier.clear(); 

     }

     Edge findEdge(Node u, Node v, Edge prev = INVALID) const {

       UEdge uedge = Parent::findUEdge(u, v, prev);

       if (uedge != INVALID) {

         return Parent::direct(uedge, Parent::aNode(u));

       } else {

         return INVALID;

       }

     }

   };

 }

 #endif