source: lemon-0.x/lemon/ugraph_adaptor.h @ 1979:c2992fd74dad

/* -*- C++ -*-
 *
 * This file is a part of LEMON, a generic C++ optimization library
 *
 * Copyright (C) 2003-2006
 * 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_UGRAPH_ADAPTOR_H
#define LEMON_UGRAPH_ADAPTOR_H

///\ingroup graph_adaptors
///\file
///\brief Several graph adaptors.
///
///This file contains several useful ugraph adaptor functions.
///
///\author Balazs Dezso

#include <lemon/invalid.h>
#include <lemon/maps.h>

#include <lemon/bits/graph_adaptor_extender.h>

#include <lemon/traits.h>

#include <iostream>

namespace lemon {

  /// \ingroup graph_adaptors
  ///
  /// \brief Base type for the Graph Adaptors
  ///
  /// \warning Graph adaptors are in even more experimental state than the 
  /// other parts of the lib. Use them at you own risk.
  ///
  /// This is the base type for most of LEMON graph adaptors. 
  /// This class implements a trivial graph adaptor i.e. it only wraps the 
  /// functions and types of the graph. The purpose of this class is to 
  /// make easier implementing graph adaptors. E.g. if an adaptor is 
  /// considered which differs from the wrapped graph only in some of its 
  /// functions or types, then it can be derived from GraphAdaptor, and only 
  /// the differences should be implemented.
  ///
  /// \author Balazs Dezso 
  template<typename _UGraph>
  class UGraphAdaptorBase {
  public:
    typedef _UGraph Graph;
    typedef Graph ParentGraph;

  protected:
    Graph* graph;

    UGraphAdaptorBase() : graph(0) {}

    void setGraph(Graph& _graph) { graph=&_graph; }

    Graph& getGraph() { return *graph; }
    const Graph& getGraph() const { return *graph; }

  public:
    UGraphAdaptorBase(Graph& _graph) : graph(&_graph) {}
 
    typedef typename Graph::Node Node;
    typedef typename Graph::Edge Edge;
    typedef typename Graph::UEdge UEdge;
   
    void first(Node& i) const { graph->first(i); }
    void first(Edge& i) const { graph->first(i); }
    void first(UEdge& i) const { graph->first(i); }
    void firstIn(Edge& i, const Node& n) const { graph->firstIn(i, n); }
    void firstOut(Edge& i, const Node& n ) const { graph->firstOut(i, n); }
    void firstInc(UEdge &i, bool &d, const Node &n) const {
      graph->firstInc(i, d, n);
    }

    void next(Node& i) const { graph->next(i); }
    void next(Edge& i) const { graph->next(i); }
    void next(UEdge& i) const { graph->next(i); }
    void nextIn(Edge& i) const { graph->nextIn(i); }
    void nextOut(Edge& i) const { graph->nextOut(i); }
    void nextInc(UEdge &i, bool &d) const { graph->nextInc(i, d); }


    Node source(const UEdge& e) const { return graph->source(e); }
    Node target(const UEdge& e) const { return graph->target(e); }

    Node source(const Edge& e) const { return graph->source(e); }
    Node target(const Edge& e) const { return graph->target(e); }

    typedef NodeNumTagIndicator<Graph> NodeNumTag;
    int nodeNum() const { return graph->nodeNum(); }
    
    typedef EdgeNumTagIndicator<Graph> EdgeNumTag;
    int edgeNum() const { return graph->edgeNum(); }

    typedef FindEdgeTagIndicator<Graph> FindEdgeTag;
    Edge findEdge(const Node& source, const Node& target, 
                  const Edge& prev = INVALID) {
      return graph->findEdge(source, target, prev);
    }

    UEdge findUEdge(const Node& source, const Node& target, 
                    const UEdge& prev = INVALID) {
      return graph->findUEdge(source, target, prev);
    }
  
    Node addNode() const { return graph->addNode(); }
    UEdge addEdge(const Node& source, const Node& target) const { 
      return graph->addEdge(source, target); 
    }

    void erase(const Node& i) const { graph->erase(i); }
    void erase(const Edge& i) const { graph->erase(i); }
  
    void clear() const { graph->clear(); }
    
    int id(const Node& v) const { return graph->id(v); }
    int id(const UEdge& e) const { return graph->id(e); }

    bool direction(const Edge& e) const { return graph->direction(e); }
    Edge direct(const UEdge& e, bool d) const { return graph->direct(e, d); }
    Edge direct(const UEdge& e, const Node& n) const { 
      return graph->direct(e, n); 
    }

    Node oppositeNode(const Node& n, const Edge& e) const { 
      return graph->oppositeNode(n, e); 
    }

    Edge oppositeEdge(const Edge& e) const { 
      return graph->oppositeEdge(e); 
    }


    template <typename _Value>
    class NodeMap : public Graph::template NodeMap<_Value> {
    public:
      typedef typename Graph::template NodeMap<_Value> Parent;
      explicit NodeMap(const UGraphAdaptorBase<Graph>& ga) 
        : Parent(*ga.graph) {}
      NodeMap(const UGraphAdaptorBase<Graph>& ga, const _Value& value)
        : Parent(*ga.graph, value) {}

      NodeMap& operator=(const NodeMap& cmap) {
        return operator=<NodeMap>(cmap);
      }

      template <typename CMap>
      NodeMap& operator=(const CMap& cmap) {
        checkConcept<concept::ReadMap<Node, _Value>, CMap>();
        const typename Parent::Graph* graph = Parent::getGraph();
        Node it;
        for (graph->first(it); it != INVALID; graph->next(it)) {
          Parent::set(it, cmap[it]);
        }
        return *this;
      }
    };

    template <typename _Value>
    class EdgeMap : public Graph::template EdgeMap<_Value> {
    public:
      typedef typename Graph::template EdgeMap<_Value> Parent;
      explicit EdgeMap(const UGraphAdaptorBase<Graph>& ga) 
        : Parent(*ga.graph) {}
      EdgeMap(const UGraphAdaptorBase<Graph>& ga, const _Value& value)
        : Parent(*ga.graph, value) {}

      EdgeMap& operator=(const EdgeMap& cmap) {
        return operator=<EdgeMap>(cmap);
      }

      template <typename CMap>
      EdgeMap& operator=(const CMap& cmap) {
        checkConcept<concept::ReadMap<Edge, _Value>, CMap>();
        const typename Parent::Graph* graph = Parent::getGraph();
        Edge it;
        for (graph->first(it); it != INVALID; graph->next(it)) {
          Parent::set(it, cmap[it]);
        }
        return *this;
      }
    };

    template <typename _Value>
    class UEdgeMap : public Graph::template UEdgeMap<_Value> {
    public:
      typedef typename Graph::template UEdgeMap<_Value> Parent;
      explicit UEdgeMap(const UGraphAdaptorBase<Graph>& ga) 
        : Parent(*ga.graph) {}
      UEdgeMap(const UGraphAdaptorBase<Graph>& ga, const _Value& value)
        : Parent(*ga.graph, value) {}

      UEdgeMap& operator=(const UEdgeMap& cmap) {
        return operator=<UEdgeMap>(cmap);
      }

      template <typename CMap>
      UEdgeMap& operator=(const CMap& cmap) {
        checkConcept<concept::ReadMap<UEdge, _Value>, CMap>();
        const typename Parent::Graph* graph = Parent::getGraph();
        UEdge it;
        for (graph->first(it); it != INVALID; graph->next(it)) {
          Parent::set(it, cmap[it]);
        }
        return *this;
      }
    };

  };

  /// \ingroup graph_adaptors
  template <typename _UGraph>
  class UGraphAdaptor 
    : public UGraphAdaptorExtender< UGraphAdaptorBase<_UGraph> > { 
  public:
    typedef _UGraph Graph;
    typedef UGraphAdaptorExtender<UGraphAdaptorBase<_UGraph> > Parent;
  protected:
    UGraphAdaptor() : Parent() {}

  public:
    explicit UGraphAdaptor(Graph& _graph) { setGraph(_graph); }
  };

  template <typename _UGraph, typename NodeFilterMap, 
            typename UEdgeFilterMap, bool checked = true>
  class SubUGraphAdaptorBase : public UGraphAdaptorBase<_UGraph> {
  public:
    typedef _UGraph Graph;
    typedef UGraphAdaptorBase<_UGraph> Parent;
  protected:

    NodeFilterMap* node_filter_map;
    UEdgeFilterMap* uedge_filter_map;

    SubUGraphAdaptorBase() 
      : Parent(), node_filter_map(0), uedge_filter_map(0) { }

    void setNodeFilterMap(NodeFilterMap& _node_filter_map) {
      node_filter_map=&_node_filter_map;
    }
    void setUEdgeFilterMap(UEdgeFilterMap& _uedge_filter_map) {
      uedge_filter_map=&_uedge_filter_map;
    }

  public:

    typedef typename Parent::Node Node;
    typedef typename Parent::Edge Edge;
    typedef typename Parent::UEdge UEdge;

    void first(Node& i) const { 
      Parent::first(i); 
      while (i!=INVALID && !(*node_filter_map)[i]) Parent::next(i); 
    }

    void first(Edge& i) const { 
      Parent::first(i); 
      while (i!=INVALID && (!(*uedge_filter_map)[i] 
             || !(*node_filter_map)[Parent::source(i)]
             || !(*node_filter_map)[Parent::target(i)])) Parent::next(i); 
    }

    void first(UEdge& i) const { 
      Parent::first(i); 
      while (i!=INVALID && (!(*uedge_filter_map)[i] 
             || !(*node_filter_map)[Parent::source(i)]
             || !(*node_filter_map)[Parent::target(i)])) Parent::next(i); 
    }

    void firstIn(Edge& i, const Node& n) const { 
      Parent::firstIn(i, n); 
      while (i!=INVALID && (!(*uedge_filter_map)[i] 
             || !(*node_filter_map)[Parent::source(i)])) Parent::nextIn(i); 
    }

    void firstOut(Edge& i, const Node& n) const { 
      Parent::firstOut(i, n); 
      while (i!=INVALID && (!(*uedge_filter_map)[i] 
             || !(*node_filter_map)[Parent::target(i)])) Parent::nextOut(i); 
    }

    void firstInc(UEdge& i, bool& d, const Node& n) const { 
      Parent::firstInc(i, d, n); 
      while (i!=INVALID && (!(*uedge_filter_map)[i] 
            || !(*node_filter_map)[Parent::target(i)])) Parent::nextInc(i, d); 
    }

    void next(Node& i) const { 
      Parent::next(i); 
      while (i!=INVALID && !(*node_filter_map)[i]) Parent::next(i); 
    }

    void next(Edge& i) const { 
      Parent::next(i); 
      while (i!=INVALID && (!(*uedge_filter_map)[i] 
             || !(*node_filter_map)[Parent::source(i)]
             || !(*node_filter_map)[Parent::target(i)])) Parent::next(i); 
    }

    void next(UEdge& i) const { 
      Parent::next(i); 
      while (i!=INVALID && (!(*uedge_filter_map)[i] 
             || !(*node_filter_map)[Parent::source(i)]
             || !(*node_filter_map)[Parent::target(i)])) Parent::next(i); 
    }

    void nextIn(Edge& i) const { 
      Parent::nextIn(i); 
      while (i!=INVALID && (!(*uedge_filter_map)[i] 
             || !(*node_filter_map)[Parent::source(i)])) Parent::nextIn(i); 
    }

    void nextOut(Edge& i) const { 
      Parent::nextOut(i); 
      while (i!=INVALID && (!(*uedge_filter_map)[i] 
             || !(*node_filter_map)[Parent::target(i)])) Parent::nextOut(i); 
    }

    void nextInc(UEdge& i, bool& d) const { 
      Parent::nextInc(i, d); 
      while (i!=INVALID && (!(*uedge_filter_map)[i] 
            || !(*node_filter_map)[Parent::source(i)])) Parent::nextInc(i, d); 
    }

    ///\e

    /// This function hides \c n in the graph, i.e. the iteration 
    /// jumps over it. This is done by simply setting the value of \c n  
    /// to be false in the corresponding node-map.
    void hide(const Node& n) const { node_filter_map->set(n, false); }

    ///\e

    /// This function hides \c e in the graph, i.e. the iteration 
    /// jumps over it. This is done by simply setting the value of \c e  
    /// to be false in the corresponding edge-map.
    void hide(const UEdge& e) const { uedge_filter_map->set(e, false); }

    ///\e

    /// The value of \c n is set to be true in the node-map which stores 
    /// hide information. If \c n was hidden previuosly, then it is shown 
    /// again
     void unHide(const Node& n) const { node_filter_map->set(n, true); }

    ///\e

    /// The value of \c e is set to be true in the edge-map which stores 
    /// hide information. If \c e was hidden previuosly, then it is shown 
    /// again
    void unHide(const UEdge& e) const { uedge_filter_map->set(e, true); }

    /// Returns true if \c n is hidden.
    
    ///\e
    ///
    bool hidden(const Node& n) const { return !(*node_filter_map)[n]; }

    /// Returns true if \c n is hidden.
    
    ///\e
    ///
    bool hidden(const UEdge& e) const { return !(*uedge_filter_map)[e]; }

    typedef False NodeNumTag;
    typedef False EdgeNumTag;
  };

  template <typename _UGraph, typename NodeFilterMap, typename UEdgeFilterMap>
  class SubUGraphAdaptorBase<_UGraph, NodeFilterMap, UEdgeFilterMap, false> 
    : public UGraphAdaptorBase<_UGraph> {
  public:
    typedef _UGraph Graph;
    typedef UGraphAdaptorBase<_UGraph> Parent;
  protected:
    NodeFilterMap* node_filter_map;
    UEdgeFilterMap* uedge_filter_map;
    SubUGraphAdaptorBase() : Parent(), 
                            node_filter_map(0), uedge_filter_map(0) { }

    void setNodeFilterMap(NodeFilterMap& _node_filter_map) {
      node_filter_map=&_node_filter_map;
    }
    void setUEdgeFilterMap(UEdgeFilterMap& _uedge_filter_map) {
      uedge_filter_map=&_uedge_filter_map;
    }

  public:

    typedef typename Parent::Node Node;
    typedef typename Parent::Edge Edge;
    typedef typename Parent::UEdge UEdge;

    void first(Node& i) const { 
      Parent::first(i); 
      while (i!=INVALID && !(*node_filter_map)[i]) Parent::next(i); 
    }

    void first(Edge& i) const { 
      Parent::first(i); 
      while (i!=INVALID && !(*uedge_filter_map)[i]) Parent::next(i); 
    }

    void first(UEdge& i) const { 
      Parent::first(i); 
      while (i!=INVALID && !(*uedge_filter_map)[i]) Parent::next(i); 
    }

    void firstIn(Edge& i, const Node& n) const { 
      Parent::firstIn(i, n); 
      while (i!=INVALID && !(*uedge_filter_map)[i]) Parent::nextIn(i); 
    }

    void firstOut(Edge& i, const Node& n) const { 
      Parent::firstOut(i, n); 
      while (i!=INVALID && !(*uedge_filter_map)[i]) Parent::nextOut(i); 
    }

    void firstInc(UEdge& i, bool& d, const Node& n) const { 
      Parent::firstInc(i, d, n); 
      while (i!=INVALID && !(*uedge_filter_map)[i]) Parent::nextInc(i, d); 
    }

    void next(Node& i) const { 
      Parent::next(i); 
      while (i!=INVALID && !(*node_filter_map)[i]) Parent::next(i); 
    }
    void next(Edge& i) const { 
      Parent::next(i); 
      while (i!=INVALID && !(*uedge_filter_map)[i]) Parent::next(i); 
    }
    void next(UEdge& i) const { 
      Parent::next(i); 
      while (i!=INVALID && !(*uedge_filter_map)[i]) Parent::next(i); 
    }
    void nextIn(Edge& i) const { 
      Parent::nextIn(i); 
      while (i!=INVALID && !(*uedge_filter_map)[i]) Parent::nextIn(i); 
    }

    void nextOut(Edge& i) const { 
      Parent::nextOut(i); 
      while (i!=INVALID && !(*uedge_filter_map)[i]) Parent::nextOut(i); 
    }
    void nextInc(UEdge& i, bool& d) const { 
      Parent::nextInc(i, d); 
      while (i!=INVALID && !(*uedge_filter_map)[i]) Parent::nextInc(i, d); 
    }

    ///\e

    /// This function hides \c n in the graph, i.e. the iteration 
    /// jumps over it. This is done by simply setting the value of \c n  
    /// to be false in the corresponding node-map.
    void hide(const Node& n) const { node_filter_map->set(n, false); }

    ///\e

    /// This function hides \c e in the graph, i.e. the iteration 
    /// jumps over it. This is done by simply setting the value of \c e  
    /// to be false in the corresponding edge-map.
    void hide(const UEdge& e) const { uedge_filter_map->set(e, false); }

    ///\e

    /// The value of \c n is set to be true in the node-map which stores 
    /// hide information. If \c n was hidden previuosly, then it is shown 
    /// again
     void unHide(const Node& n) const { node_filter_map->set(n, true); }

    ///\e

    /// The value of \c e is set to be true in the edge-map which stores 
    /// hide information. If \c e was hidden previuosly, then it is shown 
    /// again
    void unHide(const UEdge& e) const { uedge_filter_map->set(e, true); }

    /// Returns true if \c n is hidden.
    
    ///\e
    ///
    bool hidden(const Node& n) const { return !(*node_filter_map)[n]; }

    /// Returns true if \c n is hidden.
    
    ///\e
    ///
    bool hidden(const UEdge& e) const { return !(*uedge_filter_map)[e]; }

    typedef False NodeNumTag;
    typedef False EdgeNumTag;
  };

  /// \ingroup graph_adaptors
  ///
  /// \brief A graph adaptor for hiding nodes and edges from an undirected 
  /// graph.
  /// 
  /// \warning Graph adaptors are in even more experimental state than the
  /// other parts of the lib. Use them at you own risk.
  /// 
  /// SubUGraphAdaptor shows the undirected graph with filtered node-set and 
  /// edge-set. If the \c checked parameter is true then it filters the edgeset
  /// to do not get invalid edges without source or target.
  /// 
  /// If the \c checked template parameter is false then we have to note that 
  /// the node-iterator cares only the filter on the node-set, and the 
  /// edge-iterator cares only the filter on the edge-set.
  /// This way the edge-map
  /// should filter all edges which's source or target is filtered by the 
  /// node-filter.
  ///
  /// Note that \c n is of type \c SubGA::NodeIt, but it can be converted to
  /// \c Graph::Node that is why \c g.id(n) can be applied.
  /// 
  /// For examples see also the documentation of NodeSubUGraphAdaptor and 
  /// EdgeSubUGraphAdaptor.
  /// 
  /// \author Marton Makai

  template<typename _UGraph, typename NodeFilterMap, 
           typename UEdgeFilterMap, bool checked = true>
  class SubUGraphAdaptor : 
    public UGraphAdaptorExtender<
    SubUGraphAdaptorBase<_UGraph, NodeFilterMap, UEdgeFilterMap, checked> > {
  public:
    typedef _UGraph Graph;
    typedef UGraphAdaptorExtender<
      SubUGraphAdaptorBase<_UGraph, NodeFilterMap, UEdgeFilterMap> > Parent;
  protected:
    SubUGraphAdaptor() { }
  public:
    SubUGraphAdaptor(Graph& _graph, NodeFilterMap& _node_filter_map, 
                    UEdgeFilterMap& _uedge_filter_map) { 
      setGraph(_graph);
      setNodeFilterMap(_node_filter_map);
      setUEdgeFilterMap(_uedge_filter_map);
    }
  };

  /// \ingroup graph_adaptors
  ///
  /// \brief An adaptor for hiding nodes from an undorected graph.
  ///
  /// \warning Graph adaptors are in even more experimental state
  /// than the other
  /// parts of the lib. Use them at you own risk.
  ///
  /// An adaptor for hiding nodes from an undirected graph.
  /// This adaptor specializes SubUGraphAdaptor in the way that only
  /// the node-set 
  /// can be filtered. In usual case the checked parameter is true, we get the
  /// induced subgraph. But if the checked parameter is false then we can only
  /// filter only isolated nodes.
  /// \author Marton Makai
  template<typename _UGraph, typename NodeFilterMap, bool checked = true>
  class NodeSubUGraphAdaptor : 
    public SubUGraphAdaptor<_UGraph, NodeFilterMap, 
                            ConstMap<typename _UGraph::UEdge, bool>, checked> {
  public:
    typedef SubUGraphAdaptor<_UGraph, NodeFilterMap, 
                             ConstMap<typename _UGraph::UEdge, bool> > Parent;
    typedef _UGraph Graph;
  protected:
    ConstMap<typename _UGraph::Edge, bool> const_true_map;
  public:
    NodeSubUGraphAdaptor(Graph& _graph, NodeFilterMap& _node_filter_map) : 
      Parent(), const_true_map(true) { 
      Parent::setGraph(_graph);
      Parent::setNodeFilterMap(_node_filter_map);
      Parent::setUEdgeFilterMap(const_true_map);
    }
  };

  template<typename UGraph, typename NodeFilterMap>
  NodeSubUGraphAdaptor<const UGraph, NodeFilterMap>
  nodeSubUGraphAdaptor(const UGraph& graph, NodeFilterMap& nfm) {
    return NodeSubUGraphAdaptor<const UGraph, NodeFilterMap>(graph, nfm);
  }

  template<typename UGraph, typename NodeFilterMap>
  NodeSubUGraphAdaptor<const UGraph, const NodeFilterMap>
  nodeSubUGraphAdaptor(const UGraph& graph, const NodeFilterMap& nfm) {
    return NodeSubUGraphAdaptor<const UGraph, const NodeFilterMap>(graph, nfm);
  }


  /// \brief An adaptor for hiding undirected edges from an undirected graph.
  ///
  /// \warning Graph adaptors are in even more experimental state
  /// than the other parts of the lib. Use them at you own risk.
  ///
  /// An adaptor for hiding undirected edges from an undirected graph.
  /// This adaptor specializes SubUGraphAdaptor in the way that
  /// only the edge-set 
  /// can be filtered.
  ///
  ///\author Marton Makai
  template<typename _UGraph, typename UEdgeFilterMap>
  class EdgeSubUGraphAdaptor : 
    public SubUGraphAdaptor<_UGraph, ConstMap<typename _UGraph::Node,bool>, 
                            UEdgeFilterMap, false> {
  public:
    typedef SubUGraphAdaptor<_UGraph, ConstMap<typename _UGraph::Node,bool>, 
                             UEdgeFilterMap, false> Parent;
    typedef _UGraph Graph;
  protected:
    ConstMap<typename Graph::Node, bool> const_true_map;
  public:
    EdgeSubUGraphAdaptor(Graph& _graph, UEdgeFilterMap& _uedge_filter_map) : 
      Parent(), const_true_map(true) { 
      Parent::setGraph(_graph);
      Parent::setNodeFilterMap(const_true_map);
      Parent::setUEdgeFilterMap(_uedge_filter_map);
    }
  };

  template<typename UGraph, typename EdgeFilterMap>
  EdgeSubUGraphAdaptor<const UGraph, EdgeFilterMap>
  edgeSubUGraphAdaptor(const UGraph& graph, EdgeFilterMap& efm) {
    return EdgeSubUGraphAdaptor<const UGraph, EdgeFilterMap>(graph, efm);
  }

  template<typename UGraph, typename EdgeFilterMap>
  EdgeSubUGraphAdaptor<const UGraph, const EdgeFilterMap>
  edgeSubUGraphAdaptor(const UGraph& graph, const EdgeFilterMap& efm) {
    return EdgeSubUGraphAdaptor<const UGraph, const EdgeFilterMap>(graph, efm);
  }

  template <typename _UGraph, typename _DirectionMap>
  class DirectUGraphAdaptorBase {
  public:
    
    typedef _UGraph Graph;
    typedef _DirectionMap DirectionMap;

    typedef typename _UGraph::Node Node;
    typedef typename _UGraph::UEdge Edge;
   
    void first(Node& i) const { graph->first(i); }
    void first(Edge& i) const { graph->first(i); }
    void firstIn(Edge& i, const Node& n) const {
      bool d;
      graph->firstInc(i, d, n);
      while (i != INVALID && d == (*direction)[i]) graph->nextInc(i, d);
    }
    void firstOut(Edge& i, const Node& n ) const { 
      bool d;
      graph->firstInc(i, d, n);
      while (i != INVALID && d != (*direction)[i]) graph->nextInc(i, d);
    }

    void next(Node& i) const { graph->next(i); }
    void next(Edge& i) const { graph->next(i); }
    void nextIn(Edge& i) const {
      bool d = !(*direction)[i];
      graph->nextInc(i, d);
      while (i != INVALID && d == (*direction)[i]) graph->nextInc(i, d);
    }
    void nextOut(Edge& i) const {
      bool d = (*direction)[i];
      graph->nextInc(i, d);
      while (i != INVALID && d != (*direction)[i]) graph->nextInc(i, d);
    }

    Node source(const Edge& e) const { 
      return (*direction)[e] ? graph->source(e) : graph->target(e); 
    }
    Node target(const Edge& e) const { 
      return (*direction)[e] ? graph->target(e) : graph->source(e); 
    }

    typedef NodeNumTagIndicator<Graph> NodeNumTag;
    int nodeNum() const { return graph->nodeNum(); }
    
    typedef EdgeNumTagIndicator<Graph> EdgeNumTag;
    int edgeNum() const { return graph->uEdgeNum(); }

    typedef FindEdgeTagIndicator<Graph> FindEdgeTag;
    Edge findEdge(const Node& source, const Node& target, 
                  const Edge& prev = INVALID) {
      Edge edge = prev;
      bool d = edge == INVALID ? true : (*direction)[edge];
      if (d) {
        edge = graph->findUEdge(source, target, edge);
        while (edge != INVALID && !(*direction)[edge]) {
          graph->findUEdge(source, target, edge);
        }
        if (edge != INVALID) return edge;
      }
      graph->findUEdge(target, source, edge);
      while (edge != INVALID && (*direction)[edge]) {
        graph->findUEdge(source, target, edge);
      }
      return edge;
    }
  
    Node addNode() const { 
      return Node(graph->addNode()); 
    }

    Edge addEdge(const Node& source, const Node& target) const {
      Edge edge = graph->addEdge(source, target);
      (*direction)[edge] = graph->source(edge) == source;
      return edge; 
    }

    void erase(const Node& i) const { graph->erase(i); }
    void erase(const Edge& i) const { graph->erase(i); }
  
    void clear() const { graph->clear(); }
    
    int id(const Node& v) const { return graph->id(v); }
    int id(const Edge& e) const { return graph->id(e); }

    void reverseEdge(const Edge& edge) {
      direction->set(edge, !(*direction)[edge]);
    }

    template <typename _Value>
    class NodeMap : public _UGraph::template NodeMap<_Value> {
    public:
      typedef typename _UGraph::template NodeMap<_Value> Parent;
      explicit NodeMap(const DirectUGraphAdaptorBase& ga) 
        : Parent(*ga.graph) { }
      NodeMap(const DirectUGraphAdaptorBase& ga, const _Value& value)
        : Parent(*ga.graph, value) { }
    };

    template <typename _Value>
    class EdgeMap : public _UGraph::template UEdgeMap<_Value> {
    public:
      typedef typename _UGraph::template EdgeMap<_Value> Parent;
      explicit EdgeMap(const DirectUGraphAdaptorBase& ga) 
        : Parent(*ga.graph) { }
      EdgeMap(const DirectUGraphAdaptorBase& ga, const _Value& value)
        : Parent(*ga.graph, value) { }
    };

    

  protected:
    Graph* graph;
    DirectionMap* direction;

    void setDirectionMap(DirectionMap& _direction) {
      direction = &_direction;
    }

    void setGraph(Graph& _graph) {
      graph = &_graph;
    }

  };


  template<typename _Graph, typename DirectionMap> 
  class DirectUGraphAdaptor : 
    public GraphAdaptorExtender<
    DirectUGraphAdaptorBase<_Graph, DirectionMap> > {
  public:
    typedef _Graph Graph;
    typedef GraphAdaptorExtender<
      DirectUGraphAdaptorBase<_Graph, DirectionMap> > Parent;
  protected:
    DirectUGraphAdaptor() { }
  public:
    DirectUGraphAdaptor(_Graph& _graph, DirectionMap& _direction_map) { 
      setGraph(_graph);
      setDirectionMap(_direction_map);
    }
  };

  template<typename UGraph, typename DirectionMap>
  DirectUGraphAdaptor<const UGraph, DirectionMap>
  directUGraphAdaptor(const UGraph& graph, DirectionMap& dm) {
    return DirectUGraphAdaptor<const UGraph, DirectionMap>(graph, dm);
  }

  template<typename UGraph, typename DirectionMap>
  DirectUGraphAdaptor<const UGraph, const DirectionMap>
  directUGraphAdaptor(const UGraph& graph, const DirectionMap& dm) {
    return DirectUGraphAdaptor<const UGraph, const DirectionMap>(graph, dm);
  }

}

#endif