diff --git a/lemon/dfs.h b/lemon/dfs.h
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+/* -*- 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_DFS_H
+#define LEMON_DFS_H
+
+///\ingroup search
+///\file
+///\brief Dfs algorithm.
+
+#include <lemon/list_graph.h>
+#include <lemon/graph_utils.h>
+#include <lemon/bits/path_dump.h>
+#include <lemon/bits/invalid.h>
+#include <lemon/error.h>
+#include <lemon/maps.h>
+
+#include <lemon/concept_check.h>
+
+namespace lemon {
+
+  
+  ///Default traits class of Dfs class.
+
+  ///Default traits class of Dfs class.
+  ///\param GR Digraph type.
+  template<class GR>
+  struct DfsDefaultTraits
+  {
+    ///The digraph type the algorithm runs on. 
+    typedef GR Digraph;
+    ///\brief The type of the map that stores the last
+    ///arcs of the %DFS paths.
+    /// 
+    ///The type of the map that stores the last
+    ///arcs of the %DFS paths.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
+    ///
+    typedef typename Digraph::template NodeMap<typename GR::Arc> PredMap;
+    ///Instantiates a PredMap.
+ 
+    ///This function instantiates a \ref PredMap. 
+    ///\param G is the digraph, to which we would like to define the PredMap.
+    ///\todo The digraph alone may be insufficient to initialize
+    static PredMap *createPredMap(const GR &G) 
+    {
+      return new PredMap(G);
+    }
+
+    ///The type of the map that indicates which nodes are processed.
+ 
+    ///The type of the map that indicates which nodes are processed.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
+    ///\todo named parameter to set this type, function to read and write.
+    typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
+    ///Instantiates a ProcessedMap.
+ 
+    ///This function instantiates a \ref ProcessedMap. 
+    ///\param g is the digraph, to which
+    ///we would like to define the \ref ProcessedMap
+#ifdef DOXYGEN
+    static ProcessedMap *createProcessedMap(const GR &g)
+#else
+    static ProcessedMap *createProcessedMap(const GR &)
+#endif
+    {
+      return new ProcessedMap();
+    }
+    ///The type of the map that indicates which nodes are reached.
+ 
+    ///The type of the map that indicates which nodes are reached.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
+    ///\todo named parameter to set this type, function to read and write.
+    typedef typename Digraph::template NodeMap<bool> ReachedMap;
+    ///Instantiates a ReachedMap.
+ 
+    ///This function instantiates a \ref ReachedMap. 
+    ///\param G is the digraph, to which
+    ///we would like to define the \ref ReachedMap.
+    static ReachedMap *createReachedMap(const GR &G)
+    {
+      return new ReachedMap(G);
+    }
+    ///The type of the map that stores the dists of the nodes.
+ 
+    ///The type of the map that stores the dists of the nodes.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
+    ///
+    typedef typename Digraph::template NodeMap<int> DistMap;
+    ///Instantiates a DistMap.
+ 
+    ///This function instantiates a \ref DistMap. 
+    ///\param G is the digraph, to which we would like to define the \ref DistMap
+    static DistMap *createDistMap(const GR &G)
+    {
+      return new DistMap(G);
+    }
+  };
+  
+  ///%DFS algorithm class.
+  
+  ///\ingroup search
+  ///This class provides an efficient implementation of the %DFS algorithm.
+  ///
+  ///\param GR The digraph type the algorithm runs on. The default value is
+  ///\ref ListDigraph. The value of GR is not used directly by Dfs, it
+  ///is only passed to \ref DfsDefaultTraits.
+  ///\param TR Traits class to set various data types used by the algorithm.
+  ///The default traits class is
+  ///\ref DfsDefaultTraits "DfsDefaultTraits<GR>".
+  ///See \ref DfsDefaultTraits for the documentation of
+  ///a Dfs traits class.
+  ///
+  ///\author Jacint Szabo and Alpar Juttner
+#ifdef DOXYGEN
+  template <typename GR,
+	    typename TR>
+#else
+  template <typename GR=ListDigraph,
+	    typename TR=DfsDefaultTraits<GR> >
+#endif
+  class Dfs {
+  public:
+    /**
+     * \brief \ref Exception for uninitialized parameters.
+     *
+     * This error represents problems in the initialization
+     * of the parameters of the algorithms.
+     */
+    class UninitializedParameter : public lemon::UninitializedParameter {
+    public:
+      virtual const char* what() const throw() {
+	return "lemon::Dfs::UninitializedParameter";
+      }
+    };
+
+    typedef TR Traits;
+    ///The type of the underlying digraph.
+    typedef typename TR::Digraph Digraph;
+    ///\e
+    typedef typename Digraph::Node Node;
+    ///\e
+    typedef typename Digraph::NodeIt NodeIt;
+    ///\e
+    typedef typename Digraph::Arc Arc;
+    ///\e
+    typedef typename Digraph::OutArcIt OutArcIt;
+    
+    ///\brief The type of the map that stores the last
+    ///arcs of the %DFS paths.
+    typedef typename TR::PredMap PredMap;
+    ///The type of the map indicating which nodes are reached.
+    typedef typename TR::ReachedMap ReachedMap;
+    ///The type of the map indicating which nodes are processed.
+    typedef typename TR::ProcessedMap ProcessedMap;
+    ///The type of the map that stores the dists of the nodes.
+    typedef typename TR::DistMap DistMap;
+  private:
+    /// Pointer to the underlying digraph.
+    const Digraph *G;
+    ///Pointer to the map of predecessors arcs.
+    PredMap *_pred;
+    ///Indicates if \ref _pred is locally allocated (\c true) or not.
+    bool local_pred;
+    ///Pointer to the map of distances.
+    DistMap *_dist;
+    ///Indicates if \ref _dist is locally allocated (\c true) or not.
+    bool local_dist;
+    ///Pointer to the map of reached status of the nodes.
+    ReachedMap *_reached;
+    ///Indicates if \ref _reached is locally allocated (\c true) or not.
+    bool local_reached;
+    ///Pointer to the map of processed status of the nodes.
+    ProcessedMap *_processed;
+    ///Indicates if \ref _processed is locally allocated (\c true) or not.
+    bool local_processed;
+
+    std::vector<typename Digraph::OutArcIt> _stack;
+    int _stack_head;
+
+    ///Creates the maps if necessary.
+    
+    ///\todo Better memory allocation (instead of new).
+    void create_maps() 
+    {
+      if(!_pred) {
+	local_pred = true;
+	_pred = Traits::createPredMap(*G);
+      }
+      if(!_dist) {
+	local_dist = true;
+	_dist = Traits::createDistMap(*G);
+      }
+      if(!_reached) {
+	local_reached = true;
+	_reached = Traits::createReachedMap(*G);
+      }
+      if(!_processed) {
+	local_processed = true;
+	_processed = Traits::createProcessedMap(*G);
+      }
+    }
+
+  protected:
+
+    Dfs() {}
+    
+  public:
+
+    typedef Dfs Create;
+
+    ///\name Named template parameters
+
+    ///@{
+
+    template <class T>
+    struct DefPredMapTraits : public Traits {
+      typedef T PredMap;
+      static PredMap *createPredMap(const Digraph &G) 
+      {
+	throw UninitializedParameter();
+      }
+    };
+    ///\brief \ref named-templ-param "Named parameter" for setting
+    ///PredMap type
+    ///
+    ///\ref named-templ-param "Named parameter" for setting PredMap type
+    ///
+    template <class T>
+    struct DefPredMap : public Dfs<Digraph, DefPredMapTraits<T> > {
+      typedef Dfs<Digraph, DefPredMapTraits<T> > Create;
+    };
+    
+    
+    template <class T>
+    struct DefDistMapTraits : public Traits {
+      typedef T DistMap;
+      static DistMap *createDistMap(const Digraph &) 
+      {
+	throw UninitializedParameter();
+      }
+    };
+    ///\brief \ref named-templ-param "Named parameter" for setting
+    ///DistMap type
+    ///
+    ///\ref named-templ-param "Named parameter" for setting DistMap
+    ///type
+    template <class T>
+    struct DefDistMap {
+      typedef Dfs<Digraph, DefDistMapTraits<T> > Create;
+    };
+    
+    template <class T>
+    struct DefReachedMapTraits : public Traits {
+      typedef T ReachedMap;
+      static ReachedMap *createReachedMap(const Digraph &) 
+      {
+	throw UninitializedParameter();
+      }
+    };
+    ///\brief \ref named-templ-param "Named parameter" for setting
+    ///ReachedMap type
+    ///
+    ///\ref named-templ-param "Named parameter" for setting ReachedMap type
+    ///
+    template <class T>
+    struct DefReachedMap : public Dfs< Digraph, DefReachedMapTraits<T> > {
+      typedef Dfs< Digraph, DefReachedMapTraits<T> > Create;
+    };
+
+    template <class T>
+    struct DefProcessedMapTraits : public Traits {
+      typedef T ProcessedMap;
+      static ProcessedMap *createProcessedMap(const Digraph &) 
+      {
+	throw UninitializedParameter();
+      }
+    };
+    ///\brief \ref named-templ-param "Named parameter" for setting
+    ///ProcessedMap type
+    ///
+    ///\ref named-templ-param "Named parameter" for setting ProcessedMap type
+    ///
+    template <class T>
+    struct DefProcessedMap : public Dfs< Digraph, DefProcessedMapTraits<T> > { 
+      typedef Dfs< Digraph, DefProcessedMapTraits<T> > Create;
+    };
+    
+    struct DefDigraphProcessedMapTraits : public Traits {
+      typedef typename Digraph::template NodeMap<bool> ProcessedMap;
+      static ProcessedMap *createProcessedMap(const Digraph &G) 
+      {
+	return new ProcessedMap(G);
+      }
+    };
+    ///\brief \ref named-templ-param "Named parameter"
+    ///for setting the ProcessedMap type to be Digraph::NodeMap<bool>.
+    ///
+    ///\ref named-templ-param "Named parameter"
+    ///for setting the ProcessedMap type to be Digraph::NodeMap<bool>.
+    ///If you don't set it explicitely, it will be automatically allocated.
+    template <class T>
+    class DefProcessedMapToBeDefaultMap :
+      public Dfs< Digraph, DefDigraphProcessedMapTraits> { 
+      typedef Dfs< Digraph, DefDigraphProcessedMapTraits> Create;
+    };
+    
+    ///@}
+
+  public:      
+    
+    ///Constructor.
+    
+    ///\param _G the digraph the algorithm will run on.
+    ///
+    Dfs(const Digraph& _G) :
+      G(&_G),
+      _pred(NULL), local_pred(false),
+      _dist(NULL), local_dist(false),
+      _reached(NULL), local_reached(false),
+      _processed(NULL), local_processed(false)
+    { }
+    
+    ///Destructor.
+    ~Dfs() 
+    {
+      if(local_pred) delete _pred;
+      if(local_dist) delete _dist;
+      if(local_reached) delete _reached;
+      if(local_processed) delete _processed;
+    }
+
+    ///Sets the map storing the predecessor arcs.
+
+    ///Sets the map storing the predecessor arcs.
+    ///If you don't use this function before calling \ref run(),
+    ///it will allocate one. The destuctor deallocates this
+    ///automatically allocated map, of course.
+    ///\return <tt> (*this) </tt>
+    Dfs &predMap(PredMap &m) 
+    {
+      if(local_pred) {
+	delete _pred;
+	local_pred=false;
+      }
+      _pred = &m;
+      return *this;
+    }
+
+    ///Sets the map storing the distances calculated by the algorithm.
+
+    ///Sets the map storing the distances calculated by the algorithm.
+    ///If you don't use this function before calling \ref run(),
+    ///it will allocate one. The destuctor deallocates this
+    ///automatically allocated map, of course.
+    ///\return <tt> (*this) </tt>
+    Dfs &distMap(DistMap &m) 
+    {
+      if(local_dist) {
+	delete _dist;
+	local_dist=false;
+      }
+      _dist = &m;
+      return *this;
+    }
+
+    ///Sets the map indicating if a node is reached.
+
+    ///Sets the map indicating if a node is reached.
+    ///If you don't use this function before calling \ref run(),
+    ///it will allocate one. The destuctor deallocates this
+    ///automatically allocated map, of course.
+    ///\return <tt> (*this) </tt>
+    Dfs &reachedMap(ReachedMap &m) 
+    {
+      if(local_reached) {
+	delete _reached;
+	local_reached=false;
+      }
+      _reached = &m;
+      return *this;
+    }
+
+    ///Sets the map indicating if a node is processed.
+
+    ///Sets the map indicating if a node is processed.
+    ///If you don't use this function before calling \ref run(),
+    ///it will allocate one. The destuctor deallocates this
+    ///automatically allocated map, of course.
+    ///\return <tt> (*this) </tt>
+    Dfs &processedMap(ProcessedMap &m) 
+    {
+      if(local_processed) {
+	delete _processed;
+	local_processed=false;
+      }
+      _processed = &m;
+      return *this;
+    }
+
+  public:
+    ///\name Execution control
+    ///The simplest way to execute the algorithm is to use
+    ///one of the member functions called \c run(...).
+    ///\n
+    ///If you need more control on the execution,
+    ///first you must call \ref init(), then you can add a source node
+    ///with \ref addSource().
+    ///Finally \ref start() will perform the actual path
+    ///computation.
+
+    ///@{
+
+    ///Initializes the internal data structures.
+
+    ///Initializes the internal data structures.
+    ///
+    void init()
+    {
+      create_maps();
+      _stack.resize(countNodes(*G));
+      _stack_head=-1;
+      for ( NodeIt u(*G) ; u!=INVALID ; ++u ) {
+	_pred->set(u,INVALID);
+	// _predNode->set(u,INVALID);
+	_reached->set(u,false);
+	_processed->set(u,false);
+      }
+    }
+    
+    ///Adds a new source node.
+
+    ///Adds a new source node to the set of nodes to be processed.
+    ///
+    ///\warning dists are wrong (or at least strange)
+    ///in case of multiple sources.
+    void addSource(Node s)
+    {
+      if(!(*_reached)[s])
+	{
+	  _reached->set(s,true);
+	  _pred->set(s,INVALID);
+	  OutArcIt e(*G,s);
+	  if(e!=INVALID) {
+	    _stack[++_stack_head]=e;
+	    _dist->set(s,_stack_head);
+	  }
+	  else {
+	    _processed->set(s,true);
+	    _dist->set(s,0);
+	  }
+	}
+    }
+    
+    ///Processes the next arc.
+
+    ///Processes the next arc.
+    ///
+    ///\return The processed arc.
+    ///
+    ///\pre The stack must not be empty!
+    Arc processNextArc()
+    { 
+      Node m;
+      Arc e=_stack[_stack_head];
+      if(!(*_reached)[m=G->target(e)]) {
+	_pred->set(m,e);
+	_reached->set(m,true);
+	++_stack_head;
+	_stack[_stack_head] = OutArcIt(*G, m);
+	_dist->set(m,_stack_head);
+      }
+      else {
+	m=G->source(e);
+	++_stack[_stack_head];
+      }
+      while(_stack_head>=0 && _stack[_stack_head]==INVALID) {
+	_processed->set(m,true);
+	--_stack_head;
+	if(_stack_head>=0) {
+	  m=G->source(_stack[_stack_head]);
+	  ++_stack[_stack_head];
+	}
+      }
+      return e;
+    }
+    ///Next arc to be processed.
+
+    ///Next arc to be processed.
+    ///
+    ///\return The next arc to be processed or INVALID if the stack is
+    /// empty.
+    OutArcIt nextArc()
+    { 
+      return _stack_head>=0?_stack[_stack_head]:INVALID;
+    }
+
+    ///\brief Returns \c false if there are nodes
+    ///to be processed in the queue
+    ///
+    ///Returns \c false if there are nodes
+    ///to be processed in the queue
+    bool emptyQueue() { return _stack_head<0; }
+    ///Returns the number of the nodes to be processed.
+    
+    ///Returns the number of the nodes to be processed in the queue.
+    int queueSize() { return _stack_head+1; }
+    
+    ///Executes the algorithm.
+
+    ///Executes the algorithm.
+    ///
+    ///\pre init() must be called and at least one node should be added
+    ///with addSource() before using this function.
+    ///
+    ///This method runs the %DFS algorithm from the root node(s)
+    ///in order to
+    ///compute the
+    ///%DFS path to each node. The algorithm computes
+    ///- The %DFS tree.
+    ///- The distance of each node from the root(s) in the %DFS tree.
+    ///
+    void start()
+    {
+      while ( !emptyQueue() ) processNextArc();
+    }
+    
+    ///Executes the algorithm until \c dest is reached.
+
+    ///Executes the algorithm until \c dest is reached.
+    ///
+    ///\pre init() must be called and at least one node should be added
+    ///with addSource() before using this function.
+    ///
+    ///This method runs the %DFS algorithm from the root node(s)
+    ///in order to
+    ///compute the
+    ///%DFS path to \c dest. The algorithm computes
+    ///- The %DFS path to \c  dest.
+    ///- The distance of \c dest from the root(s) in the %DFS tree.
+    ///
+    void start(Node dest)
+    {
+      while ( !emptyQueue() && G->target(_stack[_stack_head])!=dest ) 
+	processNextArc();
+    }
+    
+    ///Executes the algorithm until a condition is met.
+
+    ///Executes the algorithm until a condition is met.
+    ///
+    ///\pre init() must be called and at least one node should be added
+    ///with addSource() before using this function.
+    ///
+    ///\param em must be a bool (or convertible) arc map. The algorithm
+    ///will stop when it reaches an arc \c e with <tt>em[e]</tt> true.
+    ///
+    ///\return The reached arc \c e with <tt>em[e]</tt> true or
+    ///\c INVALID if no such arc was found.
+    ///
+    ///\warning Contrary to \ref Bfs and \ref Dijkstra, \c em is an arc map,
+    ///not a node map.
+    template<class EM>
+    Arc start(const EM &em)
+    {
+      while ( !emptyQueue() && !em[_stack[_stack_head]] )
+        processNextArc();
+      return emptyQueue() ? INVALID : _stack[_stack_head];
+    }
+
+    ///Runs %DFS algorithm to visit all nodes in the digraph.
+    
+    ///This method runs the %DFS algorithm in order to
+    ///compute the
+    ///%DFS path to each node. The algorithm computes
+    ///- The %DFS tree.
+    ///- The distance of each node from the root in the %DFS tree.
+    ///
+    ///\note d.run() is just a shortcut of the following code.
+    ///\code
+    ///  d.init();
+    ///  for (NodeIt it(digraph); it != INVALID; ++it) {
+    ///    if (!d.reached(it)) {
+    ///      d.addSource(it);
+    ///      d.start();
+    ///    }
+    ///  }
+    ///\endcode
+    void run() {
+      init();
+      for (NodeIt it(*G); it != INVALID; ++it) {
+        if (!reached(it)) {
+          addSource(it);
+          start();
+        }
+      }
+    }
+
+    ///Runs %DFS algorithm from node \c s.
+    
+    ///This method runs the %DFS algorithm from a root node \c s
+    ///in order to
+    ///compute the
+    ///%DFS path to each node. The algorithm computes
+    ///- The %DFS tree.
+    ///- The distance of each node from the root in the %DFS tree.
+    ///
+    ///\note d.run(s) is just a shortcut of the following code.
+    ///\code
+    ///  d.init();
+    ///  d.addSource(s);
+    ///  d.start();
+    ///\endcode
+    void run(Node s) {
+      init();
+      addSource(s);
+      start();
+    }
+    
+    ///Finds the %DFS path between \c s and \c t.
+    
+    ///Finds the %DFS path between \c s and \c t.
+    ///
+    ///\return The length of the %DFS s---t path if there exists one,
+    ///0 otherwise.
+    ///\note Apart from the return value, d.run(s,t) is
+    ///just a shortcut of the following code.
+    ///\code
+    ///  d.init();
+    ///  d.addSource(s);
+    ///  d.start(t);
+    ///\endcode
+    int run(Node s,Node t) {
+      init();
+      addSource(s);
+      start(t);
+      return reached(t)?_stack_head+1:0;
+    }
+    
+    ///@}
+
+    ///\name Query Functions
+    ///The result of the %DFS algorithm can be obtained using these
+    ///functions.\n
+    ///Before the use of these functions,
+    ///either run() or start() must be called.
+    
+    ///@{
+
+    typedef PredMapPath<Digraph, PredMap> Path;
+
+    ///Gives back the shortest path.
+    
+    ///Gives back the shortest path.
+    ///\pre The \c t should be reachable from the source.
+    Path path(Node t) 
+    {
+      return Path(*G, *_pred, t);
+    }
+
+    ///The distance of a node from the root(s).
+
+    ///Returns the distance of a node from the root(s).
+    ///\pre \ref run() must be called before using this function.
+    ///\warning If node \c v is unreachable from the root(s) then the return 
+    ///value of this funcion is undefined.
+    int dist(Node v) const { return (*_dist)[v]; }
+
+    ///Returns the 'previous arc' of the %DFS tree.
+
+    ///For a node \c v it returns the 'previous arc'
+    ///of the %DFS path,
+    ///i.e. it returns the last arc of a %DFS path from the root(s) to \c
+    ///v. It is \ref INVALID
+    ///if \c v is unreachable from the root(s) or \c v is a root. The
+    ///%DFS tree used here is equal to the %DFS tree used in
+    ///\ref predNode().
+    ///\pre Either \ref run() or \ref start() must be called before using
+    ///this function.
+    Arc predArc(Node v) const { return (*_pred)[v];}
+
+    ///Returns the 'previous node' of the %DFS tree.
+
+    ///For a node \c v it returns the 'previous node'
+    ///of the %DFS tree,
+    ///i.e. it returns the last but one node from a %DFS path from the
+    ///root(s) to \c v.
+    ///It is INVALID if \c v is unreachable from the root(s) or
+    ///if \c v itself a root.
+    ///The %DFS tree used here is equal to the %DFS
+    ///tree used in \ref predArc().
+    ///\pre Either \ref run() or \ref start() must be called before
+    ///using this function.
+    Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
+				  G->source((*_pred)[v]); }
+    
+    ///Returns a reference to the NodeMap of distances.
+
+    ///Returns a reference to the NodeMap of distances.
+    ///\pre Either \ref run() or \ref init() must
+    ///be called before using this function.
+    const DistMap &distMap() const { return *_dist;}
+ 
+    ///Returns a reference to the %DFS arc-tree map.
+
+    ///Returns a reference to the NodeMap of the arcs of the
+    ///%DFS tree.
+    ///\pre Either \ref run() or \ref init()
+    ///must be called before using this function.
+    const PredMap &predMap() const { return *_pred;}
+ 
+    ///Checks if a node is reachable from the root.
+
+    ///Returns \c true if \c v is reachable from the root(s).
+    ///\warning The source nodes are inditated as unreachable.
+    ///\pre Either \ref run() or \ref start()
+    ///must be called before using this function.
+    ///
+    bool reached(Node v) { return (*_reached)[v]; }
+    
+    ///@}
+  };
+
+  ///Default traits class of Dfs function.
+
+  ///Default traits class of Dfs function.
+  ///\param GR Digraph type.
+  template<class GR>
+  struct DfsWizardDefaultTraits
+  {
+    ///The digraph type the algorithm runs on. 
+    typedef GR Digraph;
+    ///\brief The type of the map that stores the last
+    ///arcs of the %DFS paths.
+    /// 
+    ///The type of the map that stores the last
+    ///arcs of the %DFS paths.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
+    ///
+    typedef NullMap<typename Digraph::Node,typename GR::Arc> PredMap;
+    ///Instantiates a PredMap.
+ 
+    ///This function instantiates a \ref PredMap. 
+    ///\param g is the digraph, to which we would like to define the PredMap.
+    ///\todo The digraph alone may be insufficient to initialize
+#ifdef DOXYGEN
+    static PredMap *createPredMap(const GR &g) 
+#else
+    static PredMap *createPredMap(const GR &) 
+#endif
+    {
+      return new PredMap();
+    }
+
+    ///The type of the map that indicates which nodes are processed.
+ 
+    ///The type of the map that indicates which nodes are processed.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
+    ///\todo named parameter to set this type, function to read and write.
+    typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
+    ///Instantiates a ProcessedMap.
+ 
+    ///This function instantiates a \ref ProcessedMap. 
+    ///\param g is the digraph, to which
+    ///we would like to define the \ref ProcessedMap
+#ifdef DOXYGEN
+    static ProcessedMap *createProcessedMap(const GR &g)
+#else
+    static ProcessedMap *createProcessedMap(const GR &)
+#endif
+    {
+      return new ProcessedMap();
+    }
+    ///The type of the map that indicates which nodes are reached.
+ 
+    ///The type of the map that indicates which nodes are reached.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
+    ///\todo named parameter to set this type, function to read and write.
+    typedef typename Digraph::template NodeMap<bool> ReachedMap;
+    ///Instantiates a ReachedMap.
+ 
+    ///This function instantiates a \ref ReachedMap. 
+    ///\param G is the digraph, to which
+    ///we would like to define the \ref ReachedMap.
+    static ReachedMap *createReachedMap(const GR &G)
+    {
+      return new ReachedMap(G);
+    }
+    ///The type of the map that stores the dists of the nodes.
+ 
+    ///The type of the map that stores the dists of the nodes.
+    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
+    ///
+    typedef NullMap<typename Digraph::Node,int> DistMap;
+    ///Instantiates a DistMap.
+ 
+    ///This function instantiates a \ref DistMap. 
+    ///\param g is the digraph, to which we would like to define the \ref DistMap
+#ifdef DOXYGEN
+    static DistMap *createDistMap(const GR &g)
+#else
+    static DistMap *createDistMap(const GR &)
+#endif
+    {
+      return new DistMap();
+    }
+  };
+  
+  /// Default traits used by \ref DfsWizard
+
+  /// To make it easier to use Dfs algorithm
+  ///we have created a wizard class.
+  /// This \ref DfsWizard class needs default traits,
+  ///as well as the \ref Dfs class.
+  /// The \ref DfsWizardBase is a class to be the default traits of the
+  /// \ref DfsWizard class.
+  template<class GR>
+  class DfsWizardBase : public DfsWizardDefaultTraits<GR>
+  {
+
+    typedef DfsWizardDefaultTraits<GR> Base;
+  protected:
+    /// Type of the nodes in the digraph.
+    typedef typename Base::Digraph::Node Node;
+
+    /// Pointer to the underlying digraph.
+    void *_g;
+    ///Pointer to the map of reached nodes.
+    void *_reached;
+    ///Pointer to the map of processed nodes.
+    void *_processed;
+    ///Pointer to the map of predecessors arcs.
+    void *_pred;
+    ///Pointer to the map of distances.
+    void *_dist;
+    ///Pointer to the source node.
+    Node _source;
+    
+    public:
+    /// Constructor.
+    
+    /// This constructor does not require parameters, therefore it initiates
+    /// all of the attributes to default values (0, INVALID).
+    DfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0),
+			   _dist(0), _source(INVALID) {}
+
+    /// Constructor.
+    
+    /// This constructor requires some parameters,
+    /// listed in the parameters list.
+    /// Others are initiated to 0.
+    /// \param g is the initial value of  \ref _g
+    /// \param s is the initial value of  \ref _source
+    DfsWizardBase(const GR &g, Node s=INVALID) :
+      _g(reinterpret_cast<void*>(const_cast<GR*>(&g))), 
+      _reached(0), _processed(0), _pred(0), _dist(0), _source(s) {}
+
+  };
+  
+  /// A class to make the usage of the Dfs algorithm easier
+
+  /// This class is created to make it easier to use the Dfs algorithm.
+  /// It uses the functions and features of the plain \ref Dfs,
+  /// but it is much simpler to use it.
+  ///
+  /// Simplicity means that the way to change the types defined
+  /// in the traits class is based on functions that returns the new class
+  /// and not on templatable built-in classes.
+  /// When using the plain \ref Dfs
+  /// the new class with the modified type comes from
+  /// the original class by using the ::
+  /// operator. In the case of \ref DfsWizard only
+  /// a function have to be called and it will
+  /// return the needed class.
+  ///
+  /// It does not have own \ref run method. When its \ref run method is called
+  /// it initiates a plain \ref Dfs object, and calls the \ref Dfs::run
+  /// method of it.
+  template<class TR>
+  class DfsWizard : public TR
+  {
+    typedef TR Base;
+
+    ///The type of the underlying digraph.
+    typedef typename TR::Digraph Digraph;
+    //\e
+    typedef typename Digraph::Node Node;
+    //\e
+    typedef typename Digraph::NodeIt NodeIt;
+    //\e
+    typedef typename Digraph::Arc Arc;
+    //\e
+    typedef typename Digraph::OutArcIt OutArcIt;
+    
+    ///\brief The type of the map that stores
+    ///the reached nodes
+    typedef typename TR::ReachedMap ReachedMap;
+    ///\brief The type of the map that stores
+    ///the processed nodes
+    typedef typename TR::ProcessedMap ProcessedMap;
+    ///\brief The type of the map that stores the last
+    ///arcs of the %DFS paths.
+    typedef typename TR::PredMap PredMap;
+    ///The type of the map that stores the distances of the nodes.
+    typedef typename TR::DistMap DistMap;
+
+  public:
+    /// Constructor.
+    DfsWizard() : TR() {}
+
+    /// Constructor that requires parameters.
+
+    /// Constructor that requires parameters.
+    /// These parameters will be the default values for the traits class.
+    DfsWizard(const Digraph &g, Node s=INVALID) :
+      TR(g,s) {}
+
+    ///Copy constructor
+    DfsWizard(const TR &b) : TR(b) {}
+
+    ~DfsWizard() {}
+
+    ///Runs Dfs algorithm from a given node.
+    
+    ///Runs Dfs algorithm from a given node.
+    ///The node can be given by the \ref source function.
+    void run()
+    {
+      if(Base::_source==INVALID) throw UninitializedParameter();
+      Dfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g));
+      if(Base::_reached) 
+        alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached));
+      if(Base::_processed) 
+        alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
+      if(Base::_pred) 
+        alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
+      if(Base::_dist) 
+        alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
+      alg.run(Base::_source);
+    }
+
+    ///Runs Dfs algorithm from the given node.
+
+    ///Runs Dfs algorithm from the given node.
+    ///\param s is the given source.
+    void run(Node s)
+    {
+      Base::_source=s;
+      run();
+    }
+
+    template<class T>
+    struct DefPredMapBase : public Base {
+      typedef T PredMap;
+      static PredMap *createPredMap(const Digraph &) { return 0; };
+      DefPredMapBase(const TR &b) : TR(b) {}
+    };
+    
+    ///\brief \ref named-templ-param "Named parameter"
+    ///function for setting PredMap type
+    ///
+    /// \ref named-templ-param "Named parameter"
+    ///function for setting PredMap type
+    ///
+    template<class T>
+    DfsWizard<DefPredMapBase<T> > predMap(const T &t) 
+    {
+      Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
+      return DfsWizard<DefPredMapBase<T> >(*this);
+    }
+    
+ 
+    template<class T>
+    struct DefReachedMapBase : public Base {
+      typedef T ReachedMap;
+      static ReachedMap *createReachedMap(const Digraph &) { return 0; };
+      DefReachedMapBase(const TR &b) : TR(b) {}
+    };
+    
+    ///\brief \ref named-templ-param "Named parameter"
+    ///function for setting ReachedMap
+    ///
+    /// \ref named-templ-param "Named parameter"
+    ///function for setting ReachedMap
+    ///
+    template<class T>
+    DfsWizard<DefReachedMapBase<T> > reachedMap(const T &t) 
+    {
+      Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
+      return DfsWizard<DefReachedMapBase<T> >(*this);
+    }
+    
+
+    template<class T>
+    struct DefProcessedMapBase : public Base {
+      typedef T ProcessedMap;
+      static ProcessedMap *createProcessedMap(const Digraph &) { return 0; };
+      DefProcessedMapBase(const TR &b) : TR(b) {}
+    };
+    
+    ///\brief \ref named-templ-param "Named parameter"
+    ///function for setting ProcessedMap
+    ///
+    /// \ref named-templ-param "Named parameter"
+    ///function for setting ProcessedMap
+    ///
+    template<class T>
+    DfsWizard<DefProcessedMapBase<T> > processedMap(const T &t) 
+    {
+      Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
+      return DfsWizard<DefProcessedMapBase<T> >(*this);
+    }
+    
+    template<class T>
+    struct DefDistMapBase : public Base {
+      typedef T DistMap;
+      static DistMap *createDistMap(const Digraph &) { return 0; };
+      DefDistMapBase(const TR &b) : TR(b) {}
+    };
+    
+    ///\brief \ref named-templ-param "Named parameter"
+    ///function for setting DistMap type
+    ///
+    /// \ref named-templ-param "Named parameter"
+    ///function for setting DistMap type
+    ///
+    template<class T>
+    DfsWizard<DefDistMapBase<T> > distMap(const T &t) 
+    {
+      Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t));
+      return DfsWizard<DefDistMapBase<T> >(*this);
+    }
+    
+    /// Sets the source node, from which the Dfs algorithm runs.
+
+    /// Sets the source node, from which the Dfs algorithm runs.
+    /// \param s is the source node.
+    DfsWizard<TR> &source(Node s) 
+    {
+      Base::_source=s;
+      return *this;
+    }
+    
+  };
+  
+  ///Function type interface for Dfs algorithm.
+
+  ///\ingroup search
+  ///Function type interface for Dfs algorithm.
+  ///
+  ///This function also has several
+  ///\ref named-templ-func-param "named parameters",
+  ///they are declared as the members of class \ref DfsWizard.
+  ///The following
+  ///example shows how to use these parameters.
+  ///\code
+  ///  dfs(g,source).predMap(preds).run();
+  ///\endcode
+  ///\warning Don't forget to put the \ref DfsWizard::run() "run()"
+  ///to the end of the parameter list.
+  ///\sa DfsWizard
+  ///\sa Dfs
+  template<class GR>
+  DfsWizard<DfsWizardBase<GR> >
+  dfs(const GR &g,typename GR::Node s=INVALID)
+  {
+    return DfsWizard<DfsWizardBase<GR> >(g,s);
+  }
+
+#ifdef DOXYGEN
+  /// \brief Visitor class for dfs.
+  ///  
+  /// It gives a simple interface for a functional interface for dfs 
+  /// traversal. The traversal on a linear data structure. 
+  template <typename _Digraph>
+  struct DfsVisitor {
+    typedef _Digraph Digraph;
+    typedef typename Digraph::Arc Arc;
+    typedef typename Digraph::Node Node;
+    /// \brief Called when the arc reach a node.
+    /// 
+    /// It is called when the dfs find an arc which target is not
+    /// reached yet.
+    void discover(const Arc& arc) {}
+    /// \brief Called when the node reached first time.
+    /// 
+    /// It is Called when the node reached first time.
+    void reach(const Node& node) {}
+    /// \brief Called when we step back on an arc.
+    /// 
+    /// It is called when the dfs should step back on the arc.
+    void backtrack(const Arc& arc) {}
+    /// \brief Called when we step back from the node.
+    /// 
+    /// It is called when we step back from the node.
+    void leave(const Node& node) {}
+    /// \brief Called when the arc examined but target of the arc 
+    /// already discovered.
+    /// 
+    /// It called when the arc examined but the target of the arc 
+    /// already discovered.
+    void examine(const Arc& arc) {}
+    /// \brief Called for the source node of the dfs.
+    /// 
+    /// It is called for the source node of the dfs.
+    void start(const Node& node) {}
+    /// \brief Called when we leave the source node of the dfs.
+    /// 
+    /// It is called when we leave the source node of the dfs.
+    void stop(const Node& node) {}
+
+  };
+#else
+  template <typename _Digraph>
+  struct DfsVisitor {
+    typedef _Digraph Digraph;
+    typedef typename Digraph::Arc Arc;
+    typedef typename Digraph::Node Node;
+    void discover(const Arc&) {}
+    void reach(const Node&) {}
+    void backtrack(const Arc&) {}
+    void leave(const Node&) {}
+    void examine(const Arc&) {}
+    void start(const Node&) {}
+    void stop(const Node&) {}
+
+    template <typename _Visitor>
+    struct Constraints {
+      void constraints() {
+	Arc arc;
+	Node node;
+	visitor.discover(arc);
+	visitor.reach(node);
+	visitor.backtrack(arc);
+	visitor.leave(node);
+	visitor.examine(arc);
+	visitor.start(node);
+	visitor.stop(arc);
+      }
+      _Visitor& visitor;
+    };
+  };
+#endif
+
+  /// \brief Default traits class of DfsVisit class.
+  ///
+  /// Default traits class of DfsVisit class.
+  /// \param _Digraph Digraph type.
+  template<class _Digraph>
+  struct DfsVisitDefaultTraits {
+
+    /// \brief The digraph type the algorithm runs on. 
+    typedef _Digraph Digraph;
+
+    /// \brief The type of the map that indicates which nodes are reached.
+    /// 
+    /// The type of the map that indicates which nodes are reached.
+    /// It must meet the \ref concepts::WriteMap "WriteMap" concept.
+    /// \todo named parameter to set this type, function to read and write.
+    typedef typename Digraph::template NodeMap<bool> ReachedMap;
+
+    /// \brief Instantiates a ReachedMap.
+    ///
+    /// This function instantiates a \ref ReachedMap. 
+    /// \param digraph is the digraph, to which
+    /// we would like to define the \ref ReachedMap.
+    static ReachedMap *createReachedMap(const Digraph &digraph) {
+      return new ReachedMap(digraph);
+    }
+
+  };
+  
+  /// %DFS Visit algorithm class.
+  
+  /// \ingroup search
+  /// This class provides an efficient implementation of the %DFS algorithm
+  /// with visitor interface.
+  ///
+  /// The %DfsVisit class provides an alternative interface to the Dfs
+  /// class. It works with callback mechanism, the DfsVisit object calls
+  /// on every dfs event the \c Visitor class member functions. 
+  ///
+  /// \param _Digraph The digraph type the algorithm runs on. The default value is
+  /// \ref ListDigraph. The value of _Digraph is not used directly by Dfs, it
+  /// is only passed to \ref DfsDefaultTraits.
+  /// \param _Visitor The Visitor object for the algorithm. The 
+  /// \ref DfsVisitor "DfsVisitor<_Digraph>" is an empty Visitor which
+  /// does not observe the Dfs events. If you want to observe the dfs
+  /// events you should implement your own Visitor class.
+  /// \param _Traits Traits class to set various data types used by the 
+  /// algorithm. The default traits class is
+  /// \ref DfsVisitDefaultTraits "DfsVisitDefaultTraits<_Digraph>".
+  /// See \ref DfsVisitDefaultTraits for the documentation of
+  /// a Dfs visit traits class.
+  ///
+  /// \author Jacint Szabo, Alpar Juttner and Balazs Dezso
+#ifdef DOXYGEN
+  template <typename _Digraph, typename _Visitor, typename _Traits>
+#else
+  template <typename _Digraph = ListDigraph,
+	    typename _Visitor = DfsVisitor<_Digraph>,
+	    typename _Traits = DfsDefaultTraits<_Digraph> >
+#endif
+  class DfsVisit {
+  public:
+    
+    /// \brief \ref Exception for uninitialized parameters.
+    ///
+    /// This error represents problems in the initialization
+    /// of the parameters of the algorithms.
+    class UninitializedParameter : public lemon::UninitializedParameter {
+    public:
+      virtual const char* what() const throw() 
+      {
+	return "lemon::DfsVisit::UninitializedParameter";
+      }
+    };
+
+    typedef _Traits Traits;
+
+    typedef typename Traits::Digraph Digraph;
+
+    typedef _Visitor Visitor;
+
+    ///The type of the map indicating which nodes are reached.
+    typedef typename Traits::ReachedMap ReachedMap;
+
+  private:
+
+    typedef typename Digraph::Node Node;
+    typedef typename Digraph::NodeIt NodeIt;
+    typedef typename Digraph::Arc Arc;
+    typedef typename Digraph::OutArcIt OutArcIt;
+
+    /// Pointer to the underlying digraph.
+    const Digraph *_digraph;
+    /// Pointer to the visitor object.
+    Visitor *_visitor;
+    ///Pointer to the map of reached status of the nodes.
+    ReachedMap *_reached;
+    ///Indicates if \ref _reached is locally allocated (\c true) or not.
+    bool local_reached;
+
+    std::vector<typename Digraph::Arc> _stack;
+    int _stack_head;
+
+    /// \brief Creates the maps if necessary.
+    ///
+    /// Creates the maps if necessary.
+    void create_maps() {
+      if(!_reached) {
+	local_reached = true;
+	_reached = Traits::createReachedMap(*_digraph);
+      }
+    }
+
+  protected:
+
+    DfsVisit() {}
+    
+  public:
+
+    typedef DfsVisit Create;
+
+    /// \name Named template parameters
+
+    ///@{
+    template <class T>
+    struct DefReachedMapTraits : public Traits {
+      typedef T ReachedMap;
+      static ReachedMap *createReachedMap(const Digraph &digraph) {
+	throw UninitializedParameter();
+      }
+    };
+    /// \brief \ref named-templ-param "Named parameter" for setting 
+    /// ReachedMap type
+    ///
+    /// \ref named-templ-param "Named parameter" for setting ReachedMap type
+    template <class T>
+    struct DefReachedMap : public DfsVisit< Digraph, Visitor,
+					    DefReachedMapTraits<T> > {
+      typedef DfsVisit< Digraph, Visitor, DefReachedMapTraits<T> > Create;
+    };
+    ///@}
+
+  public:      
+    
+    /// \brief Constructor.
+    ///
+    /// Constructor.
+    ///
+    /// \param digraph the digraph the algorithm will run on.
+    /// \param visitor The visitor of the algorithm.
+    ///
+    DfsVisit(const Digraph& digraph, Visitor& visitor) 
+      : _digraph(&digraph), _visitor(&visitor),
+	_reached(0), local_reached(false) {}
+    
+    /// \brief Destructor.
+    ///
+    /// Destructor.
+    ~DfsVisit() {
+      if(local_reached) delete _reached;
+    }
+
+    /// \brief Sets the map indicating if a node is reached.
+    ///
+    /// Sets the map indicating if a node is reached.
+    /// If you don't use this function before calling \ref run(),
+    /// it will allocate one. The destuctor deallocates this
+    /// automatically allocated map, of course.
+    /// \return <tt> (*this) </tt>
+    DfsVisit &reachedMap(ReachedMap &m) {
+      if(local_reached) {
+	delete _reached;
+	local_reached=false;
+      }
+      _reached = &m;
+      return *this;
+    }
+
+  public:
+    /// \name Execution control
+    /// The simplest way to execute the algorithm is to use
+    /// one of the member functions called \c run(...).
+    /// \n
+    /// If you need more control on the execution,
+    /// first you must call \ref init(), then you can adda source node
+    /// with \ref addSource().
+    /// Finally \ref start() will perform the actual path
+    /// computation.
+
+    /// @{
+    /// \brief Initializes the internal data structures.
+    ///
+    /// Initializes the internal data structures.
+    ///
+    void init() {
+      create_maps();
+      _stack.resize(countNodes(*_digraph));
+      _stack_head = -1;
+      for (NodeIt u(*_digraph) ; u != INVALID ; ++u) {
+	_reached->set(u, false);
+      }
+    }
+    
+    /// \brief Adds a new source node.
+    ///
+    /// Adds a new source node to the set of nodes to be processed.
+    void addSource(Node s) {
+      if(!(*_reached)[s]) {
+	  _reached->set(s,true);
+	  _visitor->start(s);
+	  _visitor->reach(s);
+	  Arc e; 
+	  _digraph->firstOut(e, s);
+	  if (e != INVALID) {
+	    _stack[++_stack_head] = e;
+	  } else {
+	    _visitor->leave(s);
+	  }
+	}
+    }
+    
+    /// \brief Processes the next arc.
+    ///
+    /// Processes the next arc.
+    ///
+    /// \return The processed arc.
+    ///
+    /// \pre The stack must not be empty!
+    Arc processNextArc() { 
+      Arc e = _stack[_stack_head];
+      Node m = _digraph->target(e);
+      if(!(*_reached)[m]) {
+	_visitor->discover(e);
+	_visitor->reach(m);
+	_reached->set(m, true);
+	_digraph->firstOut(_stack[++_stack_head], m);
+      } else {
+	_visitor->examine(e);
+	m = _digraph->source(e);
+	_digraph->nextOut(_stack[_stack_head]);
+      }
+      while (_stack_head>=0 && _stack[_stack_head] == INVALID) {
+	_visitor->leave(m);
+	--_stack_head;
+	if (_stack_head >= 0) {
+	  _visitor->backtrack(_stack[_stack_head]);
+	  m = _digraph->source(_stack[_stack_head]);
+	  _digraph->nextOut(_stack[_stack_head]);
+	} else {
+	  _visitor->stop(m);	  
+	}
+      }
+      return e;
+    }
+
+    /// \brief Next arc to be processed.
+    ///
+    /// Next arc to be processed.
+    ///
+    /// \return The next arc to be processed or INVALID if the stack is
+    /// empty.
+    Arc nextArc() { 
+      return _stack_head >= 0 ? _stack[_stack_head] : INVALID;
+    }
+
+    /// \brief Returns \c false if there are nodes
+    /// to be processed in the queue
+    ///
+    /// Returns \c false if there are nodes
+    /// to be processed in the queue
+    bool emptyQueue() { return _stack_head < 0; }
+
+    /// \brief Returns the number of the nodes to be processed.
+    ///
+    /// Returns the number of the nodes to be processed in the queue.
+    int queueSize() { return _stack_head + 1; }
+    
+    /// \brief Executes the algorithm.
+    ///
+    /// Executes the algorithm.
+    ///
+    /// \pre init() must be called and at least one node should be added
+    /// with addSource() before using this function.
+    void start() {
+      while ( !emptyQueue() ) processNextArc();
+    }
+    
+    /// \brief Executes the algorithm until \c dest is reached.
+    ///
+    /// Executes the algorithm until \c dest is reached.
+    ///
+    /// \pre init() must be called and at least one node should be added
+    /// with addSource() before using this function.
+    void start(Node dest) {
+      while ( !emptyQueue() && _digraph->target(_stack[_stack_head]) != dest ) 
+	processNextArc();
+    }
+    
+    /// \brief Executes the algorithm until a condition is met.
+    ///
+    /// Executes the algorithm until a condition is met.
+    ///
+    /// \pre init() must be called and at least one node should be added
+    /// with addSource() before using this function.
+    ///
+    /// \param em must be a bool (or convertible) arc map. The algorithm
+    /// will stop when it reaches an arc \c e with <tt>em[e]</tt> true.
+    ///
+    ///\return The reached arc \c e with <tt>em[e]</tt> true or
+    ///\c INVALID if no such arc was found.
+    ///
+    /// \warning Contrary to \ref Bfs and \ref Dijkstra, \c em is an arc map,
+    /// not a node map.
+    template <typename EM>
+    Arc start(const EM &em) {
+      while ( !emptyQueue() && !em[_stack[_stack_head]] )
+        processNextArc();
+      return emptyQueue() ? INVALID : _stack[_stack_head];
+    }
+
+    /// \brief Runs %DFSVisit algorithm from node \c s.
+    ///
+    /// This method runs the %DFS algorithm from a root node \c s.
+    /// \note d.run(s) is just a shortcut of the following code.
+    ///\code
+    ///   d.init();
+    ///   d.addSource(s);
+    ///   d.start();
+    ///\endcode
+    void run(Node s) {
+      init();
+      addSource(s);
+      start();
+    }
+
+    /// \brief Runs %DFSVisit algorithm to visit all nodes in the digraph.
+    
+    /// This method runs the %DFS algorithm in order to
+    /// compute the %DFS path to each node. The algorithm computes
+    /// - The %DFS tree.
+    /// - The distance of each node from the root in the %DFS tree.
+    ///
+    ///\note d.run() is just a shortcut of the following code.
+    ///\code
+    ///  d.init();
+    ///  for (NodeIt it(digraph); it != INVALID; ++it) {
+    ///    if (!d.reached(it)) {
+    ///      d.addSource(it);
+    ///      d.start();
+    ///    }
+    ///  }
+    ///\endcode
+    void run() {
+      init();
+      for (NodeIt it(*_digraph); it != INVALID; ++it) {
+        if (!reached(it)) {
+          addSource(it);
+          start();
+        }
+      }
+    }
+    ///@}
+
+    /// \name Query Functions
+    /// The result of the %DFS algorithm can be obtained using these
+    /// functions.\n
+    /// Before the use of these functions,
+    /// either run() or start() must be called.
+    ///@{
+    /// \brief Checks if a node is reachable from the root.
+    ///
+    /// Returns \c true if \c v is reachable from the root(s).
+    /// \warning The source nodes are inditated as unreachable.
+    /// \pre Either \ref run() or \ref start()
+    /// must be called before using this function.
+    ///
+    bool reached(Node v) { return (*_reached)[v]; }
+    ///@}
+  };
+
+
+} //END OF NAMESPACE LEMON
+
+#endif
+