LEMON/LEMON-official Changeset - r1007:e24922c56bc2

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Changeset - r1007:e24922c56bc2

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r1007:e24922c56bc2

Wed, 22 Sep 2010 08:53:09

[Not Reviewed]

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alpar (Alpar Juttner)
alpar@cs.elte.hu

Bug fix in Dfs::start(s,t) (#392)

0 2 0

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2 files changed with 14 insertions and 3 deletions:

lemon/dfs.h

test/dfs_test.cc

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lemon/dfs.h

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 		/* -*- mode: C++; indent-tabs-mode: nil; -*-
+		 *
 		 * 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/bits/path_dump.h>
 		#include <lemon/core.h>
 		#include <lemon/error.h>
 		#include <lemon/maps.h>
 		#include <lemon/path.h>
 		namespace lemon {
 		  ///Default traits class of Dfs class.
 		  ///Default traits class of Dfs class.
 		  ///\tparam GR Digraph type.
 		  template<class GR>
 		  struct DfsDefaultTraits
+		  {
 		    ///The type of the digraph the algorithm runs on.
 		    typedef GR Digraph;
 		    ///\brief The type of the map that stores the predecessor
 		    ///arcs of the %DFS paths.
 		    ///
 		    ///The type of the map that stores the predecessor
 		    ///arcs of the %DFS paths.
 		    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
 		    typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
 		    ///Instantiates a PredMap.
 		    ///This function instantiates a PredMap.
 		    ///\param g is the digraph, to which we would like to define the
 		    ///PredMap.
 		    static PredMap *createPredMap(const Digraph &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.
 		    typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
 		    ///Instantiates a ProcessedMap.
 		    ///This function instantiates a ProcessedMap.
 		    ///\param g is the digraph, to which
 		    ///we would like to define the ProcessedMap
 		#ifdef DOXYGEN
 		    static ProcessedMap *createProcessedMap(const Digraph &g)
 		#else
 		    static ProcessedMap *createProcessedMap(const Digraph &)
 		#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::ReadWriteMap "ReadWriteMap" concept.
 		    typedef typename Digraph::template NodeMap<bool> ReachedMap;
 		    ///Instantiates a ReachedMap.
 		    ///This function instantiates a ReachedMap.
 		    ///\param g is the digraph, to which
 		    ///we would like to define the ReachedMap.
 		    static ReachedMap *createReachedMap(const Digraph &g)
+		    {
 		      return new ReachedMap(g);
+		    }
 		    ///The type of the map that stores the distances of the nodes.
 		    ///The type of the map that stores the distances 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 DistMap.
 		    ///\param g is the digraph, to which we would like to define the
 		    ///DistMap.
 		    static DistMap *createDistMap(const Digraph &g)
+		    {
 		      return new DistMap(g);
+		    }
 		  };
 		  ///%DFS algorithm class.
 		  ///\ingroup search
 		  ///This class provides an efficient implementation of the %DFS algorithm.
 		  ///
 		  ///There is also a \ref dfs() "function-type interface" for the DFS
 		  ///algorithm, which is convenient in the simplier cases and it can be
 		  ///used easier.
 		  ///
 		  ///\tparam GR The type of the digraph the algorithm runs on.
 		  ///The default value is \ref ListDigraph. The value of GR is not used
 		  ///directly by \ref Dfs, it is only passed to \ref DfsDefaultTraits.
 		  ///\tparam 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.
 		#ifdef DOXYGEN
 		  template <typename GR,
 		            typename TR>
 		#else
 		  template <typename GR=ListDigraph,
 		            typename TR=DfsDefaultTraits<GR> >
 		#endif
 		  class Dfs {
 		  public:
 		    ///The type of the digraph the algorithm runs on.
 		    typedef typename TR::Digraph Digraph;
 		    ///\brief The type of the map that stores the predecessor 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;
 		    ///The type of the map that indicates which nodes are reached.
 		    typedef typename TR::ReachedMap ReachedMap;
 		    ///The type of the map that indicates which nodes are processed.
 		    typedef typename TR::ProcessedMap ProcessedMap;
 		    ///The type of the paths.
 		    typedef PredMapPath<Digraph, PredMap> Path;
 		    ///The traits class.
 		    typedef TR Traits;
 		  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 *G;
 		    //Pointer to the map of predecessor arcs.
 		    PredMap *_pred;
 		    //Indicates if _pred is locally allocated (true) or not.
 		    bool local_pred;
 		    //Pointer to the map of distances.
 		    DistMap *_dist;
 		    //Indicates if _dist is locally allocated (true) or not.
 		    bool local_dist;
 		    //Pointer to the map of reached status of the nodes.
 		    ReachedMap *_reached;
 		    //Indicates if _reached is locally allocated (true) or not.
 		    bool local_reached;
 		    //Pointer to the map of processed status of the nodes.
 		    ProcessedMap *_processed;
 		    //Indicates if _processed is locally allocated (true) or not.
 		    bool local_processed;
 		    std::vector<typename Digraph::OutArcIt> _stack;
 		    int _stack_head;
 		    //Creates the maps if necessary.
 		    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 SetPredMapTraits : public Traits {
 		      typedef T PredMap;
 		      static PredMap *createPredMap(const Digraph &)
+		      {
 		        LEMON_ASSERT(false, "PredMap is not initialized");
 		        return 0; // ignore warnings
+		      }
 		    };
 		    ///\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 SetPredMap : public Dfs<Digraph, SetPredMapTraits<T> > {
 		      typedef Dfs<Digraph, SetPredMapTraits<T> > Create;
 		    };
 		    template <class T>
 		    struct SetDistMapTraits : public Traits {
 		      typedef T DistMap;
 		      static DistMap *createDistMap(const Digraph &)
+		      {
 		        LEMON_ASSERT(false, "DistMap is not initialized");
 		        return 0; // ignore warnings
+		      }
 		    };
 		    ///\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 SetDistMap : public Dfs< Digraph, SetDistMapTraits<T> > {
 		      typedef Dfs<Digraph, SetDistMapTraits<T> > Create;
 		    };
 		    template <class T>
 		    struct SetReachedMapTraits : public Traits {
 		      typedef T ReachedMap;
 		      static ReachedMap *createReachedMap(const Digraph &)
+		      {
 		        LEMON_ASSERT(false, "ReachedMap is not initialized");
 		        return 0; // ignore warnings
+		      }
 		    };
 		    ///\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 SetReachedMap : public Dfs< Digraph, SetReachedMapTraits<T> > {
 		      typedef Dfs< Digraph, SetReachedMapTraits<T> > Create;
 		    };
 		    template <class T>
 		    struct SetProcessedMapTraits : public Traits {
 		      typedef T ProcessedMap;
 		      static ProcessedMap *createProcessedMap(const Digraph &)
+		      {
 		        LEMON_ASSERT(false, "ProcessedMap is not initialized");
 		        return 0; // ignore warnings
+		      }
 		    };
 		    ///\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 SetProcessedMap : public Dfs< Digraph, SetProcessedMapTraits<T> > {
 		      typedef Dfs< Digraph, SetProcessedMapTraits<T> > Create;
 		    };
 		    struct SetStandardProcessedMapTraits : 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
 		    ///ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
 		    ///
 		    ///\ref named-templ-param "Named parameter" for setting
 		    ///ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
 		    ///If you don't set it explicitly, it will be automatically allocated.
 		    struct SetStandardProcessedMap :
 		      public Dfs< Digraph, SetStandardProcessedMapTraits > {
 		      typedef Dfs< Digraph, SetStandardProcessedMapTraits > Create;
 		    };
 		    ///@}
 		  public:
 		    ///Constructor.
 		    ///Constructor.
 		    ///\param g The digraph the algorithm runs 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 that stores the predecessor arcs.
 		    ///Sets the map that stores the predecessor arcs.
 		    ///If you don't use this function before calling \ref run(),
 		    ///it will allocate one. The destructor 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 that indicates which nodes are reached.
 		    ///Sets the map that indicates which nodes are reached.
 		    ///If you don't use this function before calling \ref run(),
 		    ///it will allocate one. The destructor 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 that indicates which nodes are processed.
 		    ///Sets the map that indicates which nodes are processed.
 		    ///If you don't use this function before calling \ref run(),
 		    ///it will allocate one. The destructor 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;
+		    }
 		    ///Sets the map that stores the distances of the nodes.
 		    ///Sets the map that stores the distances of the nodes calculated by
 		    ///the algorithm.
 		    ///If you don't use this function before calling \ref run(),
 		    ///it will allocate one. The destructor 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;
+		    }
 		  public:
 		    ///\name Execution control
 		    ///The simplest way to execute the algorithm is to use
 		    ///one of the member functions called \ref lemon::Dfs::run() "run()".
 		    ///\n
 		    ///If you need more control on the execution, first you must call
 		    ///\ref lemon::Dfs::init() "init()", then you can add a source node
 		    ///with \ref lemon::Dfs::addSource() "addSource()".
 		    ///Finally \ref lemon::Dfs::start() "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);
 		        _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.
 		    ///
 		    ///\pre The stack must be empty. (Otherwise the algorithm gives
 		    ///false results.)
 		    ///
 		    ///\warning Distances will be wrong (or at least strange) in case of
 		    ///multiple sources.
 		    void addSource(Node s)
+		    {
 		      LEMON_DEBUG(emptyQueue(), "The stack is not empty.");
 		      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 \c INVALID if the stack
 		    ///is empty.
 		    OutArcIt nextArc() const
+		    {
 		      return _stack_head>=0?_stack[_stack_head]:INVALID;
+		    }
 		    ///\brief Returns \c false if there are nodes
 		    ///to be processed.
 		    ///
 		    ///Returns \c false if there are nodes
 		    ///to be processed in the queue (stack).
 		    bool emptyQueue() const { 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 (stack).
 		    int queueSize() const { return _stack_head+1; }
 		    ///Executes the algorithm.
 		    ///Executes the algorithm.
 		    ///
 		    ///This method runs the %DFS algorithm from the root node
 		    ///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.
 		    ///
 		    ///\pre init() must be called and a root node should be
 		    ///added with addSource() before using this function.
 		    ///
 		    ///\note <tt>d.start()</tt> is just a shortcut of the following code.
 		    ///\code
 		    ///  while ( !d.emptyQueue() ) {
 		    ///    d.processNextArc();
 		    ///  }
 		    ///\endcode
 		    void start()
+		    {
 		      while ( !emptyQueue() ) processNextArc();
+		    }
 		    ///Executes the algorithm until the given target node is reached.
 		    ///Executes the algorithm until the given target node is reached.
 		    ///
 		    ///This method runs the %DFS algorithm from the root node
 		    ///in order to compute the DFS path to \c t.
 		    ///
 		    ///The algorithm computes
 		    ///- the %DFS path to \c t,
 		    ///- the distance of \c t from the root in the %DFS tree.
 		    ///
 		    ///\pre init() must be called and a root node should be
 		    ///added with addSource() before using this function.
 		    void start(Node t)
+		    {
-		      while ( !emptyQueue() && G->target(_stack[_stack_head])!=t )
+		      while ( !emptyQueue() && !(*_reached)[t] )
 		        processNextArc();
+		    }
 		    ///Executes the algorithm until a condition is met.
 		    ///Executes the algorithm until a condition is met.
 		    ///
 		    ///This method runs the %DFS algorithm from the root node
 		    ///until an arc \c a with <tt>am[a]</tt> true is found.
 		    ///
 		    ///\param am A \c bool (or convertible) arc map. The algorithm
 		    ///will stop when it reaches an arc \c a with <tt>am[a]</tt> true.
 		    ///
 		    ///\return The reached arc \c a with <tt>am[a]</tt> true or
 		    ///\c INVALID if no such arc was found.
 		    ///
 		    ///\pre init() must be called and a root node should be
 		    ///added with addSource() before using this function.
 		    ///
 		    ///\warning Contrary to \ref Bfs and \ref Dijkstra, \c am is an arc map,
 		    ///not a node map.
 		    template<class ArcBoolMap>
 		    Arc start(const ArcBoolMap &am)
+		    {
 		      while ( !emptyQueue() && !am[_stack[_stack_head]] )
 		        processNextArc();
 		      return emptyQueue() ? INVALID : _stack[_stack_head];
+		    }
 		    ///Runs the algorithm from the given source node.
 		    ///This method runs the %DFS algorithm from 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 <tt>d.run(s)</tt> 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.
 		    ///This method runs the %DFS algorithm from node \c s
 		    ///in order to compute the DFS path to node \c t
 		    ///(it stops searching when \c t is processed)
 		    ///
 		    ///\return \c true if \c t is reachable form \c s.
 		    ///
 		    ///\note Apart from the return value, <tt>d.run(s,t)</tt> is
 		    ///just a shortcut of the following code.
 		    ///\code
 		    ///  d.init();
 		    ///  d.addSource(s);
 		    ///  d.start(t);
 		    ///\endcode
 		    bool run(Node s,Node t) {
 		      init();
 		      addSource(s);
 		      start(t);
 		      return reached(t);
+		    }
 		    ///Runs the 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 <tt>d.run()</tt> is just a shortcut of the following code.
 		    ///\code
 		    ///  d.init();
 		    ///  for (NodeIt n(digraph); n != INVALID; ++n) {
 		    ///    if (!d.reached(n)) {
 		    ///      d.addSource(n);
 		    ///      d.start();
 		    ///    }
 		    ///  }
 		    ///\endcode
 		    void run() {
 		      init();
 		      for (NodeIt it(*G); 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
 		    ///Either \ref lemon::Dfs::run() "run()" or \ref lemon::Dfs::start()
 		    ///"start()" must be called before using them.
 		    ///@{
 		    ///The DFS path to a node.
 		    ///Returns the DFS path to a node.
 		    ///
 		    ///\warning \c t should be reachable from the root.
 		    ///
 		    ///\pre Either \ref run() or \ref start() must be called before
 		    ///using this function.
 		    Path path(Node t) const { return Path(*G, *_pred, t); }
 		    ///The distance of a node from the root.
 		    ///Returns the distance of a node from the root.
 		    ///
 		    ///\warning If node \c v is not reachable from the root, then
 		    ///the return value of this function is undefined.
 		    ///
 		    ///\pre Either \ref run() or \ref start() must be called before
 		    ///using this function.
 		    int dist(Node v) const { return (*_dist)[v]; }
 		    ///Returns the 'previous arc' of the %DFS tree for a node.
 		    ///This function returns the 'previous arc' of the %DFS tree for the
 		    ///node \c v, i.e. it returns the last arc of a %DFS path from the
 		    ///root to \c v. It is \c INVALID
 		    ///if \c v is not reachable from the root(s) or if \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.
 		    ///This function returns the 'previous node' of the %DFS
 		    ///tree for the node \c v, i.e. it returns the last but one node
 		    ///from a %DFS path from the root to \c v. It is \c INVALID
 		    ///if \c v is not reachable from the root(s) or if \c v is 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]); }
 		    ///\brief Returns a const reference to the node map that stores the
 		    ///distances of the nodes.
 		    ///
 		    ///Returns a const reference to the node map that stores the
 		    ///distances of the nodes calculated by the algorithm.
 		    ///
 		    ///\pre Either \ref run() or \ref init()
 		    ///must be called before using this function.
 		    const DistMap &distMap() const { return *_dist;}
 		    ///\brief Returns a const reference to the node map that stores the
 		    ///predecessor arcs.
 		    ///
 		    ///Returns a const reference to the node map that stores the predecessor
 		    ///arcs, which form 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(s).
 		    ///Returns \c true if \c v is reachable from the root(s).
 		    ///\pre Either \ref run() or \ref start()
 		    ///must be called before using this function.
 		    bool reached(Node v) const { return (*_reached)[v]; }
 		    ///@}
 		  };
 		  ///Default traits class of dfs() function.
 		  ///Default traits class of dfs() function.
 		  ///\tparam GR Digraph type.
 		  template<class GR>
 		  struct DfsWizardDefaultTraits
+		  {
 		    ///The type of the digraph the algorithm runs on.
 		    typedef GR Digraph;
 		    ///\brief The type of the map that stores the predecessor
 		    ///arcs of the %DFS paths.
 		    ///
 		    ///The type of the map that stores the predecessor
 		    ///arcs of the %DFS paths.
 		    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
 		    typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
 		    ///Instantiates a PredMap.
 		    ///This function instantiates a PredMap.
 		    ///\param g is the digraph, to which we would like to define the
 		    ///PredMap.
 		    static PredMap *createPredMap(const Digraph &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.
 		    ///By default it is a NullMap.
 		    typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
 		    ///Instantiates a ProcessedMap.
 		    ///This function instantiates a ProcessedMap.
 		    ///\param g is the digraph, to which
 		    ///we would like to define the ProcessedMap.
 		#ifdef DOXYGEN
 		    static ProcessedMap *createProcessedMap(const Digraph &g)
 		#else
 		    static ProcessedMap *createProcessedMap(const Digraph &)
 		#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::ReadWriteMap "ReadWriteMap" concept.
 		    typedef typename Digraph::template NodeMap<bool> ReachedMap;
 		    ///Instantiates a ReachedMap.
 		    ///This function instantiates a ReachedMap.
 		    ///\param g is the digraph, to which
 		    ///we would like to define the ReachedMap.
 		    static ReachedMap *createReachedMap(const Digraph &g)
+		    {
 		      return new ReachedMap(g);
+		    }
 		    ///The type of the map that stores the distances of the nodes.
 		    ///The type of the map that stores the distances 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 DistMap.
 		    ///\param g is the digraph, to which we would like to define
 		    ///the DistMap
 		    static DistMap *createDistMap(const Digraph &g)
+		    {
 		      return new DistMap(g);
+		    }
 		    ///The type of the DFS paths.
 		    ///The type of the DFS paths.
 		    ///It must meet the \ref concepts::Path "Path" concept.
 		    typedef lemon::Path<Digraph> Path;
 		  };
 		  /// Default traits class used by 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:
 		    //The type of the nodes in the digraph.
 		    typedef typename Base::Digraph::Node Node;
 		    //Pointer to the digraph the algorithm runs on.
 		    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 DFS path to the target node.
 		    void *_path;
 		    //Pointer to the distance of the target node.
 		    int *_di;
 		    public:
 		    /// Constructor.
 		    /// This constructor does not require parameters, therefore it initiates
 		    /// all of the attributes to \c 0.
 		    DfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0),
 		                      _dist(0), _path(0), _di(0) {}
 		    /// Constructor.
 		    /// This constructor requires one parameter,
 		    /// others are initiated to \c 0.
 		    /// \param g The digraph the algorithm runs on.
 		    DfsWizardBase(const GR &g) :
 		      _g(reinterpret_cast<void*>(const_cast<GR*>(&g))),
 		      _reached(0), _processed(0), _pred(0), _dist(0),  _path(0), _di(0) {}
 		  };
 		  /// Auxiliary class for the function-type interface of DFS algorithm.
 		  /// This auxiliary class is created to implement the
 		  /// \ref dfs() "function-type interface" of \ref Dfs algorithm.
 		  /// It does not have own \ref run() method, it uses the functions
 		  /// and features of the plain \ref Dfs.
 		  ///
 		  /// This class should only be used through the \ref dfs() function,
 		  /// which makes it easier to use the algorithm.
 		  template<class TR>
 		  class DfsWizard : public TR
+		  {
 		    typedef TR Base;
 		    ///The type of the digraph the algorithm runs on.
 		    typedef typename TR::Digraph Digraph;
 		    typedef typename Digraph::Node Node;
 		    typedef typename Digraph::NodeIt NodeIt;
 		    typedef typename Digraph::Arc Arc;
 		    typedef typename Digraph::OutArcIt OutArcIt;
 		    ///\brief The type of the map that stores the predecessor
 		    ///arcs of the DFS paths.
 		    typedef typename TR::PredMap PredMap;
 		    ///\brief The type of the map that stores the distances of the nodes.
 		    typedef typename TR::DistMap DistMap;
 		    ///\brief The type of the map that indicates which nodes are reached.
 		    typedef typename TR::ReachedMap ReachedMap;
 		    ///\brief The type of the map that indicates which nodes are processed.
 		    typedef typename TR::ProcessedMap ProcessedMap;
 		    ///The type of the DFS paths
 		    typedef typename TR::Path Path;
 		  public:
 		    /// Constructor.
 		    DfsWizard() : TR() {}
 		    /// Constructor that requires parameters.
 		    /// Constructor that requires parameters.
 		    /// These parameters will be the default values for the traits class.
 		    /// \param g The digraph the algorithm runs on.
 		    DfsWizard(const Digraph &g) :
 		      TR(g) {}
 		    ///Copy constructor
 		    DfsWizard(const TR &b) : TR(b) {}
 		    ~DfsWizard() {}
 		    ///Runs DFS algorithm from the given source node.
 		    ///This method runs DFS algorithm from node \c s
 		    ///in order to compute the DFS path to each node.
 		    void run(Node s)
+		    {
 		      Dfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g));
 		      if (Base::_pred)
 		        alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
 		      if (Base::_dist)
 		        alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
 		      if (Base::_reached)
 		        alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached));
 		      if (Base::_processed)
 		        alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
 		      if (s!=INVALID)
 		        alg.run(s);
 		      else
 		        alg.run();
+		    }
 		    ///Finds the DFS path between \c s and \c t.
 		    ///This method runs DFS algorithm from node \c s
 		    ///in order to compute the DFS path to node \c t
 		    ///(it stops searching when \c t is processed).
 		    ///
 		    ///\return \c true if \c t is reachable form \c s.
 		    bool run(Node s, Node t)
+		    {
 		      Dfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g));
 		      if (Base::_pred)
 		        alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred));
 		      if (Base::_dist)
 		        alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist));
 		      if (Base::_reached)
 		        alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached));
 		      if (Base::_processed)
 		        alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed));
 		      alg.run(s,t);
 		      if (Base::_path)
 		        *reinterpret_cast<Path*>(Base::_path) = alg.path(t);
 		      if (Base::_di)
 		        *Base::_di = alg.dist(t);
 		      return alg.reached(t);
+		      }
 		    ///Runs DFS algorithm to visit all nodes in the digraph.
 		    ///This method runs DFS algorithm in order to compute
 		    ///the DFS path to each node.
 		    void run()
+		    {
 		      run(INVALID);
+		    }
 		    template<class T>
 		    struct SetPredMapBase : public Base {
 		      typedef T PredMap;
 		      static PredMap *createPredMap(const Digraph &) { return 0; };
 		      SetPredMapBase(const TR &b) : TR(b) {}
 		    };
 		    ///\brief \ref named-func-param "Named parameter"
 		    ///for setting PredMap object.
 		    ///
 		    ///\ref named-func-param "Named parameter"
 		    ///for setting PredMap object.
 		    template<class T>
 		    DfsWizard<SetPredMapBase<T> > predMap(const T &t)
+		    {
 		      Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));
 		      return DfsWizard<SetPredMapBase<T> >(*this);
+		    }
 		    template<class T>
 		    struct SetReachedMapBase : public Base {
 		      typedef T ReachedMap;
 		      static ReachedMap *createReachedMap(const Digraph &) { return 0; };
 		      SetReachedMapBase(const TR &b) : TR(b) {}
 		    };
 		    ///\brief \ref named-func-param "Named parameter"
 		    ///for setting ReachedMap object.
 		    ///
 		    /// \ref named-func-param "Named parameter"
 		    ///for setting ReachedMap object.
 		    template<class T>
 		    DfsWizard<SetReachedMapBase<T> > reachedMap(const T &t)
+		    {
 		      Base::_reached=reinterpret_cast<void*>(const_cast<T*>(&t));
 		      return DfsWizard<SetReachedMapBase<T> >(*this);
+		    }
 		    template<class T>
 		    struct SetDistMapBase : public Base {
 		      typedef T DistMap;
 		      static DistMap *createDistMap(const Digraph &) { return 0; };
 		      SetDistMapBase(const TR &b) : TR(b) {}
 		    };
 		    ///\brief \ref named-func-param "Named parameter"
 		    ///for setting DistMap object.
 		    ///
 		    /// \ref named-func-param "Named parameter"
 		    ///for setting DistMap object.
 		    template<class T>
 		    DfsWizard<SetDistMapBase<T> > distMap(const T &t)
+		    {
 		      Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t));
 		      return DfsWizard<SetDistMapBase<T> >(*this);
+		    }
 		    template<class T>
 		    struct SetProcessedMapBase : public Base {
 		      typedef T ProcessedMap;
 		      static ProcessedMap *createProcessedMap(const Digraph &) { return 0; };
 		      SetProcessedMapBase(const TR &b) : TR(b) {}
 		    };
 		    ///\brief \ref named-func-param "Named parameter"
 		    ///for setting ProcessedMap object.
 		    ///
 		    /// \ref named-func-param "Named parameter"
 		    ///for setting ProcessedMap object.
 		    template<class T>
 		    DfsWizard<SetProcessedMapBase<T> > processedMap(const T &t)
+		    {
 		      Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t));
 		      return DfsWizard<SetProcessedMapBase<T> >(*this);
+		    }
 		    template<class T>
 		    struct SetPathBase : public Base {
 		      typedef T Path;
 		      SetPathBase(const TR &b) : TR(b) {}
 		    };
 		    ///\brief \ref named-func-param "Named parameter"
 		    ///for getting the DFS path to the target node.
 		    ///
 		    ///\ref named-func-param "Named parameter"
 		    ///for getting the DFS path to the target node.
 		    template<class T>
 		    DfsWizard<SetPathBase<T> > path(const T &t)
+		    {
 		      Base::_path=reinterpret_cast<void*>(const_cast<T*>(&t));
 		      return DfsWizard<SetPathBase<T> >(*this);
+		    }
 		    ///\brief \ref named-func-param "Named parameter"
 		    ///for getting the distance of the target node.
 		    ///
 		    ///\ref named-func-param "Named parameter"
 		    ///for getting the distance of the target node.
 		    DfsWizard dist(const int &d)
+		    {
 		      Base::_di=const_cast<int*>(&d);
 		      return *this;
+		    }
 		  };
 		  ///Function-type interface for DFS algorithm.
 		  ///\ingroup search
 		  ///Function-type interface for DFS algorithm.
 		  ///
 		  ///This function also has several \ref named-func-param "named parameters",
 		  ///they are declared as the members of class \ref DfsWizard.
 		  ///The following examples show how to use these parameters.
 		  ///\code
 		  ///  // Compute the DFS tree
 		  ///  dfs(g).predMap(preds).distMap(dists).run(s);
 		  ///
 		  ///  // Compute the DFS path from s to t
 		  ///  bool reached = dfs(g).path(p).dist(d).run(s,t);
 		  ///\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 &digraph)
+		  {
 		    return DfsWizard<DfsWizardBase<GR> >(digraph);
+		  }
 		#ifdef DOXYGEN
 		  /// \brief Visitor class for DFS.
 		  ///
 		  /// This class defines the interface of the DfsVisit events, and
 		  /// it could be the base of a real visitor class.
 		  template <typename _Digraph>
 		  struct DfsVisitor {
 		    typedef _Digraph Digraph;
 		    typedef typename Digraph::Arc Arc;
 		    typedef typename Digraph::Node Node;
 		    /// \brief Called for the source node of the DFS.
 		    ///
 		    /// This function is called for the source node of the DFS.
 		    void start(const Node& node) {}
 		    /// \brief Called when the source node is leaved.
 		    ///
 		    /// This function is called when the source node is leaved.
 		    void stop(const Node& node) {}
 		    /// \brief Called when a node is reached first time.
 		    ///
 		    /// This function is called when a node is reached first time.
 		    void reach(const Node& node) {}
 		    /// \brief Called when an arc reaches a new node.
 		    ///
 		    /// This function is called when the DFS finds an arc whose target node
 		    /// is not reached yet.
 		    void discover(const Arc& arc) {}
 		    /// \brief Called when an arc is examined but its target node is
 		    /// already discovered.
 		    ///
 		    /// This function is called when an arc is examined but its target node is
 		    /// already discovered.
 		    void examine(const Arc& arc) {}
 		    /// \brief Called when the DFS steps back from a node.
 		    ///
 		    /// This function is called when the DFS steps back from a node.
 		    void leave(const Node& node) {}
 		    /// \brief Called when the DFS steps back on an arc.
 		    ///
 		    /// This function is called when the DFS steps back on an arc.
 		    void backtrack(const Arc& arc) {}
 		  };
 		#else
 		  template <typename _Digraph>
 		  struct DfsVisitor {
 		    typedef _Digraph Digraph;
 		    typedef typename Digraph::Arc Arc;
 		    typedef typename Digraph::Node Node;
 		    void start(const Node&) {}
 		    void stop(const Node&) {}
 		    void reach(const Node&) {}
 		    void discover(const Arc&) {}
 		    void examine(const Arc&) {}
 		    void leave(const Node&) {}
 		    void backtrack(const Arc&) {}
 		    template <typename _Visitor>
 		    struct Constraints {
 		      void constraints() {
 		        Arc arc;
 		        Node node;
 		        visitor.start(node);
 		        visitor.stop(arc);
 		        visitor.reach(node);
 		        visitor.discover(arc);
 		        visitor.examine(arc);
 		        visitor.leave(node);
 		        visitor.backtrack(arc);
+		      }
 		      _Visitor& visitor;
 		    };
 		  };
 		#endif
 		  /// \brief Default traits class of DfsVisit class.
 		  ///
 		  /// Default traits class of DfsVisit class.
 		  /// \tparam _Digraph The type of the digraph the algorithm runs on.
 		  template<class _Digraph>
 		  struct DfsVisitDefaultTraits {
 		    /// \brief The type of the digraph 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::ReadWriteMap "ReadWriteMap" concept.
 		    typedef typename Digraph::template NodeMap<bool> ReachedMap;
 		    /// \brief Instantiates a ReachedMap.
 		    ///
 		    /// This function instantiates a ReachedMap.
 		    /// \param digraph is the digraph, to which
 		    /// we would like to define the ReachedMap.
 		    static ReachedMap *createReachedMap(const Digraph &digraph) {
 		      return new ReachedMap(digraph);
+		    }
 		  };
 		  /// \ingroup search
 		  ///
 		  /// \brief %DFS algorithm class with visitor interface.
 		  ///
 		  /// 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
 		  /// the member functions of the \c Visitor class on every DFS event.
 		  ///
 		  /// This interface of the DFS algorithm should be used in special cases
 		  /// when extra actions have to be performed in connection with certain
 		  /// events of the DFS algorithm. Otherwise consider to use Dfs or dfs()
 		  /// instead.
 		  ///
 		  /// \tparam _Digraph The type of the digraph the algorithm runs on.
 		  /// The default value is
 		  /// \ref ListDigraph. The value of _Digraph is not used directly by
 		  /// \ref DfsVisit, it is only passed to \ref DfsVisitDefaultTraits.
 		  /// \tparam _Visitor The Visitor type that is used by the algorithm.
 		  /// \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.
 		  /// \tparam _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.
 		#ifdef DOXYGEN
 		  template <typename _Digraph, typename _Visitor, typename _Traits>
 		#else
 		  template <typename _Digraph = ListDigraph,
 		            typename _Visitor = DfsVisitor<_Digraph>,
 		            typename _Traits = DfsVisitDefaultTraits<_Digraph> >
 		#endif
 		  class DfsVisit {
 		  public:
 		    ///The traits class.
 		    typedef _Traits Traits;
 		    ///The type of the digraph the algorithm runs on.
 		    typedef typename Traits::Digraph Digraph;
 		    ///The visitor type used by the algorithm.
 		    typedef _Visitor Visitor;
 		    ///The type of the map that indicates 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 _reached is locally allocated (true) or not.
 		    bool local_reached;
 		    std::vector<typename Digraph::Arc> _stack;
 		    int _stack_head;
 		    //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 SetReachedMapTraits : public Traits {
 		      typedef T ReachedMap;
 		      static ReachedMap *createReachedMap(const Digraph &digraph) {
 		        LEMON_ASSERT(false, "ReachedMap is not initialized");
 		        return 0; // ignore warnings
+		      }
 		    };
 		    /// \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 SetReachedMap : public DfsVisit< Digraph, Visitor,
 		                                            SetReachedMapTraits<T> > {
 		      typedef DfsVisit< Digraph, Visitor, SetReachedMapTraits<T> > Create;
 		    };
 		    ///@}
 		  public:
 		    /// \brief Constructor.
 		    ///
 		    /// Constructor.
 		    ///
 		    /// \param digraph The digraph the algorithm runs on.
 		    /// \param visitor The visitor object of the algorithm.
 		    DfsVisit(const Digraph& digraph, Visitor& visitor)
 		      : _digraph(&digraph), _visitor(&visitor),
 		        _reached(0), local_reached(false) {}
 		    /// \brief Destructor.
 		    ~DfsVisit() {
 		      if(local_reached) delete _reached;
+		    }
 		    /// \brief Sets the map that indicates which nodes are reached.
 		    ///
 		    /// Sets the map that indicates which nodes are reached.
 		    /// If you don't use this function before calling \ref run(),
 		    /// it will allocate one. The destructor 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 \ref lemon::DfsVisit::run()
 		    /// "run()".
 		    /// \n
 		    /// If you need more control on the execution, first you must call
 		    /// \ref lemon::DfsVisit::init() "init()", then you can add several
 		    /// source nodes with \ref lemon::DfsVisit::addSource() "addSource()".
 		    /// Finally \ref lemon::DfsVisit::start() "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);
+		      }
+		    }
 		    ///Adds a new source node.
 		    ///Adds a new source node to the set of nodes to be processed.
 		    ///
 		    ///\pre The stack must be empty. (Otherwise the algorithm gives
 		    ///false results.)
 		    ///
 		    ///\warning Distances will be wrong (or at least strange) in case of
 		    ///multiple sources.
 		    void addSource(Node s)
+		    {
 		      LEMON_DEBUG(emptyQueue(), "The stack is not empty.");
 		      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() const {
 		      return _stack_head >= 0 ? _stack[_stack_head] : INVALID;
+		    }
 		    /// \brief Returns \c false if there are nodes
 		    /// to be processed.
 		    ///
 		    /// Returns \c false if there are nodes
 		    /// to be processed in the queue (stack).
 		    bool emptyQueue() const { 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 (stack).
 		    int queueSize() const { return _stack_head + 1; }
 		    /// \brief Executes the algorithm.
 		    ///
 		    /// Executes the algorithm.
 		    ///
 		    /// This method runs the %DFS algorithm from the root node
 		    /// 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.
 		    ///
 		    /// \pre init() must be called and a root node should be
 		    /// added with addSource() before using this function.
 		    ///
 		    /// \note <tt>d.start()</tt> is just a shortcut of the following code.
 		    /// \code
 		    ///   while ( !d.emptyQueue() ) {
 		    ///     d.processNextArc();
 		    ///   }
 		    /// \endcode
 		    void start() {
 		      while ( !emptyQueue() ) processNextArc();
+		    }
 		    /// \brief Executes the algorithm until the given target node is reached.
 		    ///
 		    /// Executes the algorithm until the given target node is reached.
 		    ///
 		    /// This method runs the %DFS algorithm from the root node
 		    /// in order to compute the DFS path to \c t.
 		    ///
 		    /// The algorithm computes
 		    /// - the %DFS path to \c t,
 		    /// - the distance of \c t from the root in the %DFS tree.
 		    ///
 		    /// \pre init() must be called and a root node should be added
 		    /// with addSource() before using this function.
 		    void start(Node t) {
-		      while ( !emptyQueue() && _digraph->target(_stack[_stack_head]) != t )
+		      while ( !emptyQueue() && !(*_reached)[t] )
 		        processNextArc();
+		    }
 		    /// \brief Executes the algorithm until a condition is met.
 		    ///
 		    /// Executes the algorithm until a condition is met.
 		    ///
 		    /// This method runs the %DFS algorithm from the root node
 		    /// until an arc \c a with <tt>am[a]</tt> true is found.
 		    ///
 		    /// \param am A \c bool (or convertible) arc map. The algorithm
 		    /// will stop when it reaches an arc \c a with <tt>am[a]</tt> true.
 		    ///
 		    /// \return The reached arc \c a with <tt>am[a]</tt> true or
 		    /// \c INVALID if no such arc was found.
 		    ///
 		    /// \pre init() must be called and a root node should be added
 		    /// with addSource() before using this function.
 		    ///
 		    /// \warning Contrary to \ref Bfs and \ref Dijkstra, \c am is an arc map,
 		    /// not a node map.
 		    template <typename AM>
 		    Arc start(const AM &am) {
 		      while ( !emptyQueue() && !am[_stack[_stack_head]] )
 		        processNextArc();
 		      return emptyQueue() ? INVALID : _stack[_stack_head];
+		    }
 		    /// \brief Runs the algorithm from the given source node.
 		    ///
 		    /// This method runs the %DFS algorithm from 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 <tt>d.run(s)</tt> 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 Finds the %DFS path between \c s and \c t.
 		    /// This method runs the %DFS algorithm from node \c s
 		    /// in order to compute the DFS path to node \c t
 		    /// (it stops searching when \c t is processed).
 		    ///
 		    /// \return \c true if \c t is reachable form \c s.
 		    ///
 		    /// \note Apart from the return value, <tt>d.run(s,t)</tt> is
 		    /// just a shortcut of the following code.
 		    ///\code
 		    ///   d.init();
 		    ///   d.addSource(s);
 		    ///   d.start(t);
 		    ///\endcode
 		    bool run(Node s,Node t) {
 		      init();
 		      addSource(s);
 		      start(t);
 		      return reached(t);
+		    }
 		    /// \brief Runs the 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 <tt>d.run()</tt> is just a shortcut of the following code.
 		    ///\code
 		    ///   d.init();
 		    ///   for (NodeIt n(digraph); n != INVALID; ++n) {
 		    ///     if (!d.reached(n)) {
 		    ///       d.addSource(n);
 		    ///       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
 		    /// Either \ref lemon::DfsVisit::run() "run()" or
 		    /// \ref lemon::DfsVisit::start() "start()" must be called before
 		    /// using them.
 		    ///@{
 		    /// \brief Checks if a node is reachable from the root(s).
 		    ///
 		    /// Returns \c true if \c v is reachable from the root(s).
 		    /// \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

test/dfs_test.cc

Show inline comments

 		/* -*- mode: C++; indent-tabs-mode: nil; -*-
+		 *
 		 * 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.
+		 *
 		 */
 		#include <lemon/concepts/digraph.h>
 		#include <lemon/smart_graph.h>
 		#include <lemon/list_graph.h>
 		#include <lemon/lgf_reader.h>
 		#include <lemon/dfs.h>
 		#include <lemon/path.h>
 		#include "graph_test.h"
 		#include "test_tools.h"
 		using namespace lemon;
 		char test_lgf[] =
 		  "@nodes\n"
 		  "label\n"
 		  "0\n"
 		  "1\n"
 		  "2\n"
 		  "3\n"
 		  "4\n"
 		  "5\n"
 		  "6\n"
 		  "@arcs\n"
 		  "     label\n"
 		  "0 1  0\n"
 		  "1 2  1\n"
 		  "2 3  2\n"
 		  "1 4  3\n"
 		  "4 2  4\n"
 		  "4 5  5\n"
 		  "5 0  6\n"
 		  "6 3  7\n"
 		  "@attributes\n"
 		  "source 0\n"
-		  "target 5\n";
 		  "target 5\n"
 		  "source1 6\n"
 		  "target1 3\n";
 		void checkDfsCompile()
+		{
 		  typedef concepts::Digraph Digraph;
 		  typedef Dfs<Digraph> DType;
 		  typedef Digraph::Node Node;
 		  typedef Digraph::Arc Arc;
 		  Digraph G;
 		  Node s, t;
 		  Arc e;
 		  int l;
 		  bool b;
 		  DType::DistMap d(G);
 		  DType::PredMap p(G);
 		  Path<Digraph> pp;
+		  {
 		    DType dfs_test(G);
 		    dfs_test.run(s);
 		    dfs_test.run(s,t);
 		    dfs_test.run();
 		    l  = dfs_test.dist(t);
 		    e  = dfs_test.predArc(t);
 		    s  = dfs_test.predNode(t);
 		    b  = dfs_test.reached(t);
 		    d  = dfs_test.distMap();
 		    p  = dfs_test.predMap();
 		    pp = dfs_test.path(t);
+		  }
+		  {
 		    DType
 		      ::SetPredMap<concepts::ReadWriteMap<Node,Arc> >
 		      ::SetDistMap<concepts::ReadWriteMap<Node,int> >
 		      ::SetReachedMap<concepts::ReadWriteMap<Node,bool> >
 		      ::SetProcessedMap<concepts::WriteMap<Node,bool> >
 		      ::SetStandardProcessedMap
 		      ::Create dfs_test(G);
 		    dfs_test.run(s);
 		    dfs_test.run(s,t);
 		    dfs_test.run();
 		    l  = dfs_test.dist(t);
 		    e  = dfs_test.predArc(t);
 		    s  = dfs_test.predNode(t);
 		    b  = dfs_test.reached(t);
 		    pp = dfs_test.path(t);
+		  }
+		}
 		void checkDfsFunctionCompile()
+		{
 		  typedef int VType;
 		  typedef concepts::Digraph Digraph;
 		  typedef Digraph::Arc Arc;
 		  typedef Digraph::Node Node;
 		  Digraph g;
 		  bool b;
 		  dfs(g).run(Node());
 		  b=dfs(g).run(Node(),Node());
 		  dfs(g).run();
 		  dfs(g)
 		    .predMap(concepts::ReadWriteMap<Node,Arc>())
 		    .distMap(concepts::ReadWriteMap<Node,VType>())
 		    .reachedMap(concepts::ReadWriteMap<Node,bool>())
 		    .processedMap(concepts::WriteMap<Node,bool>())
 		    .run(Node());
 		  b=dfs(g)
 		    .predMap(concepts::ReadWriteMap<Node,Arc>())
 		    .distMap(concepts::ReadWriteMap<Node,VType>())
 		    .reachedMap(concepts::ReadWriteMap<Node,bool>())
 		    .processedMap(concepts::WriteMap<Node,bool>())
 		    .path(concepts::Path<Digraph>())
 		    .dist(VType())
 		    .run(Node(),Node());
 		  dfs(g)
 		    .predMap(concepts::ReadWriteMap<Node,Arc>())
 		    .distMap(concepts::ReadWriteMap<Node,VType>())
 		    .reachedMap(concepts::ReadWriteMap<Node,bool>())
 		    .processedMap(concepts::WriteMap<Node,bool>())
 		    .run();
+		}
 		template <class Digraph>
 		void checkDfs() {
 		  TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
 		  Digraph G;
 		  Node s, t;
 		  Node s1, t1;
 		  std::istringstream input(test_lgf);
 		  digraphReader(G, input).
 		    node("source", s).
 		    node("target", t).
 		    node("source1", s1).
 		    node("target1", t1).
 		    run();
 		  Dfs<Digraph> dfs_test(G);
 		  dfs_test.run(s);
 		  Path<Digraph> p = dfs_test.path(t);
 		  check(p.length() == dfs_test.dist(t),"path() found a wrong path.");
 		  check(checkPath(G, p),"path() found a wrong path.");
 		  check(pathSource(G, p) == s,"path() found a wrong path.");
 		  check(pathTarget(G, p) == t,"path() found a wrong path.");
 		  for(NodeIt v(G); v!=INVALID; ++v) {
 		    if (dfs_test.reached(v)) {
 		      check(v==s || dfs_test.predArc(v)!=INVALID, "Wrong tree.");
 		      if (dfs_test.predArc(v)!=INVALID ) {
 		        Arc e=dfs_test.predArc(v);
 		        Node u=G.source(e);
 		        check(u==dfs_test.predNode(v),"Wrong tree.");
 		        check(dfs_test.dist(v) - dfs_test.dist(u) == 1,
 		              "Wrong distance. (" << dfs_test.dist(u) << "->"
 		              << dfs_test.dist(v) << ")");
+		      }
+		    }
+		  }
+		  {
 		  Dfs<Digraph> dfs(G);
 		  check(dfs.run(s1,t1) && dfs.reached(t1),"Node 3 is reachable from Node 6.");
+		  }
+		  {
 		    NullMap<Node,Arc> myPredMap;
 		    dfs(G).predMap(myPredMap).run(s);
+		  }
+		}
 		int main()
+		{
 		  checkDfs<ListDigraph>();
 		  checkDfs<SmartDigraph>();
 		  return 0;
+		}

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