lemon/dfs.h
changeset 802 994c7df296c9
parent 503 9605e051942f
child 713 4ac30454f1c1
child 716 f47b6c94577e
child 959 17e36e175725
     1.1 --- a/lemon/dfs.h	Fri Nov 13 12:33:33 2009 +0100
     1.2 +++ b/lemon/dfs.h	Thu Dec 10 17:05:35 2009 +0100
     1.3 @@ -2,7 +2,7 @@
     1.4   *
     1.5   * This file is a part of LEMON, a generic C++ optimization library.
     1.6   *
     1.7 - * Copyright (C) 2003-2008
     1.8 + * Copyright (C) 2003-2009
     1.9   * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
    1.10   * (Egervary Research Group on Combinatorial Optimization, EGRES).
    1.11   *
    1.12 @@ -49,11 +49,11 @@
    1.13      ///arcs of the %DFS paths.
    1.14      ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
    1.15      typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;
    1.16 -    ///Instantiates a PredMap.
    1.17 +    ///Instantiates a \c PredMap.
    1.18  
    1.19 -    ///This function instantiates a PredMap.
    1.20 +    ///This function instantiates a \ref PredMap.
    1.21      ///\param g is the digraph, to which we would like to define the
    1.22 -    ///PredMap.
    1.23 +    ///\ref PredMap.
    1.24      static PredMap *createPredMap(const Digraph &g)
    1.25      {
    1.26        return new PredMap(g);
    1.27 @@ -64,11 +64,11 @@
    1.28      ///The type of the map that indicates which nodes are processed.
    1.29      ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
    1.30      typedef NullMap<typename Digraph::Node,bool> ProcessedMap;
    1.31 -    ///Instantiates a ProcessedMap.
    1.32 +    ///Instantiates a \c ProcessedMap.
    1.33  
    1.34 -    ///This function instantiates a ProcessedMap.
    1.35 +    ///This function instantiates a \ref ProcessedMap.
    1.36      ///\param g is the digraph, to which
    1.37 -    ///we would like to define the ProcessedMap
    1.38 +    ///we would like to define the \ref ProcessedMap.
    1.39  #ifdef DOXYGEN
    1.40      static ProcessedMap *createProcessedMap(const Digraph &g)
    1.41  #else
    1.42 @@ -83,11 +83,11 @@
    1.43      ///The type of the map that indicates which nodes are reached.
    1.44      ///It must meet the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
    1.45      typedef typename Digraph::template NodeMap<bool> ReachedMap;
    1.46 -    ///Instantiates a ReachedMap.
    1.47 +    ///Instantiates a \c ReachedMap.
    1.48  
    1.49 -    ///This function instantiates a ReachedMap.
    1.50 +    ///This function instantiates a \ref ReachedMap.
    1.51      ///\param g is the digraph, to which
    1.52 -    ///we would like to define the ReachedMap.
    1.53 +    ///we would like to define the \ref ReachedMap.
    1.54      static ReachedMap *createReachedMap(const Digraph &g)
    1.55      {
    1.56        return new ReachedMap(g);
    1.57 @@ -98,11 +98,11 @@
    1.58      ///The type of the map that stores the distances of the nodes.
    1.59      ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
    1.60      typedef typename Digraph::template NodeMap<int> DistMap;
    1.61 -    ///Instantiates a DistMap.
    1.62 +    ///Instantiates a \c DistMap.
    1.63  
    1.64 -    ///This function instantiates a DistMap.
    1.65 +    ///This function instantiates a \ref DistMap.
    1.66      ///\param g is the digraph, to which we would like to define the
    1.67 -    ///DistMap.
    1.68 +    ///\ref DistMap.
    1.69      static DistMap *createDistMap(const Digraph &g)
    1.70      {
    1.71        return new DistMap(g);
    1.72 @@ -119,13 +119,7 @@
    1.73    ///used easier.
    1.74    ///
    1.75    ///\tparam GR The type of the digraph the algorithm runs on.
    1.76 -  ///The default value is \ref ListDigraph. The value of GR is not used
    1.77 -  ///directly by \ref Dfs, it is only passed to \ref DfsDefaultTraits.
    1.78 -  ///\tparam TR Traits class to set various data types used by the algorithm.
    1.79 -  ///The default traits class is
    1.80 -  ///\ref DfsDefaultTraits "DfsDefaultTraits<GR>".
    1.81 -  ///See \ref DfsDefaultTraits for the documentation of
    1.82 -  ///a Dfs traits class.
    1.83 +  ///The default type is \ref ListDigraph.
    1.84  #ifdef DOXYGEN
    1.85    template <typename GR,
    1.86              typename TR>
    1.87 @@ -151,7 +145,7 @@
    1.88      ///The type of the paths.
    1.89      typedef PredMapPath<Digraph, PredMap> Path;
    1.90  
    1.91 -    ///The traits class.
    1.92 +    ///The \ref DfsDefaultTraits "traits class" of the algorithm.
    1.93      typedef TR Traits;
    1.94  
    1.95    private:
    1.96 @@ -212,7 +206,7 @@
    1.97  
    1.98      typedef Dfs Create;
    1.99  
   1.100 -    ///\name Named template parameters
   1.101 +    ///\name Named Template Parameters
   1.102  
   1.103      ///@{
   1.104  
   1.105 @@ -226,10 +220,11 @@
   1.106        }
   1.107      };
   1.108      ///\brief \ref named-templ-param "Named parameter" for setting
   1.109 -    ///PredMap type.
   1.110 +    ///\c PredMap type.
   1.111      ///
   1.112      ///\ref named-templ-param "Named parameter" for setting
   1.113 -    ///PredMap type.
   1.114 +    ///\c PredMap type.
   1.115 +    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
   1.116      template <class T>
   1.117      struct SetPredMap : public Dfs<Digraph, SetPredMapTraits<T> > {
   1.118        typedef Dfs<Digraph, SetPredMapTraits<T> > Create;
   1.119 @@ -245,10 +240,11 @@
   1.120        }
   1.121      };
   1.122      ///\brief \ref named-templ-param "Named parameter" for setting
   1.123 -    ///DistMap type.
   1.124 +    ///\c DistMap type.
   1.125      ///
   1.126      ///\ref named-templ-param "Named parameter" for setting
   1.127 -    ///DistMap type.
   1.128 +    ///\c DistMap type.
   1.129 +    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
   1.130      template <class T>
   1.131      struct SetDistMap : public Dfs< Digraph, SetDistMapTraits<T> > {
   1.132        typedef Dfs<Digraph, SetDistMapTraits<T> > Create;
   1.133 @@ -264,10 +260,11 @@
   1.134        }
   1.135      };
   1.136      ///\brief \ref named-templ-param "Named parameter" for setting
   1.137 -    ///ReachedMap type.
   1.138 +    ///\c ReachedMap type.
   1.139      ///
   1.140      ///\ref named-templ-param "Named parameter" for setting
   1.141 -    ///ReachedMap type.
   1.142 +    ///\c ReachedMap type.
   1.143 +    ///It must meet the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
   1.144      template <class T>
   1.145      struct SetReachedMap : public Dfs< Digraph, SetReachedMapTraits<T> > {
   1.146        typedef Dfs< Digraph, SetReachedMapTraits<T> > Create;
   1.147 @@ -283,10 +280,11 @@
   1.148        }
   1.149      };
   1.150      ///\brief \ref named-templ-param "Named parameter" for setting
   1.151 -    ///ProcessedMap type.
   1.152 +    ///\c ProcessedMap type.
   1.153      ///
   1.154      ///\ref named-templ-param "Named parameter" for setting
   1.155 -    ///ProcessedMap type.
   1.156 +    ///\c ProcessedMap type.
   1.157 +    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.
   1.158      template <class T>
   1.159      struct SetProcessedMap : public Dfs< Digraph, SetProcessedMapTraits<T> > {
   1.160        typedef Dfs< Digraph, SetProcessedMapTraits<T> > Create;
   1.161 @@ -300,10 +298,10 @@
   1.162        }
   1.163      };
   1.164      ///\brief \ref named-templ-param "Named parameter" for setting
   1.165 -    ///ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
   1.166 +    ///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
   1.167      ///
   1.168      ///\ref named-templ-param "Named parameter" for setting
   1.169 -    ///ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
   1.170 +    ///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.
   1.171      ///If you don't set it explicitly, it will be automatically allocated.
   1.172      struct SetStandardProcessedMap :
   1.173        public Dfs< Digraph, SetStandardProcessedMapTraits > {
   1.174 @@ -338,9 +336,10 @@
   1.175      ///Sets the map that stores the predecessor arcs.
   1.176  
   1.177      ///Sets the map that stores the predecessor arcs.
   1.178 -    ///If you don't use this function before calling \ref run(),
   1.179 -    ///it will allocate one. The destructor deallocates this
   1.180 -    ///automatically allocated map, of course.
   1.181 +    ///If you don't use this function before calling \ref run(Node) "run()"
   1.182 +    ///or \ref init(), an instance will be allocated automatically.
   1.183 +    ///The destructor deallocates this automatically allocated map,
   1.184 +    ///of course.
   1.185      ///\return <tt> (*this) </tt>
   1.186      Dfs &predMap(PredMap &m)
   1.187      {
   1.188 @@ -355,9 +354,10 @@
   1.189      ///Sets the map that indicates which nodes are reached.
   1.190  
   1.191      ///Sets the map that indicates which nodes are reached.
   1.192 -    ///If you don't use this function before calling \ref run(),
   1.193 -    ///it will allocate one. The destructor deallocates this
   1.194 -    ///automatically allocated map, of course.
   1.195 +    ///If you don't use this function before calling \ref run(Node) "run()"
   1.196 +    ///or \ref init(), an instance will be allocated automatically.
   1.197 +    ///The destructor deallocates this automatically allocated map,
   1.198 +    ///of course.
   1.199      ///\return <tt> (*this) </tt>
   1.200      Dfs &reachedMap(ReachedMap &m)
   1.201      {
   1.202 @@ -372,9 +372,10 @@
   1.203      ///Sets the map that indicates which nodes are processed.
   1.204  
   1.205      ///Sets the map that indicates which nodes are processed.
   1.206 -    ///If you don't use this function before calling \ref run(),
   1.207 -    ///it will allocate one. The destructor deallocates this
   1.208 -    ///automatically allocated map, of course.
   1.209 +    ///If you don't use this function before calling \ref run(Node) "run()"
   1.210 +    ///or \ref init(), an instance will be allocated automatically.
   1.211 +    ///The destructor deallocates this automatically allocated map,
   1.212 +    ///of course.
   1.213      ///\return <tt> (*this) </tt>
   1.214      Dfs &processedMap(ProcessedMap &m)
   1.215      {
   1.216 @@ -390,9 +391,10 @@
   1.217  
   1.218      ///Sets the map that stores the distances of the nodes calculated by
   1.219      ///the algorithm.
   1.220 -    ///If you don't use this function before calling \ref run(),
   1.221 -    ///it will allocate one. The destructor deallocates this
   1.222 -    ///automatically allocated map, of course.
   1.223 +    ///If you don't use this function before calling \ref run(Node) "run()"
   1.224 +    ///or \ref init(), an instance will be allocated automatically.
   1.225 +    ///The destructor deallocates this automatically allocated map,
   1.226 +    ///of course.
   1.227      ///\return <tt> (*this) </tt>
   1.228      Dfs &distMap(DistMap &m)
   1.229      {
   1.230 @@ -406,22 +408,20 @@
   1.231  
   1.232    public:
   1.233  
   1.234 -    ///\name Execution control
   1.235 -    ///The simplest way to execute the algorithm is to use
   1.236 -    ///one of the member functions called \ref lemon::Dfs::run() "run()".
   1.237 -    ///\n
   1.238 -    ///If you need more control on the execution, first you must call
   1.239 -    ///\ref lemon::Dfs::init() "init()", then you can add a source node
   1.240 -    ///with \ref lemon::Dfs::addSource() "addSource()".
   1.241 -    ///Finally \ref lemon::Dfs::start() "start()" will perform the
   1.242 -    ///actual path computation.
   1.243 +    ///\name Execution Control
   1.244 +    ///The simplest way to execute the DFS algorithm is to use one of the
   1.245 +    ///member functions called \ref run(Node) "run()".\n
   1.246 +    ///If you need more control on the execution, first you have to call
   1.247 +    ///\ref init(), then you can add a source node with \ref addSource()
   1.248 +    ///and perform the actual computation with \ref start().
   1.249 +    ///This procedure can be repeated if there are nodes that have not
   1.250 +    ///been reached.
   1.251  
   1.252      ///@{
   1.253  
   1.254 +    ///\brief Initializes the internal data structures.
   1.255 +    ///
   1.256      ///Initializes the internal data structures.
   1.257 -
   1.258 -    ///Initializes the internal data structures.
   1.259 -    ///
   1.260      void init()
   1.261      {
   1.262        create_maps();
   1.263 @@ -438,11 +438,10 @@
   1.264  
   1.265      ///Adds a new source node to the set of nodes to be processed.
   1.266      ///
   1.267 -    ///\pre The stack must be empty. (Otherwise the algorithm gives
   1.268 -    ///false results.)
   1.269 -    ///
   1.270 -    ///\warning Distances will be wrong (or at least strange) in case of
   1.271 -    ///multiple sources.
   1.272 +    ///\pre The stack must be empty. Otherwise the algorithm gives
   1.273 +    ///wrong results. (One of the outgoing arcs of all the source nodes
   1.274 +    ///except for the last one will not be visited and distances will
   1.275 +    ///also be wrong.)
   1.276      void addSource(Node s)
   1.277      {
   1.278        LEMON_DEBUG(emptyQueue(), "The stack is not empty.");
   1.279 @@ -506,16 +505,16 @@
   1.280        return _stack_head>=0?_stack[_stack_head]:INVALID;
   1.281      }
   1.282  
   1.283 -    ///\brief Returns \c false if there are nodes
   1.284 -    ///to be processed.
   1.285 -    ///
   1.286 -    ///Returns \c false if there are nodes
   1.287 -    ///to be processed in the queue (stack).
   1.288 +    ///Returns \c false if there are nodes to be processed.
   1.289 +
   1.290 +    ///Returns \c false if there are nodes to be processed
   1.291 +    ///in the queue (stack).
   1.292      bool emptyQueue() const { return _stack_head<0; }
   1.293  
   1.294      ///Returns the number of the nodes to be processed.
   1.295  
   1.296 -    ///Returns the number of the nodes to be processed in the queue (stack).
   1.297 +    ///Returns the number of the nodes to be processed
   1.298 +    ///in the queue (stack).
   1.299      int queueSize() const { return _stack_head+1; }
   1.300  
   1.301      ///Executes the algorithm.
   1.302 @@ -637,8 +636,8 @@
   1.303      ///%DFS path to each node.
   1.304      ///
   1.305      ///The algorithm computes
   1.306 -    ///- the %DFS tree,
   1.307 -    ///- the distance of each node from the root in the %DFS tree.
   1.308 +    ///- the %DFS tree (forest),
   1.309 +    ///- the distance of each node from the root(s) in the %DFS tree.
   1.310      ///
   1.311      ///\note <tt>d.run()</tt> is just a shortcut of the following code.
   1.312      ///\code
   1.313 @@ -663,10 +662,10 @@
   1.314      ///@}
   1.315  
   1.316      ///\name Query Functions
   1.317 -    ///The result of the %DFS algorithm can be obtained using these
   1.318 +    ///The results of the DFS algorithm can be obtained using these
   1.319      ///functions.\n
   1.320 -    ///Either \ref lemon::Dfs::run() "run()" or \ref lemon::Dfs::start()
   1.321 -    ///"start()" must be called before using them.
   1.322 +    ///Either \ref run(Node) "run()" or \ref start() should be called
   1.323 +    ///before using them.
   1.324  
   1.325      ///@{
   1.326  
   1.327 @@ -674,49 +673,49 @@
   1.328  
   1.329      ///Returns the DFS path to a node.
   1.330      ///
   1.331 -    ///\warning \c t should be reachable from the root.
   1.332 +    ///\warning \c t should be reached from the root(s).
   1.333      ///
   1.334 -    ///\pre Either \ref run() or \ref start() must be called before
   1.335 -    ///using this function.
   1.336 +    ///\pre Either \ref run(Node) "run()" or \ref init()
   1.337 +    ///must be called before using this function.
   1.338      Path path(Node t) const { return Path(*G, *_pred, t); }
   1.339  
   1.340 -    ///The distance of a node from the root.
   1.341 +    ///The distance of a node from the root(s).
   1.342  
   1.343 -    ///Returns the distance of a node from the root.
   1.344 +    ///Returns the distance of a node from the root(s).
   1.345      ///
   1.346 -    ///\warning If node \c v is not reachable from the root, then
   1.347 +    ///\warning If node \c v is not reached from the root(s), then
   1.348      ///the return value of this function is undefined.
   1.349      ///
   1.350 -    ///\pre Either \ref run() or \ref start() must be called before
   1.351 -    ///using this function.
   1.352 +    ///\pre Either \ref run(Node) "run()" or \ref init()
   1.353 +    ///must be called before using this function.
   1.354      int dist(Node v) const { return (*_dist)[v]; }
   1.355  
   1.356      ///Returns the 'previous arc' of the %DFS tree for a node.
   1.357  
   1.358      ///This function returns the 'previous arc' of the %DFS tree for the
   1.359 -    ///node \c v, i.e. it returns the last arc of a %DFS path from the
   1.360 -    ///root to \c v. It is \c INVALID
   1.361 -    ///if \c v is not reachable from the root(s) or if \c v is a root.
   1.362 +    ///node \c v, i.e. it returns the last arc of a %DFS path from a
   1.363 +    ///root to \c v. It is \c INVALID if \c v is not reached from the
   1.364 +    ///root(s) or if \c v is a root.
   1.365      ///
   1.366      ///The %DFS tree used here is equal to the %DFS tree used in
   1.367      ///\ref predNode().
   1.368      ///
   1.369 -    ///\pre Either \ref run() or \ref start() must be called before using
   1.370 -    ///this function.
   1.371 +    ///\pre Either \ref run(Node) "run()" or \ref init()
   1.372 +    ///must be called before using this function.
   1.373      Arc predArc(Node v) const { return (*_pred)[v];}
   1.374  
   1.375      ///Returns the 'previous node' of the %DFS tree.
   1.376  
   1.377      ///This function returns the 'previous node' of the %DFS
   1.378      ///tree for the node \c v, i.e. it returns the last but one node
   1.379 -    ///from a %DFS path from the root to \c v. It is \c INVALID
   1.380 -    ///if \c v is not reachable from the root(s) or if \c v is a root.
   1.381 +    ///from a %DFS path from a root to \c v. It is \c INVALID
   1.382 +    ///if \c v is not reached from the root(s) or if \c v is a root.
   1.383      ///
   1.384      ///The %DFS tree used here is equal to the %DFS tree used in
   1.385      ///\ref predArc().
   1.386      ///
   1.387 -    ///\pre Either \ref run() or \ref start() must be called before
   1.388 -    ///using this function.
   1.389 +    ///\pre Either \ref run(Node) "run()" or \ref init()
   1.390 +    ///must be called before using this function.
   1.391      Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID:
   1.392                                    G->source((*_pred)[v]); }
   1.393  
   1.394 @@ -726,7 +725,7 @@
   1.395      ///Returns a const reference to the node map that stores the
   1.396      ///distances of the nodes calculated by the algorithm.
   1.397      ///
   1.398 -    ///\pre Either \ref run() or \ref init()
   1.399 +    ///\pre Either \ref run(Node) "run()" or \ref init()
   1.400      ///must be called before using this function.
   1.401      const DistMap &distMap() const { return *_dist;}
   1.402  
   1.403 @@ -736,14 +735,15 @@
   1.404      ///Returns a const reference to the node map that stores the predecessor
   1.405      ///arcs, which form the DFS tree.
   1.406      ///
   1.407 -    ///\pre Either \ref run() or \ref init()
   1.408 +    ///\pre Either \ref run(Node) "run()" or \ref init()
   1.409      ///must be called before using this function.
   1.410      const PredMap &predMap() const { return *_pred;}
   1.411  
   1.412 -    ///Checks if a node is reachable from the root(s).
   1.413 +    ///Checks if a node is reached from the root(s).
   1.414  
   1.415 -    ///Returns \c true if \c v is reachable from the root(s).
   1.416 -    ///\pre Either \ref run() or \ref start()
   1.417 +    ///Returns \c true if \c v is reached from the root(s).
   1.418 +    ///
   1.419 +    ///\pre Either \ref run(Node) "run()" or \ref init()
   1.420      ///must be called before using this function.
   1.421      bool reached(Node v) const { return (*_reached)[v]; }
   1.422  
   1.423 @@ -889,8 +889,8 @@
   1.424  
   1.425    /// This auxiliary class is created to implement the
   1.426    /// \ref dfs() "function-type interface" of \ref Dfs algorithm.
   1.427 -  /// It does not have own \ref run() method, it uses the functions
   1.428 -  /// and features of the plain \ref Dfs.
   1.429 +  /// It does not have own \ref run(Node) "run()" method, it uses the
   1.430 +  /// functions and features of the plain \ref Dfs.
   1.431    ///
   1.432    /// This class should only be used through the \ref dfs() function,
   1.433    /// which makes it easier to use the algorithm.
   1.434 @@ -1110,8 +1110,7 @@
   1.435    ///  // Compute the DFS path from s to t
   1.436    ///  bool reached = dfs(g).path(p).dist(d).run(s,t);
   1.437    ///\endcode
   1.438 -
   1.439 -  ///\warning Don't forget to put the \ref DfsWizard::run() "run()"
   1.440 +  ///\warning Don't forget to put the \ref DfsWizard::run(Node) "run()"
   1.441    ///to the end of the parameter list.
   1.442    ///\sa DfsWizard
   1.443    ///\sa Dfs
   1.444 @@ -1127,9 +1126,9 @@
   1.445    ///
   1.446    /// This class defines the interface of the DfsVisit events, and
   1.447    /// it could be the base of a real visitor class.
   1.448 -  template <typename _Digraph>
   1.449 +  template <typename GR>
   1.450    struct DfsVisitor {
   1.451 -    typedef _Digraph Digraph;
   1.452 +    typedef GR Digraph;
   1.453      typedef typename Digraph::Arc Arc;
   1.454      typedef typename Digraph::Node Node;
   1.455      /// \brief Called for the source node of the DFS.
   1.456 @@ -1165,9 +1164,9 @@
   1.457      void backtrack(const Arc& arc) {}
   1.458    };
   1.459  #else
   1.460 -  template <typename _Digraph>
   1.461 +  template <typename GR>
   1.462    struct DfsVisitor {
   1.463 -    typedef _Digraph Digraph;
   1.464 +    typedef GR Digraph;
   1.465      typedef typename Digraph::Arc Arc;
   1.466      typedef typename Digraph::Node Node;
   1.467      void start(const Node&) {}
   1.468 @@ -1200,11 +1199,11 @@
   1.469    ///
   1.470    /// Default traits class of DfsVisit class.
   1.471    /// \tparam _Digraph The type of the digraph the algorithm runs on.
   1.472 -  template<class _Digraph>
   1.473 +  template<class GR>
   1.474    struct DfsVisitDefaultTraits {
   1.475  
   1.476      /// \brief The type of the digraph the algorithm runs on.
   1.477 -    typedef _Digraph Digraph;
   1.478 +    typedef GR Digraph;
   1.479  
   1.480      /// \brief The type of the map that indicates which nodes are reached.
   1.481      ///
   1.482 @@ -1225,12 +1224,12 @@
   1.483  
   1.484    /// \ingroup search
   1.485    ///
   1.486 -  /// \brief %DFS algorithm class with visitor interface.
   1.487 +  /// \brief DFS algorithm class with visitor interface.
   1.488    ///
   1.489 -  /// This class provides an efficient implementation of the %DFS algorithm
   1.490 +  /// This class provides an efficient implementation of the DFS algorithm
   1.491    /// with visitor interface.
   1.492    ///
   1.493 -  /// The %DfsVisit class provides an alternative interface to the Dfs
   1.494 +  /// The DfsVisit class provides an alternative interface to the Dfs
   1.495    /// class. It works with callback mechanism, the DfsVisit object calls
   1.496    /// the member functions of the \c Visitor class on every DFS event.
   1.497    ///
   1.498 @@ -1239,37 +1238,37 @@
   1.499    /// events of the DFS algorithm. Otherwise consider to use Dfs or dfs()
   1.500    /// instead.
   1.501    ///
   1.502 -  /// \tparam _Digraph The type of the digraph the algorithm runs on.
   1.503 -  /// The default value is
   1.504 -  /// \ref ListDigraph. The value of _Digraph is not used directly by
   1.505 -  /// \ref DfsVisit, it is only passed to \ref DfsVisitDefaultTraits.
   1.506 -  /// \tparam _Visitor The Visitor type that is used by the algorithm.
   1.507 -  /// \ref DfsVisitor "DfsVisitor<_Digraph>" is an empty visitor, which
   1.508 +  /// \tparam GR The type of the digraph the algorithm runs on.
   1.509 +  /// The default type is \ref ListDigraph.
   1.510 +  /// The value of GR is not used directly by \ref DfsVisit,
   1.511 +  /// it is only passed to \ref DfsVisitDefaultTraits.
   1.512 +  /// \tparam VS The Visitor type that is used by the algorithm.
   1.513 +  /// \ref DfsVisitor "DfsVisitor<GR>" is an empty visitor, which
   1.514    /// does not observe the DFS events. If you want to observe the DFS
   1.515    /// events, you should implement your own visitor class.
   1.516 -  /// \tparam _Traits Traits class to set various data types used by the
   1.517 +  /// \tparam TR Traits class to set various data types used by the
   1.518    /// algorithm. The default traits class is
   1.519 -  /// \ref DfsVisitDefaultTraits "DfsVisitDefaultTraits<_Digraph>".
   1.520 +  /// \ref DfsVisitDefaultTraits "DfsVisitDefaultTraits<GR>".
   1.521    /// See \ref DfsVisitDefaultTraits for the documentation of
   1.522    /// a DFS visit traits class.
   1.523  #ifdef DOXYGEN
   1.524 -  template <typename _Digraph, typename _Visitor, typename _Traits>
   1.525 +  template <typename GR, typename VS, typename TR>
   1.526  #else
   1.527 -  template <typename _Digraph = ListDigraph,
   1.528 -            typename _Visitor = DfsVisitor<_Digraph>,
   1.529 -            typename _Traits = DfsVisitDefaultTraits<_Digraph> >
   1.530 +  template <typename GR = ListDigraph,
   1.531 +            typename VS = DfsVisitor<GR>,
   1.532 +            typename TR = DfsVisitDefaultTraits<GR> >
   1.533  #endif
   1.534    class DfsVisit {
   1.535    public:
   1.536  
   1.537      ///The traits class.
   1.538 -    typedef _Traits Traits;
   1.539 +    typedef TR Traits;
   1.540  
   1.541      ///The type of the digraph the algorithm runs on.
   1.542      typedef typename Traits::Digraph Digraph;
   1.543  
   1.544      ///The visitor type used by the algorithm.
   1.545 -    typedef _Visitor Visitor;
   1.546 +    typedef VS Visitor;
   1.547  
   1.548      ///The type of the map that indicates which nodes are reached.
   1.549      typedef typename Traits::ReachedMap ReachedMap;
   1.550 @@ -1309,7 +1308,7 @@
   1.551  
   1.552      typedef DfsVisit Create;
   1.553  
   1.554 -    /// \name Named template parameters
   1.555 +    /// \name Named Template Parameters
   1.556  
   1.557      ///@{
   1.558      template <class T>
   1.559 @@ -1351,9 +1350,10 @@
   1.560      /// \brief Sets the map that indicates which nodes are reached.
   1.561      ///
   1.562      /// Sets the map that indicates which nodes are reached.
   1.563 -    /// If you don't use this function before calling \ref run(),
   1.564 -    /// it will allocate one. The destructor deallocates this
   1.565 -    /// automatically allocated map, of course.
   1.566 +    /// If you don't use this function before calling \ref run(Node) "run()"
   1.567 +    /// or \ref init(), an instance will be allocated automatically.
   1.568 +    /// The destructor deallocates this automatically allocated map,
   1.569 +    /// of course.
   1.570      /// \return <tt> (*this) </tt>
   1.571      DfsVisit &reachedMap(ReachedMap &m) {
   1.572        if(local_reached) {
   1.573 @@ -1366,16 +1366,14 @@
   1.574  
   1.575    public:
   1.576  
   1.577 -    /// \name Execution control
   1.578 -    /// The simplest way to execute the algorithm is to use
   1.579 -    /// one of the member functions called \ref lemon::DfsVisit::run()
   1.580 -    /// "run()".
   1.581 -    /// \n
   1.582 -    /// If you need more control on the execution, first you must call
   1.583 -    /// \ref lemon::DfsVisit::init() "init()", then you can add several
   1.584 -    /// source nodes with \ref lemon::DfsVisit::addSource() "addSource()".
   1.585 -    /// Finally \ref lemon::DfsVisit::start() "start()" will perform the
   1.586 -    /// actual path computation.
   1.587 +    /// \name Execution Control
   1.588 +    /// The simplest way to execute the DFS algorithm is to use one of the
   1.589 +    /// member functions called \ref run(Node) "run()".\n
   1.590 +    /// If you need more control on the execution, first you have to call
   1.591 +    /// \ref init(), then you can add a source node with \ref addSource()
   1.592 +    /// and perform the actual computation with \ref start().
   1.593 +    /// This procedure can be repeated if there are nodes that have not
   1.594 +    /// been reached.
   1.595  
   1.596      /// @{
   1.597  
   1.598 @@ -1391,15 +1389,14 @@
   1.599        }
   1.600      }
   1.601  
   1.602 -    ///Adds a new source node.
   1.603 -
   1.604 -    ///Adds a new source node to the set of nodes to be processed.
   1.605 +    /// \brief Adds a new source node.
   1.606      ///
   1.607 -    ///\pre The stack must be empty. (Otherwise the algorithm gives
   1.608 -    ///false results.)
   1.609 +    /// Adds a new source node to the set of nodes to be processed.
   1.610      ///
   1.611 -    ///\warning Distances will be wrong (or at least strange) in case of
   1.612 -    ///multiple sources.
   1.613 +    /// \pre The stack must be empty. Otherwise the algorithm gives
   1.614 +    /// wrong results. (One of the outgoing arcs of all the source nodes
   1.615 +    /// except for the last one will not be visited and distances will
   1.616 +    /// also be wrong.)
   1.617      void addSource(Node s)
   1.618      {
   1.619        LEMON_DEBUG(emptyQueue(), "The stack is not empty.");
   1.620 @@ -1413,6 +1410,7 @@
   1.621              _stack[++_stack_head] = e;
   1.622            } else {
   1.623              _visitor->leave(s);
   1.624 +            _visitor->stop(s);
   1.625            }
   1.626          }
   1.627      }
   1.628 @@ -1589,8 +1587,8 @@
   1.629      /// compute the %DFS path to each node.
   1.630      ///
   1.631      /// The algorithm computes
   1.632 -    /// - the %DFS tree,
   1.633 -    /// - the distance of each node from the root in the %DFS tree.
   1.634 +    /// - the %DFS tree (forest),
   1.635 +    /// - the distance of each node from the root(s) in the %DFS tree.
   1.636      ///
   1.637      /// \note <tt>d.run()</tt> is just a shortcut of the following code.
   1.638      ///\code
   1.639 @@ -1615,19 +1613,20 @@
   1.640      ///@}
   1.641  
   1.642      /// \name Query Functions
   1.643 -    /// The result of the %DFS algorithm can be obtained using these
   1.644 +    /// The results of the DFS algorithm can be obtained using these
   1.645      /// functions.\n
   1.646 -    /// Either \ref lemon::DfsVisit::run() "run()" or
   1.647 -    /// \ref lemon::DfsVisit::start() "start()" must be called before
   1.648 -    /// using them.
   1.649 +    /// Either \ref run(Node) "run()" or \ref start() should be called
   1.650 +    /// before using them.
   1.651 +
   1.652      ///@{
   1.653  
   1.654 -    /// \brief Checks if a node is reachable from the root(s).
   1.655 +    /// \brief Checks if a node is reached from the root(s).
   1.656      ///
   1.657 -    /// Returns \c true if \c v is reachable from the root(s).
   1.658 -    /// \pre Either \ref run() or \ref start()
   1.659 +    /// Returns \c true if \c v is reached from the root(s).
   1.660 +    ///
   1.661 +    /// \pre Either \ref run(Node) "run()" or \ref init()
   1.662      /// must be called before using this function.
   1.663 -    bool reached(Node v) { return (*_reached)[v]; }
   1.664 +    bool reached(Node v) const { return (*_reached)[v]; }
   1.665  
   1.666      ///@}
   1.667