RhodeCode

/* -*- 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.

 *

 */

///\ingroup demos

///\file

///\brief Demonstrating graph input and output

///

/// This program gives an example of how to read and write a digraph

/// and additional maps from/to a stream or a file using the

/// \ref lgf-format "LGF" format.

///

/// The \c "digraph.lgf" file:

/// \include digraph.lgf

///

/// And the program which reads it and prints the digraph to the

/// standard output:

/// \include lgf_demo.cc

#include <iostream>

#include <lemon/smart_graph.h>

#include <lemon/lgf_reader.h>

#include <lemon/lgf_writer.h>

using namespace lemon;

int main() {

  SmartDigraph g;

  SmartDigraph::ArcMap<int> cap(g);

  SmartDigraph::Node s, t;

  try {

    digraphReader(g, "digraph.lgf"). // read the directed graph into g

      arcMap("capacity", cap).       // read the 'capacity' arc map into cap

      node("source", s).             // read 'source' node to s

      node("target", t).             // read 'target' node to t

      run();

    std::cerr << "Error: " << error.what() << std::endl;

    return -1;

  }

  std::cout << "A digraph is read from 'digraph.lgf'." << std::endl;

  std::cout << "Number of nodes: " << countNodes(g) << std::endl;

  std::cout << "Number of arcs: " << countArcs(g) << std::endl;

  std::cout << "We can write it to the standard output:" << std::endl;

  digraphWriter(g).                // write g to the standard output

    arcMap("capacity", cap).       // write cap into 'capacity'

    node("source", s).             // write s to 'source'

    node("target", t).             // write t to 'target'

    run();

  return 0;

}

    ///Constructor

    ArgParser(int argc, const char **argv);

    ~ArgParser();

    ///\name Options

    ///

    ///@{

    ///Add a new integer type option

    ///Add a new integer type option.

    ///\param name The name of the option. The leading '-' must be omitted.

    ///\param help A help string.

    ///\param value A default value for the option.

    ///\param obl Indicate if the option is mandatory.

    ArgParser &intOption(const std::string &name,

                    const std::string &help,

                    int value=0, bool obl=false);

    ///Add a new floating point type option

    ///Add a new floating point type option.

    ///\param name The name of the option. The leading '-' must be omitted.

    ///\param help A help string.

    ///\param value A default value for the option.

    ///\param obl Indicate if the option is mandatory.

    ArgParser &doubleOption(const std::string &name,

                      const std::string &help,

                      double value=0, bool obl=false);

    ///Add a new bool type option

    ///Add a new bool type option.

    ///\param name The name of the option. The leading '-' must be omitted.

    ///\param help A help string.

    ///\param value A default value for the option.

    ///\param obl Indicate if the option is mandatory.

    ///\note A mandatory bool obtion is of very little use.

    ArgParser &boolOption(const std::string &name,

                      const std::string &help,

                      bool value=false, bool obl=false);

    ///Add a new string type option

    ///Add a new string type option.

    ///\param name The name of the option. The leading '-' must be omitted.

    ///\param help A help string.

    ///\param value A default value for the option.

    ///\param obl Indicate if the option is mandatory.

    ArgParser &stringOption(const std::string &name,

                      const std::string &help,

                      std::string value="", bool obl=false);

    ///Give help string for non-parsed arguments.

    ///With this function you can give help string for non-parsed arguments.

    ///The parameter \c name will be printed in the short usage line, while

    ///\c help gives a more detailed description.

    ArgParser &other(const std::string &name,

                     const std::string &help="");

    ///@}

    ///\name Options with External Storage

    ///Using this functions, the value of the option will be directly written

    ///into a variable once the option appears in the command line.

    ///@{

    ///Add a new integer type option with a storage reference

    ///Add a new integer type option with a storage reference.

    ///\param name The name of the option. The leading '-' must be omitted.

    ///\param help A help string.

    ///\param obl Indicate if the option is mandatory.

    ///\retval ref The value of the argument will be written to this variable.

    ArgParser &refOption(const std::string &name,

                    const std::string &help,

                    int &ref, bool obl=false);

    ///Add a new floating type option with a storage reference

    ///Add a new floating type option with a storage reference.

    ///\param name The name of the option. The leading '-' must be omitted.

    ///\param help A help string.

    ///\param obl Indicate if the option is mandatory.

    ///\retval ref The value of the argument will be written to this variable.

    ArgParser &refOption(const std::string &name,

                      const std::string &help,

                      double &ref, bool obl=false);

    ///Add a new bool type option with a storage reference

    ///Add a new bool type option with a storage reference.

    ///\param name The name of the option. The leading '-' must be omitted.

    ///\param help A help string.

    ///\param obl Indicate if the option is mandatory.

    ///\retval ref The value of the argument will be written to this variable.

    ///\note A mandatory bool obtion is of very little use.

    ArgParser &refOption(const std::string &name,

                      const std::string &help,

                      bool &ref, bool obl=false);

    ///Add a new string type option with a storage reference

    ///Add a new string type option with a storage reference.

    ///\param name The name of the option. The leading '-' must be omitted.

    ///\param help A help string.

    ///\param obl Indicate if the option is mandatory.

    ///\retval ref The value of the argument will be written to this variable.

    ArgParser &refOption(const std::string &name,

                      const std::string &help,

                      std::string &ref, bool obl=false);

    ///@}

    ///\name Option Groups and Synonyms

    ///

    ///@{

    ///Bundle some options into a group

    /// You can group some option by calling this function repeatedly for each

    /// option to be grouped with the same groupname.

    ///\param group The group name.

    ///\param opt The option name.

    ArgParser &optionGroup(const std::string &group,

                           const std::string &opt);

    ///Make the members of a group exclusive

    ///If you call this function for a group, than at most one of them can be

    ///given at the same time.

    ArgParser &onlyOneGroup(const std::string &group);

    ///Make a group mandatory

    ///Using this function, at least one of the members of \c group

    ///must be given.

    ArgParser &mandatoryGroup(const std::string &group);

    ///Create synonym to an option

    ///With this function you can create a synonym \c syn of the

    ///option \c opt.

    ArgParser &synonym(const std::string &syn,

                           const std::string &opt);

    ///@}

  private:

    void show(std::ostream &os,Opts::const_iterator i) const;

    void show(std::ostream &os,Groups::const_iterator i) const;

    void showHelp(Opts::const_iterator i) const;

    void showHelp(std::vector<OtherArg>::const_iterator i) const;

    void unknownOpt(std::string arg) const;

    void requiresValue(std::string arg, OptType t) const;

    void checkMandatories() const;

    void shortHelp() const;

    void showHelp() const;

  public:

    ///Start the parsing process

    ArgParser &parse();

    /// Synonym for parse()

    ArgParser &run()

    {

      return parse();

    }

    ///Give back the command name (the 0th argument)

    const std::string &commandName() const { return _command_name; }

    ///Check if an opion has been given to the command.

    bool given(std::string op) const

    {

      Opts::const_iterator i = _opts.find(op);

      return i!=_opts.end()?i->second.set:false;

    }

    ///Magic type for operator[]

    ///This is the type of the return value of ArgParser::operator[]().

    ///It automatically converts to \c int, \c double, \c bool or

    class RefType

    {

      const ArgParser &_parser;

      std::string _name;

    public:

      ///\e

      RefType(const ArgParser &p,const std::string &n) :_parser(p),_name(n) {}

      ///\e

      operator bool()

      {

        Opts::const_iterator i = _parser._opts.find(_name);

        LEMON_ASSERT(i!=_parser._opts.end(),

                     std::string()+"Unkown option: '"+_name+"'");

        LEMON_ASSERT(i->second.type==ArgParser::BOOL,

                     std::string()+"'"+_name+"' is a bool option");

        return *(i->second.bool_p);

      }

      ///\e

      operator std::string()

      {

        Opts::const_iterator i = _parser._opts.find(_name);

        LEMON_ASSERT(i!=_parser._opts.end(),

                     std::string()+"Unkown option: '"+_name+"'");

        LEMON_ASSERT(i->second.type==ArgParser::STRING,

                     std::string()+"'"+_name+"' is a string option");

        return *(i->second.string_p);

      }

      ///\e

      operator double()

      {

        Opts::const_iterator i = _parser._opts.find(_name);

        LEMON_ASSERT(i!=_parser._opts.end(),

                     std::string()+"Unkown option: '"+_name+"'");

        LEMON_ASSERT(i->second.type==ArgParser::DOUBLE ||

                     i->second.type==ArgParser::INTEGER,

                     std::string()+"'"+_name+"' is a floating point option");

        return i->second.type==ArgParser::DOUBLE ?

          *(i->second.double_p) : *(i->second.int_p);

      }

      ///\e

      operator int()

      {

        Opts::const_iterator i = _parser._opts.find(_name);

        LEMON_ASSERT(i!=_parser._opts.end(),

                     std::string()+"Unkown option: '"+_name+"'");

        LEMON_ASSERT(i->second.type==ArgParser::INTEGER,

                     std::string()+"'"+_name+"' is an integer option");

        return *(i->second.int_p);

      }

    };

    ///Give back the value of an option

    ///Give back the value of an option.

    ///\sa RefType

    RefType operator[](const std::string &n) const

    {

      return RefType(*this, n);

    }

    ///Give back the non-option type arguments.

    ///Give back a reference to a vector consisting of the program arguments

    ///not starting with a '-' character.

    const std::vector<std::string> &files() const { return _file_args; }

  };

}

#endif // LEMON_ARG_PARSER_H

/* -*- 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_BFS_H

#define LEMON_BFS_H

///\ingroup search

///\file

///\brief BFS 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 Bfs class.

  ///Default traits class of Bfs class.

  ///\tparam GR Digraph type.

  template<class GR>

  struct BfsDefaultTraits

  {

    ///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 shortest paths.

    ///

    ///The type of the map that stores the predecessor

    ///arcs of the shortest paths.

    ///It must meet the \ref concepts::WriteMap "WriteMap" concept.

    typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap;

    ///Instantiates a \ref PredMap.

    ///This function instantiates a \ref PredMap.

    ///\param g is the digraph, to which we would like to define the

    ///\ref 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 \ref ProcessedMap.

    ///This function instantiates a \ref ProcessedMap.

    ///\param g is the digraph, to which

    ///we would like to define the \ref ProcessedMap

#ifdef DOXYGEN

    static ProcessedMap *createProcessedMap(const 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 \ref ReachedMap.

    ///This function instantiates a \ref ReachedMap.

    ///\param g is the digraph, to which

    ///we would like to define the \ref ReachedMap.

    static ReachedMap *createReachedMap(const 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 \ref DistMap.

    ///This function instantiates a \ref DistMap.

    ///\param g is the digraph, to which we would like to define the

    ///\ref DistMap.

    static DistMap *createDistMap(const Digraph &g)

    {

      return new DistMap(g);

    }

  };

  ///%BFS algorithm class.

  ///\ingroup search

  ///This class provides an efficient implementation of the %BFS algorithm.

  ///

  ///There is also a \ref bfs() "function-type interface" for the BFS

  ///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 Bfs, it is only passed to \ref BfsDefaultTraits.

  ///\tparam TR Traits class to set various data types used by the algorithm.

  ///The default traits class is

  ///\ref BfsDefaultTraits "BfsDefaultTraits<GR>".

  ///See \ref BfsDefaultTraits for the documentation of

  ///a Bfs traits class.

#ifdef DOXYGEN

  template <typename GR,

            typename TR>

#else

  template <typename GR=ListDigraph,

            typename TR=BfsDefaultTraits<GR> >

#endif

  class Bfs {

  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

    ///shortest 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::Node> _queue;

    int _queue_head,_queue_tail,_queue_next_dist;

    int _curr_dist;

    //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:

    Bfs() {}

  public:

    typedef Bfs Create;

    ///\name Named template parameters

    ///@{

    template <class T>

    struct SetPredMapTraits : public Traits {

      typedef T PredMap;

      static PredMap *createPredMap(const Digraph &)

      {

      }

    };

    ///\brief \ref named-templ-param "Named parameter" for setting

    ///\ref PredMap type.

    ///

    ///\ref named-templ-param "Named parameter" for setting

    ///\ref PredMap type.

    template <class T>

    struct SetPredMap : public Bfs< Digraph, SetPredMapTraits<T> > {

      typedef Bfs< Digraph, SetPredMapTraits<T> > Create;

    };

    template <class T>

    struct SetDistMapTraits : public Traits {

      typedef T DistMap;

      static DistMap *createDistMap(const Digraph &)

      {

      }

    };

    ///\brief \ref named-templ-param "Named parameter" for setting

    ///\ref DistMap type.

    ///

    ///\ref named-templ-param "Named parameter" for setting

    ///\ref DistMap type.

    template <class T>

    struct SetDistMap : public Bfs< Digraph, SetDistMapTraits<T> > {

      typedef Bfs< Digraph, SetDistMapTraits<T> > Create;

    };

    template <class T>

    struct SetReachedMapTraits : public Traits {

      typedef T ReachedMap;

      static ReachedMap *createReachedMap(const Digraph &)

      {

      }

    };

    ///\brief \ref named-templ-param "Named parameter" for setting

    ///\ref ReachedMap type.

    ///

    ///\ref named-templ-param "Named parameter" for setting

    ///\ref ReachedMap type.

    template <class T>

    struct SetReachedMap : public Bfs< Digraph, SetReachedMapTraits<T> > {

      typedef Bfs< Digraph, SetReachedMapTraits<T> > Create;

    };

    template <class T>

    struct SetProcessedMapTraits : public Traits {

      typedef T ProcessedMap;

      static ProcessedMap *createProcessedMap(const Digraph &)

      {

      }

    };

    ///\brief \ref named-templ-param "Named parameter" for setting

    ///\ref ProcessedMap type.

    ///

    ///\ref named-templ-param "Named parameter" for setting

    ///\ref ProcessedMap type.

    template <class T>

    struct SetProcessedMap : public Bfs< Digraph, SetProcessedMapTraits<T> > {

      typedef Bfs< 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

    ///\ref ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.

    ///

    ///\ref named-templ-param "Named parameter" for setting

    ///\ref ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>.

    ///If you don't set it explicitly, it will be automatically allocated.

    struct SetStandardProcessedMap :

      public Bfs< Digraph, SetStandardProcessedMapTraits > {

      typedef Bfs< Digraph, SetStandardProcessedMapTraits > Create;

    };

    ///@}

  public:

    ///Constructor.

    ///Constructor.

    ///\param g The digraph the algorithm runs on.

    Bfs(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.

    ~Bfs()

    {

      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>

    Bfs &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>

    Bfs &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>

    Bfs &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>

    Bfs &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::Bfs::run() "run()".

    ///\n

    ///If you need more control on the execution, first you must call

    ///\ref lemon::Bfs::init() "init()", then you can add several source

    ///nodes with \ref lemon::Bfs::addSource() "addSource()".

    ///Finally \ref lemon::Bfs::start() "start()" will perform the

    ///actual path computation.

    ///@{

    ///Initializes the internal data structures.

    ///Initializes the internal data structures.

    ///

    void init()

    {

      create_maps();

      _queue.resize(countNodes(*G));

      _queue_head=_queue_tail=0;

      _curr_dist=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.

    ///

    void addSource(Node s)

    {

      if(!(*_reached)[s])

        {

          _reached->set(s,true);

          _pred->set(s,INVALID);

          _dist->set(s,0);

          _queue[_queue_head++]=s;

          _queue_next_dist=_queue_head;

        }

    }

    ///Processes the next node.

    ///Processes the next node.

    ///

    ///\return The processed node.

    ///

    ///\pre The queue must not be empty.

    Node processNextNode()

    {

      if(_queue_tail==_queue_next_dist) {

        _curr_dist++;

        _queue_next_dist=_queue_head;

      }

      Node n=_queue[_queue_tail++];

      _processed->set(n,true);

      Node m;

      for(OutArcIt e(*G,n);e!=INVALID;++e)

        if(!(*_reached)[m=G->target(e)]) {

          _queue[_queue_head++]=m;

          _reached->set(m,true);

          _pred->set(m,e);

          _dist->set(m,_curr_dist);

        }

      return n;

    }

    ///Processes the next node.

    ///Processes the next node and checks if the given target node

    ///is reached. If the target node is reachable from the processed

    ///node, then the \c reach parameter will be set to \c true.

    ///

    ///\param target The target node.

    ///\retval reach Indicates if the target node is reached.

    ///It should be initially \c false.

    ///

    ///\return The processed node.

    ///

    }

    ///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 \ref ProcessedMap.

    ///This function instantiates a \ref ProcessedMap.

    ///\param g is the digraph, to which

    ///we would like to define the \ref ProcessedMap.

#ifdef DOXYGEN

    static ProcessedMap *createProcessedMap(const 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 \ref ReachedMap.

    ///This function instantiates a \ref ReachedMap.

    ///\param g is the digraph, to which

    ///we would like to define the \ref ReachedMap.

    static ReachedMap *createReachedMap(const 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 \ref DistMap.

    ///This function instantiates a \ref DistMap.

    ///\param g is the digraph, to which we would like to define

    ///the \ref DistMap

    static DistMap *createDistMap(const Digraph &g)

    {

      return new DistMap(g);

    }

    ///The type of the shortest paths.

    ///The type of the shortest paths.

    ///It must meet the \ref concepts::Path "Path" concept.

    typedef lemon::Path<Digraph> Path;

  };

  /// Default traits class used by \ref BfsWizard

  /// To make it easier to use Bfs algorithm

  /// we have created a wizard class.

  /// This \ref BfsWizard class needs default traits,

  /// as well as the \ref Bfs class.

  /// The \ref BfsWizardBase is a class to be the default traits of the

  /// \ref BfsWizard class.

  template<class GR>

  class BfsWizardBase : public BfsWizardDefaultTraits<GR>

  {

    typedef BfsWizardDefaultTraits<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 shortest 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.

    BfsWizardBase() : _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.

    BfsWizardBase(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 BFS algorithm.

  /// This auxiliary class is created to implement the

  /// \ref bfs() "function-type interface" of \ref Bfs algorithm.

  /// It does not have own \ref run() method, it uses the functions

  /// and features of the plain \ref Bfs.

  ///

  /// This class should only be used through the \ref bfs() function,

  /// which makes it easier to use the algorithm.

  template<class TR>

  class BfsWizard : 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 shortest 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 shortest paths

    typedef typename TR::Path Path;

  public:

    /// Constructor.

    BfsWizard() : 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.

    BfsWizard(const Digraph &g) :

      TR(g) {}

    ///Copy constructor

    BfsWizard(const TR &b) : TR(b) {}

    ~BfsWizard() {}

    ///Runs BFS algorithm from the given source node.

    ///This method runs BFS algorithm from node \c s

    ///in order to compute the shortest path to each node.

    void run(Node s)

    {

      Bfs<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 shortest path between \c s and \c t.

    ///This method runs BFS algorithm from node \c s

    ///in order to compute the shortest 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)

    {

      Bfs<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 BFS algorithm to visit all nodes in the digraph.

    ///This method runs BFS algorithm in order to compute

    ///the shortest 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 \ref PredMap object.

    ///

    ///\ref named-func-param "Named parameter"

    ///for setting \ref PredMap object.

    template<class T>

    BfsWizard<SetPredMapBase<T> > predMap(const T &t)

    {

      Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t));

      return BfsWizard<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 \ref ReachedMap object.

    ///

    /// \ref named-func-param "Named parameter"

    ///for setting \ref ReachedMap object.

    template<class T>

    BfsWizard<SetReachedMapBase<T> > reachedMap(const T &t)

    {

      Base::_reached=reinterpret_cast<void*>(const_cast<T*>(&t));