edge_xover.cpp

/*
* <edge_xover.cpp>
* Copyright (C) DOLPHIN Project-Team, INRIA Futurs, 2006-2007
* (C) OPAC Team, LIFL, 2002-2007
*
* Sebastien Cahon, Alexandru-Adrian Tantar
*
* This software is governed by the CeCILL license under French law and
* abiding by the rules of distribution of free software.  You can  use,
* modify and/ or redistribute the software under the terms of the CeCILL
* license as circulated by CEA, CNRS and INRIA at the following URL
* "http://www.cecill.info".
*
* As a counterpart to the access to the source code and  rights to copy,
* modify and redistribute granted by the license, users are provided only
* with a limited warranty  and the software's author,  the holder of the
* economic rights,  and the successive licensors  have only  limited liability.
*
* In this respect, the user's attention is drawn to the risks associated
* with loading,  using,  modifying and/or developing or reproducing the
* software by the user in light of its specific status of free software,
* that may mean  that it is complicated to manipulate,  and  that  also
* therefore means  that it is reserved for developers  and  experienced
* professionals having in-depth computer knowledge. Users are therefore
* encouraged to load and test the software's suitability as regards their
* requirements in conditions enabling the security of their systems and/or
* data to be ensured and,  more generally, to use and operate it in the
* same conditions as regards security.
* The fact that you are presently reading this means that you have had
* knowledge of the CeCILL license and that you accept its terms.
*
* ParadisEO WebSite : http://paradiseo.gforge.inria.fr
* Contact: paradiseo-help@lists.gforge.inria.fr
*
*/

#include <assert.h>
#include <values.h>

#include <utils/eoRNG.h>

#include "edge_xover.h"

void EdgeXover :: build_map (const Route & __par1, const Route & __par2)
{

  unsigned len = __par1.size () ;

  /* Initialization */
  _map.clear () ;
  _map.resize (len) ;

  for (unsigned i = 0 ; i < len ; i ++)
    {
      _map [__par1 [i]].insert (__par1 [(i + 1) % len]) ;
      _map [__par2 [i]].insert (__par2 [(i + 1) % len]) ;
      _map [__par1 [i]].insert (__par1 [(i - 1 + len) % len]) ;
      _map [__par2 [i]].insert (__par2 [(i - 1 + len) % len]) ;
    }

  visited.clear () ;
  visited.resize (len, false) ;
}

void EdgeXover :: remove_entry (unsigned __vertex, std :: vector <std :: set <unsigned> > & __map)
{

  std :: set <unsigned> & neigh = __map [__vertex] ;

  for (std :: set <unsigned> :: iterator it = neigh.begin () ;
       it != neigh.end () ;
       it ++)
    __map [* it].erase (__vertex) ;

}

void EdgeXover :: add_vertex (unsigned __vertex, Route & __child)
{

  visited [__vertex] = true ;
  __child.push_back (__vertex) ;
  remove_entry (__vertex, _map) ; /* Removing entries */
}

void EdgeXover :: cross (const Route & __par1, const Route & __par2, Route & __child)
{

  build_map (__par1, __par2) ;

  unsigned len = __par1.size () ;

  /* Go ! */
  __child.clear () ;

  unsigned cur_vertex = rng.random (len) ;

  add_vertex (cur_vertex, __child) ;

  for (unsigned i = 1 ; i < len ; i ++)
    {

      unsigned len_min_entry = MAXINT ;

      std :: set <unsigned> & neigh = _map [cur_vertex] ;

      for (std :: set <unsigned> :: iterator it = neigh.begin () ;
           it != neigh.end () ;
           it ++)
        {
          unsigned l = _map [* it].size () ;
          if (len_min_entry > l)
            len_min_entry = l ;
        }

      std :: vector <unsigned> cand ; /* Candidates */

      for (std :: set <unsigned> :: iterator it = neigh.begin () ;
           it != neigh.end () ;
           it ++)
        {
          unsigned l = _map [* it].size () ;
          if (len_min_entry == l)
            cand.push_back (* it) ;
        }

      if (! cand.size ())
        {

          /* Oh no ! Implicit mutation */
          for (unsigned j = 0 ; j < len ; j ++)
            if (! visited [j])
              cand.push_back (j) ;
        }

      cur_vertex = cand [rng.random (cand.size ())] ;

      add_vertex (cur_vertex, __child) ;
    }
}

bool EdgeXover :: operator () (Route & __route1, Route & __route2)
{

  // Init. copy
  Route par [2] ;
  par [0] = __route1 ;
  par [1] = __route2 ;

  cross (par [0], par [1], __route1) ;
  cross (par [1], par [0], __route2) ;

  __route1.invalidate () ;
  __route2.invalidate () ;

  return true ;
}

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