minmax.icc

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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
 *  Main authors:
 *     Guido Tack <tack@gecode.org>
 *     Christian Schulte <schulte@gecode.org>
 *     Gabor Szokoli <szokoli@gecode.org>
 *
 *  Copyright:
 *     Guido Tack, 2004
 *     Christian Schulte, 2004
 *     Gabor Szokoli, 2004
 *
 *  Last modified:
 *     $Date: 2008-02-20 10:27:10 +0100 (Wed, 20 Feb 2008) $ by $Author: tack $
 *     $Revision: 6241 $
 *
 *  This file is part of Gecode, the generic constraint
 *  development environment:
 *     http://www.gecode.org
 *
 *  Permission is hereby granted, free of charge, to any person obtaining
 *  a copy of this software and associated documentation files (the
 *  "Software"), to deal in the Software without restriction, including
 *  without limitation the rights to use, copy, modify, merge, publish,
 *  distribute, sublicense, and/or sell copies of the Software, and to
 *  permit persons to whom the Software is furnished to do so, subject to
 *  the following conditions:
 *
 *  The above copyright notice and this permission notice shall be
 *  included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */



#include "gecode/set.hh"
#include "gecode/int.hh"

namespace Gecode { namespace Set { namespace Int {

  template <class View>
  forceinline
  MinElement<View>::MinElement(Space* home, View y0, Gecode::Int::IntView y1)
    : IntSetPropagator<View,PC_SET_ANY,
                       Gecode::Int::PC_INT_BND> (home, y0, y1) {}

  template <class View>
  forceinline ExecStatus
  MinElement<View>::post(Space* home, View x0, Gecode::Int::IntView x1) {
    GECODE_ME_CHECK(x0.cardMin(home,1));
    (void) new (home) MinElement(home,x0,x1);
    return ES_OK;
  }

  template <class View>
  forceinline
  MinElement<View>::MinElement(Space* home, bool share, MinElement& p)
    : IntSetPropagator<View,PC_SET_ANY,
                       Gecode::Int::PC_INT_BND> (home, share, p) {}

  template <class View>
  Actor*
  MinElement<View>::copy(Space* home, bool share) {
   return new (home) MinElement(home,share,*this);
  }

  template <class View>
  Support::Symbol
  MinElement<View>::ati(void) {
   return Reflection::mangle<View>("Gecode::Set::Int::MinElement");
  }

  template <class View>
  Reflection::ActorSpec
  MinElement<View>::spec(const Space* home, Reflection::VarMap& m) const {
   return IntSetPropagator<View,PC_SET_ANY,Gecode::Int::PC_INT_BND>
     ::spec(home, m, ati());
  }

  template <class View>
  void
  MinElement<View>::post(Space* home, Reflection::VarMap& vars,
                         const Reflection::ActorSpec& spec) {
    spec.checkArity(2);
    View x0(home, vars, spec[0]);
    Gecode::Int::IntView x1(home, vars, spec[1]);
    (void) post(home,x0,x1);
  }

  template <class View>
  ExecStatus
  MinElement<View>::propagate(Space* home, ModEventDelta) {
    //x1 is an element of x0.ub
    //x1 =< smallest element of x0.lb
    //x1 =< x0.cardinialityMin-est largest element of x0.ub
    //(these 2 take care of determined x0)
    //No element in x0 is smaller than x1
    //if x1 is determined, it is part of the ub.

    //Consequently:
    //The domain of x1 is a subset of x0.ub up to the first element in x0.lb.
    //x0 lacks everything smaller than smallest possible x1.

    {
      LubRanges<View> ub(x0);
      GECODE_ME_CHECK(x1.inter_r(home,ub,false));
    }
    GECODE_ME_CHECK(x1.lq(home,x0.glbMin()));
    //if cardMin>lbSize?
    assert(x0.cardMin()>=1);

    {
      int size = 0;
      int maxN = BndSet::MAX_OF_EMPTY;
      for (LubRanges<View> ubr(x0); ubr(); ++ubr, ++size) {}
      GECODE_AUTOARRAY(int, ub, size*2);
      int i=0;
      for (LubRanges<View> ubr(x0); ubr(); ++ubr, ++i) {
        ub[2*i]   = ubr.min();
        ub[2*i+1] = ubr.max();
      }
      int x0cm = x0.cardMin()-1;
      for (int i=size; i--;) {
        int width = ub[2*i+1]-ub[2*i]+1;
        if (width > x0cm) {
          maxN = ub[2*i+1]-x0cm;
          break;
        }
        x0cm -= width;
      }
      GECODE_ME_CHECK(x1.lq(home,maxN));
    }

    GECODE_ME_CHECK( x0.exclude(home,
                                Limits::min, x1.min()-1) );

    if (x1.assigned()) {
      GECODE_ME_CHECK(x0.include(home,x1.val()));
      GECODE_ME_CHECK(x0.exclude(home,
                                 Limits::min, x1.val()-1));
      return ES_SUBSUMED(this,home);
    }

    return ES_FIX;
  }

  template <class View>
  forceinline
  MaxElement<View>::MaxElement(Space* home, View y0, Gecode::Int::IntView y1)
    : IntSetPropagator<View,PC_SET_ANY,
                       Gecode::Int::PC_INT_BND> (home, y0, y1) {}

  template <class View>
  forceinline
  MaxElement<View>::MaxElement(Space* home, bool share, MaxElement& p)
    : IntSetPropagator<View,PC_SET_ANY,
                       Gecode::Int::PC_INT_BND> (home, share, p) {}

  template <class View>
  ExecStatus
  MaxElement<View>::post(Space* home, View x0,
                              Gecode::Int::IntView x1) {
    GECODE_ME_CHECK(x0.cardMin(home,1));
    (void) new (home) MaxElement(home,x0,x1);
    return ES_OK;
  }

  template <class View>
  Actor*
  MaxElement<View>::copy(Space* home, bool share) {
    return new (home) MaxElement(home,share,*this);
  }

  template <class View>
  Support::Symbol
  MaxElement<View>::ati(void) {
    return Reflection::mangle<View>("Gecode::Set::Int::MaxElement");
  }

  template <class View>
  Reflection::ActorSpec
  MaxElement<View>::spec(const Space* home, Reflection::VarMap& m) const {
    return IntSetPropagator<View,PC_SET_ANY,Gecode::Int::PC_INT_BND>
      ::spec(home, m, ati());
  }

  template <class View>
  void
  MaxElement<View>::post(Space* home, Reflection::VarMap& vars,
                         const Reflection::ActorSpec& spec) {
    spec.checkArity(2);
    View x0(home, vars, spec[0]);
    Gecode::Int::IntView x1(home, vars, spec[1]);
    (void) new (home) MaxElement<View>(home,x0,x1);
  }

  template <class View>
  ExecStatus
  MaxElement<View>::propagate(Space* home, ModEventDelta) {
    LubRanges<View> ub(x0);
    GECODE_ME_CHECK(x1.inter_r(home,ub,false));
    GECODE_ME_CHECK(x1.gq(home,x0.glbMax()));
    assert(x0.cardMin()>=1);
    GECODE_ME_CHECK(x1.gq(home,x0.lubMinN(x0.cardMin()-1)));
    GECODE_ME_CHECK(x0.exclude(home,
                               x1.max()+1,Limits::max) );

    if (x1.assigned()) {
      GECODE_ME_CHECK(x0.include(home,x1.val()));
      GECODE_ME_CHECK( x0.exclude(home,
                                  x1.val()+1,Limits::max) );
      return ES_SUBSUMED(this,home);
    }

    return ES_FIX;
  }  
}}}

// STATISTICS: set-prop