dom.icc

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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
 *  Main authors:
 *     Christian Schulte <schulte@gecode.org>
 *
 *  Copyright:
 *     Christian Schulte, 2007
 *
 *  Last modified:
 *     $Date: 2008-01-31 18:29:16 +0100 (Thu, 31 Jan 2008) $ by $Author: tack $
 *     $Revision: 6017 $
 *
 *  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.
 *
 */

namespace Gecode { namespace Int { namespace Circuit {

  /*
   * The actual propagator
   *
   */
  template <class View>
  forceinline
  Dom<View>::Dom(Space* home, ViewArray<View>& x)
    : Base<View>(home,x) {}

  template <class View>
  forceinline
  Dom<View>::Dom(Space* home, bool share, Dom<View>& p)
    : Base<View>(home,share,p) {}

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

  template <class View>
  PropCost
  Dom<View>::cost(ModEventDelta med) const {
    return (View::me(med) == ME_INT_VAL) ? PC_LINEAR_HI : PC_QUADRATIC_HI;
  }

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

  template <class View>
  Reflection::ActorSpec
  Dom<View>::spec(const Space* home, Reflection::VarMap& m) const {
    return Base<View>::spec(home, m, ati());
  }

  template <class View>
  void
  Dom<View>::post(Space* home, Reflection::VarMap& vars,
                  const Reflection::ActorSpec& spec) {
    spec.checkArity(1);
    ViewArray<View> x(home, vars, spec[0]);
    (void) new (home) Dom<View>(home, x);
  }

  template <class View>
  ExecStatus
  Dom<View>::propagate(Space* home, ModEventDelta med) {
    if (View::me(med) == ME_INT_VAL) {
      GECODE_ES_CHECK((Distinct::prop_val<View,true>(home,y)));
      ExecStatus escv = connected(home);
      if (escv != ES_FIX)
        return escv;
      if (y.size() < 2)
        return ES_SUBSUMED(this,home);
      return ES_FIX_PARTIAL(this,View::med(ME_INT_DOM));
    }

    if (dc.available()) {
      GECODE_ES_CHECK(dc.sync());
    } else {
      GECODE_ES_CHECK(dc.init(home,y.size(),&y[0]));
    }
    bool assigned;
    GECODE_ES_CHECK(dc.propagate(home,assigned));

    ExecStatus esc = connected(home);
    if (esc != ES_FIX)
      return esc;

    // Elminiate assigned views from y, as they have been assigned
    // and propagated by domain consistent propagation. This is required
    // as we need to know how many assigned views actually exist.
    if (assigned)
      for (int i=y.size(); i--; )
        if (y[i].assigned())
          y.move_lst(i);

    return path(home);
  }

  template <class View>
  ExecStatus
  Dom<View>::post(Space* home, ViewArray<View>& x) {
    int n = x.size();
    if (n == 1) {
      GECODE_ME_CHECK(x[0].eq(home,0));
    } else if (n == 2) {
      GECODE_ME_CHECK(x[0].eq(home,1));
      GECODE_ME_CHECK(x[1].eq(home,0));
    } else {
      for (int i=n; i--; ) {
        GECODE_ME_CHECK(x[i].gq(home,0));
        GECODE_ME_CHECK(x[i].le(home,n));
        GECODE_ME_CHECK(x[i].nq(home,i));
      }
      (void) new (home) Dom<View>(home,x);
    }
    return ES_OK;
  }

}}}

// STATISTICS: int-prop