gecode » set » rel
re-subset.hpp

00001 /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
00002 /*
00003  *  Main authors:
00004  *     Guido Tack <tack@gecode.org>
00005  *     Christian Schulte <schulte@gecode.org>
00006  *
00007  *  Copyright:
00008  *     Guido Tack, 2004
00009  *     Christian Schulte, 2004
00010  *
00011  *  Last modified:
00012  *     $Date: 2009-10-14 12:19:49 +0200 (Wed, 14 Oct 2009) $ by $Author: schulte $
00013  *     $Revision: 9909 $
00014  *
00015  *  This file is part of Gecode, the generic constraint
00016  *  development environment:
00017  *     http://www.gecode.org
00018  *
00019  *  Permission is hereby granted, free of charge, to any person obtaining
00020  *  a copy of this software and associated documentation files (the
00021  *  "Software"), to deal in the Software without restriction, including
00022  *  without limitation the rights to use, copy, modify, merge, publish,
00023  *  distribute, sublicense, and/or sell copies of the Software, and to
00024  *  permit persons to whom the Software is furnished to do so, subject to
00025  *  the following conditions:
00026  *
00027  *  The above copyright notice and this permission notice shall be
00028  *  included in all copies or substantial portions of the Software.
00029  *
00030  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
00031  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
00032  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00033  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
00034  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
00035  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
00036  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00037  *
00038  */
00039 
00040 namespace Gecode { namespace Set { namespace Rel {
00041 
00042   template<class View0, class View1>
00043   forceinline
00044   ReSubset<View0,View1>::ReSubset(Home home, View0 y0,
00045                                   View1 y1, Gecode::Int::BoolView y2)
00046     : Propagator(home), x0(y0), x1(y1), b(y2) {
00047     b.subscribe(home,*this, Gecode::Int::PC_INT_VAL);
00048     x0.subscribe(home,*this, PC_SET_ANY);
00049     x1.subscribe(home,*this, PC_SET_ANY);
00050   }
00051 
00052   template<class View0, class View1>
00053   forceinline
00054   ReSubset<View0,View1>::ReSubset(Space& home, bool share, ReSubset& p)
00055     : Propagator(home,share,p) {
00056     x0.update(home,share,p.x0);
00057     x1.update(home,share,p.x1);
00058     b.update(home,share,p.b);
00059   }
00060 
00061   template<class View0, class View1>
00062   PropCost
00063   ReSubset<View0,View1>::cost(const Space&, const ModEventDelta&) const {
00064     return PropCost::ternary(PropCost::LO);
00065   }
00066 
00067   template<class View0, class View1>
00068   size_t
00069   ReSubset<View0,View1>::dispose(Space& home) {
00070     assert(!home.failed());
00071     b.cancel(home,*this, Gecode::Int::PC_INT_VAL);
00072     x0.cancel(home,*this, PC_SET_ANY);
00073     x1.cancel(home,*this, PC_SET_ANY);
00074     (void) Propagator::dispose(home);
00075     return sizeof(*this);
00076   }
00077 
00078   template<class View0, class View1>
00079   ExecStatus
00080   ReSubset<View0,View1>::post(Home home, View0 x0, View1 x1,
00081                               Gecode::Int::BoolView b) {
00082     (void) new (home) ReSubset<View0,View1>(home,x0,x1,b);
00083     return ES_OK;
00084   }
00085 
00086   template<class View0, class View1>
00087   Actor*
00088   ReSubset<View0,View1>::copy(Space& home, bool share) {
00089     return new (home) ReSubset<View0,View1>(home,share,*this);
00090   }
00091 
00092   template<class View0, class View1>
00093   ExecStatus
00094   ReSubset<View0,View1>::propagate(Space& home, const ModEventDelta&) {
00095     if (b.one())
00096       GECODE_REWRITE(*this,(Subset<View0,View1>::post(home(*this),x0,x1)));
00097     if (b.zero())
00098       GECODE_REWRITE(*this,(NoSubset<View0,View1>::post(home(*this),x0,x1)));
00099 
00100     // check whether cardinalities still allow subset
00101     if (x0.cardMin() > x1.cardMax()) {
00102       GECODE_ME_CHECK(b.zero_none(home));
00103       return ES_SUBSUMED(*this,home);
00104     }
00105 
00106     // check lub(x0) subset glb(x1)
00107     {
00108       LubRanges<View0> x0ub(x0);
00109       GlbRanges<View1> x1lb(x1);
00110       Iter::Ranges::Diff<LubRanges<View0>,GlbRanges<View1> > d(x0ub,x1lb);
00111       if (!d()) {
00112         GECODE_ME_CHECK(b.one_none(home));
00113         return ES_SUBSUMED(*this,home);
00114       }
00115     }
00116 
00117     // check glb(x0) subset lub(x1)
00118     {
00119       GlbRanges<View0> x0lb(x0);
00120       LubRanges<View1> x1ub(x1);
00121       Iter::Ranges::Diff<GlbRanges<View0>,LubRanges<View1> > d(x0lb,x1ub);
00122       if (d()) {
00123         GECODE_ME_CHECK(b.zero_none(home));
00124         return ES_SUBSUMED(*this,home);
00125       } else if (x0.assigned() && x1.assigned()) {
00126         GECODE_ME_CHECK(b.one_none(home));
00127         return ES_SUBSUMED(*this,home);
00128       }
00129     }
00130 
00131     if (x0.cardMin() > 0) {
00132       LubRanges<View0> x0ub(x0);
00133       LubRanges<View1> x1ub(x1);
00134       Iter::Ranges::Inter<LubRanges<View0>,LubRanges<View1> >
00135         i(x0ub,x1ub);
00136       if (!i()) {
00137         GECODE_ME_CHECK(b.zero_none(home));
00138         return ES_SUBSUMED(*this,home);
00139       }
00140     }
00141 
00142     return ES_FIX;
00143   }
00144 
00145 }}}
00146 
00147 // STATISTICS: set-prop