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view-eq.hpp

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00001 /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
00002 /*
00003  *  Main authors:
00004  *     Christian Schulte <schulte@gecode.org>
00005  *
00006  *  Copyright:
00007  *     Christian Schulte, 2003
00008  *
00009  *  Last modified:
00010  *     $Date: 2011-09-20 13:58:39 +0200 (Tue, 20 Sep 2011) $ by $Author: schulte $
00011  *     $Revision: 12404 $
00012  *
00013  *  This file is part of Gecode, the generic constraint
00014  *  development environment:
00015  *     http://www.gecode.org
00016  *
00017  *  Permission is hereby granted, free of charge, to any person obtaining
00018  *  a copy of this software and associated documentation files (the
00019  *  "Software"), to deal in the Software without restriction, including
00020  *  without limitation the rights to use, copy, modify, merge, publish,
00021  *  distribute, sublicense, and/or sell copies of the Software, and to
00022  *  permit persons to whom the Software is furnished to do so, subject to
00023  *  the following conditions:
00024  *
00025  *  The above copyright notice and this permission notice shall be
00026  *  included in all copies or substantial portions of the Software.
00027  *
00028  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
00029  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
00030  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00031  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
00032  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
00033  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
00034  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00035  *
00036  */
00037 
00038 namespace Gecode { namespace Int { namespace Count {
00039 
00040   template<class VX, class VY, class VZ, bool shr, bool dom>
00041   forceinline
00042   EqView<VX,VY,VZ,shr,dom>::EqView(Home home,
00043                                ViewArray<VX>& x, VY y, VZ z, int c)
00044     : ViewBase<VX,VY,VZ>(home,x,y,z,c) {}
00045 
00046   template<class VX, class VY, class VZ, bool shr, bool dom>
00047   ExecStatus
00048   EqView<VX,VY,VZ,shr,dom>::post(Home home,
00049                              ViewArray<VX>& x, VY y, VZ z, int c) {
00050     GECODE_ME_CHECK(z.gq(home,-c));
00051     GECODE_ME_CHECK(z.lq(home,x.size()-c));
00052     if ((vtd(y) != VTD_VARVIEW) && z.assigned())
00053       return EqInt<VX,VY>::post(home,x,y,z.val()+c);
00054     if (sharing(x,y,z))
00055       (void) new (home) EqView<VX,VY,VZ,true,dom>(home,x,y,z,c);
00056     else
00057       (void) new (home) EqView<VX,VY,VZ,false,dom>(home,x,y,z,c);
00058     return ES_OK;
00059   }
00060 
00061   template<class VX, class VY, class VZ, bool shr, bool dom>
00062   forceinline
00063   EqView<VX,VY,VZ,shr,dom>::EqView(Space& home, bool share,
00064                                EqView<VX,VY,VZ,shr,dom>& p)
00065     : ViewBase<VX,VY,VZ>(home,share,p) {}
00066 
00067   template<class VX, class VY, class VZ, bool shr, bool dom>
00068   Actor*
00069   EqView<VX,VY,VZ,shr,dom>::copy(Space& home, bool share) {
00070     return new (home) EqView<VX,VY,VZ,shr,dom>(home,share,*this);
00071   }
00072 
00073   template<class VX, class VY, class VZ, bool shr, bool dom>
00074   ExecStatus
00075   EqView<VX,VY,VZ,shr,dom>::propagate(Space& home, const ModEventDelta&) {
00076     count(home);
00077 
00078     GECODE_ME_CHECK(z.gq(home,atleast()));
00079     GECODE_ME_CHECK(z.lq(home,atmost()));
00080 
00081     if (z.assigned()) {
00082       if (z.val() == atleast()) {
00083         GECODE_ES_CHECK(post_false(home,x,y));
00084         return home.ES_SUBSUMED(*this);
00085       }
00086       if (z.val() == atmost()) {
00087         GECODE_ES_CHECK(post_true(home,x,y));
00088         return home.ES_SUBSUMED(*this);
00089       }
00090       if (!dom || (vtd(y) != VTD_VARVIEW)) {
00091         VY yc(y);
00092         GECODE_REWRITE(*this,(EqInt<VX,VY>
00093                               ::post(home(*this),x,yc,z.val()+c)));    
00094       }
00095     }
00096 
00097 
00098     if (dom && (vtd(y) == VTD_VARVIEW) && (z.min() > 0)) {
00099       /* 
00100        * Only if the propagator is at fixpoint here, continue
00101        * when things are shared: the reason is that prune
00102        * requires that the views in x overlap with y!
00103        */
00104       if (shr && (VX::me(Propagator::modeventdelta()) != ME_INT_NONE))
00105         return ES_NOFIX;
00106 
00107       GECODE_ES_CHECK(prune(home,x,y));
00108 
00109       return ES_NOFIX;
00110     }
00111     
00112     return shr ? ES_NOFIX : ES_FIX;
00113   }
00114 
00115 }}}
00116 
00117 // STATISTICS: int-prop