gecode » int » branch
select-values.hpp

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, 2008
00008  *
00009  *  Last modified:
00010  *     $Date: 2009-10-12 17:36:53 +0200 (Mon, 12 Oct 2009) $ by $Author: schulte $
00011  *     $Revision: 9878 $
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 Branch {
00039 
00045   template<class ViewSel, class View>
00046   class PosValuesChoice : public PosChoice<ViewSel> {
00047   private:
00049     class PosMin {
00050     public:
00052       unsigned int pos;
00054       int min;
00055     };
00057     unsigned int n;
00059     PosMin* pm;
00060   public:
00062     PosValuesChoice(const Brancher& b, const Pos& p,
00063                     const typename ViewSel::Choice& viewc, View x);
00065     int val(unsigned int a) const;
00067     virtual size_t size(void) const;
00069     virtual ~PosValuesChoice(void);
00070   };
00071 
00072 
00073   template<class ViewSel, class View>
00074   forceinline
00075   PosValuesChoice<ViewSel,View>::
00076   PosValuesChoice(const Brancher& b, const Pos& p,
00077                 const typename ViewSel::Choice& viewc, View x)
00078     : PosChoice<ViewSel>(b,x.size(),p,viewc), n(0) {
00079     for (ViewRanges<View> r(x); r(); ++r)
00080       n++;
00081     pm = heap.alloc<PosMin>(n+1);
00082     unsigned int w=0;
00083     int i=0;
00084     for (ViewRanges<View> r(x); r(); ++r) {
00085       pm[i].min = r.min();
00086       pm[i].pos = w;
00087       w += r.width(); i++;
00088     }
00089     pm[i].pos = w;
00090   }
00091 
00092   template<class ViewSel, class View>
00093   forceinline int
00094   PosValuesChoice<ViewSel,View>::val(unsigned int a) const {
00095     PosMin* l = &pm[0];
00096     PosMin* r = &pm[n-1];
00097     while (true) {
00098       PosMin* m = l + (r-l)/2;
00099       if (a < m->pos) {
00100         r=m-1;
00101       } else if (a >= (m+1)->pos) {
00102         l=m+1;
00103       } else {
00104         return m->min + static_cast<int>(a - m->pos);
00105       }
00106     }
00107     GECODE_NEVER;
00108     return 0;
00109   }
00110 
00111   template<class ViewSel, class View>
00112   size_t
00113   PosValuesChoice<ViewSel,View>::size(void) const {
00114     return sizeof(PosValuesChoice<ViewSel,View>)+(n+1)*sizeof(PosMin);
00115   }
00116 
00117   template<class ViewSel, class View>
00118   PosValuesChoice<ViewSel,View>::~PosValuesChoice(void) {
00119     heap.free<PosMin>(pm,n+1);
00120   }
00121 
00122 
00123   template<class ViewSel, class View>
00124   forceinline
00125   ViewValuesBrancher<ViewSel,View>::
00126   ViewValuesBrancher(Home home, ViewArray<typename ViewSel::View>& x,
00127                       ViewSel& vi_s)
00128     : ViewBrancher<ViewSel>(home,x,vi_s) {}
00129 
00130   template<class ViewSel, class View>
00131   forceinline
00132   ViewValuesBrancher<ViewSel,View>::
00133   ViewValuesBrancher(Space& home, bool share, ViewValuesBrancher& b)
00134     : ViewBrancher<ViewSel>(home,share,b) {}
00135 
00136   template<class ViewSel, class View>
00137   Actor*
00138   ViewValuesBrancher<ViewSel,View>::copy(Space& home, bool share) {
00139     return new (home)
00140       ViewValuesBrancher<ViewSel,View>(home,share,*this);
00141   }
00142 
00143   template<class ViewSel, class View>
00144   const Choice*
00145   ViewValuesBrancher<ViewSel,View>::choice(Space& home) {
00146     Pos p = ViewBrancher<ViewSel>::pos(home);
00147     View v(ViewBrancher<ViewSel>::view(p).var());
00148     return new PosValuesChoice<ViewSel,View>
00149       (*this,p,viewsel.choice(home),v);
00150   }
00151 
00152   template<class ViewSel, class View>
00153   ExecStatus
00154   ViewValuesBrancher<ViewSel,View>
00155   ::commit(Space& home, const Choice& c, unsigned int a) {
00156     const PosValuesChoice<ViewSel,View>& pvc
00157       = static_cast<const PosValuesChoice<ViewSel,View>&>(c);
00158     View v(ViewBrancher<ViewSel>::view(pvc.pos()).var());
00159     viewsel.commit(home, pvc.viewchoice(), a);
00160     return me_failed(v.eq(home,pvc.val(a))) ? ES_FAILED : ES_OK;
00161   }
00162 
00163 }}}
00164 
00165 // STATISTICS: int-branch