Generated on Fri Oct 19 11:25:01 2018 for Gecode by doxygen 1.6.3

lq.hpp

Go to the documentation of this file.
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, 2006
00008  *
00009  *  This file is part of Gecode, the generic constraint
00010  *  development environment:
00011  *     http://www.gecode.org
00012  *
00013  *  Permission is hereby granted, free of charge, to any person obtaining
00014  *  a copy of this software and associated documentation files (the
00015  *  "Software"), to deal in the Software without restriction, including
00016  *  without limitation the rights to use, copy, modify, merge, publish,
00017  *  distribute, sublicense, and/or sell copies of the Software, and to
00018  *  permit persons to whom the Software is furnished to do so, subject to
00019  *  the following conditions:
00020  *
00021  *  The above copyright notice and this permission notice shall be
00022  *  included in all copies or substantial portions of the Software.
00023  *
00024  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
00025  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
00026  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00027  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
00028  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
00029  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
00030  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00031  *
00032  */
00033 
00034 namespace Gecode { namespace Int { namespace Bool {
00035 
00036   /*
00037    * Less or equal propagator
00038    *
00039    */
00040 
00041   template<class BV>
00042   forceinline
00043   Lq<BV>::Lq(Home home, BV b0, BV b1)
00044     : BoolBinary<BV,BV>(home,b0,b1) {}
00045 
00046   template<class BV>
00047   forceinline
00048   Lq<BV>::Lq(Space& home, Lq<BV>& p)
00049     : BoolBinary<BV,BV>(home,p) {}
00050 
00051   template<class BV>
00052   Actor*
00053   Lq<BV>::copy(Space& home) {
00054     return new (home) Lq<BV>(home,*this);
00055   }
00056 
00057   template<class BV>
00058   inline ExecStatus
00059   Lq<BV>::post(Home home, BV b0, BV b1) {
00060     if (b0.zero()) {
00061       return ES_OK;
00062     } else if (b0.one()) {
00063       GECODE_ME_CHECK(b1.one(home));
00064     } else if (b1.zero()) {
00065       GECODE_ME_CHECK(b0.zero(home));
00066     } else if (b1.one()) {
00067       return ES_OK;
00068     } else {
00069       (void) new (home) Lq<BV>(home,b0,b1);
00070     }
00071     return ES_OK;
00072   }
00073 
00074   template<class BV>
00075   ExecStatus
00076   Lq<BV>::propagate(Space& home, const ModEventDelta&) {
00077 #define GECODE_INT_STATUS(S0,S1) \
00078   ((BV::S0<<(1*BV::BITS))|(BV::S1<<(0*BV::BITS)))
00079     switch ((x0.status()<<(1*BV::BITS)) | (x1.status()<<(0*BV::BITS))) {
00080     case GECODE_INT_STATUS(NONE,NONE):
00081       GECODE_NEVER;
00082     case GECODE_INT_STATUS(NONE,ZERO):
00083       GECODE_ME_CHECK(x0.zero_none(home)); break;
00084     case GECODE_INT_STATUS(NONE,ONE):
00085     case GECODE_INT_STATUS(ZERO,NONE):
00086     case GECODE_INT_STATUS(ZERO,ZERO):
00087     case GECODE_INT_STATUS(ZERO,ONE):
00088       break;
00089     case GECODE_INT_STATUS(ONE,NONE):
00090       GECODE_ME_CHECK(x1.one_none(home)); break;
00091     case GECODE_INT_STATUS(ONE,ZERO):
00092       return ES_FAILED;
00093     case GECODE_INT_STATUS(ONE,ONE):
00094       break;
00095     default:
00096       GECODE_NEVER;
00097     }
00098     return home.ES_SUBSUMED(*this);
00099 #undef GECODE_INT_STATUS
00100   }
00101 
00102 
00103   /*
00104    * N-ary Boolean less or equal propagator
00105    *
00106    */
00107 
00108   template<class VX>
00109   forceinline
00110   NaryLq<VX>::NaryLq(Home home, ViewArray<VX>& x)
00111     : NaryPropagator<VX,PC_BOOL_NONE>(home,x),
00112       run(false), n_zero(0), n_one(0), c(home) {
00113     x.subscribe(home,*new (home) Advisor(home,*this,c));
00114   }
00115 
00116   template<class VX>
00117   forceinline
00118   NaryLq<VX>::NaryLq(Space& home, NaryLq<VX>& p)
00119     : NaryPropagator<VX,PC_BOOL_NONE>(home,p),
00120       run(false), n_zero(0), n_one(0) {
00121     c.update(home,p.c);
00122   }
00123 
00124   template<class VX>
00125   Actor*
00126   NaryLq<VX>::copy(Space& home) {
00127     return new (home) NaryLq<VX>(home,*this);
00128   }
00129 
00130   template<class VX>
00131   inline ExecStatus
00132   NaryLq<VX>::post(Home home, ViewArray<VX>& x) {
00133     int i = 0;
00134     while (i < x.size())
00135       if (x[i].zero()) {
00136         // All x[j] left of i must be zero as well
00137         for (int j=0; j<i; j++)
00138           GECODE_ME_CHECK(x[j].zero_none(home));
00139         x.drop_fst(i+1); i=0;
00140       } else if (x[i].one()) {
00141         // All x[j] right of i must be one as well
00142         for (int j=i+1; j<x.size(); j++)
00143           GECODE_ME_CHECK(x[j].one(home));
00144         x.drop_lst(i-1); break;
00145       } else {
00146         i++;
00147       }
00148 
00149     if (x.size() == 2)
00150       return Lq<VX>::post(home,x[0],x[1]);
00151     if (x.size() > 2)
00152       (void) new (home) NaryLq(home,x);
00153     return ES_OK;
00154   }
00155 
00156   template<class VX>
00157   PropCost
00158   NaryLq<VX>::cost(const Space&, const ModEventDelta&) const {
00159     return PropCost::binary(PropCost::LO);
00160   }
00161 
00162   template<class VX>
00163   ExecStatus
00164   NaryLq<VX>::advise(Space&, Advisor&, const Delta& d) {
00165     if (VX::zero(d))
00166       n_zero++;
00167     else
00168       n_one++;
00169     return run ? ES_FIX : ES_NOFIX;
00170   }
00171 
00172   template<class VX>
00173   forceinline size_t
00174   NaryLq<VX>::dispose(Space& home) {
00175     Advisors<Advisor> as(c);
00176     x.cancel(home,as.advisor());
00177     c.dispose(home);
00178     (void) NaryPropagator<VX,PC_BOOL_NONE>::dispose(home);
00179     return sizeof(*this);
00180   }
00181 
00182   template<class VX>
00183   ExecStatus
00184   NaryLq<VX>::propagate(Space& home, const ModEventDelta&) {
00185     run = true;
00186     while (n_zero > 0) {
00187       int i = 0;
00188       while (x[i].none())
00189         i++;
00190       if (x[i].one())
00191         return ES_FAILED;
00192       // As the x[j] might be shared, only zero() but not zero_none()
00193       for (int j=0; j<i; j++)
00194         GECODE_ME_CHECK(x[j].zero(home));
00195       n_zero -= i + 1;
00196       assert(n_zero >= 0);
00197       x.drop_fst(i+1);
00198     }
00199 
00200     while (n_one > 0) {
00201       int i = x.size() - 1;
00202       while (x[i].none())
00203         i--;
00204       assert(x[i].one());
00205       // As the x[j] might be shared, only one() but not one_none()
00206       for (int j=i+1; j<x.size(); j++)
00207         GECODE_ME_CHECK(x[j].one(home));
00208       n_one -= x.size() - i;
00209       assert(n_one >= 0);
00210       x.drop_lst(i-1);
00211     }
00212 
00213     if (x.size() < 2)
00214       return home.ES_SUBSUMED(*this);
00215 
00216     run = false;
00217     return ES_FIX;
00218   }
00219 
00220 
00221   /*
00222    * Less posting
00223    *
00224    */
00225 
00226   template<class BV>
00227   forceinline ExecStatus
00228   Le<BV>::post(Home home, BV b0, BV b1) {
00229     GECODE_ME_CHECK(b0.zero(home));
00230     GECODE_ME_CHECK(b1.one(home));
00231     return ES_OK;
00232   }
00233 
00234 }}}
00235 
00236 // STATISTICS: int-prop
00237