gecode » int » element
int.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, 2004
00008  *
00009  *  Last modified:
00010  *     $Date: 2009-10-14 10:56:06 +0200 (Wed, 14 Oct 2009) $ by $Author: schulte $
00011  *     $Revision: 9902 $
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 Element {
00039 
00040 
00041   // Index value pairs
00042   template<class V0, class V1, class Idx, class Val>
00043   forceinline void
00044   Int<V0,V1,Idx,Val>::IdxVal::mark(void) {
00045     idx = -1;
00046   }
00047   template<class V0, class V1, class Idx, class Val>
00048   forceinline bool
00049   Int<V0,V1,Idx,Val>::IdxVal::marked(void) const {
00050     return idx<0;
00051   }
00052 
00053   // Index iterator
00054   template<class V0, class V1, class Idx, class Val>
00055   forceinline
00056   Int<V0,V1,Idx,Val>::IterIdx::IterIdx(IdxVal* iv0)
00057     : iv(iv0) {
00058     Idx p=0;
00059     i = iv[p].idx_next;
00060     while ((i != 0) && iv[i].marked())
00061       i=iv[i].idx_next;
00062     iv[p].idx_next=i;
00063   }
00064   template<class V0, class V1, class Idx, class Val>
00065   forceinline bool
00066   Int<V0,V1,Idx,Val>::IterIdx::operator ()(void) const {
00067     return i != 0;
00068   }
00069   template<class V0, class V1, class Idx, class Val>
00070   forceinline void
00071   Int<V0,V1,Idx,Val>::IterIdx::operator ++(void) {
00072     int p=i;
00073     i = iv[p].idx_next;
00074     while ((i != 0) && iv[i].marked())
00075       i=iv[i].idx_next;
00076     iv[p].idx_next=i;
00077   }
00078   template<class V0, class V1, class Idx, class Val>
00079   forceinline Idx
00080   Int<V0,V1,Idx,Val>::IterIdx::val(void) const {
00081     assert(!iv[i].marked());
00082     return iv[i].idx;
00083   }
00084 
00085 
00086 
00087   template<class V0, class V1, class Idx, class Val>
00088   forceinline
00089   Int<V0,V1,Idx,Val>::IterVal::IterVal(IdxVal* iv0)
00090     : iv(iv0), i(iv[0].val_next) {}
00091   template<class V0, class V1, class Idx, class Val>
00092   forceinline bool
00093   Int<V0,V1,Idx,Val>::IterVal::operator ()(void) const {
00094     return i != 0;
00095   }
00096   template<class V0, class V1, class Idx, class Val>
00097   forceinline void
00098   Int<V0,V1,Idx,Val>::IterVal::operator ++(void) {
00099     i=iv[i].val_next;
00100   }
00101   template<class V0, class V1, class Idx, class Val>
00102   forceinline Val
00103   Int<V0,V1,Idx,Val>::IterVal::val(void) const {
00104     assert(!iv[i].marked());
00105     return iv[i].val;
00106   }
00107 
00108 
00109 
00110   // Sort function
00111   template<class V0, class V1, class Idx, class Val>
00112   forceinline
00113   Int<V0,V1,Idx,Val>::ByVal::ByVal(const IdxVal* iv0)
00114     : iv(iv0) {}
00115   template<class V0, class V1, class Idx, class Val>
00116   forceinline bool
00117   Int<V0,V1,Idx,Val>::ByVal::operator ()(Idx& i, Idx& j) {
00118     return iv[i].val < iv[j].val;
00119   }
00120 
00121 
00122   /*
00123    * Element propagator proper
00124    *
00125    */
00126   template<class V0, class V1, class Idx, class Val>
00127   forceinline
00128   Int<V0,V1,Idx,Val>::Int(Home home, IntSharedArray& c0, V0 y0, V1 y1)
00129     : Propagator(home), x0(y0), x1(y1), c(c0), iv(NULL) {
00130     home.notice(*this,AP_DISPOSE);
00131     x0.subscribe(home,*this,PC_INT_DOM);
00132     x1.subscribe(home,*this,PC_INT_DOM);
00133   }
00134 
00135   template<class V0, class V1, class Idx, class Val>
00136   forceinline size_t
00137   Int<V0,V1,Idx,Val>::dispose(Space& home) {
00138     home.ignore(*this,AP_DISPOSE);
00139     if (!home.failed()) {
00140       x0.cancel(home,*this,PC_INT_DOM);
00141       x1.cancel(home,*this,PC_INT_DOM);
00142     }
00143     c.~IntSharedArray();
00144     (void) Propagator::dispose(home);
00145     return sizeof(*this);
00146   }
00147 
00148   template<class V0, class V1, class Idx, class Val>
00149   ExecStatus
00150   Int<V0,V1,Idx,Val>::post(Home home, IntSharedArray& c, V0 x0, V1 x1) {
00151     if (x0.assigned()) {
00152       GECODE_ME_CHECK(x1.eq(home,c[x0.val()]));
00153     } else {
00154       (void) new (home) Int<V0,V1,Idx,Val>(home,c,x0,x1);
00155     }
00156     return ES_OK;
00157   }
00158 
00159   template<class V0, class V1, class Idx, class Val>
00160   forceinline
00161   Int<V0,V1,Idx,Val>::Int(Space& home, bool share, Int& p)
00162     : Propagator(home,share,p), iv(NULL) {
00163     c.update(home,share,p.c);
00164     x0.update(home,share,p.x0);
00165     x1.update(home,share,p.x1);
00166   }
00167 
00168   template<class V0, class V1, class Idx, class Val>
00169   Actor*
00170   Int<V0,V1,Idx,Val>::copy(Space& home, bool share) {
00171     return new (home) Int<V0,V1,Idx,Val>(home,share,*this);
00172   }
00173 
00174   template<class V0, class V1, class Idx, class Val>
00175   PropCost
00176   Int<V0,V1,Idx,Val>::cost(const Space&, const ModEventDelta&) const {
00177     return PropCost::binary(PropCost::HI);
00178   }
00179 
00180   template<class V0, class V1, class Idx, class Val>
00181   ExecStatus
00182   Int<V0,V1,Idx,Val>::propagate(Space& home, const ModEventDelta&) {
00183     bool assigned = x0.assigned() && x1.assigned();
00184     if (iv == NULL) {
00185       // Initialize data structure
00186       iv = home.alloc<IdxVal>(x0.size() + 1);
00187 
00188       // The first element in iv[0] is used as sentinel
00189       // Enter information sorted by idx
00190       IdxVal* by_idx = &iv[1];
00191       {
00192         Idx i = 0;
00193         ViewValues<V0> v(x0);
00194         while (v()) {
00195           by_idx[i].idx = static_cast<Idx>(v.val());
00196           by_idx[i].val = static_cast<Val>(c[v.val()]);
00197           ++i; ++v;
00198         }
00199       }
00200       Idx size = static_cast<Idx>(x0.size());
00201       // Create val links sorted by val
00202       Region r(home);
00203       Idx* by_val = r.alloc<Idx>(size);
00204       for (Idx i = size; i--; )
00205         by_val[i] = i+1;
00206       ByVal less(iv);
00207       Support::quicksort<Idx>(by_val,size,less);
00208       // Create val links
00209       for (Idx i = size-1; i--; ) {
00210         by_idx[i].idx_next = i+2;
00211         iv[by_val[i]].val_next = by_val[i+1];
00212       }
00213       by_idx[size-1].idx_next = 0;
00214       iv[by_val[size-1]].val_next = 0;
00215       // Set up sentinel element: iv[0]
00216       iv[0].idx_next = 1;
00217       iv[0].val_next = by_val[0];
00218     } else {
00219       // Prune index
00220       Idx p = 0;
00221       Idx i = iv[p].idx_next;
00222       ViewRanges<V0> v(x0);
00223       while (v() && (i != 0)) {
00224         assert(!iv[i].marked());
00225         if (iv[i].idx < v.min()) {
00226           iv[i].mark(); i=iv[i].idx_next; iv[p].idx_next=i;
00227         } else if (iv[i].idx > v.max()) {
00228           ++v;
00229         } else {
00230           p=i; i=iv[i].idx_next;
00231         }
00232       }
00233       iv[p].idx_next = 0;
00234       while (i != 0) { iv[i].mark(); i=iv[i].idx_next; }
00235     }
00236 
00237     // Prune values
00238     {
00239       Idx p = 0;
00240       Idx i = iv[p].val_next;
00241       ViewRanges<V1> v(x1);
00242       while (v() && (i != 0)) {
00243         if (iv[i].marked()) {
00244           i=iv[i].val_next; iv[p].val_next=i;
00245         } else if (iv[i].val < v.min()) {
00246           iv[i].mark(); i=iv[i].val_next; iv[p].val_next=i;
00247         } else if (iv[i].val > v.max()) {
00248           ++v;
00249         } else {
00250           p=i; i=iv[i].val_next;
00251         }
00252       }
00253       iv[p].val_next = 0;
00254       while (i != 0) { iv[i].mark(); i=iv[i].val_next; }
00255     }
00256 
00257     // Peform tell
00258     {
00259       IterIdx i(iv);
00260       GECODE_ME_CHECK(x0.narrow_v(home,i,false));
00261       IterVal v(iv);
00262       if (shared(x0,x1)) {
00263         GECODE_ME_CHECK(x1.inter_v(home,v,false));
00264         return assigned ? ES_SUBSUMED(*this,home) : ES_NOFIX;
00265       } else {
00266         GECODE_ME_CHECK(x1.narrow_v(home,v,false));
00267         return (x0.assigned() || x1.assigned()) ?
00268           ES_SUBSUMED(*this,home) : ES_FIX;
00269       }
00270     }
00271   }
00272 
00273   template<class V0, class V1>
00274   forceinline ExecStatus
00275   post_int(Home home, IntSharedArray& c, V0 x0, V1 x1) {
00276     assert(c.size() > 0);
00277     GECODE_ME_CHECK(x0.gq(home,0));
00278     GECODE_ME_CHECK(x0.le(home,c.size()));
00279     Support::IntType idx_type = Support::s_type(c.size());
00280     int min = c[0];
00281     int max = c[0];
00282     for (int i=1; i<c.size(); i++) {
00283       min = std::min(c[i],min); max = std::max(c[i],max);
00284     }
00285     GECODE_ME_CHECK(x1.gq(home,min));
00286     GECODE_ME_CHECK(x1.lq(home,max));
00287     Support::IntType val_type = 
00288       std::max(Support::s_type(min),Support::s_type(max));
00289     switch (idx_type) {
00290     case Support::IT_CHAR:
00291       switch (val_type) {
00292       case Support::IT_CHAR:
00293         return Int<V0,V1,signed char,signed char>::post(home,c,x0,x1);
00294       case Support::IT_SHRT:
00295         return Int<V0,V1,signed char,signed short int>::post(home,c,x0,x1);
00296       case Support::IT_INT:
00297         return Int<V0,V1,signed char,signed int>::post(home,c,x0,x1);
00298       default: GECODE_NEVER;
00299       }
00300       break;
00301     case Support::IT_SHRT:
00302       switch (val_type) {
00303       case Support::IT_CHAR:
00304         return Int<V0,V1,signed short int,signed char>::post(home,c,x0,x1);
00305       case Support::IT_SHRT:
00306         return Int<V0,V1,signed short int,signed short int>::post(home,c,x0,x1);
00307       case Support::IT_INT:
00308         return Int<V0,V1,signed short int,signed int>::post(home,c,x0,x1);
00309       default: GECODE_NEVER;
00310       }
00311       break;
00312     case Support::IT_INT:
00313       switch (val_type) {
00314       case Support::IT_CHAR:
00315         return Int<V0,V1,signed int,signed char>::post(home,c,x0,x1);
00316       case Support::IT_SHRT:
00317         return Int<V0,V1,signed int,signed short int>::post(home,c,x0,x1);
00318       case Support::IT_INT:
00319         return Int<V0,V1,signed int,signed int>::post(home,c,x0,x1);
00320       default: GECODE_NEVER;
00321       }
00322       break;
00323     default: GECODE_NEVER;
00324     }
00325     return ES_OK;
00326   }
00327 
00328 }}}
00329 
00330 // STATISTICS: int-prop
00331