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unionConst.hpp
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2/*
3 * Main authors:
4 * Guido Tack <tack@gecode.org>
5 * Christian Schulte <schulte@gecode.org>
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8 * Guido Tack, 2004,2006,2007
9 * Christian Schulte, 2004
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35
36namespace Gecode { namespace Set { namespace Element {
37
38 template<class SView, class RView>
41 ElementUnionConst(Home home, SView y0,
42 const IntSetArgs& iv0,
43 RView y1)
44 : Propagator(home), x0(y0), n_iv(iv0.size()), x1(y1) {
45 home.notice(*this,AP_DISPOSE);
46 x0.subscribe(home,*this, PC_SET_ANY);
47 x1.subscribe(home,*this, PC_SET_ANY);
48 iv=static_cast<Space&>(home).alloc<IntSet>(n_iv);
49 for (unsigned int i=iv0.size(); i--;)
50 iv[i]=iv0[i];
51 }
52
53 template<class SView, class RView>
57 : Propagator(home,p), n_iv(p.n_iv) {
58 x0.update(home,p.x0);
59 x1.update(home,p.x1);
60 iv=home.alloc<IntSet>(n_iv);
61 for (unsigned int i=n_iv; i--;)
62 iv[i]=p.iv[i];
63 }
64
65 template<class SView, class RView>
68 return PropCost::linear(PropCost::HI, n_iv+2);
69 }
70
71 template<class SView, class RView>
72 void
74 x0.reschedule(home,*this, PC_SET_ANY);
75 x1.reschedule(home,*this, PC_SET_ANY);
76 }
77
78 template<class SView, class RView>
79 forceinline size_t
81 home.ignore(*this,AP_DISPOSE);
82 if (!home.failed()) {
83 x0.cancel(home,*this, PC_SET_ANY);
84 x1.cancel(home,*this, PC_SET_ANY);
85 }
86 for (unsigned int i=n_iv; i--;)
87 iv[i].~IntSet();
88 (void) Propagator::dispose(home);
89 return sizeof(*this);
90 }
91
92 template<class SView, class RView>
95 post(Home home, SView x0, const IntSetArgs& xs,
96 RView x1) {
97 int n = xs.size();
98
99 // s2 \subseteq {1,...,n}
101 GECODE_ME_CHECK(x1.intersectI(home,s));
102 (void) new (home)
103 ElementUnionConst<SView,RView>(home,x0,xs,x1);
104 return ES_OK;
105 }
106
107 template<class SView, class RView>
108 Actor*
110 return new (home) ElementUnionConst<SView,RView>(home,*this);
111 }
112
113 template<class SView, class RView>
116 Region r;
117
118 bool* stillSelected = r.alloc<bool>(n_iv);
119
120 bool loopVar;
121 do {
122 loopVar = false;
123 for (int i=n_iv; i--;)
124 stillSelected[i] = false;
125
126 // Cache the upper bound iterator, as we have to
127 // modify the upper bound while iterating
128 LubRanges<RView> x1ub(x1);
129 Iter::Ranges::Cache x1ubc(r,x1ub);
131 vx1ub(x1ubc);
132
133 GlbRanges<RView> x1lb(x1);
134 Iter::Ranges::Cache x1lbc(r,x1lb);
136 vx1(x1lbc);
137
138 // In the first iteration, compute in before[i] the union
139 // of all the upper bounds of the x_i. At the same time,
140 // exclude inconsistent x_i from x1.
141
142 GLBndSet sofarBefore(home);
143 LUBndSet selectedInter(home, IntSet (Limits::min,
144 Limits::max));
145 GLBndSet* before =
146 static_cast<GLBndSet*>(r.ralloc(sizeof(GLBndSet)*n_iv));
147
148 unsigned int maxCard = 0;
149 unsigned int minCard = Limits::card;
150
151 while (vx1ub()) {
152 int i = vx1ub.val();
153
154 IntSetRanges candCardR(iv[i]);
155 unsigned int candidateCard = Iter::Ranges::size(candCardR);
156
157 IntSetRanges candlb(iv[i]);
158 LubRanges<SView> x0ub(x0);
160 LubRanges<SView> > diff(candlb, x0ub);
161
162 bool selectSingleInconsistent = false;
163 if (x1.cardMax() <= 1) {
164 GlbRanges<SView> x0lb(x0);
165 IntSetRanges candub(iv[i]);
167 IntSetRanges > diff2(x0lb, candub);
168 selectSingleInconsistent = diff2() || candidateCard < x0.cardMin();
169 }
170
171 // exclude inconsistent x_i
172 // an x_i is inconsistent if
173 // * at most one x_i can be selected and there are
174 // elements in x_0 that can't be in x_i
175 // (selectSingleInconsistent)
176 // * its min cardinality is greater than maxCard of x0
177 // * inter is not empty (there are elements in x_i
178 // that can't be in x_0)
179 if (selectSingleInconsistent ||
180 candidateCard > x0.cardMax() ||
181 diff()) {
182 ModEvent me = (x1.exclude(home,i));
183 loopVar |= me_modified(me);
184 GECODE_ME_CHECK(me);
185 } else {
186 stillSelected[i] = true;
187 // if x_i is consistent, check whether we know
188 // that its index is in x1
189 if (vx1() && vx1.val()==i) {
190 // x0 >= candidate, candidate <= x0
191 // GlbRanges<SView> candlb(candidate);
192 IntSetRanges candlb(iv[i]);
193 ModEvent me = x0.includeI(home,candlb);
194 loopVar |= me_modified(me);
195 GECODE_ME_CHECK(me);
196 ++vx1;
197 }
198 new (&before[i]) GLBndSet(home);
199 before[i].update(home,sofarBefore);
200 IntSetRanges cub(iv[i]);
201 sofarBefore.includeI(home,cub);
202 IntSetRanges clb(iv[i]);
203 selectedInter.intersectI(home,clb);
204 maxCard = std::max(maxCard, candidateCard);
205 minCard = std::min(minCard, candidateCard);
206 }
207
208 ++vx1ub;
209 }
210
211 if (x1.cardMax()==0) {
212 // Selector is empty, hence the result must be empty
213 {
214 GECODE_ME_CHECK(x0.cardMax(home,0));
215 }
216 for (int i=n_iv; i--;)
217 if (stillSelected[i])
218 before[i].dispose(home);
219 selectedInter.dispose(home);
220 sofarBefore.dispose(home);
221 return home.ES_SUBSUMED(*this);
222 }
223
224 if (x1.cardMin() > 0) {
225 // Selector is not empty, hence the intersection of the
226 // possibly selected lower bounds is contained in x0
227 BndSetRanges si(selectedInter);
228 ModEvent me = x0.includeI(home, si);
229 loopVar |= me_modified(me);
230 GECODE_ME_CHECK(me);
231 me = x0.cardMin(home, minCard);
232 loopVar |= me_modified(me);
233 GECODE_ME_CHECK(me);
234 }
235 selectedInter.dispose(home);
236
237 if (x1.cardMax() <= 1) {
238 ModEvent me = x0.cardMax(home, maxCard);
239 loopVar |= me_modified(me);
240 GECODE_ME_CHECK(me);
241 }
242
243 {
244 // x0 <= sofarBefore
245 BndSetRanges sfB(sofarBefore);
246 ModEvent me = x0.intersectI(home,sfB);
247 loopVar |= me_modified(me);
248 GECODE_ME_CHECK(me);
249 }
250
251 sofarBefore.dispose(home);
252
253 GLBndSet sofarAfter(home);
254
255 // In the second iteration, this time backwards, compute
256 // sofarAfter as the union of all lub(x_j) with j>i
257 for (int i=n_iv; i--;) {
258 if (!stillSelected[i])
259 continue;
260 BndSetRanges b(before[i]);
261 BndSetRanges s(sofarAfter);
262 GlbRanges<SView> x0lb(x0);
266 if (diff()) {
267 ModEvent me = (x1.include(home,i));
268 loopVar |= me_modified(me);
269 GECODE_ME_CHECK(me);
270
271 // candidate != extra
272 IntSetRanges ivi(iv[i]);
273 if (!Iter::Ranges::subset(diff, ivi))
275 }
276
277 IntSetRanges iviub(iv[i]);
278 sofarAfter.includeI(home,iviub);
279 before[i].dispose(home);
280 }
281 sofarAfter.dispose(home);
282
283 } while (loopVar);
284
285 if (x1.assigned()) {
286 assert(x0.assigned());
287 return home.ES_SUBSUMED(*this);
288 }
289
290 return ES_FIX;
291 }
292
293}}}
294
295// STATISTICS: set-prop
struct Gecode::@603::NNF::@65::@66 b
For binary nodes (and, or, eqv)
int p
Number of positive literals for node type.
Definition: bool-expr.cpp:232
int n
Number of negative literals for node type.
Definition: bool-expr.cpp:234
Base-class for both propagators and branchers.
Definition: core.hpp:628
virtual size_t dispose(Space &home)
Delete actor and return its size.
Definition: core.hpp:3252
int size(void) const
Return size of array (number of elements)
Definition: array.hpp:1607
Home class for posting propagators
Definition: core.hpp:856
void notice(Actor &a, ActorProperty p, bool duplicate=false)
Notice actor property.
Definition: core.hpp:3219
Range iterator for integer sets.
Definition: int.hh:292
Integer sets.
Definition: int.hh:174
Range iterator cache
Range iterator for computing set difference.
Definition: ranges-diff.hpp:43
Range iterator for singleton range.
Value iterator from range iterator.
int val(void) const
Return current value.
Range iterator for computing union (binary)
Propagation cost.
Definition: core.hpp:486
static PropCost linear(PropCost::Mod m, unsigned int n)
Linear complexity for modifier pcm and size measure n.
Definition: core.hpp:4796
@ HI
Expensive.
Definition: core.hpp:514
Base-class for propagators.
Definition: core.hpp:1064
Handle to region.
Definition: region.hpp:55
Range iterator for integer sets.
Definition: var-imp.hpp:185
void update(Space &home, BndSet &x)
Update this set to be a clone of set x.
Definition: integerset.hpp:140
void dispose(Space &home)
Free memory used by this set.
Definition: integerset.hpp:60
Propagator for element with union of constant sets
Definition: element.hh:157
virtual void reschedule(Space &home)
Schedule function.
Definition: unionConst.hpp:73
Growing sets of integers.
Definition: var-imp.hpp:205
bool includeI(Space &home, I &i)
Include the set represented by i in this set.
Definition: integerset.hpp:296
Range iterator for the greatest lower bound.
Definition: var-imp.hpp:359
Shrinking sets of integers.
Definition: var-imp.hpp:243
bool intersectI(Space &home, I &i)
Exclude all elements not in the set represented by i from this set.
Definition: integerset.hpp:370
Range iterator for the least upper bound.
Definition: var-imp.hpp:317
Computation spaces.
Definition: core.hpp:1742
T * alloc(long unsigned int n)
Allocate block of n objects of type T from space heap.
Definition: core.hpp:2837
ExecStatus ES_SUBSUMED(Propagator &p)
Definition: core.hpp:3563
void ignore(Actor &a, ActorProperty p, bool duplicate=false)
Ignore actor property.
Definition: core.hpp:4074
int ModEventDelta
Modification event deltas.
Definition: core.hpp:89
bool failed(void) const
Check whether space is failed.
Definition: core.hpp:4044
#define GECODE_ME_CHECK(me)
Check whether modification event me is failed, and forward failure.
Definition: macros.hpp:52
bool me_modified(ModEvent me)
Check whether modification event me describes variable modification.
Definition: modevent.hpp:59
@ AP_DISPOSE
Actor must always be disposed.
Definition: core.hpp:562
const int min
Smallest allowed integer value.
Definition: int.hh:118
const int max
Largest allowed integer value.
Definition: int.hh:116
bool subset(I &i, J &j)
Check whether range iterator i is subset of range iterator j.
unsigned int size(I &i)
Size of all ranges of range iterator i.
const unsigned int card
Maximum cardinality of an integer set.
Definition: set.hh:101
const Gecode::PropCond PC_SET_ANY
Propagate when any bound or the cardinality of a view changes.
Definition: var-type.hpp:248
const Gecode::ModEvent ME_SET_FAILED
Domain operation has resulted in failure.
Definition: var-type.hpp:138
Gecode toplevel namespace
Post propagator for SetVar SetOpType SetVar SetRelType r
Definition: set.hh:767
SetExpr inter(const SetVarArgs &)
Intersection of set variables.
Definition: set-expr.cpp:696
ExecStatus
Definition: core.hpp:472
@ ES_OK
Execution is okay.
Definition: core.hpp:476
@ ES_FIX
Propagation has computed fixpoint.
Definition: core.hpp:477
int ModEvent
Type for modification events.
Definition: core.hpp:62
#define forceinline
Definition: config.hpp:194