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dekker.one
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Christopher Mears <chris.mears@monash.edu>
5 *
6 * Copyright:
7 * Christopher Mears, 2012
8 *
9 * This file is part of Gecode, the generic constraint
10 * development environment:
11 * http://www.gecode.org
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining
14 * a copy of this software and associated documentation files (the
15 * "Software"), to deal in the Software without restriction, including
16 * without limitation the rights to use, copy, modify, merge, publish,
17 * distribute, sublicense, and/or sell copies of the Software, and to
18 * permit persons to whom the Software is furnished to do so, subject to
19 * the following conditions:
20 *
21 * The above copyright notice and this permission notice shall be
22 * included in all copies or substantial portions of the Software.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
28 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
29 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
30 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 *
32 */
33
34#include <deque>
35#include <set>
36
37namespace Gecode { namespace Int { namespace LDSB {
38
39 forceinline
40 Literal::Literal(void)
41 : _variable(-1), _value(-1) {}
42
43 forceinline
44 Literal::Literal(int idx, int val)
45 : _variable(idx), _value(val) {}
46
47 forceinline
48 bool
49 Literal::operator <(const Literal &rhs) const {
50 int d = rhs._variable - _variable;
51 if (d > 0) return true;
52 else if (d == 0) return rhs._value > _value;
53 else return false;
54 }
55
56
57 template<class Val>
58 inline
59 LDSBChoice<Val>::LDSBChoice(const Brancher& b, unsigned int a, const Pos& p,
60 const Val& n, const Literal* literals,
61 int nliterals)
62 : PosValChoice<Val>(b,a,p,n), _literals(literals), _nliterals(nliterals)
63 {}
64
65 template<class Val>
66 LDSBChoice<Val>::~LDSBChoice(void) {
67 delete [] _literals;
68 }
69
70 template<class Val>
71 forceinline const Literal*
72 LDSBChoice<Val>::literals(void) const { return _literals; }
73
74 template<class Val>
75 forceinline int
76 LDSBChoice<Val>::nliterals(void) const { return _nliterals; }
77
78 template<class Val>
79 void
80 LDSBChoice<Val>::archive(Archive& e) const {
81 PosValChoice<Val>::archive(e);
82 e << _nliterals;
83 for (int i = 0 ; i < _nliterals ; i++) {
84 e << _literals[i]._variable;
85 e << _literals[i]._value;
86 }
87 }
88
89
90
91 template<class View, int n, class Val, unsigned int a,
92 class Filter, class Print>
93 LDSBBrancher<View,n,Val,a,Filter,Print>
94 ::LDSBBrancher(Home home, ViewArray<View>& x,
95 ViewSel<View>* vs[n],
96 ValSelCommitBase<View,Val>* vsc,
97 SymmetryImp<View>** syms, int nsyms,
98 BranchFilter<typename LDSBBrancher<View,n,Val,a,Filter,Print>::Var> bf,
99 VarValPrint<typename LDSBBrancher<View,n,Val,a,Filter,Print>::Var,Val> vvp)
100 : ViewValBrancher<View,n,Val,a,Filter,Print>(home, x, vs, vsc, bf, vvp),
101 _syms(syms),
102 _nsyms(nsyms),
103 _prevPos(-1)
104 {
105 home.notice(*this, AP_DISPOSE, true);
106 }
107
108 template<class View, int n, class Val, unsigned int a,
109 class Filter, class Print>
110 forceinline void
111 LDSBBrancher<View,n,Val,a,Filter,Print>::
112 post(Home home, ViewArray<View>& x,
113 ViewSel<View>* vs[n], ValSelCommitBase<View,Val>* vsc,
114 SymmetryImp<View>** syms, int nsyms,
115 BranchFilter<typename LDSBBrancher<View,n,Val,a,Filter,Print>::Var> bf,
116 VarValPrint<typename LDSBBrancher<View,n,Val,a,Filter,Print>::Var,Val> vvp) {
117 (void) new (home) LDSBBrancher<View,n,Val,a,Filter,Print>
118 (home,x,vs,vsc,syms,nsyms,bf,vvp);
119 }
120
121 template<class View, int n, class Val, unsigned int a,
122 class Filter, class Print>
123 forceinline
124 LDSBBrancher<View,n,Val,a,Filter,Print>::
125 LDSBBrancher(Space& home,
126 LDSBBrancher<View,n,Val,a,Filter,Print>& b)
127 : ViewValBrancher<View,n,Val,a,Filter,Print>(home,b),
128 _nsyms(b._nsyms),
129 _prevPos(b._prevPos) {
130 _syms = home.alloc<SymmetryImp<View>*>(_nsyms);
131 for (int i = 0 ; i < _nsyms ; i++)
132 _syms[i] = b._syms[i]->copy(home);
133 }
134
135 template<class View, int n, class Val, unsigned int a,
136 class Filter, class Print>
137 Actor*
138 LDSBBrancher<View,n,Val,a,Filter,Print>::copy(Space& home) {
139 return new (home) LDSBBrancher<View,n,Val,a,Filter,Print>
140 (home,*this);
141 }
142
143
144 // Compute choice
145 template<class View, int n, class Val, unsigned int a,
146 class Filter, class Print>
147 const Choice*
148 LDSBBrancher<View,n,Val,a,Filter,Print>::choice(Space& home) {
149 // Making the PVC here is not so nice, I think.
150 const Choice* c = ViewValBrancher<View,n,Val,a,Filter,Print>::choice(home);
151 const PosValChoice<Val>* pvc = static_cast<const PosValChoice<Val>* >(c);
152
153 // Compute symmetries.
154
155 int choicePos = pvc->pos().pos;
156 int choiceVal = pvc->val();
157 delete c;
158
159 _prevPos = choicePos;
160
161 // TODO: It should be possible to use simpler containers than the
162 // STL ones here.
163 std::deque<Literal> queue;
164 std::set<Literal> seen;
165
166 seen.insert(Literal(choicePos, choiceVal));
167 queue.push_back(Literal(choicePos, choiceVal));
168
169 do {
170 Literal l = queue[0];
171 queue.pop_front();
172
173 for (int i = 0 ; i < _nsyms ; i++) {
174 ArgArray<Literal> toExclude = _syms[i]->symmetric(l, this->x);
175 for (int j = 0 ; j < toExclude.size() ; ++j) {
176 if (seen.find(toExclude[j]) == seen.end())
177 queue.push_back(toExclude[j]);
178 seen.insert(toExclude[j]);
179 }
180 }
181 } while (queue.size() > 0);
182
183 // Convert "seen" vector into array.
184 int nliterals = static_cast<int>(seen.size());
185 Literal* literals = new Literal[nliterals];
186 std::set<Literal>::iterator it = seen.begin();
187 for (int i = 0 ; i < nliterals ; i++) {
188 literals[i] = *it;
189 ++it;
190 }
191
192 return new LDSBChoice<Val>(*this,a,choicePos,choiceVal, literals, nliterals);
193 }
194
195
196 template<class View, int n, class Val, unsigned int a,
197 class Filter, class Print>
198 const Choice*
199 LDSBBrancher<View,n,Val,a,Filter,Print>::choice(const Space& home,
200 Archive& e) {
201 (void) home;
202 int p; e >> p;
203 Val v; e >> v;
204 int nliterals; e >> nliterals;
205 Literal* literals = new Literal[nliterals];
206 for (int i = 0 ; i < nliterals ; i++) {
207 e >> literals[i]._variable;
208 e >> literals[i]._value;
209 }
210 return new LDSBChoice<Val>(*this,a,p,v, literals, nliterals);
211 }
212
213 template <>
214 inline
215 ModEvent
216 prune<Int::IntView>(Space& home, Int::IntView x, int v) {
217 return x.nq(home, v);
218 }
219
220 template <>
221 inline
222 ModEvent
223 prune<Int::BoolView>(Space& home, Int::BoolView x, int v) {
224 return x.nq(home, v);
225 }
226
227
228 template<class View, int n, class Val, unsigned int a,
229 class Filter, class Print>
230 ExecStatus
231 LDSBBrancher<View,n,Val,a,Filter,Print>
232 ::commit(Space& home, const Choice& c, unsigned int b) {
233 const LDSBChoice<Val>& pvc
234 = static_cast<const LDSBChoice<Val>&>(c);
235 int choicePos = pvc.pos().pos;
236 int choiceVal = pvc.val();
237
238 if (b == 0) {
239 // Post the branching constraint.
240 ExecStatus fromBase = ViewValBrancher<View,n,Val,a,Filter,Print>
241 ::commit(home, c, b);
242 GECODE_ES_CHECK(fromBase);
243 for (int i = 0 ; i < this->_nsyms ; i++)
244 this->_syms[i]->update(Literal(choicePos, choiceVal));
245 } else if (b == 1) {
246 // Post the branching constraint.
247 ExecStatus fromBase = ViewValBrancher<View,n,Val,a,Filter,Print>
248 ::commit(home, c, b);
249 GECODE_ES_CHECK(fromBase);
250
251 // Post prunings.
252 int nliterals = pvc.nliterals();
253 const Literal* literals = pvc.literals();
254 for (int i = 0 ; i < nliterals ; i++) {
255 const Literal& l = literals[i];
256 ModEvent me = prune<View>(home, this->x[l._variable], l._value);
257 GECODE_ME_CHECK(me);
258 }
259 }
260
261 return ES_OK;
262 }
263
264 template<class View, int n, class Val, unsigned int a,
265 class Filter, class Print>
266 size_t
267 LDSBBrancher<View,n,Val,a,Filter,Print>::dispose(Space& home) {
268 home.ignore(*this,AP_DISPOSE,true);
269 (void) ViewValBrancher<View,n,Val,a,Filter,Print>::dispose(home);
270 return sizeof(LDSBBrancher<View,n,Val,a,Filter,Print>);
271 }
272
273 template<class View, int n, class Val, unsigned int a>
274 forceinline void
275 postldsbbrancher(Home home,
276 ViewArray<View>& x,
277 ViewSel<View>* vs[n],
278 ValSelCommitBase<View,Val>* vsc,
279 SymmetryImp<View>** syms, int nsyms,
280 BranchFilter<typename View::VarType> bf,
281 VarValPrint<typename View::VarType,Val> vvp) {
282 if (bf) {
283 if (vvp) {
284 LDSBBrancher<View,n,Val,a,BrancherFilter<View>,BrancherPrint<View,Val>>
285 ::post(home,x,vs,vsc,syms,nsyms,bf,vvp);
286 } else {
287 LDSBBrancher<View,n,Val,a,BrancherFilter<View>,BrancherNoPrint<View,Val> >
288 ::post(home,x,vs,vsc,syms,nsyms,bf,vvp);
289 }
290 } else {
291 if (vvp) {
292 LDSBBrancher<View,n,Val,a,BrancherNoFilter<View>,BrancherPrint<View,Val>>
293 ::post(home,x,vs,vsc,syms,nsyms,bf,vvp);
294 } else {
295 LDSBBrancher<View,n,Val,a,BrancherNoFilter<View>,BrancherNoPrint<View,Val> >
296 ::post(home,x,vs,vsc,syms,nsyms,bf,vvp);
297 }
298 }
299 }
300
301}}}
302
303// STATISTICS: int-branch