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dekker.one
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Christian Schulte <schulte@gecode.org>
5 * Vincent Barichard <Vincent.Barichard@univ-angers.fr>
6 *
7 * Copyright:
8 * Christian Schulte, 2004
9 * Vincent Barichard, 2012
10 *
11 * This file is part of Gecode, the generic constraint
12 * development environment:
13 * http://www.gecode.org
14 *
15 * Permission is hereby granted, free of charge, to any person obtaining
16 * a copy of this software and associated documentation files (the
17 * "Software"), to deal in the Software without restriction, including
18 * without limitation the rights to use, copy, modify, merge, publish,
19 * distribute, sublicense, and/or sell copies of the Software, and to
20 * permit persons to whom the Software is furnished to do so, subject to
21 * the following conditions:
22 *
23 * The above copyright notice and this permission notice shall be
24 * included in all copies or substantial portions of the Software.
25 *
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
27 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
28 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
29 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
30 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
31 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
32 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
33 *
34 */
35
36#include <cmath>
37
38namespace Gecode { namespace Float { namespace Arithmetic {
39
40 /*
41 * Bounds consistent min propagator
42 *
43 */
44 template<class A, class B, class C>
45 forceinline
46 Min<A,B,C>::Min(Home home, A x0, B x1, C x2)
47 : MixTernaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND,C,PC_FLOAT_BND>(home,x0,x1,x2) {}
48
49 template<class A, class B, class C>
50 forceinline
51 Min<A,B,C>::Min(Space& home, Min<A,B,C>& p)
52 : MixTernaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND,C,PC_FLOAT_BND>(home,p) {}
53
54 template<class A, class B, class C>
55 forceinline
56 Min<A,B,C>::Min(Space& home, Propagator& p,
57 A x0, B x1, C x2)
58 : MixTernaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND,C,PC_FLOAT_BND>(home,p,x0,x1,x2) {}
59
60 template<class A, class B, class C>
61 Actor*
62 Min<A,B,C>::copy(Space& home) {
63 return new (home) Min<A,B,C>(home,*this);
64 }
65
66 template<class A, class B, class C>
67 ExecStatus
68 Min<A,B,C>::post(Home home, A x0, B x1, C x2) {
69 GECODE_ME_CHECK(x2.eq(home,min(x0.domain(),x1.domain())));
70 GECODE_ME_CHECK(x0.gq(home,x2.min()));
71 GECODE_ME_CHECK(x1.gq(home,x2.min()));
72 (void) new (home) Min<A,B,C>(home,x0,x1,x2);
73 return ES_OK;
74 }
75
76 template<class A, class B, class C>
77 ExecStatus
78 Min<A,B,C>::propagate(Space& home, const ModEventDelta&) {
79 GECODE_ME_CHECK(x2.eq(home,min(x0.domain(),x1.domain())));
80 GECODE_ME_CHECK(x0.gq(home,x2.min()));
81 GECODE_ME_CHECK(x1.gq(home,x2.min()));
82 if (x0 == x1) {
83 GECODE_ME_CHECK(x0.lq(home,x2.max()));
84 } else {
85 if (!overlap(x1.val(),x2.val())) GECODE_ME_CHECK(x0.lq(home,x2.max()));
86 if (!overlap(x0.val(),x2.val())) GECODE_ME_CHECK(x1.lq(home,x2.max()));
87 }
88 return (x0.assigned() && x1.assigned()) ? home.ES_SUBSUMED(*this) : ES_FIX;
89 }
90
91 /*
92 * Bounds consistent max propagator
93 *
94 */
95
96 template<class A, class B, class C>
97 forceinline
98 Max<A,B,C>::Max(Home home, A x0, B x1, C x2)
99 : MixTernaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND,C,PC_FLOAT_BND>(home,x0,x1,x2) {}
100
101 template<class A, class B, class C>
102 forceinline
103 Max<A,B,C>::Max(Space& home, Max<A,B,C>& p)
104 : MixTernaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND,C,PC_FLOAT_BND>(home,p) {}
105
106 template<class A, class B, class C>
107 forceinline
108 Max<A,B,C>::Max(Space& home, Propagator& p,
109 A x0, B x1, C x2)
110 : MixTernaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND,C,PC_FLOAT_BND>(home,p,x0,x1,x2) {}
111
112 template<class A, class B, class C>
113 Actor*
114 Max<A,B,C>::copy(Space& home) {
115 return new (home) Max<A,B,C>(home,*this);
116 }
117
118 template<class A, class B, class C>
119 ExecStatus
120 Max<A,B,C>::post(Home home, A x0, B x1, C x2) {
121 GECODE_ME_CHECK(x2.eq(home,max(x0.domain(),x1.domain())));
122 GECODE_ME_CHECK(x0.lq(home,x2.max()));
123 GECODE_ME_CHECK(x1.lq(home,x2.max()));
124 (void) new (home) Max<A,B,C>(home,x0,x1,x2);
125 return ES_OK;
126 }
127
128 template<class A, class B, class C>
129 ExecStatus
130 Max<A,B,C>::propagate(Space& home, const ModEventDelta&) {
131 GECODE_ME_CHECK(x2.eq(home,max(x0.domain(),x1.domain())));
132 GECODE_ME_CHECK(x0.lq(home,x2.max()));
133 GECODE_ME_CHECK(x1.lq(home,x2.max()));
134 if (x0 == x1) {
135 GECODE_ME_CHECK(x0.gq(home,x2.min()));
136 } else {
137 if (!overlap(x1.val(),x2.val())) GECODE_ME_CHECK(x0.gq(home,x2.min()));
138 if (!overlap(x0.val(),x2.val())) GECODE_ME_CHECK(x1.gq(home,x2.min()));
139 }
140 return (x0.assigned() && x1.assigned()) ? home.ES_SUBSUMED(*this) : ES_FIX;
141 }
142
143 /*
144 * Nary bounds consistent maximum
145 *
146 */
147
148 template<class View>
149 forceinline
150 NaryMax<View>::NaryMax(Home home, ViewArray<View>& x, View y)
151 : NaryOnePropagator<View,PC_FLOAT_BND>(home,x,y) {}
152
153 template<class View>
154 ExecStatus
155 NaryMax<View>::post(Home home, ViewArray<View>& x, View y) {
156 assert(x.size() > 0);
157 x.unique();
158 if (x.size() == 1)
159 return Rel::Eq<View,View>::post(home,x[0],y);
160 if (x.size() == 2)
161 return Max<View,View,View>::post(home,x[0],x[1],y);
162 FloatNum l = Float::Limits::min;
163 FloatNum u = Float::Limits::min;
164 for (int i=x.size(); i--; ) {
165 l = std::max(l,x[i].min());
166 u = std::max(u,x[i].max());
167 }
168 GECODE_ME_CHECK(y.gq(home,l));
169 GECODE_ME_CHECK(y.lq(home,u));
170 if (x.same(y)) {
171 // Check whether y occurs in x
172 for (int i=x.size(); i--; )
173 GECODE_ES_CHECK((Rel::Lq<View>::post(home,x[i],y)));
174 } else {
175 (void) new (home) NaryMax<View>(home,x,y);
176 }
177 return ES_OK;
178 }
179
180 template<class View>
181 forceinline
182 NaryMax<View>::NaryMax(Space& home, NaryMax<View>& p)
183 : NaryOnePropagator<View,PC_FLOAT_BND>(home,p) {}
184
185 template<class View>
186 Actor*
187 NaryMax<View>::copy(Space& home) {
188 if (x.size() == 1)
189 return new (home) Rel::Eq<View,View>(home,*this,x[0],y);
190 if (x.size() == 2)
191 return new (home) Max<View,View,View>(home,*this,x[0],x[1],y);
192 return new (home) NaryMax<View>(home,*this);
193 }
194
195 /// Status of propagation for nary max
196 enum MaxPropStatus {
197 MPS_ASSIGNED = 1<<0, ///< All views are assigned
198 MPS_REMOVED = 1<<1, ///< A view is removed
199 MPS_NEW_BOUND = 1<<2 ///< Telling has found a new upper bound
200 };
201
202 template<class View>
203 forceinline ExecStatus
204 prop_nary_max(Space& home, Propagator& p,
205 ViewArray<View>& x, View y, PropCond pc) {
206 rerun:
207 assert(x.size() > 0);
208 FloatNum maxmax = x[x.size()-1].max();
209 FloatNum maxmin = x[x.size()-1].min();
210 for (int i = x.size()-1; i--; ) {
211 maxmax = std::max(x[i].max(),maxmax);
212 maxmin = std::max(x[i].min(),maxmin);
213 }
214 GECODE_ME_CHECK(y.lq(home,maxmax));
215 GECODE_ME_CHECK(y.gq(home,maxmin));
216 maxmin = y.min();
217 maxmax = y.max();
218 int status = MPS_ASSIGNED;
219 for (int i = x.size(); i--; ) {
220 ModEvent me = x[i].lq(home,maxmax);
221 if (me == ME_FLOAT_FAILED)
222 return ES_FAILED;
223 if (me_modified(me) && (x[i].max() != maxmax))
224 status |= MPS_NEW_BOUND;
225 if (x[i].max() < maxmin) {
226 x.move_lst(i,home,p,pc);
227 status |= MPS_REMOVED;
228 } else if (!x[i].assigned())
229 status &= ~MPS_ASSIGNED;
230 }
231 if (x.size() == 0)
232 return ES_FAILED;
233 if ((status & MPS_REMOVED) != 0)
234 goto rerun;
235 if (((status & MPS_ASSIGNED) != 0) && y.assigned())
236 return home.ES_SUBSUMED(p);
237 return ((status & MPS_NEW_BOUND) != 0) ? ES_NOFIX : ES_FIX;
238 }
239
240 template<class View>
241 ExecStatus
242 NaryMax<View>::propagate(Space& home, const ModEventDelta&) {
243 return prop_nary_max(home,*this,x,y,PC_FLOAT_BND);
244 }
245
246}}}
247
248// STATISTICS: float-prop
249