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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 *
6 * Copyright:
7 * Christian Schulte, 2011
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 <gecode/int/rel.hh>
35
36namespace Gecode { namespace Int { namespace Member {
37
38 template<class View>
39 forceinline
40 Prop<View>::Prop(Home home, ValSet& vs0, ViewArray<View>& x, View y)
41 : NaryOnePropagator<View,PC_INT_DOM>(home,x,y),
42 vs(vs0) {}
43
44 template<class View>
45 forceinline void
46 Prop<View>::add(Space& home, ValSet& vs, ViewArray<View>& x) {
47 int n=x.size();
48 for (int i=n; i--; )
49 if (x[i].assigned()) {
50 vs.add(home, x[i].val());
51 x[i] = x[--n];
52 }
53 x.size(n);
54 }
55
56 template<class View>
57 forceinline void
58 Prop<View>::eliminate(Space& home) {
59 int n=x.size();
60 for (int i=n; i--; )
61 if ((rtest_eq_dom(x[i],y) == RT_FALSE) || vs.subset(x[i])) {
62 // x[i] is different from y or values are contained in vs
63 x[i].cancel(home, *this, PC_INT_DOM);
64 x[i] = x[--n];
65 }
66 x.size(n);
67 }
68
69 template<class View>
70 inline ExecStatus
71 Prop<View>::post(Home home, ViewArray<View>& x, View y) {
72 if (x.size() == 0)
73 return ES_FAILED;
74
75 x.unique();
76
77 if (x.size() == 1)
78 return Rel::EqDom<View,View>::post(home,x[0],y);
79
80 if (x.same(y))
81 return ES_OK;
82
83 // Eliminate assigned views and store them into the value set
84 ValSet vs;
85 add(home, vs, x);
86
87 if (x.size() == 0) {
88 ValSet::Ranges vsr(vs);
89 GECODE_ME_CHECK(y.inter_r(home,vsr,false));
90 return ES_OK;
91 }
92
93 (void) new (home) Prop<View>(home, vs, x, y);
94 return ES_OK;
95 }
96
97 template<class View>
98 forceinline ExecStatus
99 Prop<View>::post(Home home, ValSet& vs, ViewArray<View>& x, View y) {
100 (void) new (home) Prop<View>(home, vs, x, y);
101 return ES_OK;
102 }
103
104 template<class View>
105 forceinline
106 Prop<View>::Prop(Space& home, Prop<View>& p)
107 : NaryOnePropagator<View,PC_INT_DOM>(home, p) {
108 vs.update(home, p.vs);
109 }
110
111 template<class View>
112 Propagator*
113 Prop<View>::copy(Space& home) {
114 return new (home) Prop<View>(home, *this);
115 }
116
117 template<class View>
118 forceinline size_t
119 Prop<View>::dispose(Space& home) {
120 vs.dispose(home);
121 (void) NaryOnePropagator<View,PC_INT_DOM>::dispose(home);
122 return sizeof(*this);
123 }
124
125 template<class View>
126 PropCost
127 Prop<View>::cost(const Space&, const ModEventDelta&) const {
128 return PropCost::linear(PropCost::HI, x.size()+1);
129 }
130
131 template<class View>
132 ExecStatus
133 Prop<View>::propagate(Space& home, const ModEventDelta& med) {
134 // Add assigned views to value set
135 if (View::me(med) == ME_INT_VAL)
136 add(home,vs,x);
137
138 // Eliminate views from x
139 eliminate(home);
140
141 if (x.size() == 0) {
142 // y must have values in the value set
143 ValSet::Ranges vsr(vs);
144 GECODE_ME_CHECK(y.inter_r(home,vsr,false));
145 return home.ES_SUBSUMED(*this);
146 }
147
148 // Constrain y to union of x and value set
149 Region r;
150
151 assert(x.size() > 0);
152 ValSet::Ranges vsr(vs);
153 ViewRanges<View> xsr(x[0]);
154 Iter::Ranges::NaryUnion u(r,vsr,xsr);
155 for (int i=1; i<x.size(); i++) {
156 ViewRanges<View> xir(x[i]);
157 u |= xir;
158 }
159
160 GECODE_ME_CHECK(y.inter_r(home,u,false));
161
162 // Check whether all values in y are already in the value set
163 if (vs.subset(y))
164 return home.ES_SUBSUMED(*this);
165
166 return ES_FIX;
167 }
168
169}}}
170
171// STATISTICS: int-prop