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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#include <gecode/int/distinct.hh>
36
37namespace Gecode { namespace Int { namespace NValues {
38
39 template<class VY>
40 forceinline
41 LqInt<VY>::LqInt(Home home, ValSet& vs, ViewArray<IntView>& x, VY y)
42 : IntBase<VY>(home,vs,x,y) {
43 home.notice(*this, AP_WEAKLY);
44 }
45
46 template<class VY>
47 inline ExecStatus
48 LqInt<VY>::post(Home home, ViewArray<IntView>& x, VY y) {
49 if (x.size() == 0) {
50 GECODE_ME_CHECK(y.eq(home,0));
51 return ES_OK;
52 }
53
54 x.unique();
55
56 GECODE_ME_CHECK(y.gq(home,1));
57
58 if (x.size() == 1)
59 return ES_OK;
60
61 if (y.max() == 1) {
62 assert(y.assigned());
63 return Rel::NaryEqDom<IntView>::post(home,x);
64 }
65
66 if (y.min() >= x.size())
67 return ES_OK;
68
69 // Eliminate assigned views and store them into the value set
70 ValSet vs;
71 int n = x.size();
72 for (int i=n; i--; )
73 if (x[i].assigned()) {
74 vs.add(home, x[i].val());
75 x[i] = x[--n];
76 }
77
78 GECODE_ME_CHECK(y.gq(home,vs.size()));
79
80 if (n == 0) {
81 assert(y.min() >= vs.size());
82 return ES_OK;
83 }
84
85 x.size(n);
86
87 (void) new (home) LqInt<VY>(home, vs, x, y);
88 return ES_OK;
89 }
90
91 template<class VY>
92 forceinline
93 LqInt<VY>::LqInt(Space& home, LqInt<VY>& p)
94 : IntBase<VY>(home, p) {}
95
96 template<class VY>
97 Propagator*
98 LqInt<VY>::copy(Space& home) {
99 return new (home) LqInt<VY>(home, *this);
100 }
101
102 template<class VY>
103 forceinline size_t
104 LqInt<VY>::dispose(Space& home) {
105 home.ignore(*this, AP_WEAKLY);
106 (void) IntBase<VY>::dispose(home);
107 return sizeof(*this);
108 }
109
110 template<class VY>
111 ExecStatus
112 LqInt<VY>::propagate(Space& home, const ModEventDelta& med) {
113 // Add assigned views to value set
114 if (IntView::me(med) == ME_INT_VAL)
115 add(home);
116
117 GECODE_ME_CHECK(y.gq(home, vs.size()));
118
119 if (x.size() == 0)
120 return home.ES_SUBSUMED(*this);
121
122 // All values must be in the value set
123 if (y.max() == vs.size())
124 return all_in_valset(home);
125
126 if (x.size() + vs.size() <= y.min())
127 return home.ES_SUBSUMED(*this);
128
129 // Compute positions of disjoint views
130 Region r;
131 int* dis; int n_dis;
132 disjoint(home,r,dis,n_dis);
133
134 // Some views might have been eliminated as they are subsumed
135 if (x.size() == 0)
136 return home.ES_SUBSUMED(*this);
137
138 // No lower bound pruning possible
139 if (n_dis == 0)
140 return ES_NOFIX;
141
142 // Do lower bound-based pruning
143 GECODE_ES_CHECK(prune_lower(home,dis,n_dis));
144
145 return ES_NOFIX;
146 }
147
148}}}
149
150// STATISTICS: int-prop