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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 <gecode/set/ldsb.hh>
35
36namespace Gecode { namespace Set { namespace LDSB {
37 // XXX: implementation of equalValues could be improved?
38
39 /// Do two set variables have equal least-upper-bounds?
40 bool
41 equalLUB(const Set::SetView& x, const Set::SetView& y) {
42 unsigned int n = x.lubSize();
43 if (n != y.lubSize()) return false;
44 for (unsigned int i = 0 ; i < n ; i++)
45 if (x.lubMinN(i) != y.lubMinN(i))
46 return false;
47 return true;
48 }
49}}}
50
51// Note carefully that this is in the Gecode::Int::LDSB namespace, not
52// Gecode::Set::LDSB.
53namespace Gecode { namespace Int { namespace LDSB {
54 template <>
55 ArgArray<Literal>
56 VariableSymmetryImp<Set::SetView>
57 ::symmetric(Literal l, const ViewArray<Set::SetView>& x) const {
58 (void) x;
59 if (indices.valid(l._variable) && indices.get(l._variable)) {
60 int n = 0;
61 for (Iter::Values::BitSetOffset<Support::BitSetOffset<Space> > i(indices) ; i() ; ++i)
62 n++;
63 ArgArray<Literal> lits(n);
64 int j = 0;
65 for (Iter::Values::BitSetOffset<Support::BitSetOffset<Space> > i(indices) ; i() ; ++i) {
66 lits[j++] = Literal(i.val(), l._value);
67 }
68 return lits;
69 } else {
70 return ArgArray<Literal>(0);
71 }
72 }
73
74 template <>
75 ArgArray<Literal>
76 ValueSymmetryImp<Set::SetView>
77 ::symmetric(Literal l, const ViewArray<Set::SetView>& x) const {
78 (void) x;
79 if (values.valid(l._value) && values.get(l._value)) {
80 int n = 0;
81 for (Iter::Values::BitSetOffset<Support::BitSetOffset<Space> > i(values) ; i() ; ++i)
82 n++;
83 ArgArray<Literal> lits(n);
84 int j = 0;
85 for (Iter::Values::BitSetOffset<Support::BitSetOffset<Space> > i(values) ; i() ; ++i) {
86 lits[j++] = Literal(l._variable, i.val());
87 }
88 return lits;
89 } else {
90 return ArgArray<Literal>(0);
91 }
92 }
93
94 template <>
95 ArgArray<Literal>
96 VariableSequenceSymmetryImp<Set::SetView>
97 ::symmetric(Literal l, const ViewArray<Set::SetView>& x) const {
98 Region region;
99 Support::DynamicStack<Literal,Region> s(region);
100 if (l._variable < (int)lookup_size) {
101 int posIt = lookup[l._variable];
102 if (posIt == -1) {
103 return dynamicStackToArgArray(s);
104 }
105 unsigned int seqNum = posIt / seq_size;
106 unsigned int seqPos = posIt % seq_size;
107 for (unsigned int seq = 0 ; seq < n_seqs ; seq++) {
108 if (seq == seqNum) {
109 continue;
110 }
111 if (x[getVal(seq, seqPos)].assigned()) {
112 continue;
113 }
114 bool active = true;
115 const unsigned int *firstSeq = &indices[seqNum*seq_size];
116 const unsigned int *secondSeq = &indices[seq*seq_size];
117 for (unsigned int i = 0 ; i < seq_size ; i++) {
118 const Set::SetView& xv = x[firstSeq[i]];
119 const Set::SetView& yv = x[secondSeq[i]];
120 if ((!xv.assigned() && !yv.assigned())
121 || (xv.assigned() && yv.assigned() && Set::LDSB::equalLUB(xv, yv))) {
122 continue;
123 } else {
124 active = false;
125 break;
126 }
127 }
128
129 if (active) {
130 s.push(Literal(secondSeq[seqPos], l._value));
131 }
132 }
133 }
134 return dynamicStackToArgArray(s);
135 }
136
137 template <>
138 ArgArray<Literal>
139 ValueSequenceSymmetryImp<Set::SetView>
140 ::symmetric(Literal l, const ViewArray<Set::SetView>& x) const {
141 (void) x;
142 Region region;
143 Support::DynamicStack<Literal,Region> s(region);
144 std::pair<int,int> location = findVar(values, n_values, seq_size, l._value);
145 if (location.first == -1) return dynamicStackToArgArray(s);
146 unsigned int seqNum = location.first;
147 unsigned int seqPos = location.second;
148 for (unsigned int seq = 0 ; seq < n_seqs ; seq++) {
149 if (seq == seqNum) continue;
150 if (dead_sequences.get(seq)) continue;
151 s.push(Literal(l._variable, getVal(seq,seqPos)));
152 }
153 return dynamicStackToArgArray(s);
154 }
155}}}
156
157// STATISTICS: set-branch