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sym-imp.cpp
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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
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33
34#include <gecode/set/ldsb.hh>
35
36namespace Gecode { namespace Set { namespace LDSB {
37 // XXX: implementation of equalValues could be improved?
38
40 bool
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 <>
78 (void) x;
79 if (values.valid(l._value) && values.get(l._value)) {
80 int n = 0;
82 n++;
83 ArgArray<Literal> lits(n);
84 int j = 0;
86 lits[j++] = Literal(l._variable, i.val());
87 }
88 return lits;
89 } else {
90 return ArgArray<Literal>(0);
91 }
92 }
93
94 template <>
98 Region 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 <>
141 (void) x;
142 Region 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
NNF * l
Left subtree.
int n
Number of negative literals for node type.
Argument array for non-primitive types.
Definition array.hpp:691
A Literal is a pair of variable index and value.
Definition ldsb.hh:46
Implementation of a value sequence symmetry.
Definition ldsb.hh:266
Implementation of a value symmetry.
Definition ldsb.hh:204
Implementation of a variable sequence symmetry.
Definition ldsb.hh:224
Value iterator for values in an offset bitset.
Handle to region.
Definition region.hpp:55
unsigned int lubSize(void) const
Return number of elements in the least upper bound.
Definition set.hpp:66
Set view for set variables
Definition view.hpp:56
Bitsets with index offset.
Stack with arbitrary number of elements.
void push(const T &x)
Push element x on top of stack.
bool assigned(void) const
Test whether view is assigned.
Definition view.hpp:516
View arrays.
Definition array.hpp:253
std::pair< int, int > findVar(int *indices, unsigned int n_values, unsigned int seq_size, int index)
Find the location of an integer in a collection of sequences.
Definition ldsb.cpp:42
ArgArray< T > dynamicStackToArgArray(const Support::DynamicStack< T, A > &s)
Convert a DynamicStack<T,A> into an ArgArray<T>
Definition sym-imp.hpp:39
bool equalLUB(const Set::SetView &x, const Set::SetView &y)
Do two set variables have equal least-upper-bounds?
Definition sym-imp.cpp:41
Gecode toplevel namespace
void values(Home home, const IntVarArgs &x, IntSet y, IntPropLevel ipl=IPL_DEF)
Post constraint .
Definition aliases.hpp:143
Post propagator for SetVar SetOpType SetVar y
Definition set.hh:767
Post propagator for SetVar x
Definition set.hh:767