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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, 2007
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/bool.hh>
36
37/**
38 * \namespace Gecode::Int::Unshare
39 * \brief Unsharing shared variables
40 */
41
42namespace Gecode { namespace Int { namespace Unshare {
43
44 /// Sort order for variables
45 template<class Var>
46 class VarPtrLess {
47 public:
48 forceinline bool
49 operator ()(const Var* a, const Var* b) {
50 return a->varimp() < b->varimp();
51 }
52 };
53
54
55 /// Replace by fresh yet equal integer variables
56 forceinline void
57 link(Home home, IntVar** x, int n, IntPropLevel ipl) {
58 if (home.failed()) {
59 for (int i=1; i<n; i++)
60 *x[i]=IntVar(home,x[0]->min(),x[0]->min());
61 } else if (n > 2) {
62 ViewArray<IntView> y(home,n);
63 y[0]=*x[0];
64 for (int i=1; i<n; i++)
65 y[i]=*x[i]=IntVar(home,x[0]->min(),x[0]->max());
66 if ((ipl == IPL_DOM) || (ipl == IPL_DEF)) {
67 ExecStatus es = Rel::NaryEqDom<IntView>::post(home,y);
68 (void) es; assert(es == ES_OK);
69 } else {
70 ExecStatus es = Rel::NaryEqBnd<IntView>::post(home,y);
71 (void) es; assert(es == ES_OK);
72 }
73 } else if (n == 2) {
74 *x[1]=IntVar(home,x[0]->min(),x[0]->max());
75 if ((ipl == IPL_DOM) || (ipl == IPL_DEF)) {
76 ExecStatus es = Rel::EqDom<IntView,IntView>::post(home,*x[0],*x[1]);
77 (void) es; assert(es == ES_OK);
78 } else {
79 ExecStatus es = Rel::EqBnd<IntView,IntView>::post(home,*x[0],*x[1]);
80 (void) es; assert(es == ES_OK);
81 }
82 }
83 }
84
85 /// Replace by fresh yet equal Boolean variables
86 forceinline void
87 link(Home home, BoolVar** x, int n, IntPropLevel) {
88 if (home.failed()) {
89 for (int i=1; i<n; i++)
90 *x[i]=BoolVar(home,0,0);
91 } else if (n > 2) {
92 ViewArray<BoolView> y(home,n);
93 y[0]=*x[0];
94 for (int i=1; i<n; i++)
95 y[i]=*x[i]=BoolVar(home,0,1);
96 ExecStatus es = Bool::NaryEq<BoolView>::post(home,y);
97 (void) es; assert(es == ES_OK);
98 } else if (n == 2) {
99 *x[1] = BoolVar(home,0,1);
100 ExecStatus es = Bool::Eq<BoolView,BoolView>::post(home,*x[0],*x[1]);
101 (void) es; assert(es == ES_OK);
102 }
103 }
104
105 /// Replace unassigned shared variables by fresh, yet equal variables
106 template<class Var>
107 forceinline void
108 unshare(Home home, VarArgArray<Var>& x, IntPropLevel ipl) {
109 int n=x.size();
110 if (n < 2)
111 return;
112
113 Region r;
114 Var** y = r.alloc<Var*>(n);
115 for (int i=0; i<n; i++)
116 y[i]=&x[i];
117
118 VarPtrLess<Var> vpl;
119 Support::quicksort<Var*,VarPtrLess<Var> >(y,n,vpl);
120
121 // Replace all shared variables with new and equal variables
122 for (int i=0; i<n;) {
123 int j=i++;
124 while ((i<n) && (y[j]->varimp() == y[i]->varimp()))
125 i++;
126 if (!y[j]->assigned())
127 link(home,&y[j],i-j,ipl);
128 }
129 }
130
131}}}
132
133namespace Gecode {
134
135 void
136 unshare(Home home, IntVarArgs& x, IntPropLevel ipl) {
137 Int::Unshare::unshare<IntVar>(home,x,vbd(ipl));
138 }
139
140 void
141 unshare(Home home, BoolVarArgs& x, IntPropLevel) {
142 Int::Unshare::unshare<BoolVar>(home,x,IPL_DEF);
143 }
144
145}
146
147// STATISTICS: int-post