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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
34namespace Gecode { namespace Int { namespace Circuit {
35
36 /*
37 * The actual propagator
38 *
39 */
40 template<class View, class Offset>
41 forceinline
42 Dom<View,Offset>::Dom(Home home, ViewArray<View>& x, Offset& o)
43 : Base<View,Offset>(home,x,o) {}
44
45 template<class View, class Offset>
46 forceinline
47 Dom<View,Offset>::Dom(Space& home, Dom<View,Offset>& p)
48 : Base<View,Offset>(home,p) {}
49
50 template<class View, class Offset>
51 Actor*
52 Dom<View,Offset>::copy(Space& home) {
53 return new (home) Dom<View,Offset>(home,*this);
54 }
55
56 template<class View, class Offset>
57 PropCost
58 Dom<View,Offset>::cost(const Space&, const ModEventDelta& med) const {
59 if (View::me(med) == Int::ME_INT_VAL)
60 return PropCost::linear(PropCost::LO, x.size());
61 else
62 return PropCost::quadratic(PropCost::HI, x.size());
63 }
64
65 template<class View, class Offset>
66 void
67 Dom<View,Offset>::reschedule(Space& home) {
68 for (int i=0; i<y.size(); i++)
69 if (y[i].assigned()) {
70 View::schedule(home, *this, ME_INT_VAL);
71 return;
72 }
73 View::schedule(home, *this, ME_INT_DOM);
74 }
75
76 template<class View, class Offset>
77 ExecStatus
78 Dom<View,Offset>::propagate(Space& home, const ModEventDelta& med) {
79 if (View::me(med) == Int::ME_INT_VAL) {
80 GECODE_ES_CHECK((Int::Distinct::prop_val<View,true>(home,y)));
81 ExecStatus escv = connected(home);
82 if (escv != ES_FIX)
83 return escv;
84 if (y.size() < 2)
85 return home.ES_SUBSUMED(*this);
86 return home.ES_FIX_PARTIAL(*this,View::med(Int::ME_INT_DOM));
87 }
88
89 if (dc.available()) {
90 GECODE_ES_CHECK(dc.sync());
91 } else {
92 GECODE_ES_CHECK(dc.init(home,y));
93 }
94 bool assigned;
95 GECODE_ES_CHECK(dc.propagate(home,assigned));
96
97 ExecStatus esc = connected(home);
98 if (esc != ES_FIX)
99 return esc;
100
101 // Elminiate assigned views from y, as they have been assigned
102 // and propagated by domain consistent propagation. This is required
103 // as we need to know how many assigned views actually exist.
104 if (assigned)
105 for (int i=y.size(); i--; )
106 if (y[i].assigned())
107 y.move_lst(i);
108
109 return path(home);
110 }
111
112 template<class View, class Offset>
113 ExecStatus
114 Dom<View,Offset>::post(Home home, ViewArray<View>& x, Offset& o) {
115 int n = x.size();
116 if (n == 1) {
117 GECODE_ME_CHECK(o(x[0]).eq(home,0));
118 } else if (n == 2) {
119 GECODE_ME_CHECK(o(x[0]).eq(home,1));
120 GECODE_ME_CHECK(o(x[1]).eq(home,0));
121 } else {
122 for (int i=0; i<n; i++) {
123 GECODE_ME_CHECK(o(x[i]).gq(home,0));
124 GECODE_ME_CHECK(o(x[i]).le(home,n));
125 GECODE_ME_CHECK(o(x[i]).nq(home,i));
126 }
127 (void) new (home) Dom<View,Offset>(home,x,o);
128 }
129 return ES_OK;
130 }
131
132}}}
133
134// STATISTICS: int-prop
135