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dekker.one
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Guido Tack <tack@gecode.org>
5 * Christian Schulte <schulte@gecode.org>
6 * Gabor Szokoli <szokoli@gecode.org>
7 *
8 * Copyright:
9 * Guido Tack, 2004
10 * Christian Schulte, 2004
11 * Gabor Szokoli, 2004
12 *
13 * This file is part of Gecode, the generic constraint
14 * development environment:
15 * http://www.gecode.org
16 *
17 * Permission is hereby granted, free of charge, to any person obtaining
18 * a copy of this software and associated documentation files (the
19 * "Software"), to deal in the Software without restriction, including
20 * without limitation the rights to use, copy, modify, merge, publish,
21 * distribute, sublicense, and/or sell copies of the Software, and to
22 * permit persons to whom the Software is furnished to do so, subject to
23 * the following conditions:
24 *
25 * The above copyright notice and this permission notice shall be
26 * included in all copies or substantial portions of the Software.
27 *
28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
29 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
30 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
31 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
32 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
33 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
34 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
35 *
36 */
37
38#include <gecode/set/convex.hh>
39
40namespace Gecode { namespace Set { namespace Convex {
41
42 Actor*
43 Convex::copy(Space& home) {
44 return new (home) Convex(home,*this);
45 }
46
47 ExecStatus
48 Convex::propagate(Space& home, const ModEventDelta&) {
49 //I, drop ranges from UB that are shorter than cardMin
50 //II, add range LB.smallest to LB.largest to LB
51 //III, Drop ranges from UB that do not contain all elements of LB
52 //that is: range.min()>LB.smallest or range.max()<LB.largest
53 //This leaves only one range.
54 //II
55 if (x0.glbSize()>0) {
56 GECODE_ME_CHECK( x0.include(home,x0.glbMin(),x0.glbMax()) );
57 } else {
58 //If lower bound is empty, we can still constrain the cardinality
59 //maximum with the width of the longest range in UB.
60 //No need to do this if there is anything in LB because UB
61 //becomes a single range then.
62 LubRanges<SetView> ubRangeIt(x0);
63 unsigned int maxWidth = 0;
64 for (;ubRangeIt();++ubRangeIt) {
65 assert(ubRangeIt());
66 maxWidth = std::max(maxWidth, ubRangeIt.width());
67 }
68 GECODE_ME_CHECK( x0.cardMax(home,maxWidth) );
69 }
70
71
72 //I + III
73
74 Region r;
75 LubRanges<SetView> ubRangeIt(x0);
76 Iter::Ranges::Cache ubRangeItC(r,ubRangeIt);
77
78 for (; ubRangeItC(); ++ubRangeItC) {
79 if (ubRangeItC.width() < (unsigned int) x0.cardMin()
80 || ubRangeItC.min() > x0.glbMin() //No need to test for empty lb.
81 || ubRangeItC.max() < x0.glbMax()
82 ) {
83 GECODE_ME_CHECK( x0.exclude(home,ubRangeItC.min(), ubRangeItC.max()) );
84 }
85 }
86 if (x0.assigned())
87 return home.ES_SUBSUMED(*this);
88 return ES_FIX;
89 }
90
91}}}
92
93// STATISTICS: set-prop