Generated on Tue Jan 19 2021 06:15:49 for Gecode by doxygen 1.8.13
hull.cpp
Go to the documentation of this file.
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  *
7  * Contributing authors:
8  * Gabor Szokoli <szokoli@gecode.org>
9  *
10  * Copyright:
11  * Guido Tack, 2004
12  * Christian Schulte, 2004
13  * Gabor Szokoli, 2004
14  *
15  * This file is part of Gecode, the generic constraint
16  * development environment:
17  * http://www.gecode.org
18  *
19  * Permission is hereby granted, free of charge, to any person obtaining
20  * a copy of this software and associated documentation files (the
21  * "Software"), to deal in the Software without restriction, including
22  * without limitation the rights to use, copy, modify, merge, publish,
23  * distribute, sublicense, and/or sell copies of the Software, and to
24  * permit persons to whom the Software is furnished to do so, subject to
25  * the following conditions:
26  *
27  * The above copyright notice and this permission notice shall be
28  * included in all copies or substantial portions of the Software.
29  *
30  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
31  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
32  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
33  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
34  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
35  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
36  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
37  *
38  */
39 
40 #include <gecode/set/convex.hh>
41 
42 namespace Gecode { namespace Set { namespace Convex {
43 
44  Actor*
46  return new (home) ConvexHull(home,*this);
47  }
48 
51  //x1 is the convex hull of x0
52 
53  GECODE_ME_CHECK( x1.cardMin(home,x0.cardMin()) );
54  GECODE_ME_CHECK( x0.cardMax(home,x1.cardMax()) );
55 
56  do {
57 
58  //intersect x1 with (x0.lubMin(),x0.lubMax())
59  //This empties x1 if x0.ub is empty. twice.
61  x0.lubMin()-1) );
63  Limits::max) );
64 
65  int minElement = std::min(x1.glbMin(),x0.glbMin());
66  int maxElement = std::max(x1.glbMax(),x0.glbMax());
67 
68  if (minElement<maxElement) {
69  GECODE_ME_CHECK( x1.include(home, minElement, maxElement));
70  }
71 
72  unsigned int cardMin = x1.cardMin();
73 
74  Region r;
75  LubRanges<SetView> ubRangeIt(x1);
76  Iter::Ranges::Cache ubRangeItC(r,ubRangeIt);
77  for (;ubRangeItC();++ubRangeItC) {
78  if (ubRangeItC.width() < cardMin
79  || ubRangeItC.min() > minElement //No need to test for empty lb.
80  || ubRangeItC.max() < maxElement
81  ) {
83  ubRangeItC.min(), ubRangeItC.max()) );
84  }
85  }
86 
87  LubRanges<SetView> ubRangeIt2(x1);
88  GECODE_ME_CHECK(x0.intersectI(home,ubRangeIt2) );
89 
91  if(x1.lubMin()==x1.glbMin()) {
93  }
94  if(x1.lubMax()==x1.glbMax()) {
96  }
97  }
98  } while(x0.assigned()&&!x1.assigned());
99 
100  //If x0 is assigned, x1 should be too.
101  assert(x1.assigned() || !x0.assigned());
102 
103  if (x1.assigned()) {
104  return home.ES_SUBSUMED(*this);
105  }
106 
107  return ES_NOFIX;
108  }
109 
110 }}}
111 
112 // STATISTICS: set-prop
unsigned int cardMax(void) const
Return maximum cardinality.
Definition: set.hpp:86
ModEvent include(Space &home, int i, int j)
Update greatest lower bound to include all elements between and including i and j.
Definition: set.hpp:126
const int min
Smallest allowed integer in integer set.
Definition: set.hh:99
ExecStatus ES_SUBSUMED(Propagator &p)
Definition: core.hpp:3490
const FloatNum max
Largest allowed float value.
Definition: float.hh:844
int glbMin(void) const
Return minimum of the greatest lower bound.
Definition: set.hpp:102
unsigned int cardMin(void) const
Return minimum cardinality.
Definition: set.hpp:82
Handle to region.
Definition: region.hpp:55
static const int MIN_OF_EMPTY
Returned by empty sets when asked for their minimum element.
Definition: var-imp.hpp:112
ConvexHull(Space &home, ConvexHull &)
Constructor for cloning p.
Definition: hull.hpp:52
const int max
Largest allowed integer in integer set.
Definition: set.hh:97
Computation spaces.
Definition: core.hpp:1701
int max(void) const
Return largest value of range.
const FloatNum min
Smallest allowed float value.
Definition: float.hh:846
Range iterator for least upper bound of set variable views
Definition: set.hpp:211
#define GECODE_ME_CHECK(me)
Check whether modification event me is failed, and forward failure.
Definition: macros.hpp:52
int min(void) const
Return smallest value of range.
ModEvent intersectI(Space &home, I &iter)
Intersect least upper bound with range sequence described by i.
Definition: set.hpp:164
Post propagator for SetVar SetOpType SetVar SetRelType r
Definition: set.hh:767
virtual ExecStatus propagate(Space &home, const ModEventDelta &med)
Perform propagation.
Definition: hull.cpp:50
bool assigned(void) const
Test whether view is assigned.
Definition: view.hpp:516
Range iterator cache
ExecStatus
Definition: core.hpp:471
int glbMax(void) const
Return maximum of the greatest lower bound.
Definition: set.hpp:106
Propagation has not computed fixpoint.
Definition: core.hpp:474
ModEvent exclude(Space &home, int i, int j)
Restrict least upper bound to not contain all elements between and including i and j...
Definition: set.hpp:156
Gecode toplevel namespace
unsigned int width(void) const
Return width of range (distance between minimum and maximum)
int ModEventDelta
Modification event deltas.
Definition: core.hpp:89
int lubMin(void) const
Return minimum of the least upper bound.
Definition: set.hpp:90
virtual Actor * copy(Space &home)
Copy propagator during cloning.
Definition: hull.cpp:45
int lubMax(void) const
Return maximum of the least upper bound.
Definition: set.hpp:94