main page
modules
namespaces
classes
files
Gecode home
Generated on Sat May 25 2013 18:00:35 for Gecode by
doxygen
1.8.3.1
gecode
int
bin-packing
propagate.hpp
Go to the documentation of this file.
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, 2010
8
*
9
* Last modified:
10
* $Date: 2010-10-05 17:03:20 +0200 (Tue, 05 Oct 2010) $ by $Author: schulte $
11
* $Revision: 11448 $
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
namespace
Gecode {
namespace
Int {
namespace
BinPacking
{
39
40
/*
41
* Item
42
*
43
*/
44
forceinline
45
Item::Item
(
void
)
46
: s(0) {}
47
forceinline
48
Item::Item
(
IntView
b
,
int
s0)
49
:
DerivedView
<
IntView
>(b), s(s0) {}
50
51
forceinline
IntView
52
Item::bin
(
void
)
const
{
53
return
x
;
54
}
55
forceinline
56
void
Item::bin
(
IntView
b
) {
57
x
=
b
;
58
}
59
forceinline
int
60
Item::size
(
void
)
const
{
61
return
s
;
62
}
63
forceinline
void
64
Item::size
(
int
s0) {
65
s
= s0;
66
}
67
68
forceinline
void
69
Item::update
(
Space
& home,
bool
share,
Item
&
i
) {
70
x
.
update
(home,share,i.
x
);
71
s
= i.
s
;
72
}
73
74
75
forceinline
bool
76
same
(
const
Item
&
i
,
const
Item
& j) {
77
return
same
(i.
bin
(),j.
bin
()) && (i.
size
() == j.
size
());
78
}
79
forceinline
bool
80
before
(
const
Item
&
i
,
const
Item
& j) {
81
return
before
(i.
bin
(),j.
bin
())
82
|| (
same
(i.
bin
(),j.
bin
()) && (i.
size
() == j.
size
()));
83
}
84
86
forceinline
bool
87
operator <
(
const
Item
&
i
,
const
Item
& j) {
88
return
i.
size
() > j.
size
();
89
}
90
91
92
/*
93
* Size set
94
*
95
*/
96
forceinline
97
SizeSet::SizeSet
(
void
) {}
98
forceinline
99
SizeSet::SizeSet
(
Region
& region,
int
n_max)
100
:
n
(0),
t
(0), s(region.alloc<int>(n_max)) {}
101
forceinline
void
102
SizeSet::add
(
int
s0) {
103
t
+= s0;
s
[
n
++] = s0;
104
}
105
forceinline
int
106
SizeSet::card
(
void
)
const
{
107
return
n
;
108
}
109
forceinline
int
110
SizeSet::total
(
void
)
const
{
111
return
t
;
112
}
113
forceinline
int
114
SizeSet::operator []
(
int
i
)
const
{
115
return
s
[
i
];
116
}
117
118
forceinline
119
SizeSetMinusOne::SizeSetMinusOne
(
void
) {}
120
forceinline
121
SizeSetMinusOne::SizeSetMinusOne
(
Region
& region,
int
n_max)
122
:
SizeSet
(region,n_max),
p
(-1) {}
123
forceinline
void
124
SizeSetMinusOne::minus
(
int
s0) {
125
// This rests on the fact that items are removed in order
126
do
127
p
++;
128
while
(
s
[
p
] > s0);
129
assert(
p
<
n
);
130
}
131
forceinline
int
132
SizeSetMinusOne::card
(
void
)
const
{
133
assert(
p
>= 0);
134
return
n
- 1;
135
}
136
forceinline
int
137
SizeSetMinusOne::total
(
void
)
const
{
138
assert(
p
>= 0);
139
return
t
-
s
[
p
];
140
}
141
forceinline
int
142
SizeSetMinusOne::operator []
(
int
i
)
const
{
143
assert(
p
>= 0);
144
return
s
[(i <
p
) ? i : i+1];
145
}
146
147
148
149
/*
150
* Packing propagator
151
*
152
*/
153
154
forceinline
155
Pack::Pack
(
Home
home,
ViewArray<OffsetView>
& l0,
ViewArray<Item>
& bs0)
156
:
Propagator
(home),
l
(l0), bs(bs0),
t
(0) {
157
l
.subscribe(home,*
this
,
PC_INT_BND
);
158
bs
.subscribe(home,*
this
,
PC_INT_DOM
);
159
for
(
int
i
=
bs
.size();
i
--; )
160
t
+=
bs
[
i
].
size
();
161
}
162
163
forceinline
164
Pack::Pack
(
Space
& home,
bool
shared
,
Pack
&
p
)
165
:
Propagator
(home,shared,p),
t
(p.
t
) {
166
l
.update(home,shared,p.
l
);
167
bs
.update(home,shared,p.
bs
);
168
}
169
170
forceinline
size_t
171
Pack::dispose
(
Space
& home) {
172
l
.cancel(home,*
this
,
PC_INT_BND
);
173
bs
.cancel(home,*
this
,
PC_INT_DOM
);
174
(void)
Propagator::dispose
(home);
175
return
sizeof
(*this);
176
}
177
178
template
<
class
SizeSet>
179
forceinline
bool
180
Pack::nosum
(
const
SizeSet
& s,
int
a
,
int
b
,
int
& ap,
int
& bp) {
181
if
((a <= 0) || (b >= s.
total
()))
182
return
false
;
183
int
n
=s.
card
()-1;
184
int
sc=0;
185
int
kp=0;
186
while
(sc + s[n-kp] < a) {
187
sc += s[n-kp];
188
kp++;
189
}
190
int
k=0;
191
int
sa=0, sb = s[n-kp];
192
while
((sa < a) && (sb <= b)) {
193
sa += s[k++];
194
if
(sa < a) {
195
kp--;
196
sb += s[n-kp];
197
sc -= s[n-kp];
198
while
(sa + sc >= a) {
199
kp--;
200
sc -= s[n-kp];
201
sb += s[n-kp] - s[n-kp-k-1];
202
}
203
}
204
}
205
ap = sa + sc; bp = sb;
206
return
sa <
a
;
207
}
208
209
template
<
class
SizeSet>
210
forceinline
bool
211
Pack::nosum
(
const
SizeSet
& s,
int
a
,
int
b
) {
212
int
ap, bp;
213
return
nosum
(s, a, b, ap, bp);
214
}
215
216
}}}
217
218
// STATISTICS: int-prop
219