1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
/* Copyright (c) 1997-2018
Ewgenij Gawrilow, Michael Joswig (Technische Universitaet Berlin, Germany)
http://www.polymake.org
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version: http://www.gnu.org/licenses/gpl.txt.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
--------------------------------------------------------------------------------
*/
#ifndef __POLYMAKE_MATROID_UTIL
#define __POLYMAKE_MATROID_UTIL
namespace polymake { namespace matroid {
namespace operations {
using namespace polymake::operations;
template <typename SetRef>
struct contains {
typename pm::deref<SetRef>::type::element_type elem;
public:
typedef typename pm::deref<SetRef>::type set_type;
typedef set_type argument_type;
typedef bool result_type;
contains(typename set_type::element_type e) : elem(e) {}
result_type operator() (typename pm::function_argument<SetRef>::const_type set) const
{
return set.contains(elem);
}
};
template <typename Scalar>
struct dropshift {
typedef typename pm::deref<Scalar>::type scalar_type;
scalar_type elem;
public:
typedef scalar_type argument_type;
typedef scalar_type result_type;
dropshift(scalar_type e) : elem(e) {}
result_type operator() (argument_type value) const
{
return value < elem ? value : value-1;
}
};
}
template <typename Container>
typename std::enable_if<pm::isomorphic_to_container_of<Container, Set<int>>::value,
pm::SelectedSubset<const Container&, operations::contains<Set<int>>> >::type
select_k(const Container& sets, const int k)
{
return pm::SelectedSubset<const Container&, operations::contains<Set<int>>>(sets,operations::contains<Set<int>>(k));
}
template <typename Container>
typename std::enable_if<pm::isomorphic_to_container_of<Container, Set<int>>::value,
pm::SelectedSubset<const Container&, operations::composed11<operations::contains<Set<int>>, std::logical_not<bool>>> >::type
select_not_k(const Container& sets, const int k)
{
return pm::SelectedSubset<const Container&, operations::composed11<operations::contains<Set<int>>, std::logical_not<bool>>>(sets, operations::composed11<operations::contains<Set<int>>, std::logical_not<bool>>(operations::contains<Set<int>>(k), std::logical_not<bool>()));
}
template <typename Container>
auto drop_shift(const Container& sets, const int k)
{
return attach_operation(
attach_operation(sets, pm::operations::construct_unary2_with_arg< pm::SelectedSubset, operations::fix2<int,operations::ne> >(operations::fix2<int,operations::ne>(k))),
pm::operations::construct_unary2_with_arg<pm::TransformedContainer, operations::dropshift<int> >(operations::dropshift<int>(k)));
}
template <typename Container>
Array<Set<int>>
shift_elements(const Container& sets, const int n)
{
return Array<Set<int>>{ attach_operation(sets,
pm::operations::construct_unary2_with_arg<pm::TransformedContainer,
operations::fix2<int,operations::add> >(operations::fix2<int,operations::add>(n))) };
}
}}
#endif // __POLYMAKE_MATROID_UTIL
// Local Variables:
// mode:C++
// c-basic-offset:3
// indent-tabs-mode:nil
// End:
|
