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
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
/* combination/init.c
* based on permutation/init.c by Brian Gough
*
* Copyright (C) 2001 Szymon Jaroszewicz
*
* 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 of the License, or (at
* your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <config.h>
#include <stdlib.h>
#include <gsl/gsl_errno.h>
#include <gsl/gsl_combination.h>
gsl_combination *
gsl_combination_alloc (const size_t n, const size_t k)
{
gsl_combination * c;
if (n == 0)
{
GSL_ERROR_VAL ("combination parameter n must be positive integer",
GSL_EDOM, 0);
}
if (k > n)
{
GSL_ERROR_VAL ("combination length k must be an integer less than or equal to n",
GSL_EDOM, 0);
}
c = (gsl_combination *) malloc (sizeof (gsl_combination));
if (c == 0)
{
GSL_ERROR_VAL ("failed to allocate space for combination struct",
GSL_ENOMEM, 0);
}
if (k > 0)
{
c->data = (size_t *) malloc (k * sizeof (size_t));
if (c->data == 0)
{
free (c); /* exception in constructor, avoid memory leak */
GSL_ERROR_VAL ("failed to allocate space for combination data",
GSL_ENOMEM, 0);
}
}
else
{
c->data = 0;
}
c->n = n;
c->k = k;
return c;
}
gsl_combination *
gsl_combination_calloc (const size_t n, const size_t k)
{
size_t i;
gsl_combination * c = gsl_combination_alloc (n, k);
if (c == 0)
return 0;
/* initialize combination to identity */
for (i = 0; i < k; i++)
{
c->data[i] = i;
}
return c;
}
void
gsl_combination_init_first (gsl_combination * c)
{
const size_t k = c->k ;
size_t i;
/* initialize combination to identity */
for (i = 0; i < k; i++)
{
c->data[i] = i;
}
}
void
gsl_combination_init_last (gsl_combination * c)
{
const size_t k = c->k ;
size_t i;
size_t n = c->n;
/* initialize combination to identity */
for (i = 0; i < k; i++)
{
c->data[i] = n - k + i;
}
}
void
gsl_combination_free (gsl_combination * c)
{
if (c->k > 0) free (c->data);
free (c);
}
|
