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
|
/* Copyright (C) 1991,92,97,2000,02 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <stdlib.h>
/* Perform a binary search for KEY in BASE which has NMEMB elements
of SIZE bytes each. The comparisons are done by (*COMPAR)(). */
void *
bsearch (const void *key, const void *base, size_t nmemb, size_t size,
int (*compar) (const void *, const void *))
{
size_t l, u, idx;
const void *p;
int comparison;
l = 0;
u = nmemb;
while (l < u)
{
idx = (l + u) / 2;
p = (void *) (((const char *) base) + (idx * size));
comparison = (*compar) (key, p);
if (comparison < 0)
u = idx;
else if (comparison > 0)
l = idx + 1;
else
return (void *) p;
}
return NULL;
}
libc_hidden_def (bsearch)
|
