mirror of
https://github.com/cc65/cc65.git
synced 2024-12-25 02:29:52 +00:00
50 lines
999 B
C
50 lines
999 B
C
/*
|
|
* bsearch.c
|
|
*
|
|
* Ullrich von Bassewitz, 17.06.1998
|
|
*/
|
|
|
|
|
|
|
|
#include <stdlib.h>
|
|
|
|
|
|
|
|
void* __fastcall__ bsearch (const void* key, const void* base, size_t n,
|
|
size_t size, int (*cmp) (const void*, const void*))
|
|
{
|
|
int current;
|
|
int result;
|
|
int found = 0;
|
|
int first = 0;
|
|
int last = n - 1;
|
|
|
|
/* Binary search */
|
|
while (first <= last) {
|
|
|
|
/* Set current to mid of range */
|
|
current = (last + first) / 2;
|
|
|
|
/* Do a compare */
|
|
result = cmp ((void*) (((int) base) + current*size), key);
|
|
if (result < 0) {
|
|
first = current + 1;
|
|
} else {
|
|
last = current - 1;
|
|
if (result == 0) {
|
|
/* Found one entry that matches the search key. However there may be
|
|
* more than one entry with the same key value and ANSI guarantees
|
|
* that we return the first of a row of items with the same key.
|
|
*/
|
|
found = 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Did we find the entry? */
|
|
return (void*) (found? ((int) base) + first*size : 0);
|
|
}
|
|
|
|
|
|
|