21 lines
397 B
C
21 lines
397 B
C
|
#include <stdlib.h>
|
||
|
|
|
||
|
|
void *bsearch(const void *key, const void *base, size_t nel, size_t width, int (*cmp)(const void *, const void *))
|
||
|
|
{
|
||
|
|
void *try;
|
||
|
|
int sign;
|
||
|
|
while (nel > 0) {
|
||
|
|
try = (char *)base + width*(nel/2);
|
||
|
|
sign = cmp(key, try);
|
||
|
|
if (sign < 0) {
|
||
|
|
nel /= 2;
|
||
|
|
} else if (sign > 0) {
|
||
|
|
base = (char *)try + width;
|
||
|
|
nel -= nel/2+1;
|
||
|
|
} else {
|
||
|
|
return try;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return NULL;
|
||
|
|
}
|