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/*
* bsearch.c
*
* This is something I found on watmath. I've made some minor changes for use
* in this package.
*
* 92/06/04 11:35:15
*/
#if 0
#ifndef lint
static char *RCSid = "$OHeader: /usr/mfcf/src/accounts/libuw/RCS/bsearch.c,v 1.1 88/06/11 20:41:48 root Exp $";
#endif
#endif
#include "defs.h"
#ifdef USE_MYBSEARCH
#ifdef USE_SCCS_IDS
static char const SCCSid[] = "@(#) mytinfo bsearch.c 3.4 92/06/04 public domain, By Ross Ridge";
#endif
#ifdef USE_SHORT_BSEARCH
#define fast_int short
#else
#define fast_int mysize_t
#endif
/*
* bsearch - find an element of a sorted vector
*
* found = bsearch(key, array, dimension, width, compare)
* returns a pointer to the specified element in the array,
* or (char*)0 if the element can't be found.
* key
* pointer to the element to be searched for in the array
* array
* address of an array of elements
* dimension
* number of elements in the array
* width
* sizeof(type) of each element
* compare
* pointer to a function taking (char *) pointers to two elements
* and returning <0, 0, or >0 as the first element comes before,
* at, or after the second element. A compare function is provided
* for comparing strings.
*/
#if 0
/*
* $OLog: bsearch.c,v $
* Revision 1.1 88/06/11 20:41:48 root
* Initial revision
*
*/
#endif
static anyptr
bsearch(key, array, dimension, iwidth, compare)
anyptr key;
anyptr array;
int dimension;
mysize_t iwidth;
compar_fn compare;
{
register fast_int start; /* offset to start of current interval */
register fast_int end; /* offset to end+1 of current interval */
register fast_int middle; /* offset to middle of current interval */
auto int status;
register fast_int width;
width = iwidth / sizeof(char);
start = 0;
middle = 0;
end = dimension;
while (start < end) {
middle = (start + end) / 2;
status = (*compare)(key, ((char *)array + middle*width));
if (status < 0)
end = middle;
else if (status > 0)
start = middle + 1;
else return (anyptr)(((char *)array) + middle*width);
}
return 0;
}
#endif /* USE_MYBSEARCH */
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