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/*
* qsort.c
*
* This is actually combsort. It's an O(n log n) algorithm with
* simplicity/small code size being its main virtue.
*/
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
static inline size_t newgap(size_t gap)
{
gap = (gap * 10) / 13;
if (gap == 9 || gap == 10)
gap = 11;
if (gap < 1)
gap = 1;
return gap;
}
void qsort(void *base, size_t nmemb, size_t size,
int (*compar) (const void *, const void *))
{
size_t gap = nmemb;
size_t i, j;
char *p1, *p2;
int swapped;
if (!nmemb)
return;
do {
gap = newgap(gap);
swapped = 0;
for (i = 0, p1 = base; i < nmemb - gap; i++, p1 += size) {
j = i + gap;
if (compar(p1, p2 = (char *)base + j * size) > 0) {
memswap(p1, p2, size);
swapped = 1;
}
}
} while (gap > 1 || swapped);
}
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