void
qsort(char *a, unsigned n, int es, int (*fc) (void))
{
qscmp = fc;
qses = es;
qs1(a, a + n * es);
}
/*------------------------------------------------------------------------
* qsort - Use quicksort to sort an array
*------------------------------------------------------------------------
*/
void qsort(
char *a, /* Array to sort */
unsigned n, /* Length of the array */
int es, /* Pivot value */
int (*fc)(char *, char *) /* Comparison function */
)
{
qscmp = fc;
qses = es;
qs1(a, a + n * es);
}
/*------------------------------------------------------------------------
* qs1 - internal quicksort function
*------------------------------------------------------------------------
*/
static void qs1(
char *a,
char *l
)
{
register char *i, *j;
register int es;
char *lp, *hp;
int c;
unsigned n;
es = qses;
start:
if ((n = l - a) <= es)
{
return;
}
n = es * (n / (2 * es));
hp = lp = a + n;
i = a;
j = l - es;
for (;;)
{
if (i < lp)
{
if ((c = (*qscmp) (i, lp)) == 0)
{
qsexc(i, lp -= es);
continue;
}
if (c < 0)
{
i += es;
continue;
}
}
loop:
if (j > hp)
{
if ((c = (*qscmp) (hp, j)) == 0)
{
qsexc(hp += es, j);
goto loop;
}
if (c > 0)
{
if (i == lp)
{
qstexc(i, hp += es, j);
i = lp += es;
goto loop;
}
qsexc(i, j);
j -= es;
i += es;
continue;
}
j -= es;
goto loop;
}
if (i == lp)
{
if (lp - a >= l - hp)
{
qs1(hp + es, l);
l = lp;
}
else
{
qs1(a, lp);
a = hp + es;
}
goto start;
}
qstexc(j, lp -= es, i);
j = hp -= es;
}
}
