shell.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
/*
* Copyright (c) 1983, 1984 1985, 1986, 1987, 1988, Sun Microsystems, Inc.
* All Rights Reserved.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* SORTS UP.
* IF THERE ARE NO EXCHANGES (IEX=0) ON A SWEEP
* THE COMPARISON GAP (IGAP) IS HALVED FOR THE NEXT SWEEP
*/
shell (n, comp, exch)
int (*comp)(), (*exch)();
{
int igap, iplusg, iex, i, imax;
igap=n;
while (igap > 1)
{
igap /= 2;
imax = n-igap;
do
{
iex=0;
for(i=0; i<imax; i++)
{
iplusg = i + igap;
if ((*comp) (i, iplusg) ) continue;
(*exch) (i, iplusg);
iex=1;
}
}
while (iex>0);
}
}