BSD 4_3_Reno release

[unix-history] / usr / src / usr.bin / refer / hunt / shell.c

#ifndef lint
static char *sccsid = "@(#)shell.c      4.1 (Berkeley) 5/6/83";
#endif
/*
* 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);
       }
}