#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>

void main(int argc, char *argv[])
{
int kcount=0;
double x, h, m=0.5, p=0.0;
long a=0, b=0, e, t=0, c=1;

  struct timeval tv;
  struct fd_set readfd;
  tv.tv_sec = 0;
  tv.tv_usec = 0;


/* Initializations */
if (argc != 2) {
    printf("Usage: spfrcn [decimal]\n");
    exit(1);
}
printf("\nHit return at any time to stop...\n");
x = atof(argv[1]);
printf("Ok: %.16f\n", x);

while (1)     /* Main Loop */
{  

t++;
m+=x;
e=m;
h=((double)e / (double)t);
if (fabs(h-x) < fabs(p-x)) {
    p=h;
    a=e;
    b=t;
    printf("%ld / %ld  :  %.16f\n", a, b, p);
}

if (h==x) { exit(1); }

kcount++;
if (kcount==1000) {     /* every 1000 loops check to see if kbhit */
    kcount=0;
    FD_ZERO( &readfd );
    FD_SET( 0, &readfd );
    if (select(1, &readfd, NULL, NULL, &tv)) {
	exit(1);
    }
}

}       /* End of while(1) loop */

}