/* parallel Monte Carlo area calculation */
/* slave program for first quadrant */

#include <stdio.h>
#include <math.h>
#include <pvm3.h>
#define steps 50000
#define xmin 0.0
#define xmax 0.5
#define ymin 0.0
#define ymax 0.5

double f(double x)			/* the function for the */
{					/* border in this quadrant */
   return(-sqrt(-x*x+x)+0.5);
}

main()
{
int i, ptid, bufid, dum, type, send[1];
double x, y;

srand48(pvm_mytid());			/* seed the number generator */
					/* not a good way of doing it */
ptid = pvm_parent();

do
{
   send[0]=0;
   for (i=1; i<=steps; i++)
   {
      x= drand48()*(xmax+xmin);			/* random points in the */
      y= drand48()*(ymax+ymin);			/* quadrant */
      if (f(x)<=y) send[0]++;     		/* point is inside the figure */
   }     
   pvm_initsend(PvmDataDefault);		/* send result back to master */
   pvm_pkint(send, 1, 1); 
   pvm_send(ptid, 1);
   bufid=pvm_recv(ptid, -1);			/* any message from master */
   pvm_bufinfo(bufid, &dum, &type, &dum);	/* more work ? */
}while(type);

pvm_exit;  					/* type=0 means we are done */ 
}