/*									tab:4
 *
 * pi.sc - A simple split-c example which computes pi.
 *
 * "Copyright (c) 1993 and The Regents of the University 
 * of California.  All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without written agreement is
 * hereby granted, provided that the above copyright notice and the following
 * two paragraphs appear in all copies of this software.
 * 
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
 * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
 * CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS."
 *
 * Version:			9
 * Creation Date:	Fri Jan 22 17:01:51 1993
 * Filename:		pi.sc
 * History:
 *	LTL	8	Wed Aug  2 23:08:30 1995
 *		Used drand48() instead of rand() to get better results
 */
static char _version_string_[] = "\nVersion:8:pi.sc\0\n";

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include <split-c/split-c.h> 
#include <split-c/control.h> 
#include <split-c/com.h> 

int hit()
{
  double  x = (double) drand48();
  double  y = (double) drand48();
  if ((x*x+y*y) <= 1.0) return(1);
  else return(0);
}


/* ----------------------- splitc_main -------------------- */
splitc_main(int argc, char **argv)
{
  int i, total_hits, hits = 0;
  double pi;
  int trials, my_trials;

  /* Set the number of total iterations to compute pi */
  if (argc != 2) trials = 1000000;
  else trials = atoi(argv[1]);

  /* Calculate how many trials this processor must compute */
  my_trials = (trials + PROCS - 1 - 2*MYPROC)/PROCS;

  /* Different seed on each processor */
  srand48(MYPROC*17);		

  /* Compute the number of hits on this processor */
  for (i=0; i < my_trials; i++) hits += hit();

  /*
   * Add up the number of hits across the processors.  Note that
   * only one processor receives this sum.
   */
  total_hits = all_reduce_to_one_add(hits); 

  /* One processor displays the calculated value of pi */
  on_one {
    pi = 4.0*total_hits/trials;
    printf("PI estimated at %f from %d trials on %d processors.\n", 
		  pi, trials, PROCS);
  }
}