/* Copyright Will Wilson 1999 */
/* birth-death simulation (multiple run output) */

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

#define	MAXTIME 	1000
#define	PRNTTIME	100
#define	NUMRUNS		10
#define RUNTYPE		1 /* 1-zero stays extinct; 2-reseeding */
#define	OUTTYPE		1 /* 1-values; 2-averages */

int main(void)
{
	int	ttt, event, irun;
	int	seed, pops[NUMRUNS];
	double	alpha, beta;

	alpha = beta = 0.10;

	seed = 1456739853;
	srand48(seed);

	for(irun=0;irun<NUMRUNS;irun++) pops[irun] = 10;

	for(ttt=0;ttt<MAXTIME;ttt++)
	{
		for(irun=0;irun<NUMRUNS;irun++)
		{
#if(RUNTYPE==1)
			if(pops[irun]>0)
#endif
			{
				event = 0;
				if(drand48()<alpha) event = 1;
				if(drand48()<beta) event -= 1;

				pops[irun] += event;
				if(pops[irun]<0) pops[irun]=0;
			}
		}

		if(ttt%PRNTTIME==0)
		{
#if(OUTTYPE==1)
			printf("%4d ",ttt);
			for(irun=0;irun<NUMRUNS;irun++)
				printf(" %3d ",pops[irun]);
			printf("\n");
#endif
#if(OUTTYPE==2)
			double average=0.0;
			for(irun=0;irun<NUMRUNS;irun++)
				average += pops[irun];
			printf("%d %f\n",ttt,average/NUMRUNS);
#endif
		}
	}
	return (0);
}