/* density dependent birth-death simulation */

#include	<stdlib.h>
#include	<stdio.h>
#include	<math.h>
	
#define	MAXTIME 	(50)
#define	PRNTTIME	(1)

double growth(double, double);
double	alpha, beta, k;

int main(void)
{
	int	ttt;
	double 	n1, n2, n3, n4, n5;

	alpha = 0.2;
	beta = 0.1;
	k = 40.0;
	
	for(ttt=0;ttt<MAXTIME;ttt+=PRNTTIME)
	{
		n1 = growth( 5.0,(double)ttt);
		n2 = growth(10.0,(double)ttt);
		n3 = growth(20.0,(double)ttt);
		n4 = growth(30.0,(double)ttt);
		n5 = growth(40.0,(double)ttt);

		printf(" %d %f %f %f %f %f\n", ttt, n1, n2, n3, n4, n5);
	}
	return (0);
}

double growth(double n0, double time)
{
	return(n0*k*(alpha-beta)/(alpha*n0 + (k*(alpha-beta)-alpha*n0)
					*exp(-(alpha-beta)*time)));
}