/* birth-death simulation */

#include	<stdlib.h>
	
#define	MAXTIME 	100
#define	PRNTTIME	10

main()
{
	int	ttt, event, n, seed;
	double	alpha, beta, xrand;

	alpha = 0.1;
	beta = 0.1;
	n = 10;
	
	seed = 893456739853;
	srand48(seed);

	for(ttt=0;ttt<MAXTIME;ttt++)
	{
		event = 0;
		if(drand48()<alpha) event = 1;
		if(drand48()<beta) event = event - 1;
			
		n += event;
		if(n<0) n = 0;

		if(ttt%PRNTTIME==0) printf(" time: %3d  n: %-4d\n",ttt, n);
	}
}