#include <stdio.h>

double get_next(double *);
double get_before(double *);

static int i=0;

int main()
{
	
	double ary[] = {0.1,0.3,0.5,0.7,0.9};

	double ap;
	ap = get_next(ary);//Áú¹®!~!!!!!!
	printf("%.1lf\n",ap);
	ap = get_next(ary);
	printf("%.1lf\n",ap); 

	ap = get_before(ary);
	printf("%.1lf\n",ap);
	ap = get_before(ary);
	printf("%.1lf\n",ap); 

	return 0;
}

double get_next(double *ary)
{
	printf("nextÈ£Ãâ : ");
	
	return ary[i++];
//	return ++ap;//Áú¹®
}

double get_before(double *ary)
{
	printf("beforeÈ£Ãâ : ");

	return ary[i--];
}