#include <stdio.h>
#include "gm.h"
void	getdec(char *,DEC *);
void main(void);

void	main()
{
	int	choice, opt, nper=0, diy=365;
	DECP	pv, intr, intamt;
	DEC	*p;
	
	printf("Simple interest computation\n");
	printf("Variable to solve for --\n");
	printf("  1)  Number of days\n  2)  Interest rate\n");
	printf("  3)  Principal\n  4)  Accrued interest\n");
	printf("Your choice:  ");
	scanf("%d", &choice);
	if (choice == 1)
		opt = GM_N;
	if (choice == 2)
		opt = GM_I;
	if (choice == 3)
		opt = GM_PV;
	if (choice == 4)
		opt = GM_INTR;
	
	if (opt != GM_N)  {
		printf("Number of days:  ");
		scanf("%d", &nper);
	}
	if (opt != GM_I)
		getdec("Percentage annual interest rate:  ", intr);
	if (opt != GM_PV)
		getdec("Principal:  ", pv);
	if (opt != GM_INTR)
		getdec("Accrued interest:  ", intamt);
	dprintf("Number of days in year (360 or 365):  ");
	dscanf("%d", &diy);

	if (diy == 360)
		p = simp360(&nper, intr, pv, intamt, opt);
	else
		p = simp365(&nper, intr, pv, intamt, opt);
	
	if (opt==GM_N)
		dprintf("The result is %d\n",nper);
	else  {
		if (p)
			dprintf("The result is %v\n",p);
		else
			dprintf("Simple interest failed\n");
	}
}

void	getdec(str, x)
char	*str;
DEC	*x;
{
	int	i;
	
	do  {
		printf("%s", str);
		i = dscanf("%t", x);
	} while (i<1);
}