program 3

/* This program prompts the user to enter whether they are a teacher or non-teacher.
* Once determined, the program prompts you to enter a purchase total.
* Depending on whether the purchase is under $100 (10% discount)
* or over $100 (12% discount) it will calculate the discount.
* This discount is only applicable to teachers.
* This discount is taken out before the addition of the 5% sales tax.
* The program will then print out a receipt. */

#include <stdio.h>       			/* printf, scanf difinition */
#define SALES_TAX .05				/* defines sales tax as 5% */
#define DISCOUNT_LOW .10			/* defines discount as 10% if purchase is $100 or less */
#define DISCOUNT_HIGH .12			/* defines discount as 12% if purchase is more than $100 */
#define DISCOUNT_LIMIT .100		/* defines the limit between discount percentages */

int main(void)
{
    double purchase_total;
    double discount;
    double discounted_total;
    double sales_tax;
    double total;
    int teacher;

    /* request inputs */
    printf("Is the customer a teacher (Y/N)? ");
    scanf("%c", &teacher);
    printf("Enter total purchases ");
    scanf("%lf", &purchase_total);

    /* calculations for teacher */
    if (teacher == 'Y')
    {/*calculate discount (10% or 12%) and 5% sales tax */
        /* purchase total less than 100 */
        if (purchase_total < 100)
        {
            /* calculate 10% discount */
            discount = purchase_total * DISCOUNT_LOW;
            discounted_total = purchase_total - discount;
        }

        /*purchase total greater than 100 */
        else
        {   /* calculate 12% discount */
            discount = purchase_total * DISCOUNT_HIGH;
            discounted_total = purchase_total - discount;
		  }

        printf("\nTotal purchases              $%.2f ", purchase_total);
        printf("\nTeacher's discount             %.2f ", discount);
        printf("\nDiscounted total              %.2f ", discounted_total);
        printf("\nSales tax (5%%)                  %.2f ", sales_tax);
        printf("\nTotal                          $%.2f\n ", total);
    }


    /* calculation for nonteacher */
    if (teacher == 'N')
    {
        /* calculate only 5% sales tax */
        sales_tax = purchase_total * SALES_TAX;
        total = purchase_total + sales_tax;

        printf("\nTotal purchases               $%.2f", purchase_total);
        printf("\nSales tax (5%%)                  %.2f", sales_tax);
        printf("\nTotal                         $%.2f", total);
    }

    return(0);
}