/**
 * A simple PriceCalculator
 *
 * @author  Prof. David Bernstein, James Madison University
 * @version 1.0
 */
public class PriceCalculator
{
    private double[] discounts = {0., 1., 5., 20., 100.};


    /**
     *  Apply a quantity-based discount
     */
    public double applyDiscount(double price, int quantity)
    {
	double       discountedPrice;
	int          i;

	discountedPrice = price;

	// Find the discount and adjust the price;
	i = discounts.length - 1;
	while (i >= 0)
        {
	    if (quantity >= i)
            {
		discountedPrice = price - discounts[i];
		break;
	    }

	    --i;
	}

	// Return -1 to indicate a problem
	if (discountedPrice < 0) discountedPrice = -1;

	return discountedPrice;
    }

}