/** Functions to calculate the area of pizza purchased, given a diameter.
 *
 * @author Ian Barland
 */


class Pizzeria extends Object120 {

    /** Return the area of a pizza.
     * @param diam The diameter of the pizza (in inches.)
     * @return the area of a pizza (in sq.inches.)
     */
    static double pizzaArea( double diam ) {
        double r;
        r = diam/2;
        return Math.PI * r * r;
    }

    
    /** The amount of crust (in sq. in) on a pizza of the given diameter.
     * Our pizzeria uses 3" crust, all the way around.
     * @param d the diameter of the pizza.  Must be >= 0.
     * @return The amount of crust (in sq. in) on a pizza of diameter `d`.
     */
    static double crustArea( double d ) {
        double CRUST_WIDTH;
        CRUST_WIDTH = 3.0;
        if (d >= 2*CRUST_WIDTH) {
            return pizzaArea(d) - pizzaArea(d-2*CRUST_WIDTH);
        }
        else {
            return pizzaArea(d);
        }
    }
    
    
    /** A test driver. */
    static void testPizzeria() {
        System.out.println( "The area of a 20-inch pizza:" );
        System.out.println( "Actual: " + pizzaArea(20) );
        System.out.println( "Expect: 314 (approx)" );
        System.out.println( "" );

        System.out.println( "The area of a 0-inch pizza:" );
        System.out.println( "Actual: " + pizzaArea(0) );
        System.out.println( "Expect: 0" );
        System.out.println( "" );

        System.out.println( "The area of a 2-inch pizza:" );
        System.out.println( "Actual: " + pizzaArea(2) );
        System.out.println( "Expect: 3.14 (approx)" );
        System.out.println( "" );
        
        

        System.out.println( "The crust on a 6-inch pizza:" );
        System.out.println( "Actual: " + crustArea(6) );
        System.out.println( "Expect: ... (approx)" );
        System.out.println( "" );

        System.out.println( "The crust on a 26-inch pizza:" );
        System.out.println( "Actual: " + crustArea(26) );
        System.out.println( "Expect: ... (approx)" );
        System.out.println( "" );

        System.out.println( "The crust on a 14-inch pizza:" );
        System.out.println( "Actual: " + crustArea(14) );
        System.out.println( "Expect: ... (approx)" );
        System.out.println( "" );
        
        
        System.out.println( "Buffet price for 0 people:" );
        System.out.println( "Actual answer: " + buffetPrice(0) );
        System.out.println( "Expect answer: 0.00" );
        
        System.out.println( "Buffet price for 1 person:" );
        System.out.println( "Actual answer: " + buffetPrice(1) );
        System.out.println( "Expect answer: 8.00" );
        
        System.out.println( "Buffet price for 2 people:" );
        System.out.println( "Actual answer: " + buffetPrice(2) );
        System.out.println( "Expect answer: 12.50" );
        
        System.out.println( "Buffet price for 11 people:" );
        System.out.println( "Actual answer: " + buffetPrice(11) );
        System.out.println( "Expect answer: 53.00" );
        
        System.out.println( "========" );
        
    }

   
    /** Return the price of a buffet for large parties.
     * @param numCusts The total number of customers in party.
     * @return the price of a buffet for large parties (in USD).
     */
    static double buffetPrice( int numCusts ) {
        if (numCusts > 0) {
            return 8 + (numCusts-1)*4.5;
        }
        else {
            return 0.0;
        }
    }
    
}