import java.util.Arrays;

abstract class Shape
{
    public abstract double getArea( );
    public abstract double getPerimeter( );

    public double getSemiPerimeter( )
    {
        return getPerimeter( ) / 2.0;
    }
}

interface Stretchable  // interface == abstract class no implementation
{
    public void stretch( );
    public abstract void stretch( double factor );
}

class Square extends Shape
{
    public Square( double s )
    {
        side = s;
    }

    public double getArea( )
    {
        return side * side;
    }

    public double getPerimeter( )
    {
        return 4 * side;
    }

    public String toString( )
    {
        return "Square with side " + side;
    }

    private double side;
}

class Rectangle extends Shape implements Stretchable
{
    public Rectangle( double len, double wid )
    {
        length = len;
        width = wid;
    }

    public void stretch( )
    {
        stretch( 2.0 );
    }

    public void stretch( double factor )
    {
        length *= factor;
    }

    public double getArea( )
    {
        return length * width;
    }

    public double getPerimeter( )
    {
        return 2 * ( length + width );
    }

    public String toString( )
    {
        return "Rectangle with dimensions " + length + "*" + width;
    }

    private double length;
    private double width;
}

class Ellipse extends Shape implements Stretchable
{
    public Ellipse( double len ,double wid )
    {
        length = len;
        width = wid;
    }

    public void stretch( )
    {
        stretch( 2.0 );
    }

    public void stretch( double factor )
    {
        length *= factor;
    }

    public double getArea( )
    {
        return Circle.PI / 4 * length * width;
    }

    public double getPerimeter( )
    {
        return Circle.PI / 2 * ( length + width );
    }
    
    public String toString( )
    {
        return "Ellipse with dimensions " + length + "*" + width;
    }

    private double length;
    private double width;
}

class Circle extends Shape implements Comparable<Circle>
{
    public static final double PI = 3.14;

    public Circle( double r )
    {
        radius = r;
    }

    public int compareTo( Circle other )
    {
        if( radius < other.radius )
            return -1;
        else if( radius == other.radius )
            return 0;
        else
            return +1;
    }

    public double getPerimeter( )
    {
        return 2 * PI * radius;
    }

    public double getArea( )
    {
        return PI * radius * radius;
    }

    public String toString( )
    {
        return "Circle with radius " + radius;
    }

    private double radius;
}

public class Day12
{
    public static void printArray( String msg, Object [ ] arr )
    {
        System.out.println( msg );
        for( int i = 0; i < arr.length; i++ )
            System.out.println( "arr[" + i + "]=" + arr[ i ] );
    }

    public static double totalArea( Shape [ ] arr )
    {
        double total = 0.0;

        for( Shape s : arr )
            total += s.getArea( );

        return total;
    }

    public static void stretchAll( Stretchable [ ] arr )
    {
        for( Stretchable r : arr )
            r.stretch( );
    }

    // Not a great plan to start with
    public static void stretchAllShapes( Shape [ ] arr )
    {
        for( Shape s : arr )
        {
            if( s instanceof Stretchable )
            {
                Stretchable tmp = (Stretchable) s;
                tmp.stretch( );
            }
        }
    }


    public static void main( String [ ] args )
    {
        Square [ ] arr1 = { new Square( 3 ), new Square( 4 ) };
        printArray( "arr1:", arr1 );
        System.out.println( "Total area: " + totalArea( arr1 ) );

        Circle [ ] arr2 = { new Circle( 1 ), new Circle( 4 ), new Circle( 2 ) };
        printArray( "arr2: ", arr2 );
        Arrays.sort( arr2 );
        printArray( "arr2: ", arr2 );
        System.out.println( "Total area: " + totalArea( arr2 ) );

        Rectangle [ ] arr3 = { new Rectangle( 1, 4 ), new Rectangle( 2, 5 ) };
        printArray( "arr3: ", arr3 );
        stretchAll( arr3 );
        printArray( "arr3: ", arr3 );
        System.out.println( "Total area: " + totalArea( arr3 ) );

        Ellipse [ ] arr4 = { new Ellipse( 1, 4 ), new Ellipse( 2, 5 ) };
        printArray( "arr4: ", arr4 );
        stretchAll( arr4 );
        printArray( "arr4: ", arr4 );
        System.out.println( "Total area: " + totalArea( arr4 ) );

        Shape [ ] arr5 = { new Circle( 1 ), new Square( 1 ),
                            new Rectangle( 3, 4 ), new Ellipse( 5, 3 )  };
        printArray( "arr5: ", arr5 );
        stretchAllShapes( arr5 );
        printArray( "arr5: ", arr5 );
        System.out.println( "Total area: " + totalArea( arr5 ) );
    }

}