class Point2d {
    /* The X and Y coordinates of the point--instance variables */
    private double x;
    private double y;
    private boolean debug;	// A trick to help with debugging

    public Point2d (double px, double py) { // Constructor
	x = px;
	y = py;

	debug = false;		// turn off debugging
    }

    public Point2d () {		// Default constructor
	this (0.0, 0.0);        // Invokes 2 parameter Point2D constructor
    }
    // Note that a this() invocation must be the BEGINNING of
    // statement body of constructor

    public Point2d (Point2d pt) {	// Another consructor
	x = pt.getX();
	y = pt.getY();

	// a better method would be to replace the above code with
	//    this (pt.getX(), pt.getY());
	// especially since the above code does not initialize the
	// variable debug.  This way we are reusing code that is already
	// working.
    }

    public void dprint (String s) {
	// print the debugging string only if the "debug"
	// data member is true
	if (debug)
	    System.out.println("Debug: " + s);
    }

    public void setDebug (boolean b) {
	debug = b;
    }

    public void setX(double px) {
	dprint ("setX(): Changing value of X from " + x + " to " + px );
	x = px;
    }

    public double getX() {
	return x;
    }

    public void setY(double py)  {
	dprint ("setY(): Changing value of Y from " + y + " to " + py );
	y = py;
    }

    public double getY() {
	return y;
    }

    public void setXY(double px, double py) {
	setX(px);
	setY(py);
    }

    public double distanceFrom (Point2d pt) {
	double dx = Math.abs(x - pt.getX());
	double dy = Math.abs(y - pt.getY());

	// check out the use of dprint()
	dprint ("distanceFrom(): deltaX = " + dx);
	dprint ("distanceFrom(): deltaY = " + dy);

	return Math.sqrt((dx * dx) + (dy * dy));
    }

    public double distanceFromOrigin () {
	return distanceFrom (new Point2d ( ));
    }

    public String toStringForXY() {
	String str = "(" + x + ", " + y;
	return str;
    }

    public String toString() {
	String str = toStringForXY() + ")";
	return str;
    }
}