#include <iostream>
#include <string>
#include <cmath>

using namespace std;

#ifndef _point_h_
#define _point_h_

/* 
 * Class to represent a single point.
 */

class Point {
public:
	// Construct a point with the indicated coordinates.  Note
	// use fo a constructor list instead of assignments in the body.
	Point(double x = 0.0, double y = 0.0): m_x(x), m_y(y) { }

	// Return either ordinate.
	double abscissa() const { return m_x; }
	double ordinate() const { return m_y; }

	// Print a string on the indicated stream.  cout is type of
	// std::ostream (descendent class, actually)
	void print(std::ostream &strm) const
	{
		strm << "(" << m_x << "," << m_y << ")";
	}

	// Add or subtract two points
	Point plus(const Point &b) const
	{
		return Point(m_x + b.m_x, m_y + b.m_y);
	}
	Point minus(const Point &b) const
	{
		return Point(m_x - b.m_x, m_y - b.m_y);
	}

	// Negate the point
	Point negate() const
	{
		return Point(-m_x, -m_y);
	}

	// Move the point by a given amount
	void move(double dx, double dy)
	{
		m_x += dx;
		m_y += dy;
	}

	// Return the distance between points
	double distance(const Point &b) const
	{
		double xd = m_x - b.m_x;
		double yd = m_y - b.m_y;

		return sqrt(xd*xd + yd*yd);
	}

	// Return the area of the rectangle whose corners are the
	// current point and the argument.
	double area(const Point &b) const
	{
		return abs(m_x - b.m_x) * abs(m_y - b.m_y);
	}
private:
	// The coordinates of the point.
	double m_x, m_y;
};

/*
 * Print the point.  When you have Point p, and you say
 *   cout << p
 * the compiler translates it to
 *   p.operator<<(cout)
 */
static ostream & operator<<(std::ostream &strm, const Point &p) {
	p.print(strm);
	return strm;
}

#endif