#ifndef POINTH
#define POINTH
#include <iostream>
#include <cmath>   //for abs
using namespace std;

const double point_error = .0001;   //floating point roundoff error

//class point;
//point midpoint(const point& A, const point& B);

class point {
	double x, y;
public:
	point(double initial_x = 0.0, double initial_y = 0.0) {
		x = initial_x;
		y = initial_y;
	}

	void print() const {cout << "(" << x << ", " << y << ")";}
	void assign(const point& another) {x = another.x; y = another.y;}

	double dist() const;
	friend double dist(const point& A, const point& B);

	friend point midpoint(const point& A, const point& B) {
		return point((A.x + B.x) / 2, (A.y + B.y) / 2);
	}

	friend double area(const point& A, const point& B, const point& C);
};

point midpoint(const point& A, const point& B);

//Return true if all three points lie along the same line.

inline bool collinear(const point& A, const point& B, const point& C) {
	return abs(area(A, B, C)) < point_error;
}

bool contains(const point& A, const point& B, const point& C, const point& D);
#endif