import java.awt.geom.*;

// a class with four constructors that specified 4 line in different ways

public class Line
{
	
	// @param x: x coordinate of the given point
	// @param m: slope
	// @param intercept: intercept of the line
	
	// a line by given a point (x,y) and slope m
	public Line( Point2D.Double p, double m )
	{
		_m = m;
		_b = p.y - ( _m * p.x );
		if( -1 == _m )
			_b = 0;
	}
	
	// a line by given two points
	public Line( Point2D.Double p1, Point2D.Double p2 )
	{
		if( p2.x == p1.x )
		{
			_m = -1;
			_b = 0;
		}
		else
		{
			_m = ( p2.y - p1.y ) / ( p2.x - p1.x );
			_b = p1.y - ( _m * p1.x );
		}
	}
	
	// a line by applying equation y = mx + b
	public Line( double m, double b )
	{
		_m = m;
		_b = b;
		if( -1 == _m )
			_b = 0;
	}
	
	// a vertical line
	public Line( double a )
	{
		_m = -1;
		_b = 0;
	}
	
	// a method that check if the lines intersect to each other
	public boolean intersects( Line other )
	{
		boolean retval = false;
		if( _m != other._m )
			retval = true;

		return retval;
	}

	public boolean equals( Line other )
	{
		boolean retval = false;
		if( _m == other._m && _b == other._b )
			retval = true;
	
		return retval;
	}
	
	public boolean isParallel( Line other )
	{
		boolean retval = false;
		if( _m == other._m && _b != other._b )
			retval = true;

		return retval;
	}

	private double _m;
	private double _b;
}