point.java

清华大学第二版

import java.math.*;
public class Point {
	public int x,y,z;
	public Point()
	{}
	public Point(int a,int b)
	{x=a;y=b;}
	public Point(int x,int y,int z)
    {x=x;y=y;z=z;}
	public double distance() {
		return Math.sqrt( x*x + y*y );
	}

}