import java.applet.Applet;
import java.awt.event.*;
import java.awt.*;

/*This class does the basic arithmetic
  of 4 dimensional vectors */


public class Vector4 {
    double[] x=new double[4];
    public Vector4(){}

    public Vector4(double a,double b,double c,double d) {
	x[0]=a;
	x[1]=b;
	x[2]=c;
	x[3]=d;
    }

    public Vector4(Vector4 xx) {
	for(int i=0;i<4;++i) x[i]=xx.x[i];
    }




    public static double dist2(Vector4 V1,Vector4 V2) {
	Vector4 X=minus(V1,V2);
	double d=dot(X,X);
	return(d);
    }




    public static Vector4 plus(Vector4 V1,Vector4 V2) {
	Vector4 W=new Vector4();
	for(int i=0;i<4;++i) W.x[i]=V1.x[i]+V2.x[i];
	return(W);
    }


    public static Vector4 minus(Vector4 V1,Vector4 V2) {
	Vector4 W=new Vector4();
	for(int i=0;i<4;++i) W.x[i]=V1.x[i]-V2.x[i];
	return(W);
    }


    public static double dot(Vector4 V1,Vector4 V2) {
	double d=0;
	for(int i=0;i<4;++i) d=d+V1.x[i]*V2.x[i];
	return(d);
    }


    public void print() {
	System.out.println(x[0]+" "+x[1]+" "+x[2]+" "+x[3]);
    }


}