/*
 * T01n03.java -- Compute the distance between two 2D points, using
 * a few methods from the Math class.
 *
 * Do you see why I have that "D" at the end of the second "100" in
 * the distanceForDisplay calculation?  If not, try removing it and
 * see what happens.
 */

import java.util.*;

public class T01n03
{

    public static void main (String [] args)
    {
        double x1, y1;               // coordinates of the first point
        double x2, y2;               // coordinates of the second point
        double distance;             // distance between the two points
        double distanceForDisplay;   // rounded to two decimal places

        Scanner keyboard = new Scanner (System.in);  // still magic!


                // Gather the coordinates of the two points

        System.out.print("Enter the x-coordinate of the first point : ");
        x1 = keyboard.nextDouble();

        System.out.print("Enter the y-coordinate of the first point : ");
        y1 = keyboard.nextDouble();

        System.out.print("Enter the x-coordinate of the second point : ");
        x2 = keyboard.nextDouble();

        System.out.print("Enter the y-coordinate of the second point : ");
        y2 = keyboard.nextDouble();


                // Compute the distance between the points, and
                // round the result to two decimal places.

        distance = Math.sqrt( Math.pow(x2-x1,2) + Math.pow(y2-y1,2) );
        distanceForDisplay = Math.round(distance * 100) / 100D;


        System.out.println("\nThe distance from (" + x1 + "," + y1 + ") "
                         + "to (" + x2 + "," + y2 + ") "
                         + "is " + distanceForDisplay + " units.");
    }
}