import java.util.Scanner;

/* Java application that displays a table of square roots.
** The user is prompted to enter a lower bound, an upper bound,
** and a "delta" value, and the program displays a table
** showing the square roots of numbers in the specified range,
** differing by the specified delta.  For each such number,
** it is printed, as well as the square root of its absolute
** value, as well as the integer closest to that square root.
**
** The program serves to illustrate the use of 
** (1) "functional" methods (i.e., ones that return values)
**     (e.g., methods in the java.lang.Math class and ones defined here)
** (2) a Scanner object to read input data from the keyboard
** (3) the System.out.printf() method for formatting output
** 
*/

public class SqRootTable {

   private static Scanner keyboard = new Scanner(System.in);

   public static void main(String[] args) {

      double lower = getDoubleFromUser("Enter lower bound:");   // user enters lower
      double upper = getDoubleFromUser("Enter upper bound:");   // and upper bounds,
      double delta = getDoubleFromUser("Enter delta:");         // and the delta value

      System.out.println("     x        sqrt(|x|)     rounded sqrt(|x|)");
      System.out.println("  -------  --------------  -------------------");

      for (double x = lower; x <= upper; x = x + delta)
      {
         double sqRootOfX = Math.sqrt(Math.abs(x));
         long sqRootOfXRounded = Math.round(sqRootOfX);
         System.out.printf("%8.2f   %11.6f     %4d \n", x, sqRootOfX, sqRootOfXRounded);
      }
   }


   private static double getDoubleFromUser(String prompt) {
      System.out.print(prompt);
      return keyboard.nextDouble();
   }
}