import java.util.Scanner;

/* Java program that computes (and reports) body mass index (BMI) values for
** a particular height and the weights within a range beginning at some 
** specified lower bound up to some specified upper bound, and increasing by 
** some specified interval.
**
** This version improves upon the previous one by receiving inputs from
** the keyboard rather than them being "hard-coded" using assignment
** statements.
**
** The main purposes are to illustrate the use of Java's for-loop construct
** and reading input using a Scanner object.
*/

public class BMICalculatorApp5 {

   private static Scanner keyboard; // for reading input from an external source

   private static int height;       // height in inches (input)
   private static int lowWeight;    // lower bound weight (in pounds) (input)
   private static int highWeight;   // uppper bound weight (in pounds) (input)
   private static int weightGap;    // gap between weights (in pounds) (input)
   private static double bmi;       // BMI value (output)

   private static int weight;     // weight in pounds (loop control variable)

   public static void main(String[] args)
   {
      // Create a Scanner object and enable it to read input entered at the keyboard.
      keyboard = new Scanner(System.in);

      System.out.print("Enter height (in inches): ");

      // Read the user's response, interpreting it as a value of type int,
      // and assign that value to the 'height' input variable.
      height = keyboard.nextInt();

      System.out.print("Enter bottom weight (in pounds): ");
      lowWeight = keyboard.nextInt();

      System.out.print("Enter top weight (in pounds): ");
      highWeight = keyboard.nextInt();

      System.out.print("Enter weight gap (in pounds): ");
      weightGap = keyboard.nextInt();

      for (weight = lowWeight; weight <= highWeight; weight = weight + weightGap) {
         reportBMIValue();
      }
   }

   /* Reports the BMI value corresponding to the values in the global variables
   ** 'height' and 'weight'.
   */
   private static void reportBMIValue() {

      computeBMI();
      
      System.out.print("Height of " + height + " inches ");
      System.out.print("and weight of " + weight + " pounds yields "); 
      System.out.println("BMI value of " + bmi);
   }


   /* Assigns to global variable 'bmi' the BMI value computed from the values
   ** in global variables 'height' and 'weight'.
   */
   private static void computeBMI()
   {
      // Conversion factor needed to convert result of BMI formula when height
      // and weight are measured in inches and pounds rather than in meters
      // and kilograms, respectively.
      final int UNIT_CONVERSION_FACTOR = 703;
   
      bmi = UNIT_CONVERSION_FACTOR * ((double)weight / (height * height));
   }

}