//BMINaiveErrorCheck.java

import java.util.Scanner;

public class BMINaiveErrorCheck
{
    public static void main(String[] args)
    {
        Scanner scnr = new Scanner(System.in);
        int weightVal; // User defined weight (lbs)
        int heightVal; // User defined height (in)
        float bmiCalc; // Resulting BMI
        char quitCmd;  // Indicates quit/continue

        weightVal = 0;
        heightVal = 0;
        quitCmd = 'a';

        while (quitCmd != 'q')
        {
            // Get user data
            System.out.print("Enter weight (in pounds): ");
            weightVal = scnr.nextInt();

            // Error checking, non-negative weight
            if (weightVal < 0)
            {
                System.out.println("Invalid weight.");
            }
            else
            {
                System.out.print("Enter height (in inches): ");
                heightVal = scnr.nextInt();
                // Error checking, non-negative height

                if (heightVal < 0)
                {
                    System.out.println("Invalid height.");
                }
            }

            // Calculate BMI and print user health info if no input error
            // Source: http://www.cdc.gov/
            if ((weightVal <= 0) || (heightVal <= 0))
            {
                System.out.println("Cannot compute info.");
            }
            else
            {
                bmiCalc = ((float) weightVal /
                           (float)(heightVal * heightVal)) * 703.0f;

                System.out.println("BMI: " + bmiCalc);
                System.out.println("(CDC: 18.6-24.9 normal)");
                // Source: http://www.cdc.gov/
            }

            // Prompt user to continue/quit
            System.out.print("\nEnter any key ('q' to quit): ");
            quitCmd = scnr.next().charAt(0);
        }
    }
}