// CSE 142, Winter 2008, Marty Stepp
// 
// This program reads height and weight information from the console
// using the Scanner, computes two users' body mass indexes (BMIs),
// and compares them to find the difference between two people.
//
// This second version of the program also prints each person's weight
// class, such as underweight or obese.
// 

import java.util.*;   // so that I can use Scanner

public class BMI2 {
	public static void main(String[] args) {
		Scanner console = new Scanner(System.in);
		double bmi1 = processOnePerson(console);  // 62.5  130.5
		double bmi2 = processOnePerson(console);  // 58.5  90
		results(bmi1, bmi2);
	}
	
	// Reads the height and weight information for one person,
	// and returns the person's BMI.
	public static double processOnePerson(Scanner console) {
		System.out.println("Enter next person's information:");
		System.out.print("height (in inches: ");
		double height = console.nextDouble();
		System.out.print("weight (in pounds: ");
		double weight = console.nextDouble();
		
		// print person's weight class (this is the new code)
		double bmi = computeBMI(height, weight);
		if (bmi >= 30.0) {
			System.out.println("obese");
		} else if (bmi >= 25.0) {
			System.out.println("overweight");
		} else if (bmi >= 18.5) {
			System.out.println("normal");
		} else {
			System.out.println("underweight");
		}
		System.out.println();
		
		return bmi;
	}
	
	// Computes and returns a person's BMI based on their height and weight.
	public static double computeBMI(double height, double weight) {
		double bmi = weight / (height * height) * 703;
		return bmi;
	}

	// Displays the overall results at the end of the program.
	public static void results(double bmi1, double bmi2) {
		System.out.println("Person #1 body mass index = " + round2(bmi1));
		System.out.println("Person #2 body mass index = " + round2(bmi2));
		System.out.println("Difference = " + round2(Math.abs(bmi1 - bmi2)));
		
		// we could also use System.out.printf for this output:
		// System.out.printf("Person #1 body mass index = %.2f\n", bmi1);
		// System.out.printf("Person #2 body mass index = %.2f\n", bmi2);
		// System.out.printf("Difference = %.2f\n", Math.abs(bmi1 - bmi2));
	}
	
	// Rounds the given number to 2 decimal places and returns it.
	// To round to a different number of places, we'd multiply/divide by
	// a different power of 10 (for example, by 1000 to round to 3 places).
	public static double round2(double result) {
		result = result * 100;          // 33.333333333
		result = Math.round(result);    // 33.0
		result = result / 100;          // 0.33
		return result;
	}
}