Java第三章

3.2

import java.util.Scanner;
public class book {
    
    
    public static void main(String[] args)
    {
    
    
        int number1 = (int)(System.currentTimeMillis()%10);
        int number2 = (int)(System.currentTimeMillis()/10%10);
        int number3 = (int)(System.currentTimeMillis()/100%10);
        Scanner input = new Scanner(System.in);
        System.out.print("What is "+number1+" + "+number2+" + "+number3+"? ");
        int answer = input.nextInt();
        System.out.println(number1+" + "+number2+" + "+number3+" = "+answer+" is "+(number1+number2+number3==answer));
    }
}

3.6

import java.util.Scanner;
public class book {
    
    
    public static void main(String[] args)
    {
    
    
        Scanner input = new Scanner(System.in);
        System.out.print("Enter weight in pounds:");
        double pounds = input.nextDouble();
        System.out.print("Enter feet:");
        double feet = input.nextDouble();
        System.out.print("Enter inches:");
        double inches = input.nextDouble();
        final double KILOS_PER_POUND = 0.45359237;
        final double METERS_PER_INCH = 0.0254;
        final double METERS_PER_FOOT = 0.3048;
        double kilos = pounds*KILOS_PER_POUND;
        double meters = feet*METERS_PER_FOOT+inches*METERS_PER_INCH;
        double bmi = kilos/(meters*meters);
        System.out.println("BMI is "+bmi);
        if(bmi<18.5)
            System.out.println("Underweight");
        else if(bmi<25)
            System.out.println("Normal");
        else if(bmi<30)
            System.out.println("Overweight");
        else
            System.out.println("Obese");
    }
}