/**
 * Java. Level 1. Lesson 1. Example of homework
 *
 * @author Sergey Iryupin
 * @version dated Nov 25, 2017
 */
class HW1Lesson {

    public static void main(String[] args) {
        // call for task 2
        createVariable();
        // call for task 3
        System.out.println(calculate(1, 2, 3, 4));
        System.out.println(calculate(1, 2, 3, 0));
        System.out.println(calculate(1, 2, 0, 0));

        // tests for task 4
        System.out.println(checkSum(5, 3));
        System.out.println(checkSum(10, 5));
        System.out.println(checkSum(10, 15));

        // tests for task 5
        checkPositiveOrNegative(10);
        checkPositiveOrNegative(-5);

        // tests for task 5
        System.out.println(heckNegative(-1));
        System.out.println(heckNegative(5));

        // call for task 7
        welcomeName("World");

        // tests for task 8
        checkLeapYear(1900); // div 4 but div 100
        checkLeapYear(1996); // div 4 and not div 100
        checkLeapYear(2000); // div 400
        checkLeapYear(2016); // div 4 and not div 100
    }

    /**
     * 2.     
     *    byte, short, int, long, float, double, char, boolean, string
     */
    static void createVariable() {
        byte    b = Byte.MAX_VALUE;    // 2^7 - 1
        short   s = Short.MAX_VALUE;   // 2^15 - 1
        int     i = Integer.MAX_VALUE; // 2^31 - 1
        long    l = Long.MAX_VALUE;    // 2^63 - 1
        float   f = 123.45F;
        double  d = 567.89;
        char    c = 'a';
        boolean bool = true;
        String str = "Hello";
    }

    /**
     * 3.     a * (b + (c / d))  
     *    ,  a, b, c, d     
     */
    static double calculate(double a, double b, double c, double d) {
        return a * (b + c / d);
    }

    /**
     * 4.  ,     ,    
     *         10  20 (),    
     *    true,     false
     */
    static boolean checkSum(int a, int b) {
        return ((a + b >= 10) && (a + b