/*
 * Authro: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
 * Date: 2022-03-02
 * Description: A table of multiplication table of 1 to 9.
 *     Using nested for loop to print the table.
 * Assignemnt: #2 Question2
 * Output:

* |   1   2   3   4   5   6   7   8   9
---------------------------------------
1 |   1   2   3   4   5   6   7   8   9
2 |   2   4   6   8  10  12  14  16  18
3 |   3   6   9  12  15  18  21  24  27
4 |   4   8  12  16  20  24  28  32  36
5 |   5  10  15  20  25  30  35  40  45
6 |   6  12  18  24  30  36  42  48  54
7 |   7  14  21  28  35  42  49  56  63
8 |   8  16  24  32  40  48  56  64  72
9 |   9  18  27  36  45  54  63  72  81

 */

public class TimeTable {
    public static void printHeader() {
        System.out.println("* |   1   2   3   4   5   6   7   8   9");
        System.out.println("---------------------------------------");
    }
    public static void printLineBegin(int i) {
        System.out.print(i + " |");
    }
    public static int spaceBefore(int i) {
        // format the number to be printed
        String s = Integer.toString(i);
        // calculate the number of spaces before the number
        int len = s.length();
        // return the number of spaces
        int space = 4 - len;
        return space;
    }
    public static void main(String[] args) {
        // print the two lines header
        printHeader();

        // loop for main content
        for (int i = 1; i <= 9; i++) {

            printLineBegin(i);

            // loop for each number in the line
            for (int j = 1; j <= 9; j++) {
                int number = i * j;

                // print the space before the number
                for (int k = 0; k < spaceBefore(number); k++) {
                    System.out.print(" ");
                }

                // print the number
                System.out.print(number);
            }
            // print the end of the line
            System.out.println();
        }
    }
}