Ndtyjky

I am new to java and I have to create a simple java programm that creates a christmas tree in this form:

10|       *       |15=7+1+7

 9|      ***      |15=6+3+6

 8|     *****     |15=5+5+5

 7|    *******    |15=4+7+4

 6|   *********   |15=3+9+3

 5|  ***********  |15=2+11+2

 4| ************* |15=1+13+1

 3|***************|15=0+15+0

 2|      ***      |15=6+3+6

 1|      ***      |15=6+3+6

The height (all natural positive numbers) and the material ("*" in this case is given by the user input).
This is what I already have, but I dont know how to get the "|15=7+1+7" at the end of each line and the Tree trunk in the bottom of the tree.

Here is my actual code, and what it creates:

public class Christmas{

    public static void main(String args) {



        int height = Integer.parseInt(args[0]);

        String letters = (args[1]);

        char firstLetter = letters.charAt(0);



        //System.out.println(height+"   "+firstLetter);     



        for (int i = 0; i < height; i++) {

         // System.out.print((args.length)+"");

         int row_number = height-i;

         System.out.printf("%2d",row_number);

         System.out.print("|");



            for (int j = 1; j < height - i; j++){

            System.out.print(" ");  

            }   

                for (int k = 0; k < (2 * i + 1); k++){

                System.out.print(firstLetter+"");

                }



         System.out.println();



        }

    }

}

output:

C:UsersnameDesktopJavaFolder>javac Christmas.java && java Christmas 10 *OMEGALUL

10|         *

 9|        ***

 8|       *****

 7|      *******

 6|     *********

 5|    ***********

 4|   *************

 3|  ***************

 2| *****************

 1|*******************

How can I add the Tree trunk which is always 3 letters long and 1/4 of each tree big.(rounded) and the |15=7+1+7 at the end of each lines which contains:
The width of the tree as the sum of the spaces left + the width of the tree in the respective row + spaces on the right (left-aligned).

Here is a different approach, which calculates the number of spaces and the number of fill characters needed on a line, then uses printf to print the lines.

public static void printChristmasTree(int height, char ch) {

    if (height <= 4)

        throw new IllegalArgumentException("Height must be 5 or higher");

    for (int row = height; row > 0; row--) {

        int spaces = (row > 2 ? row - 3 : height - 4);

        int fill = (height - spaces) * 2 - 5;

        System.out.printf("%2d|%s%s%s|%d=%d+%d+%d%n", row,

                          repeat(spaces, ' '), repeat(fill, ch), repeat(spaces, ' '),

                          spaces * 2 + fill, spaces, fill, spaces);

    }

}

private static String repeat(int count, char ch) {

    char buf = new char[count];

    java.util.Arrays.fill(buf, ch);

    return new String(buf);

}

Test

printChristmasTree(10, '*');

printChristmasTree(6, '#');

Output

10|       *       |15=7+1+7

 9|      ***      |15=6+3+6

 8|     *****     |15=5+5+5

 7|    *******    |15=4+7+4

 6|   *********   |15=3+9+3

 5|  ***********  |15=2+11+2

 4| ************* |15=1+13+1

 3|***************|15=0+15+0

 2|      ***      |15=6+3+6

 1|      ***      |15=6+3+6

 6|   #   |7=3+1+3

 5|  ###  |7=2+3+2

 4| ##### |7=1+5+1

 3|#######|7=0+7+0

 2|  ###  |7=2+3+2

 1|  ###  |7=2+3+2

UPDATE

Here is logic for trunk height of height/4 (rounded), instead of the fixed height of 2 used by the code above. Trunk width is still fixed at 3.

public static void printChristmasTree(int height, char ch) {

    final int trunkHeight = (height + 2) / 4; // rounded

    final int treeWidth = (height - trunkHeight) * 2 - 1;

    final int width = (treeWidth > 3 || trunkHeight == 0 ? treeWidth : 3);

    for (int row = height; row > 0; row--) {

        int fill = (row > trunkHeight ? (height - row) * 2 + 1 : 3);

        int spaces = (width - fill) / 2;

        System.out.printf("%2d|%s%s%s|%d=%d+%d+%d%n", row,

                          repeat(spaces, ' '), repeat(fill, ch), repeat(spaces, ' '),

                          spaces * 2 + fill, spaces, fill, spaces);

    }

}

Test

printChristmasTree(5, '*');

printChristmasTree(4, '*');

printChristmasTree(3, '*');

printChristmasTree(2, '*');

printChristmasTree(1, '*');

Output

 5|   *   |7=3+1+3

 4|  ***  |7=2+3+2

 3| ***** |7=1+5+1

 2|*******|7=0+7+0

 1|  ***  |7=2+3+2

 4|  *  |5=2+1+2

 3| *** |5=1+3+1

 2|*****|5=0+5+0

 1| *** |5=1+3+1

 3| * |3=1+1+1

 2|***|3=0+3+0

 1|***|3=0+3+0

 2| * |3=1+1+1

 1|***|3=0+3+0

 1|*|1=0+1+0