Maze generator

[Michael_Keller]

Today, no business topic but it's play time 🙂 A couple of days ago, I stumbled upon the free book "10 PRINT CHR$(205.5+RND(1)); : GOTO 10". No joke, that's the title of the book. It's about an one-line Commodore 64 BASIC program that prints a maze to the screen. Because I'm a big fan of Retrocomputing, I browsed the book a little bit.

Afterwards I asked myself what ABAP report I could write in one line of 40 characters with a nice output. The answer was sobering: Nothing interesting. Even with 80 characters I just printed vertical lines to the screen 🙂 Here is my approach.

REPORT z.DO 10 TIMES.DO 80 TIMES.WRITE AT sy-index(1) '|'.ENDDO.NEW-LINE.ENDDO.

Finally I decided to give up the length restriction and wrote my own random maze generator as a homage to the original BASIC program. It uses the WRITE instruction and the characters "-" and "|" to build frames. You will find it on GitHub, too.

REPORT z_random_maze.



DATA: lr_random_int TYPE REF TO cl_abap_random_int,

      lv_random_int TYPE i,

      lv_position_x TYPE i,

      lv_position_y TYPE i,

      lv_maze_part  TYPE char2.



lr_random_int = cl_abap_random_int=>create( seed = CONV i( sy-uzeit ) min = 1 max = 9 ).



DO 20 TIMES.

  lv_position_y = sy-index.

  lv_position_x = 1.

  DO 30 TIMES.

    CLEAR lv_maze_part.

    IF lv_position_y = 20.

      lv_maze_part = '--'.

    ELSE.

      lv_random_int = lr_random_int->get_next( ).

      IF lv_random_int < 5.

        lv_maze_part = '|'.

      ELSEIF lv_random_int > 7.

        lv_maze_part = '--'.

      ENDIF.

    ENDIF.

    WRITE AT lv_position_x(2) lv_maze_part.

    lv_position_x = lv_position_x + 2.

  ENDDO.

  NEW-LINE.

ENDDO.

Relax your eyes, try to find your way through the maze and have fun 🙂 Here is a little example of the report output. And if you have a good idea for an interesting one-liner in ABAP, let me know.