Not an official ACM page
[1997 ACM Finals problem set
| My ACM problem archive
| my home page]
The Twenty-first Annual ACM International Collegiate
Programming Contest Visual Challenge
"15 Puzzle" is the official name of a puzzle consisting of a
rectangular grid of 16 tiles with one blank tile and the remaining 15
tiles labeled with the letters 'A' through 'O'. Solving the puzzle
means rearranging the tiles in order of their labels, with the blank
tile in either the upper left or lower right corner of the grid. The
only legal puzzle moves consist of exchanging the blank tile and any
of its adjacent tiles (tiles that share a side with the blank
tile). The picture below illustrates a simple 15 Puzzle that has been
Your Visual Challenge is to create a 15 Puzzle in a graphical user
interface. When the user clicks on a tile adjacent to the blank tile,
that tile and the blank tile must exchange places. Initially the
puzzle should be displayed in a solved state. In other words, the
labels of the tiles must be in alphabetical order, with the blank tile
in the upper left or lower right corner.
The judging of the visual challenge will be very subjective. Judges
will be looking for the most interesting
displays that solve the problem. Concentrate
on the visual aspects of the solution. Applets that satisfy any of the
following criteria are "acceptable," but the more of the criteria that
are satisfied, the more favorably your work will be judged.
Your solution to this problem must be written as a Java applet named
J. Do not create a standalone application.
The code for your entire solution must be a single file named
J.jav. Any additional files for your solution that are created by the
AppletWizard, Resource Editor, or ResourceWizard must be incorporated
into J.jav. (You may have to rename your source file before you
submit it.) For judging, your applet will be imbedded in the
following HTML code:
- Rectangular grid of 16 tiles.
- Criterion a, plus all tiles are labeled with appropriate letters
except the blank tile.
- Criterion b, plus clicking on a tile adjacent to the blank
exchanges the blank and the clicked tile.
- Criterion c, plus any more graphical elements that might be
desired such as colors for the tiles, a quit button, or the like. Let
your imagination guide you.
- Criterion d, plus additional puzzle functionality such as a
<applet code=J width=400 height=400> </applet>
This page maintained by
Last updated November 6, 1997