Logic Masters Deutschland e.V.

Unendliches Rundwegrätsel

(Published on 29. January 2012, 14:51 by immi)

The problem with most puzzles is that after some time, they are completely solved. Here is a puzzle that doesn't have this problem: an infinite slitherlink.

pdf-Version with higher resolution

The rules are the usual ones: Draw a closed path along the edges. The path may not touch or cross itself. Each number specifies how many of the edges surrounding that cell are used by the path. In total, the path uses infinitely many edges (otherwise, it could not touch all the cells with numbers), so it is not so clear what one means by it being "closed". However, on the example, one sees that if only looks at the path itself, it indeed does look closed.

The letters are unimportant for the puzzle. (They are there only needed for the solution code.)


A puzzle...

... and its solution,...

... which, considered by itself, indeed looks closed.

Remark: The middle of the puzzle might be difficult to recognize if your printer/screen doesn't have infinite resolution. Luckily, the puzzle is just a series of concentric rings all of which look the same, so it suffices to recognize the outer ring. Nevertheless, here is an enlarged version of the middle part:

Solution code: First determine how many "important" rings there are. All those rings where the solution is not yet periodic are important, and the first instance of the periodic part is also important. All the repetitions of that are not important anymore. (In the example, the solution becomes periodic from the second ring on; the second and third ring are the first instance of the periodic part, so the outer three rings are the important ones. Other example: If the solution would consist of rings A, B, B, A, B, A, B, A, ... then the first four rings would be important.)

The solution code consists of a sequence of numbers which specify, for all the cells with letters in the important rings, how many edges around the cell are part of the path: First, put in the numbers corresponding to all the cells with an A, starting from the outer ring and going inwards; then the cells with a B, etc. (So in total, there are 8 times as many numbers as there are important rings.)

In the example, the solution code would be "221 101" (the space is optional).

Last changed on on 2. July 2026, 17:24

Solved by CHalb, rob, lupo, Luigi, Alex, jirk, matter, zorant, relzzup, Quetzal, pirx, jessica6
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Comments

on 2. July 2026, 17:24 by immi
Fixed yet another typo

on 2. July 2026, 17:22 by immi
Fixed typo

on 2. July 2026, 17:20 by immi
Englische Beschreibung hinzugefügt

on 24. March 2012, 16:06 by jirk
Tolles Rätsel, mein persönlicher Favorit im ganzen Rätselportal!

Last changed on 18. February 2012, 13:43

on 17. February 2012, 20:39 by Alex
Super, und noch dicke unter der 3 Wochengrenze geschafft :D
Mal sehen wie lange ich nun davon traeumen werde...
Ich vergass zu fragen: wie konstruiert man so ein Monster ueberhaupt?

on 14. February 2012, 11:37 by immi
Link zu einer hochauflösenden pdf-Version hinzugefügt

on 6. February 2012, 22:23 by lupo
Also was soll ich sagen: nicht nur unendlich, auch unbeschreiblich! Und ja, nachdem man am Anfang so gut wie gar keinen Ansatzpunkt sieht, ist alles ohne T&E (wohl aber mit einigen Trugschlüssen und Widersprüchen) lösbar - zumindest wenn man achtzügige Varianten im Schach im Kopf durchrechnen kann ;-)
Genial konstruiert!

on 6. February 2012, 12:59 by CHalb
ibag, es ist ja auch erst gut eine Woche rum ;-).

on 6. February 2012, 12:52 by ibag
Boah, Glueckwunsch, lupo! Mich hat beinahe schon wieder der Mut verlassen ...

on 30. January 2012, 15:43 by Statistica
"Das Problem mit den meisten Rätseln ist, dass sie irgend wann fertig gelöst sind.". Also DAMIT hatte ich noch nie ein Problem. Aber ein 'unendliches Rätsel' ist ja auch mal was...

on 29. January 2012, 19:05 by ibag
Ja, das passt. 3 Wochen hatte ich dafür auch so ungefähr eingeplant. ;-))

Last changed on 29. January 2012, 19:07

on 29. January 2012, 19:02 by CHalb
(Entrüstet:) Aber ibag! Wie kommst du darauf? Ich wollte gerade schreiben: Nicht, dass jemand denkt, ich hab dieses irre Rätsel in 5 Stunden gelöst. Tatsächlich habe ich dafür seit Beginn des Jahres über 3 Wochen gebraucht (inkl. Fehlversuchen) und jetzt musste ich endlich ausprobieren, ob der Lösungscode tatsächlich zu meiner Lösung und deren Verständnis passt.

Last changed on 29. January 2012, 18:58

on 29. January 2012, 18:57 by ibag
@CHalb: Du schummelst ja! ;-)

on 29. January 2012, 14:59 by hopppe
"In der Mitte ist das Rätsel möglicherweise schlecht zu erkennen, wenn der Drucker/Bildschirm, den man benutzt, keine unendliche Auflösung hat."
:-)

Difficulty:5
Rating:N/A
Solved:12 times
Observed:20 times
ID:0001A8

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