Brian Damgaard pointed out it is impossible YASS 2.136 could solve Screen.77 in the Thinking Rabbit collection “Original Extra”. Who would know better than Brian…
And claims the puzzle has been changed in some collections during time so the test I made for Solvers and Optimizers was done with a false screen.77.
He is right.
But which puzzle is the ORIGINAL Screen.77 ?
The extended levelset was created for XSokoban and used as the standard test set for the Rolling Stone solver. You will still find the levelset at XSokobans website in the unix download file for the program. Check it out if you don’t believe me. You can open the file with an unzip program and will find screen.77 looks like this:
I checked my “Original Extra” copy. Here Screen.77 looks like this:
Looking for duplicates I found the above puzzle had replaced the ORIGINAL Screen.77 in the collection “Scott Lindhurst-MacSokoban”.
In the introduction to his collection Scott Lindhurst wrote: “Several years ago, someone wrote versions of Sokoban for MS-DOS and Unix machines. The version I first played only had levels 1-50. Then Joseph L. Traub collected another 35 levels and included them with XSokoban, his version for XWindows. These levels, along with a few more from the current XSokoban distribution, form my “Extra” collection.”
For unknown reasons making this collection Scott Lindhurst probably replaced the puzzle. But the puzzle wasn’t removed from Scotts collection. Just moved. You will find it where you would expect to find Original Extra Screen.53. So how about Original Extra Screen.53? It is not in Scotts collection.
The “feel” of this puzzle certainly is like some of the other puzzles in the extra part of “Original plus Extra” so it probably is a real original that should/could be included in the collection.
You will find the MacSokoban version of the “Original plus Extra” levelset at LetsLogic.com, SokobanOnline.com, Sokoban-Game.com, Sokoban.info…
And the ORIGINAL version of the “Original plus Extra” levelset at The XSokoban website, The Sokoban website at Alberta University and at Sokobano.de.
You seldom come to the last mentioned sites for downloads and neither of these provide an easy download.
So chances are you never played the ORIGINAL Screen.77
It turns out the truth isn’t exactly as described here. Truth is the levelset for XSokoban were changed. In XSokoban 3.0 you get the easy level (second illustration above). And in XSokoban 3.3.c the level were substituted with a much more interesting level (first illustration above).
Read the discussion at Sokoban@groups.io
You can download the “Original Plus Extra” collection with comments and all variants from Sokoban.dk’s level download page