Bug 198016 - Simple Simon reports "Nope, can't be won" when it can
Summary: Simple Simon reports "Nope, can't be won" when it can
Status: ASSIGNED
Alias: None
Product: kpat
Classification: Applications
Component: solver (other bugs)
Version First Reported In: unspecified
Platform: Ubuntu Unspecified
: NOR normal
Target Milestone: ---
Assignee: Shlomi Fish
URL:
Keywords:
: 308175 (view as bug list)
Depends on:
Blocks:
 
Reported: 2009-06-27 01:48 UTC by Graham Menhennitt
Modified: 2025-08-23 11:23 UTC (History)
6 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


Attachments
not winnable (252.24 KB, image/png)
2009-06-27 01:49 UTC, Graham Menhennitt
Details
not winnable (251.56 KB, image/png)
2009-06-27 01:49 UTC, Graham Menhennitt
Details
saved game (2.94 KB, application/octet-stream)
2009-06-27 23:59 UTC, Graham Menhennitt
Details
Example from 20.04.3 (19.90 KB, application/vnd.kde.kpatience.savedgame)
2020-12-22 05:13 UTC, David Gasaway
Details
Example from kpatience 23.08.0 simple simon (22.82 KB, application/xml)
2025-08-23 11:23 UTC, Hatto Von Hatzfeld
Details

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Description Graham Menhennitt 2009-06-27 01:48:04 UTC
Version:           4.2.2 (using KDE 4.2.4)
Installed from:    Ubuntu Packages

The attached two images show two positions in a Simple Simon game. The solver reports one as "yes, can win" and the other as "no, can't win" when you can easily move backwards and forwards between them by moving the 6,7,8 of spades.
Comment 1 Graham Menhennitt 2009-06-27 01:49:13 UTC
Created attachment 34853 [details]
not winnable
Comment 2 Graham Menhennitt 2009-06-27 01:49:43 UTC
Created attachment 34854 [details]
not winnable
Comment 3 Parker Coates 2009-06-27 11:26:57 UTC
Thanks for the report, but if you're able to reproduce the issue, could you please attach saved games instead of screen shots. This makes it much easier for developers to recreate the scenario.
Comment 4 Graham Menhennitt 2009-06-27 23:59:12 UTC
Created attachment 34872 [details]
saved game
Comment 5 Graham Menhennitt 2009-06-28 08:12:58 UTC
My guess is that this bug occurs when it's necessary to break up a sequence (in this case, the 6 - K of Spades) in order to solve it. The solver doesn't consider this possibility. I just had the bug occur again where this was necessary. As soon as you manually break the sequence (move the 6,7,8 over), it can find the solution.
Comment 6 Stephan Kulow 2009-07-30 13:16:45 UTC
you will have to help me here - I'm unable to solve that savegame. Please describe some more moves - preferably till the solver catches up again.
Comment 7 Graham Menhennitt 2009-07-31 09:27:16 UTC
8s -> 9h
5d -> 6s
7c -> empty
7d -> 8d
9d -> empty
9c -> 10c
10c -> empty
10s -> js
10c -> jd
qs -> empty
7h -> 8h
8h -> empty
6c -> 7c
9d -> 10d
10d -> empty
6d -> 7d
6d -> 6d
8s -> 9s
4s -> empty
5c -> 6c
4c -> 5c
jc -> qc

I'll let you figure it out from there :)
Comment 8 Stephan Kulow 2009-07-31 10:13:28 UTC
ok, solver knows how to win after 4th move. So I just need him to find these 4 moves :)
Comment 9 Stephan Kulow 2009-07-31 10:23:07 UTC
hmm, letting the solver take all possible moves into account is easy, but I wonder how this case is different from all the other sequences not to be uselessly split ;(
Comment 10 Parker Coates 2012-11-09 13:57:11 UTC
*** Bug 308175 has been marked as a duplicate of this bug. ***
Comment 11 David Gasaway 2020-12-22 05:13:26 UTC
Created attachment 134259 [details]
Example from 20.04.3

Figured I'd add an example from a more recent version (20.04.3) that I played through to solved before creating the save.  The "unsolvable" condition occurs at move 25.
Comment 12 Stephan Kulow 2023-01-18 18:17:05 UTC
Between 2009 and 2020 the simple simon solver was replaced and so the old bug is no longer relevant. For the latest comment, this is a fc-solve bug:

coolo@Kellerfenster:~/kpat> cat t
4S 7C 7D KH QD JS
AC 4H JD QS 8S 4C 3S 2D AD
5S QH 4D 6D 2S TS 3C 2C AS
TD TC 3H 2H
5C 3D 8C 9C JH TH 9S 8D 7S 6S
AH KC QC JC
KD KS 6C 5D
9H 8H 7H 6H 5H

9D
coolo@Kellerfenster:~/kpat> fc-solve -g simple_simon t
I could not solve this game.
Total number of states checked is 3.
This scan generated 3 states.

It doesnt' see that moving the "3H 2H" to the empty stack will make it winnable again.
Comment 13 Hatto Von Hatzfeld 2025-08-23 11:23:47 UTC
Created attachment 184377 [details]
Example from kpatience 23.08.0 simple simon

Resolvable game  - solver told from beginning that it is unresolvable resp. lost.