Has anyone ever tried/solved the AI Escargot?

Post puzzles for others to solve here.

Has anyone ever tried/solved the AI Escargot?

Postby JeJ » Thu Feb 10, 2011 9:55 pm

This is not a request for help, it is just that I thought this was the forum to place this message.

For those not in the know "Finnish mathematician, Arto Inkala has made what he claims is the hardest sudoku puzzle ever. According to the Finnish puzzle maker "I called the puzzle AI Escargot, because it looks like a snail. Solving it is like an intellectual culinary pleasure. AI are my initials".

If you're open for the challenge, AI Escargot presumably requires you to wrap your brain around eight casual relationships simultaneously, whereas your everyday "very hard" sudoku piece, only require you to think about a meager one or two of these relationships at once".

So has anyone ever tried it or even better solved it? I tried it but could do absolutely anything with it.

In case anyone is interested here's de puzzle:
Code: Select all
1 . .|. . 7|. 9 .
. 3 .|. 2 .| . . 8
. . 9|6 . .|5 . .
------------------
. . 5|3 . .|9 . .
. 1 .|. 8 .|. . 2
6 . .|. . 4|. . .
------------------
3 . .|. . .|. 1 .
. 4 1|. . .|. . 7
. . 7|. . .|3 . .
JeJ
 
Posts: 76
Joined: 06 January 2011

Re: Has anyone ever tried/solved the AI Escargot?

Postby StrmCkr » Fri Feb 11, 2011 9:14 am

yes, this puzzle has actually been solved manually several times on the old players forum before the crash, which threads and where i cannot say for sure..

this puzzle is difficult but it is far from the most difficult puzzles known to date even at the time of the original publication of the puzzle it was not in fact the hardest puzzle more a "self proclaimed" most difficult puzzle.

we have a hardest puzzles thread that lists the most difficult puzzles known to date.
Some do, some teach, the rest look it up.
User avatar
StrmCkr
 
Posts: 624
Joined: 05 September 2006

Re: Has anyone ever tried/solved the AI Escargot?

Postby RW » Fri Feb 11, 2011 9:41 am

StrmCkr wrote:even at the time of the original publication of the puzzle it was not in fact the hardest puzzle more a "self proclaimed" most difficult puzzle.

Actually, it was the first puzzle to beat Sudoku Explainer v1.1 and was the hardest puzzle to date back then. But within a few days from the publication of this puzzle ocean and other forum members found a lot of puzzles that were harder. When this happened ArtoI, who was an active forum member at that time, disappeared from the forum, removed all links to this forum from his homepage and continued calling the Escargot the "hardest sudoku puzzle ever"... And as Strmckr said, by now it is far from hardest. I think it's not even remotely hard enough to fit in the current database of hardest puzzles.

RW
RW
2010 Supporter
 
Posts: 1000
Joined: 16 March 2006

Postby Pat » Fri Feb 11, 2011 10:18 am

JeJ wrote:---here's de puzzle:
///

the puzzle was posted on the forum
by ArtoI (2006.Nov.3)

did you re-type it ?
as your version differs
User avatar
Pat
 
Posts: 3423
Joined: 18 July 2005

Re: Has anyone ever tried/solved the AI Escargot?

Postby daj95376 » Fri Feb 11, 2011 5:40 pm

I would also like to know where JeJ found his copy of the puzzle. I was recently in a discussion with RonK about two puzzles for Escargot differning by one clue!!!
daj95376
2014 Supporter
 
Posts: 2624
Joined: 15 May 2006

Re: Has anyone ever tried/solved the AI Escargot?

Postby ronk » Fri Feb 11, 2011 7:31 pm

daj95376 wrote:I would also like to know where JeJ found his copy of the puzzle. I was recently in a discussion with RonK about two puzzles for Escargot differning by one clue!!!

As I recall, you claimed a so-called "Escargot" was not minimal, presumably because of the same hidden single r8c3=1 that JeJ included. Where did you get your copy?
ronk
2012 Supporter
 
Posts: 4764
Joined: 02 November 2005
Location: Southeastern USA

Re: Has anyone ever tried/solved the AI Escargot?

Postby JeJ » Fri Feb 11, 2011 7:40 pm

daj95376 wrote:I would also like to know where JeJ found his copy of the puzzle. I was recently in a discussion with RonK about two puzzles for Escargot differning by one clue!!!

I fopund it at http://www.sudokuwiki.org/sudoku.htm but looking at other web pages, the "1" at r8c1 is not part of the original puzzle.
JeJ
 
Posts: 76
Joined: 06 January 2011

Re: Has anyone ever tried/solved the AI Escargot?

Postby daj95376 » Sat Feb 12, 2011 2:57 pm

ronk wrote:
daj95376 wrote:I would also like to know where JeJ found his copy of the puzzle. I was recently in a discussion with RonK about two puzzles for Escargot differning by one clue!!!

As I recall, you claimed a so-called "Escargot" was not minimal, presumably because of the same hidden single r8c3=1 that JeJ included. Where did you get your copy?

It was a long time back and I didn't save the puzzle variants or their sources. However, I (mistakenly) thought the Escargot from Artol had the extra candidate, and that someone else had published a symmetric and minimal equivalent puzzle.
daj95376
2014 Supporter
 
Posts: 2624
Joined: 15 May 2006

Re: Has anyone ever tried/solved the AI Escargot?

Postby tarek » Sat Feb 12, 2011 5:58 pm

ArtoI & his snail definitely had a claim to fame when he published it albeit for a very limited time as RW pointed out. The silent majority with all of their work did not seek the limelight. That left ArtoI enjoying it all by himself without mentioning the developments that happened in the hardest sudokus shortly afterwards for a good reason probably :D .

tarek
User avatar
tarek
 
Posts: 2608
Joined: 05 January 2006

Re: Has anyone ever tried/solved the AI Escargot?

Postby StrmCkr » Wed Feb 16, 2011 10:15 pm

Actually, it was the first puzzle to beat Sudoku Explainer v1.1 and was the hardest puzzle to date back then.
thanks for clarifying my memory on events from years back.
I am still certain that this forum has A posted harder puzzles before the sail was officially published and claimed the "hardest", but its probably an obfuscation of dates on my part.

ArtoI & his snail definitely had a claim to fame when he published it albeit for a very limited time as RW pointed out.

i'm sure if some one really wanted to clout that fame it would not take much, however I'm think that none of us really care to much on that end as its an issue that no one has never bothered to be solved for a number of years and it will probably remain that way.
Last edited by StrmCkr on Thu Oct 05, 2017 1:36 pm, edited 1 time in total.
Some do, some teach, the rest look it up.
User avatar
StrmCkr
 
Posts: 624
Joined: 05 September 2006

Re: Has anyone ever tried/solved the AI Escargot?

Postby denis_berthier » Thu Feb 17, 2011 9:30 am

I fell on this thread by chance and I felt interested by the example.

AI's collection of "hardest puzzles yet":
Searching the web, I found that AI has published (here: http://www.aisudoku.com/en/AIsudoku_Top10s1_en.pdf) a series of 10 puzzles (including his escargot). As he says they are copyrighted, I don't write them explicitly here and I'll refer to them by the number and name he gives them (his pdf is still online). Copyrighting a puzzle seems a little absurd to me, but maybe he only meant that he didn't want his puzzles to be re-published without his name, which I could understand more easily.
More recently, he has published a new puzzle in the Sun: http://www.thesun.co.uk/sol/homepage/news/3102272/Maths-whiz-Dr-Arto-Inkala-creates-hardest-Sudoku-yet.html, in a dithyrambic article. As he didn't give it any name, I'll call it here #11 and AI Sun-2010-08-19.
He claims #11 is harder, which is true according to SER, but not according to nrczt-braids theory (see below).

Everywhere here, braid means nrczt-braid.

Obviously, considering their SER, none of these 11 puzzles is close to the hardest known as of today, and the last one (and #11, SER 10.6, is published much after SER 11.6 were known).

This doesn't imply that they are not interesting.
Below, I put the number assigned to them in the original pdf, their name, their SER and the simplest type of extended braid they can be solved with (for ease of reading, I re-order them according to their braids classification).
Remember that extended braids are a way of using classical patterns as right linking objects instead of only candidates as in ordinary braids. For precise definitions, see the "abominable T&E and lovely braids" thread http://forum.enjoysudoku.com/abominable-trial-and-error-and-lovely-braids-t6390.html - unfortunately half of it has been lost in the 2008 disk crash, but the definitions are still there and for the rest you can find a summary on my web pages.
Extended braids are a way of including patterns in braids according to the general zt-ing principle. They subsume both braids and AICs. Remember also my T&E(FP, 1) vs braids(FP) theorem: a candidate zzz can be eliminated by the T&E(FP, 1) procedure if and only if it there is a full braid(FP) with target zzz (where FP is any family of patterns).

Notations:
NS+HS = Naked+Hidden Singles
BI = Basic Interactions (row/block and column/block) - equivalent to whip[1]
Subsets2 = Naked+Hidden+SuperHidden Pairs (SuperHidden=Fish)
Subsets3 = Subsets2+Naked+Hidden+SuperHidden Triplets
Subsets4 = Subsets3+Naked+Hidden+SuperHidden Quads
Subsets= Subsets4

Finned2 = Finned X-Wing
Finned3 = Finned2+Finned Swordfish
Finned4 = Finned3+Finned Jellyfish
Finned=Finned4


Results:

#7 AI squadron, SER = 9.4, Braids(NS+HS) i.e. ordinary braids
#4 AI worm hole, SER = 9.5, Braids(NS+HS) i.e. ordinary braids

#10 AI broken brick, SER = 9.6, Braids(NS+HS+BI), i.e. grouped braids
#2 AI killer application, SER = 9.8, Braids(NS+HS+BI), i.e. grouped braids
#9 AI tweezers, SER = 9.8, Braids(NS+HS+BI), i.e. grouped braids
#8 AI honeypot, SER = 9.9, Braids(NS+HS+BI), i.e. grouped braids
#5 AI labyrinth, SER = 10.0, Braids(NS+HS+BI), i.e. grouped braids

#3 AI lucky diamond, SER = 10.4, Braids(NS+HS+BI+Subsets2+Finned2)
#1 AI escargot, SER = 10.5, Braids(NS+HS+BI+Subsets2+Finned2)
#11 AI Sun-2010-08-19, SER = 10.6, Braids(NS+HS+BI+Subsets2+Finned2)

#6 AI circles, SER = 10.5, Braids(NS+HS+BI+Subsets3+Finned2)


Conclusion: the whole family forms a nice set of increasingly hard puzzles, but the types of braids needed to solve them rely on patterns no more complex than Triplets and finned X-wing. I was disappointed to find no case with quads or even finned Swordfish.

Compared to these hand built puzzles, eleven's automatised method (http://forum.enjoysudoku.com/the-making-of-a-gotchi-a-simple-way-to-find-extreme-sudokus-t30150.html) allows to create lots of much harder ones, that can be solved by no braid(NS+HS+BI+Subsets+Finned). Why doesn't he get an article in the Sun?
denis_berthier
2010 Supporter
 
Posts: 1253
Joined: 19 June 2007
Location: Paris

Re: Has anyone ever tried/solved the AI Escargot?

Postby denis_berthier » Thu Feb 17, 2011 1:33 pm

Regarding the original topic of this thread, AI escargot, it needs braids(NS+HS+BI+Subsets2+Finned2), as mentioned in my previous post.
But it has a few easy first eliminations:

***** SudoRules version 15.1.8-W *****
1....7.9..3..2...8..96..5....53..9...1..8...26....4...3......1..4......7..7...3..
23 values and 223 candidates initialised
hidden-single-in-a-column ==> r8c3 = 1
whip[3] b2n9{r2c4 r2c6} - r5n9{c6 c1} - r8n9{c1 .} ==> r7c4 <> 9
whip[3] c5n9{r7 r6} - c2n9{r6 r9} - b9n9{r9c9 .} ==> r7c6 <> 9
whip[3] r8n9{c6 c1} - c2n9{r7 r6} - c5n9{r6 .} ==> r9c4 <> 9
whip[3] c5n9{r9 r6} - c2n9{r6 r7} - r8n9{c1 .} ==> r9c6 <> 9
After this, there's no ordinary whip or braid
denis_berthier
2010 Supporter
 
Posts: 1253
Joined: 19 June 2007
Location: Paris

Postby Pat » Thu Feb 17, 2011 1:57 pm

RW wrote:
StrmCkr wrote:even at the time of the original publication of the puzzle it was not in fact the hardest puzzle more a "self proclaimed" most difficult puzzle.

Actually, it was the first puzzle to beat Sudoku Explainer v1.1
and was the hardest puzzle to date back then---


i remember JPF trying to rate the full list of 17-clue puzzles,
one puzzle could not be rated by Sudoku Explainer

when was this?
sorry i don't have it bookmarked

    EDIT: okay, found it --
      JPF (2007.Sep) wrote:

        8..2.....1.....5.......63...6...3.......1..8....4...2..3..5.1.....8............7.
    -- i.e. much later than 2006.Nov.3
User avatar
Pat
 
Posts: 3423
Joined: 18 July 2005

Re: Has anyone ever tried/solved the AI Escargot?

Postby twasack » Mon Apr 30, 2012 1:20 pm

quite sure Chewdoku can show you how to solve escargot. it gives the methods required to solve it and shows them on screen. twasack.tripod.com
twasack
 
Posts: 4
Joined: 23 June 2011

Re: Has anyone ever tried/solved the AI Escargot?

Postby denis_berthier » Wed May 02, 2012 7:17 am

denis_berthier wrote:Results:
#7 AI squadron, SER = 9.4, Braids(NS+HS) i.e. ordinary braids
#4 AI worm hole, SER = 9.5, Braids(NS+HS) i.e. ordinary braids

#10 AI broken brick, SER = 9.6, Braids(NS+HS+BI), i.e. grouped braids
#2 AI killer application, SER = 9.8, Braids(NS+HS+BI), i.e. grouped braids
#9 AI tweezers, SER = 9.8, Braids(NS+HS+BI), i.e. grouped braids
#8 AI honeypot, SER = 9.9, Braids(NS+HS+BI), i.e. grouped braids
#5 AI labyrinth, SER = 10.0, Braids(NS+HS+BI), i.e. grouped braids

#3 AI lucky diamond, SER = 10.4, Braids(NS+HS+BI+Subsets2+Finned2)
#1 AI escargot, SER = 10.5, Braids(NS+HS+BI+Subsets2+Finned2)
#11 AI Sun-2010-08-19, SER = 10.6, Braids(NS+HS+BI+Subsets2+Finned2)

#6 AI circles, SER = 10.5, Braids(NS+HS+BI+Subsets3+Finned2)


The above classification was based on Sp-braids, i.e. on braids having inner Subsets.
Considering now the B?B classification, based on Bp-braids, i.e. on braids having inner braids, only the last four results can be changed. With my simpler terminology, this now gives much simpler results:

Results:
#7 AI squadron, SER = 9.4, in B, i.e. solvable by ordinary braids
#4 AI worm hole, SER = 9.5, in B, i.e. solvable by ordinary braids

#10 AI broken brick, SER = 9.6, in gB, i.e. solvable by ordinary g-braids
#2 AI killer application, SER = 9.8, in gB, i.e. solvable by ordinary g-braids
#9 AI tweezers, SER = 9.8, in gB, i.e. solvable by ordinary g-braids
#8 AI honeypot, SER = 9.9, in gB, i.e. solvable by ordinary g-braids
#5 AI labyrinth, SER = 10.0, in gB, i.e. solvable by ordinary g-braids

#3 AI lucky diamond, SER = 10.4, in B2B, i.e. solvable by B2-braids
#1 AI escargot, SER = 10.5, B2B, in B2B, i.e. solvable by B2-braids
#11 AI Sun-2010-08-19, SER = 10.6, in B2B, i.e. solvable by B2-braids
#6 AI circles, SER = 10.5, in B2B, i.e. solvable by B2-braids

Now, even the last one requires no inner pattern of size >2.
denis_berthier
2010 Supporter
 
Posts: 1253
Joined: 19 June 2007
Location: Paris

Next

Return to Puzzles