The hardest sudokus (new thread)

Everything about Sudoku that doesn't fit in one of the other sections

Re: The hardest sudokus (new thread)

Postby mith » Fri Jun 24, 2022 4:03 am

Running a check now for max-expands that are connected by sub-puzzles; here's the first such case:

Code: Select all
   862        864
    |         /\
    |        /  \
    73     904  83
    | \   / |  /
    |  \ /  | /
    \  929 177
     \  |  /
      \ | /
       228

...4.67.9..6....32.89.....5.9184......86.7.9167......4.649.8....1..74.....716....|32|862
...4.67....6....32.89.....5.9184......86.7.9167......4.649.8....1..74.....716....|31|73

...4.67.9..6....32.89.....5.9184..76..86.7.9167......4.6.9.8....1..74......16....|32|864
...4.67....6....32.89.....5.9184..76..86.7.9167......4.6.9.8....1..74......16....|31|83
...4.67.9..6....32.89.....5.9184..7...86.7.9167......4.6.9.8....1..74......16....|31|904
...4.67....6....32.89.....5.9184..7...86.7.9167......4.6.9.8....1..74......16....|30|177

...4.67.9..6....32.89.....5.9184......86.7.9167......4.6.9.8....1..74......16....|30|929
...4.67....6....32.89.....5.9184......86.7.9167......4.6.9.8....1..74......16....|29|228
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Re: The hardest sudokus (new thread)

Postby mith » Fri Jun 24, 2022 4:35 am

The largest case is four max-expands; there are four such families, here's the earliest:

Code: Select all
max-expands:
1.3...78..56789...78....5.....59.67..6..728...7.6.8.2...7...2.86.28.795....92..67|37|1229
1.3...78..56789...78....5.....59.67..6..728.5.7.6.8.2.......2..6.28.795....92..6.|35|203207
1.3....8..56789...78......6...59.67..6..728...7.6.8.2..........6.28.795....92..6.|32|10703
1.3....8..56789...78..........59.67..6..728...7.6.8.2.....6....6.28.795....92..6.|32|10706

min-expand:
1.3....8..56789...78..........59.67..6..728...7.6.8.2..........6.28.795....92..6.|31|16475
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Re: The hardest sudokus (new thread)

Postby hendrik_monard » Fri Jun 24, 2022 3:50 pm

mith wrote:hendrik, to make sure I don't miss anything would you mind compiling a single list of your 11.6+ puzzles since my March 21 post (the-hardest-sudokus-new-thread-t6539-1230.html#p318907)?



The last time I consulted this thread was about a week ago, so I saw your post only just now.
After March 21st I posted lists of 11.6+s on April 5th and May 15th.
I did not check them against the expanded minlex list you posted on March 21 assuming that your list was a different presentation of previously posted puzzles.

I am ready to put them all together in a single list but the question is how to transfer this long list? Do you have a website where I can upload them, or can I send them by PM to you?

P.S. After reading your more recent posts I want to ask if you still need the list you requested on June 20th?
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Re: The hardest sudokus (new thread)

Postby mith » Fri Jun 24, 2022 4:43 pm

hendrik, let's just do it this way: here's the list I put together: monh-202206

Can you check that I haven't missed any?
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Re: The hardest sudokus (new thread)

Postby mith » Sat Jun 25, 2022 12:21 am

This is not unexpected, but I ran a check anyway:

All known depth 3 puzzles have the properties that...

1. Exactly three digits appear at most once each. (Obviously at least two must appear. It's a pretty even split between ...110 and ...111 distributions, slightly more of the latter.)
2. Those digits (the ones that appear at all) appear in the same box.

This will make identifying TH patterns simple for the current set: they must occur in the four boxes not seeing that single box, and they much include all cells in those four boxes limited to the three digits with this property. This should allow for a quick script to get the count of guardian cells for all the min-expands. I'll work on that next (possibly two versions - one with the puzzle as is, one with the puzzle after basics, since hidden pairs in the TH boxes are fairly common from what I've seen).
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Re: The hardest sudokus (new thread)

Postby denis_berthier » Sat Jun 25, 2022 4:46 am

mith wrote:This will make identifying TH patterns simple for the current set: they must occur in the four boxes not seeing that single box, and they much include all cells in those four boxes limited to the three digits with this property. This should allow for a quick script to get the count of guardian cells for all the min-expands. I'll work on that next (possibly two versions - one with the puzzle as is, one with the puzzle after basics, since hidden pairs in the TH boxes are fairly common from what I've seen).

Not only Hidden Pairs but any Subset of size ≤ 3.
Moreover, in many cases, the pattern appears (or appears in simpler form, with much fewer additional candidates) only after applying many more rules than only Subsets.
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Re: The hardest sudokus (new thread)

Postby hendrik_monard » Sat Jun 25, 2022 7:10 am

mith wrote:hendrik, let's just do it this way: here's the list I put together: monh-202206

Can you check that I haven't missed any?

Hi mith,

One batch of 615 11.6s (my second post of April 5th) are not in the list you compiled. You can find them (a hidden list) here:
the-hardest-sudokus-new-thread-t6539-1230.html#p319648
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Re: The hardest sudokus (new thread)

Postby denis_berthier » Sat Jun 25, 2022 10:29 am

.
See my first analyses of the collection here: http://forum.enjoysudoku.com/the-tridagon-rule-t39859-60.html
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Re: The hardest sudokus (new thread)

Postby mith » Sat Jun 25, 2022 6:39 pm

hendrik_monard wrote:
mith wrote:hendrik, let's just do it this way: here's the list I put together: monh-202206

Can you check that I haven't missed any?

Hi mith,

One batch of 615 11.6s (my second post of April 5th) are not in the list you compiled. You can find them (a hidden list) here:
the-hardest-sudokus-new-thread-t6539-1230.html#p319648


Thanks hendrik, I will process these before I start my scripts back up, and include the resulting expanded forms in the next batch.
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Re: The hardest sudokus (new thread)

Postby mith » Sat Jun 25, 2022 8:07 pm

Looks like I had already gotten them in April, just missed them this week double-checking.
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Re: The hardest sudokus (new thread)

Postby hendrik_monard » Mon Jun 27, 2022 10:26 am

I took the time to have a closer look at the list posted by mith on March 21st. (the-hardest-sudokus-new-thread-t6539-1230.html#p318907)
It reminds me of a list I made in september 2021. I wanted to know if in ph_2010, all puzzles with equivalent solutions were 'closely' related.
This list was the result of the analysis of all 11.2+ puzzles in ph_2010. It contains groups of puzzles with equivalent solutions. Only groups with at least two members are listed.
The largest group (of puzzles with SER >= 11.2 and equivalent solutions) counted 523 members, all closely related.
The first line of each group is the canonical morph of the common (equivalent) solution of all members of the group.
column 2: line number in ph_2010
col. 3: ID
col. 4: first digits of original puzzle
col. 5: additional puzzle data (unfortunately, on my screen this column goes to a new line)

This is the top of the list (first 7 groups):
Hidden Text: Show
Code: Select all
987654321653921874214873695832495716791368452546712938428137569365289147179546283
9.....3....3..1.7....8....5.....5.1..9..6.4.....7....842...7....6.2...4...9.4.2..   3   2      12..3....4....1.2...   11.90;11.90;11.30;elev;second flush;2;23;
9.....3....3..1.74...8....5.....5.1..9..6.4.....7....842...7....6.2.......9.4.2..   33092   39354      98.7..6..5...4......   11.20;1.20;1.20;GP;12_07;39354;23;
987654321653921874241783956829536417715492638364178295572869143438217569196345782
.8.6...2.....2...42....39..8..5...1..15.......6..7.........9..3..82...6.....4.7..   5   4      .2.4...8.....8...68.   11.90;11.90;9.90;elev;3;4;22;
.8.6...2.........42....39..8..5...1..15.......6..7........69..3..82...6.....4.7..   6406   910      .2.4...8.........68.   11.30;11.30;9.30;elev;721;910;22;
987654321654321987321987654896135472735248196142796835519473268473862519268519743
9.......1..43...8..2....6......35.7...5..8....4.7......1....2..4...6...9..85...4.   12   7      1.......9..67...2..8   11.80;11.80;11.60;elev;15;7;22;
9.......1..43...8..2....6......35.7.7.5.48......7......1....2..4...6...9..85...4.   19553   15522      98.76....75....6....   11.20;11.20;11.10;GP;kz1a;15522;23;
987654321653921874124783659849362715762815943531497268476139582315278496298546137
......3..6....1.7..2.7....9..9...7.57...1..4..3....2..4..1...8...5..8.......46...   15   11      98.7.....6...5......   11.80;11.80;11.40;GP;H1;11;22;
......3..6....1.7..2.78...9..9.....57...1..4..3....2..4..1...8...5..8.......46...   2261   423      98.7..6....5.9..4...   11.40;11.40;2.60;GP;H72;423;22;
......3..6....1.7..2.7....9..9.6...57...1..4..3....2..4..1...8...5..8.......46...   3276   529      98.7.....6.....97...   11.40;1.20;1.20;GP;H86;529;22;
..76..3..6....1.7..2.7....9..9.....57...1..4..3....2..4..1...8...5..8.......4...7   13504   15710      98.7.......7.6......   11.30;1.20;1.20;GP;Kz1 b;15710;23;
..76..3..6....1....2.7....9..9...7.57...1..4..3....2..4..1...8...5..8.......4...7   13649   18770      98.7.....6...5.9....   11.30;1.20;1.20;GP;KZ1C;18770;23;
..76..3..6....1.7..2.7....9..9.6...57...1..4..3....2..4..1...8...5..8.......4....   20400   18307      98.7.......7.6......   11.20;11.20;10.60;GP;KZ1C;18307;23;
......3..6....1.7..2.7....9..9.....57...1..4..3....2..4..1...8...5..8.......46..7   38715   3312      98.7.....6.....7....   11.20;1.20;1.20;GP;H654;3312;22;
987654321653921874124873695875346219496512738312789546748295163569137482231468957
..7.5....6....1....2.8...9....3....9.9.....38......54..4.2....35....7.....1.6....   17   12      1.......2..94...5..6   11.80;11.80;11.20;tax;gsf-2007-05-24-003 64879;12;21;
..7.5....6....1....2.8...9....3..2.9.9.....38......5...4.2....35....7.....1.6....   80   100058      98.7.....7.6...8....   11.70;11.70;11.20;GP;12_11;100058;21;
..7.5....6....1....2.8...9....3..2.9.9.....38......54..4.2....35....7.....1.6....   1708   3269155      .......12.....34.5..   11.40;11.40;11.20;MITH;2020_10;3269155;22;
987654321653921874214873965869145237375269148142387659728516493531492786496738512
.8.6...2......1..4....7.9......4...7.....91....23...5..285......3.....8.4.6......   18   13      6.......2.9.4...5...   11.80;11.80;11.10;tax;coloin-04-10;13;21;
.8.6...2......1..4....7.9......4...7.....91....23...5...85....353.....8.4.6......   21188   287382      .......12.....3..4..   11.20;11.20;10.40;dob;12_12_03;287382;22;*
987654321654321987312978564876192453245763198193845276731289645528436719469517832
.8.....2....3...87......5.4..6.9.....4.7....81....5....3.2...4.5....6.....9.1....   19   14      1.......2.9.4...5...   11.80;11.80;10.80;tax;coloin-04-10;14;21;
.8....32....3...87......5....6.9.....4.7....81....5....3.2...4.5....6.....9.1....   77   39      1.......2.9.4...5...   11.70;11.70;11.20;tax;coloin-04-10;39;21;

It appears that in the overwhelming majority of groups, the members are closely related.
One of the very rare exceptions is the first member of this group:
Hidden Text: Show
Code: Select all
987654321654321987312897456865139274723465819491278563546783192238916745179542638
.8...4.2.6.4.2..87......4..86..3.2.4.2..6.8....1..8..35....3......9......7..4.6..   34734   1886884      98.76.5..7..8..9....   11.20;1.20;1.20;GP;2011_12;1886884;26;
.8.6.432.6...2..8.........6.6..3...47....5.....1.......4..8...22.89..7...7..426..   39599   1834996      98.76.5..5....9.7...   11.20;1.20;1.20;GP;2016_04_23;1834996;26;
.8.6.432.....2..8.........6.6..3...47....5.....1.......46.8...22.89..7...7..426..   39609   1834952      98.76.5..5....9.....   11.20;1.20;1.20;GP;2016_04_23;1834952;26;

And now something completely different.
My script for finding new hard puzzles stopped yesterday when skfr did not return a rating result for this puzzle:
..2.3...4...2.53.15..14.8..987......6...........85.....4.3.251....58.4.2....14.8.
I use this command line (in VBA script) for skfr:
res = Wshshell.Run("skfr_win64_v2_0_1.exe", vbHide, True)
However, SER returns this result for the same puzzle:
..2.3...4...2.53.15..14.8..987......6...........85.....4.3.251....58.4.2....14.8. ED=11.0/1.2/1.2
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Re: The hardest sudokus (new thread)

Postby mith » Mon Jun 27, 2022 3:04 pm

I've had this same occasional issue with my skfr. The puzzles it happens for have always been in the 10.9-11.0 rating range. (It doesn't happen in YZF, which I believe also uses some version of skfr for its ratings.)

Also, this reminds me that I need to filter the non-minimals out of the ph database before publishing my update for it. Had a bug early on and a few slipped through. (3269155 here is not minimal, it's just the union of the two related puzzles.)
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Postby 1to9only » Mon Jun 27, 2022 6:24 pm

hendrik_monard wrote:skfr did not return a rating result for this puzzle:
..2.3...4...2.53.15..14.8..987......6...........85.....4.3.251....58.4.2....14.8.

You'll need to run the single-threaded version to get additional (debugging) info out of skfr, it fails at this point, rating the puzzle as ED=0.0/0.0/0.5.
Code: Select all
+-------------------+-------------------+-------------------+
| 1     679   2     | 679   3     8     | 679   5     4     |
| 48    679   48    | 2     679   5     | 3     679   1     |
| 5     3679  36    | 1     4     679   | 8     2     679   |
+-------------------+-------------------+-------------------+
| 9     8     7     | 46    26    136   | 126   346   5     |
| 6     1235  135   | 479   279   1379  | 129   34    8     |
| 234   123   14    | 8     5     1369  | 12679 679   3679  |
+-------------------+-------------------+-------------------+
| 78    4     689   | 3     679   2     | 5     1     679   |
| 37    136   169   | 5     8     679   | 4     3679  2     |
| 237   25    569   | 679   1     4     | 679   8     37    |
+-------------------+-------------------+-------------------+

1.2.38.54...2.53.15..14.82.987.....56.......8...85.....4.3.251....58.4.2....14.8.

skfr does get to the 11.0 step, but falls over when doing additional checking (around lines 3051-60 in puzzle.cpp). Remove the checking, and skfr rates the puzzle as ED=11.0/1.2/1.2.
I dont know the code well enough to say if removing the checks will affect other puzzles ratings.
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Re: The hardest sudokus (new thread)

Postby yzfwsf » Mon Jun 27, 2022 10:09 pm

hendrik_monard wrote:My script for finding new hard puzzles stopped yesterday when skfr did not return a rating result for this puzzle:
..2.3...4...2.53.15..14.8..987......6...........85.....4.3.251....58.4.2....14.8.

The dll version skfr attached in my solver rates it as 11.0/1.2/1.2
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Re: The hardest sudokus (new thread)

Postby mith » Mon Jun 27, 2022 11:09 pm

Two new 11.8 expanded forms since I started my scripts running again:

Code: Select all
........1.....2.3..24...5......567.....42.....5.8.76...8267....6.52.4.8774..85...  ED=11.8/11.8/3.4 non-minimal
........1.....2.3..24...5......567.....42.....5.8.76...8276....64..85...7.52.4.86  ED=11.8/11.8/3.4 non-minimal


Two 26c minimals each. When I get the minimal database update going, I'll pull a list of all the minimals from 11.8+ depth 3 puzzles.
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