The New Sudoku Players' Forum

[tarek]

The Miracle by SudokuMonster

Anti Knight / Anti King / Ferz Non Consecutive

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.........
.....1...
.........
.........
.........
.2.......
......3..
.........
.........
..............1...............................2.............3....................

Anti-King: up to 8 neighbouring cells that are a king's move away can't be the same
Anti-Knight: up to 8 cells that are a knight's move away can't be the same
Ferz non Consecutive: Diagonally neighbouring cells can't have consecutive numbers

May the force be with you,

Tarek

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[tarek]

The Miracle Sudoku by SudokuMonster V2:



Anti King / Anti Knight / Ferz Non consecutive

This one will need knowledge of the force as well

Tarek

[Hajime]

Unique solutions for
#1

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891234567567891234234567891789123456456789123123456789678912345345678912912345678

#2

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654321987321987654987654321543219876219876543876543219432198765198765432765432198

Try this Samurai

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.................................................................................
.................................................................................
.............1....................................................2.4............
.................................................................................
.................................................................................

All grids are AN, AK, FNC

All puzzles have a lot of 123456789 (or reversed) sequences

[tarek]

Try this Samurai

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.................................................................................
.................................................................................
.............1....................................................2.4............
.................................................................................
.................................................................................

All grids are AN, AK, FNC

Sounds like a machine exercise to solve that Samurai, so I will not try it anytime soon . The puzzles I posted were intended to be solved manually (As did the original Miracle sudokus) ... I provided a small hint to indicate the level needed.

Tarek

[Hajime]

Sounds like a machine exercise to solve that Samurai...

Is not too difficult manually. The middle grid is just as difficult as yours. After solving the middle grid then a whole box is solved in grid 1,2,4 and 5. That is enough to solve the rest of those grids. All grids look alike. AN,AK and FNC is very restrictive.

[tarek]

Sounds like a machine exercise to solve that Samurai...

Is not too difficult manually. The middle grid is just as difficult as yours.

Well, I couldn't make a single placement in the middle section ... How did you solve it manually ... What techniques are you using?

[Hajime]

I also could not make a single move in both of your Miracle Sudoku's.
Because you stated that your puzzles can be solved manually, I stated that too. But it is not true.
And I have no solving method that comes even close.
Looks impossible to me. I am curious about the solution logging.

So the Star Wars force was not with me, and I went to Star Trek's Kirk method: I cheated.

Your puzzle #1 needs about 1000 guesses and #2 needs about 10.000 guesses using BruteForce method.
And a comparison with puzzle q2=98904 of champagne on 20th July with a difficulty of ED=11.7/11.7/2.6
.....1..2..3....4..2..5.6......6...5.7..2.1..8..9.......48......5...67..9......3.
that needs 'only' 100 guesses .

[tarek]

I also could not make a single move in both of your Miracle Sudoku's.
Because you stated that your puzzles can be solved manually, I stated that too. But it is not true.
And I have no solving method that comes even close.
Looks impossible to me. I am curious about the solution logging.

So the Star Wars force was not with me, and I went to Star Trek's Kirk method: I cheated.

hmmm ... As I post for other players a variety of puzzles from sudoku to variants and more over 15 years, I'm usually careful at making statements about how a puzzle is rated ... It would always be helpful to have a freely available solver that could demonstrate this like Sukaku Explainer which rates both of my puzzles at 3.2 which means "X-Wing" to solve (The Hint being may the force be with you in reference to Star Wars ... I've used this hint countless of times before "My Girandola puzzle thread being one of them"). The solving path is tedious but this is what you get with an AK AN FNC puzzle!!!

I post also puzzles targeting machine solvers as well & I also try to make sure that this is clear in the description. Rating puzzles is by far the most difficult in puzzle creation.

We have discussed a few non consecutive techniques before here: http://forum.enjoysudoku.com/post285907.html?hilit=locked%20non%20consecutive#p285907

The middle section of your Samurai is a standalone single solution puzzle which is verified by Sukaku explainer's brute force solver. With the other grids not having any clues you will need to have some information coming from that central grid so that the other grids can reduce the difficulty of solving the puzzle. Unfortunately, little information is available even after reaching SE difficulty levels of 9.0+ which basically puts it out of being a manual solving puzzle at this level. Try feeding the central grid only into Sukaku Explainer to see how far it gets. That is why I asked you about techniques just in case I was missing something!

[creint]

..............1...............................2.............3....................
34 steps in 0.8 seconds

....................................................1...2........................
48 steps in 0.9 seconds

The first one was not minimal:
..............1.............................................3....................
With my net implementation I got here after 324 seconds.
Cannot find a contradiction but some nets can fill all cells so there is at least one solution.
MiniSat solves each within 0.1 seconds

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2456789  12456789 12456789 2456789  3        2456789  56789    2456789  56789
2456789  56789    2456789  56789    246789   1        2456789  3        2456789
2456789  23456789 34       2456789  56789    2456789  56789    2456789  1
2456789  56789    2456789  1        2456789  3        2456789  56789    2456789
1456789  2456789  56789    2456789  56789    2456789  156789   246789   3
12456789 23       23456789 456789   2456789  56789    2456789  156789   2456789
56789    2456789  56789    2456789  1        2456789  3        2456789  456789
23456789 1456789  2456789  36       246789   56789    2456789  156789   2456789
39       12456789 1256789  23456789 456789   2456789  146789   2456789  2456789


The one from Hajime solves with MiniSat in 0.33 seconds.
Also not minimal: 4 can be removed.

[tarek]

The first one was not minimal:

Yes. Unfortunately couldn't find a symmetric 2 clue that is easy to solve. So decided for a symmetrically minimal 3 clue with the 1,2,3 which there are several of.

tarek

[HATMAN]

I'm surprised that there was difficulty solving tarek's two puzzles, JSudoku just uses two small fishes on the first one and then three on the second one. I solved them quite comfortably, but I am used to multiple interacting restraints. Of course after the first few placements the pretty solution is obvious especially if you know that there are only 72 solutions, nine numbers and three symmetries (up-down, left-right and increasing decreasing).

I've come across a few 72 puzzles, Mean 38 on the assassin site is one. I wonder if there are any smaller solution sets with a 9*9 sudoku?

tarek while there are plenty of two solution puzzles here I'm impressed that you found a human solvable one. On the note off human solvable I've just posted Human Solvable 25 on the assassin site.

[tarek]

I've come across a few 72 puzzles, Mean 38 on the assassin site is one. I wonder if there are any smaller solution sets with a 9*9 sudoku?

You will have half of those solutions when the forbidden pairs are non reversible. You will need the regions to not display symmetry (a.k.a asymmetric jigsaw) to go lower.

Mathmagics has invested time in Forbidden pairs & jigsaw and with his programming skills produced a single solution puzzle & presented it as the 1st Clueless 9x9 Sudoku!

The "Hands" jigsaw variant that you posted to demonstrate the 8 clue puzzles is very restrained ... It does display symmetry but if you throw an NC on it then I'm sure you would have those low solution puzzles too.

I'll check what you've posted this week

tarek

[Hajime]

Rating puzzles is by far the most difficult in puzzle creation. [...]
Try feeding the central grid only into Sukaku Explainer to see how far it gets. That is why I asked you about techniques just in case I was missing something!

I finally got home from an Android-only holiday and with the opportunity, time and courage to analyze the puzzle with Sukaku Explainer.
Your first puzzle is amazing indeed. I followed the hints and especially the FNC method to eliminate candidates was impressive. Maybe human solvable, but beyond my horizon. My Samurai middle grid is indeed much more complicated. SE >11.8 .