## inferior puzzles thread

Everything about Sudoku that doesn't fit in one of the other sections
Two minimal 20-steppers and one minimal 21-stepper with special symmtries.
(D=diagonal. L=90-degrees rotational. X=double diagonal.)

Code: Select all
`#M23. 20 steps. D-symmetry.+-------+-------+-------+ | . . . | . . 1 | . . . || . . . | . 7 . | 3 . 5 || . . . | 5 . . | 9 . . |+-------+-------+-------+ | . . 3 | 4 6 . | . . . || . 4 . | 3 . 2 | 6 . . || 2 . . | . 1 . | . . 7 | +-------+-------+-------+ | . 6 1 | . 5 . | . 9 . | | . . . | . . . | 2 . . | | . 5 . | . . 4 | . . . | +-------+-------+-------+ #M24. 20 steps. L-symmetry.+-------+-------+-------+ | 3 . . | . . . | . . 6 || . . . | 9 7 . | 2 . . || . 7 9 | . . . | 4 . . | +-------+-------+-------+ | . . . | . 5 . | . 2 . | | . 3 . | 7 . 8 | . 1 . || . 4 . | . 1 . | . . . |+-------+-------+-------+ | . . 8 | . . . | 1 5 . || . . 1 | . 9 4 | . . . || 6 . . | . . . | . . 8 |+-------+-------+-------+ #M24. 21 steps. X-symmetry.+-------+-------+-------+ | . 7 . | . . 8 | . 6 . || 9 3 . | . 4 . | . . 5 || . . . | 2 . . | . . . | +-------+-------+-------+ | . . 9 | 1 . . | . . 4 || . 2 . | . . . | . 3 . || 5 . . | . . 4 | 7 . . |+-------+-------+-------+ | . . . | . . 6 | . . . || 7 . . | . 8 . | . 9 6 || . 1 . | 5 . . | . 2 . |+-------+-------+-------+ `
Ocean

Posts: 442
Joined: 29 August 2005

a 20 stepper with full symmetry:
Code: Select all
`...|...|....4.|...|.6...2|9.7|5..-----------..7|.6.|2.....|538|.....8|.4.|9..-----------..9|2.6|8...6.|...|.5....|...|...`
ab

Posts: 451
Joined: 06 September 2005

A minimal and fully symmetric 21-stepper:

Code: Select all
`M24. 21 steps. Minimal. Full symmetry [code 8-0-6-1-0].+-------+-------+-------+| . 9 . | . . . | . 7 . || 1 . . | . . . | . . 6 || . . 5 | 4 . 9 | 3 . . |+-------+-------+-------+| . . 7 | . 8 . | 6 . . | | . . . | 5 . 6 | . . . | | . . 2 | . 9 . | 4 . . |+-------+-------+-------+| . . 3 | 6 . 7 | 9 . . || 2 . . | . . . | . . 3 || . 5 . | . . . | . 1 . |+-------+-------+-------+`
Ocean

Posts: 442
Joined: 29 August 2005

Two minimal sudokus with 21 clues: One 25-stepper, and one 23-stepper. Both with diagonal symmetry.

Code: Select all
`# M21. 25 steps. Diagonal symmetry.+-------+-------+-------+ | . 1 . | . . 2 | . 3 . || 4 . . | . . . | 1 5 . || . . . | . . 6 | . . . |+-------+-------+-------+ | . . . | . . . | . . 7 | | . . . | . . 1 | 8 . . | | 2 . 7 | . 8 . | . . . | +-------+-------+-------+ | . 3 . | . 4 . | . . . || 8 4 . | . . . | . . 6 || . . . | 5 . . | . 2 9 |+-------+-------+-------+ `

Code: Select all
`# M21. 23 steps. Diagonal symmetry.+-------+-------+-------+ | . . . | . . . | . . . || . . 1 | . 2 . | . 3 . || . 4 . | 5 6 . | 7 . . | +-------+-------+-------+ | . . 2 | . . . | . . . | | . 1 8 | . . . | . . . || . . . | . . . | 4 6 5 |+-------+-------+-------+ | . . 3 | . . 2 | . . . || . 5 . | . . 9 | . . 3 || . . . | . . 8 | . 9 1 |+-------+-------+-------+ `
Ocean

Posts: 442
Joined: 29 August 2005

This one popped up: A 26-stepper with 20 clues.

Code: Select all
`# M20. 26 steps. (Minimal + Full symmetry). *-----------* |...|.1.|...| |...|234|...| |..1|...|5..| |---+---+---| |.2.|...|.6.| |63.|...|.24| |.4.|...|.7.| |---+---+---| |..5|...|8..| |...|967|...| |...|.4.|...| *-----------*`
Ocean

Posts: 442
Joined: 29 August 2005

a 22 step puzzle:
Code: Select all
`...|...|.5.35.|7..|..28.7|.2.|...-----------...|.6.|....19|..8|4..74.|...|.1.-----------...|.1.|3...3.|59.|.4....|4..|26.`
ab

Posts: 451
Joined: 06 September 2005

a 23-stepper :

Code: Select all
`SM 26   ; 23 steps   1 . . | . . . | . 2 . . . . | 8 . . | . . . 3 . 9 | 5 . . | 1 4 .-------+-------+------- . . 3 | . . 1 | . 6 . . 5 . | 9 . 3 | . 8 . . 9 . | 4 . . | 2 . .-------+-------+------- . 6 2 | . . 9 | 3 . 5 . . . | . . 5 | . . . . 3 . | . . . | . . 223 steps : 2,1,2,1,2,2,1,1,1,2,3,2,3,3,3,3,1,3,6,3,3,4,3`

JPF
JPF
2017 Supporter

Posts: 3754
Joined: 06 December 2005
Location: Paris, France

A nice simple self-referential puzzle ...
Code: Select all
`6 8 7 3 . . . . .. . . . . . 7 2 .. . . . . 4 . . 1. 6 4 . . 8 . . 28 . . 1 . . 4 5 .. . 2 . . . . . .. 5 . . . . . . .4 1 3 7 . . . . .. . . . . 1 3 4 8`
Seriously non-minimal, but who cares!
Red Ed

Posts: 633
Joined: 06 June 2005

Inspired by Ed,
I created this puzzle:

Code: Select all
`. . .|. . .|. . .. 8 9|. . .|6 1 .7 . .|4 . 8|. . 2-----+-----+-----. . .|9 . 7|. . .. . 5|. . 3|7 2 .. 9 .|. . 5|. . 4-----+-----+-----8 . .|. . 9|. . 69 6 4|3 . .|8 7 .. . .|. . .|. . .`

It is self-explaining.

- There are 26 clues forming 2 digits.
- There are 13 steps. 13 * 2 = 26.
- The sum of all the clues is 156, which equals 2 * 6 * 13

Ruud.
Ruud

Posts: 664
Joined: 28 October 2005

Just in case, if you need one more

Code: Select all
` . 6 9 | . . . | . . 2 7 . . | 8 . . | . 3 5 . . . | . 9 . | 1 . 4-------+-------+------- . . . | . 3 . | . . 6 . . . | 5 . . | . . 7 . . 3 | . . . | . . 8-------+-------+------- . 4 . | . . . | . . 1 6 . . | . . . | . . 3 5 2 8 | 3 4 . | . . 9`

Prime divisors :

21 =3*7 digits
26 =2*13 clues
11 =1*11 steps.

JPF
JPF
2017 Supporter

Posts: 3754
Joined: 06 December 2005
Location: Paris, France

Ruud, JPF -- nice work!

But can you create examples where the puzzle spells out the number of steps, as in my 20? (Although it seems like nit-picking to find any fault in Ruud's spectacular example)
Red Ed

Posts: 633
Joined: 06 June 2005

Red Ed wrote:... But can you create examples where the puzzle spells out the number of steps, as in my 20?...

Yes
Code: Select all
` . . 1 | . . 3 | 4 . . . 2 6 | . 8 . | . 5 . 5 . 4 | . 1 . | . . 6-------+-------+------- . . 2 | . . . | . . 4 . . 7 | . . . | . . 2 . . 5 | . . . | . 3 .-------+-------+------- . . 3 | . . . | 8 . . . . 9 | . . 4 | . . . . . 8 | . 5 2 | 3 9 1`

JPF
JPF
2017 Supporter

Posts: 3754
Joined: 06 December 2005
Location: Paris, France

### Self-referential 23

Here's a self-referential 23, which is not quite minimal ...
Code: Select all
`. . . . . . 2 3 .. . . . . 7 . . 1. 5 3 . . . . . 82 . . 1 . . 3 4 .. . . 7 . . . . 6. . 8 . . 6 . . 7. 4 . . . . 1 5 .5 . . . . . . . .8 1 6 4 . . . . .`
It took 316 million iterations (digit replacements in the pattern above) to find this thing. I don't know how you people are finding 25+ steppers!
Red Ed

Posts: 633
Joined: 06 June 2005

### Re: Self-referential 23

Red Ed wrote:Here's a self-referential ...

Well ...
2^3 = 8 # 23

JPF
JPF
2017 Supporter

Posts: 3754
Joined: 06 December 2005
Location: Paris, France

Ha! I knew someone would pick me up on that. But it's not my fault, it's my wonky downward-sloping monitor: to me, the puzzle looks like a italicised 23, honest ...

`. 9 . . 8 . 2 . .. 1 . . . . 5 . .. 3 . . . . . 4 .. . . 6 . 3 4 . .8 . . . . . . . .5 . . . . . . . .. . . 1 . . . . 7. . . . . . . 8 99 . . . 6 . . . .`