The New Sudoku Players' Forum

[JPF]

Kilos of puzzles generated...

and all I could find was this 25-stepper

Code: Select all

 . 9 . | . . . | 5 . .
 6 . 7 | . . . | 3 . 9
 . . . | . . 6 | . 8 7
-------+-------+-------
 . . . | 3 . . | 4 5 1
 . . . | 1 . 5 | . . .
 1 5 3 | . . 8 | . . .
-------+-------+-------
 7 1 . | 4 . . | . . .
 8 . 2 | . . . | 6 . 5
 . . 5 | . . . | . 7 .


JPF

[Ocean]

this 1 stepper, 40 clues with some symmetry (previously posted) ...

I added this to the lowstepper list earlier. It's the lowest 1-stepper we have so far.

And a minimal full-symmetric 20-stepper:

Code: Select all

 . 9 . | . 5 . | . 1 .
 2 . . | . . . | . . 6
 . . . | 1 . 6 | . . .
-------+-------+------
 . . 8 | . 7 . | 2 . .
 7 . . | 6 . 1 | . . 3
 . . 3 | . 9 . | 4 . .
-------+-------+------
 . . . | 5 . 4 | . . .
 3 . . | . . . | . . 2
 . 5 . | . 6 . | . 7 .

[JPF]

Just to stay in good shape :

24 steppers, SM, but not M.
24 clues.

Code: Select all

 . . 7 | . . 1 | . . .
 . 4 . | 5 . . | . . .
 8 6 . | . . . | . . 3
-------+-------+-------
 . . 2 | 1 . . | . . .
 . 3 1 | 8 . 2 | 6 9 .
 . . . | . . 7 | 1 . .
-------+-------+-------
 3 . . | . . . | . 4 5
 . . . | . . 8 | . 7 .
 . . . | 7 . . | 2 . .



24 steps : 4,1,1,1,2,2,1,1,2,3,1,1,1,1,1,2,2,3,4,3,3,6,10,1

Look at the 23 rd step.

JPF

[Pat]

this one is a newspaper puzzle,
i wonder how it would rate —

• how many steps?
• how many tight steps (single-cell)?

Code: Select all

 . . . | . 1 . | 4 3 9
 4 9 . | . . . | . . .
 . . 8 | . . . | . . .
-------+-------+------
 1 . . | 5 . . | . 7 .
 9 7 . | 4 . 6 | . 2 8
 . 6 . | . . 1 | . . 5
-------+-------+------
 . . . | . . . | 6 . .
 . . . | . . . | . 5 2
 6 4 9 | . 7 . | . . .

thanks!

~ Pat

[Ruud]

how many steps? How many tight steps?

There are 13 steps.

No tight steps, the pattern is 6333334347881

Ruud.

[Pat]

thanks, Ruud!

perhaps you recognized the puzzle?
The Sunday Times #31

so i wonder,
did we find here any puzzles which Pappocom rates Very Hard??

~ Pat

[ab]

another 20 step puzzle:

Code: Select all

-------------------
|     |     |     |   
|     |6 2 3|     |   
|    5|  4  |8    |   
-------------------
|  7  |     |  3  |   
|  8 9|  5  |7 4  |   
|  3  |     |  2  |   
-------------------
|    6|  8  |9    |   
|     |4 7 2|     |   
|     |     |     |
-------------------   

It's also minimal and fully symmetric with 21 clues

[Ocean]

A 24-stepper. Full symmetry. (Symmetrically minimal, but not absolute minimal).

Code: Select all

 . 5 . | . . . | . 2 .
 6 3 . | . 9 . | . 8 7
 . . . | 3 . 2 | . . .
-------+-------+------
 . . 1 | . . . | 6 . .
 . 9 . | . . . | . 5 .
 . . 4 | . . . | 8 . .
-------+-------+------
 . . . | 4 . 7 | . . .
 4 7 . | . 5 . | . 6 8
 . 2 . | . . . | . 9 .

[ab]

Ocean, just changing one clue in your puzzle leads to this 27 stepper;

Code: Select all

-------------------                 
|  5  |     |  2  |   
|6 3  |  9  |  8 4|   
|     |3   2|     |   
-------------------
|    1|     |6    |   
|  9  |     |  5  |   
|    4|     |8    |   
-------------------
|     |4   7|     |   
|4 7  |  5  |  6 8|   
|  2  |     |  9  |
-------------------


[Ocean]

Ocean, just changing one clue in your puzzle leads to this 27 stepper;

Thanks. You make it seem so simple. The best I ever did (without help) was 25, I think.

[tarek]

The FSM (Full Symmetry, Minimal) wave has struck me....

here are two sister entries:

The first is Symmetrically minimal (FSSM), 24 stepper:

Code: Select all

 . . . | 8 9 5 | . . . 
 . . 9 | . . . | 7 . . 
 . 1 . | . . . | . 8 . 
-------+-------+------
 5 . . | . 2 . | . . 9 
 9 . . | 3 . 1 | . . 6 
 6 . . | . 8 . | . . 3 
-------+-------+------
 . 4 . | . . . | . 3 . 
 . . 7 | . . . | 4 . . 
 . . . | 4 6 7 | . . .

The second is a true FSM, 20 steps:

Code: Select all

 . . . | 8 9 5 | . . . 
 . . 9 | . . . | 7 . . 
 . 1 . | . . . | . 8 . 
-------+-------+------
 5 . . | . 2 . | . . 9 
 9 . . | 3 . 1 | . . 6 
 6 . . | . 4 . | . . 3 
-------+-------+------
 . 4 . | . . . | . 3 . 
 . . 8 | . . . | 5 . . 
 . . . | 4 6 7 | . . . 

The Symmetry is 3-4-0-1-0 or in base32 it is 34010

tarek

[JPF]

A 21-stepper. Full symmetry. (Symmetrically minimal, but not absolute minimal).

Code: Select all


 7 . . | . . . | . . 6
 . 4 . | 3 . 9 | . 2 .
 . . . | . . . | . . .
-------+-------+-------
 . 2 . | . 9 . | . 5 .
 . . . | 4 7 1 | . . .
 . 9 . | . 6 . | . 3 .
-------+-------+-------
 . . . | . . . | . . .
 . 3 . | 5 . 7 | . 9 .
 8 . . | . . . | . . 1


21 steps : 4,2,1,1,1,2,2,3,5,5,3,2,2,2,2,3,4,4,7,4,1

code FS : 0-8-6-1-1


JPF

[Ocean]

Slow progress with the low-steppers.
But here is a minimal 24-clues 5-stepper (full symmetry).

Code: Select all

5-stepper. M24. Symmetry code: [6-2-0-0-0]
+-------+-------+-------+
| . . 4 | 1 . 8 | 7 . . |
| . . . | 2 . 6 | . . . |
| 7 . . | . . . | . . 6 |
+-------+-------+-------+
| 3 7 . | . . . | . 1 2 |
| . . . | . . . | . . . |
| 4 6 . | . . . | . 5 9 |
+-------+-------+-------+
| 5 . . | . . . | . . 3 |
| . . . | 7 . 9 | . . . |
| . . 2 | 8 . 4 | 9 . . |
+-------+-------+-------+
Five single-steps: 10-15-21-30-24.

Filling a gap: The first and only minimal five-stepper I've seen.

[JPF]

In the Nick70' list of the puzzles where 19 clues are placed in the following pattern, I found seven 21-steppers.

One of them (Minimal) :

Code: Select all

 1 . . | . 5 . | . . .
 . . . | 3 . . | . 2 .
 . . 9 | . . . | 4 . .
-------+-------+-------
 . 3 . | . . 4 | . . .
 2 . . | . 3 . | . . 8
 . . . | 9 . . | . 6 .
-------+-------+-------
 . . 4 | . . . | 1 . .
 . 6 . | . . 9 | . . .
 . . . | . 2 . | . . 7


21 steps : 1,2,2,3,2,2,1,2,3,3,5,3,2,4,4,4,2,2,5,7,3



JPF

[JPF]

Same pattern as Puzzle #54(JPF), but 22 steps.

Code: Select all

22-stepper. SM21. FS code : 0-8-6-1-1

 1 . . | . . . | . . 4
 . 5 . | 6 . 9 | . 8 .
 . . . | . . . | . . .
-------+-------+-------
 . 3 . | . 9 . | . 6 .
 . . . | 2 7 4 | . . .
 . 9 . | . 1 . | . 2 .
-------+-------+-------
 . . . | . . . | . . .
 . 6 . | 5 . 7 | . 9 .
 7 . . | . . . | . . 2


22 steps : 2,2,1,1,1,1,1,3,1,2,4,7,6,1,2,1,2,2,4,4,8,4



JPF