The New Sudoku Players' Forum

[coloin]

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+---+---+---+
|...|...|...|
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|...|...|...|
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|.35|...|9..|
|6.1|5..|...|
|...|...|...|
+---+---+---+
|...|...|.1.|
|57.|...|...|
|...|..2|..3|
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Who can solve this one ?

The two clues in box 8 and 6 are significant !

[Hajime]

11 clue vanilla Sudoku?

[tarek]

Haven't got time to think deeply into this but in addition to looking for constraints to add, It can also be worth looking for symmetrical clues or a 10-x symmetry clue

tarek

[Mathimagics]

If it's a valid puzzle (one solution), and it's a known variant, then that variant must involve more than just extra houses.

There are only 7 digits in the givens, so some FP or other clue-restriction variant is suggested ...

My solver suggests that it's not an NC puzzle ...

[tarek]

I haven't seen colin posting an NC before. He has posted many that have Special qualities.

So it could be one of those puzzles that takes advantage of a special quality in the vanilla sudoku & used it to remove clues

tarek

[Mathimagics]

See my edit above, it's not an NC puzzle ...

[Mathimagics]

Venezuelan beaver Sudoku?

[Mathimagics]

Ah, how about a cricket theme?

FP with no adjacent pair adding up to 11??

I can't test it right now, as the cricket's starting!

[Leren]

Withdrawn

[tarek]

One of the puzzle variants that colin has posted before involve having automorphic vanilla sudoku grids where boxes in different bands being equal (Stormdoku). I hope I'm not diverting away from the correct path, but I'm throwing some thoughts in here

Having said that we don't have many different clues which throws it back into FP territory

tarek

[coloin]

Its great that you all are taking this seriously as the cricket ensues, but its vanilla sudoku ...
So I am giving another two clues .... but we know these clues are there don't we ?
Its two easy now !

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|...|...|..9|
|...|...|...|
|...|...|...|
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|2..|...|...|
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C

[tarek]

So ... a row normalised grid?

Cricket not that fun today

Tarek

[Mathimagics]

Oh, I thought it was tremendous fun!

So, a CF grid, doh !!!

Don't actually have a solver configured for that ...

But how many clues is in fact minimum for this "variant"? An interesting question, perhaps ...

[blue]

There are 55 row-minlex grids, that contain the clue set.
There are five minlex band 1's where adding 2r4c1 and the band as clues, gives a puzzle with a unique solution.
For two of those, the solution itself, is a minlex grid.

Something else is missing.

The two clues in box 8 and 6 are significant !

The two band 1's, are at (1-based) indicies 24 and 29.
Since the two clues in boxes 8 and 6 are 2 and 9 (respectively), and band 29 is famous as being the only band with 2-clue puzzles,
I'll guess that the solution is:

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

Its two easy now !

The proposed solution grid, also has two automorphisms !

[coloin]

But how many clues is in fact minimum for this "variant"? An interesting question, perhaps ...

yes well done !!! And well explained !!

it wasnt meant to be that hard, but it was a stab at representing each minlexgrid with the minimum of data ie here it was a 53 string with 11 clues.

The clue to the band is somewhere in the 11 clues .... whatever good way you can do it !

perhaps easier is stating the band in band 1 [ as 029]
and then as few clues as possible in band 2 and 3 could be done

Code: Select all

+---+---+---+
|...|...|..9|
|...|...|...|
|...|2..|...|
+---+---+---+
|.35|...|9..|
|6.1|5..|...|
|...|...|...|
+---+---+---+
|...|...|.1.|
|57.|...|...|
|...|..2|..3|
+---+---+---+  but 13 clues


the band was coded using clues / lack of clues in these empty cells

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+---+---+---+
|123|456|789|
|456|789|231|
|789|231|564|
+---+---+---+
|235|148|...|
|691|527|...|
|847|963|...|
+---+---+---+
|362|...|417|
|578|...|692|
|...|...|.53|
+---+---+---+