The New Sudoku Players' Forum

[m_b_metcalf]

Code: Select all

 . . . 1 2 3 . . .
 . . 1 . . . 2 . .
 . 2 . . . . . 4 .
 . 5 . . . . . . .
 . 6 . . . . . . .
 . 7 . . . . . . .
 . 8 . . . . 4 3 5
 . . 9 . . . 7 6 .
 . . . 4 7 6 . 8 .   hard

 . . . 1 2 3 . . .
 . . 4 . . . 5 . .
 . 2 . . . . . 6 .
 . 7 . . . . . . .
 . 3 . . . . . . .
 . 6 . . . . . . .
 . 8 . . . . 9 3 7
 . . 2 . . . 6 5 .
 . . . 9 6 5 . 8 .   moderate

[Leren]

Both moderate and hard puzzles solved without recourse to forcing chains. A point of interest that comes up in the Hard puzzle was this move.

Code: Select all

*--------------------------------------------------------------------------------*
| 578     49      45678    | 1       2       3        | 5689    579     789      |
| 35678   39      1        | 56789   45689   45789    | 2       579     36789    |
| 35678   2       3578     | 56789   5689    5789     |b135689  4      a136789   |
|--------------------------+--------------------------+--------------------------|
| 123489  5       2348     | 23789   134689  124789   | 3689    1279    346789   |
| 123489  6       2348     | 235789  13589   1245789  | 3589    12579   34789    |
| 123489  7       2348     | 235689  1345689 12589    | 35689   1259    34689    |
|--------------------------+--------------------------+--------------------------|
| 67      8       67       | 29      19      129      | 4       3       5        |
| 24     c14      9        | 358     358     58       | 7       6       12       |
| 235    d13      235      | 4       7       6        | 19      8       29-1     |
*--------------------------------------------------------------------------------*

(1) r3c9 = r3c7 - r8c2 = (1) r9c2 => - 1 r9c9; I imported this move from an X solver I have for another variant. The logic is clear but what is it ? A Skyscraper with a diagonal base ?

Leren

[Pat]

Nick70 would call it "Turbot"
with two non-consecutive strong sides

[Leren]

Hi Pat,

I think it is a Skyscraper. 4 cells with links S-W-S, exactly as in an ordinary Skyscraper. But let's wait to see what SE makes of this, if it comes up in it's solution, there was also a second instance.

Leren

[m_b_metcalf]

But let's wait to see what SE makes of this, if it comes up in it's solution, there was also a second instance.

Too many big steps to list. Here's a summary:

Code: Select all

Analysis results
Difficulty rating: 7.1 (Forcing Chain)
This X Sudoku can be solved using the following logical methods:
58 x Hidden Single
2 x Direct Hidden Pair
 22 x Generalized Intersections
2 x Generalized Naked Pair
1 x Hidden Pair
1 x Generalized Naked Triplet
2 x (2 Strong Links) X-Loop 011
1 x 2 Strong links 001
1 x 2-String Kite 012 2 x XY-Wing
1 x (2 Strong Links) Grouped X-Loop 156
1 x Grouped Skyscraper 115
1 x Skyscraper 016
1 x Unique Rectangle type 3
1 x WXYZ-Wing 126
2 x Bidirectional Y-Cycle
1 x Forcing Chain
The most difficult technique (ER): Forcing Chain

Mike

[Leren]

I'm sure it's a Skyscraper. Hajime used one here. Leren