The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |...|5..|.49|
 |7..|.6.|...|
 |...|..1|5..|
 |---+---+---|
 |...|23.|...|
 |..1|...|...|
 |64.|...|..8|
 |---+---+---|
 |.5.|..4|...|
 |..4|...|37.|
 |..2|..9|.51|
 *-----------*

...5...497...6.........15.....23......1......64......8.5...4.....4...37...2..9.51


Play/Print this puzzle online

[Leren]

Code: Select all

*-------------------------------------*
| 28 1  68 | 5  7  3   | 26    4    9 |
| 7  9  5  | 4  6  2   |*18   *18   3 |
| 4  23 36 | 8  9  1   | 5     26   7 |
|----------+-----------+--------------|
| 5  7  89 | 2  3  8-6 |*19+6 *19+6 4 |
| 28 23 1  | 69 4  678 | 79-6  39-6 5 |
| 6  4  39 | 19 15 57  | 279   239  8 |
|----------+-----------+--------------|
| 1  5  7  | 3  2  4   |*89   *89   6 |
| 9  8  4  | 16 15 56  | 3     7    2 |
| 3  6  2  | 7  8  9   | 4     5    1 |
*-------------------------------------*

DP (189) r247c78 => - 6 r4c6, r5c89; stte

Leren

[pjb]

Code: Select all

 28      1       68     | 5      7      3      | 26     4      9     
 7       9       5      | 4      6      2      | 18     18     3     
 4       23     b36     | 8      9      1      | 5     a26     7     
------------------------+----------------------+---------------------
 5       7       89     | 2      3      68     | 169    169    4     
 28      23      1      | 69     4      678    | 679    369    5     
 6       4      c39     | 19     15     57     | 279   d39-2   8     
------------------------+----------------------+---------------------
 1       5       7      | 3      2      4      | 89     89     6     
 9       8       4      | 16     15     56     | 3      7      2     
 3       6       2      | 7      8      9      | 4      5      1     


(2=6)r3c8 - (6=3)r3c3 - r6c3 = r6c8 => -2 r6c8; stte

Phil

[SpAce]

Just one of the many wings available:

Code: Select all

.------------------.-------------.----------------.
| 28    1      68  | 5   7   3   | 26     4     9 |
| 7     9      5   | 4   6   2   | 18     18    3 |
| 4   a[32]    6-3 | 8   9   1   | 5    a[2]6   7 |
:------------------+-------------+----------------:
| 5     7      89  | 2   3   68  | 169    169   4 |
| 28    2-3    1   | 69  4   678 | 679    369   5 |
| 6     4    b(3)9 | 19  15  57  | 279  b(32)9  8 |
:------------------+-------------+----------------:
| 1     5      7   | 3   2   4   | 89     89    6 |
| 9     8      4   | 16  15  56  | 3      7     2 |
| 3     6      2   | 7   8   9   | 4      5     1 |
'------------------'-------------'----------------'

M2-Wing:

(32)r3c28 = (23)r6c83 => -3 r3c3,r5c2; stte

explicit chain: Show

(3=2)r3c2 - r3c8 = (2-3)r6c8 = (3)r6c3 => -3 r3c3,r5c2; stte

some other wings for reference: Show

Cells r3c28,r6c38 (like the previous M2-Wing):

L2-Wing:


(2)r3c8 = (2-3)r6c8 = r6c3 - r3c3 = (3)r3c2 => -2 r3c2; stte

Cells r36c38:

M3-Wing:


(63)r36c3 = (32)r63c8 => -6 r3c8; stte
<=>
(6=3)r3c3 - r6c3 = (3-2)r6c8 = (2)r3c8 => -6 r3c8; stte
L3-Wing:


(32)r6c38 = (26)r3c83 => -3 r3c3;stte
<=>
(3)r6c3 = (3-2)r6c8 = (2-6)r3c8 = (6)r3c3 => -3 r3c3; stte
L3-Wing:


(36)r63c3 = (62)r36c8 => -3 r6c8; stte
<=>
(3)r6c3 = (3-6)r3c3 = (6-2)r3c8 = (2)r6c8 => -3 r6c8; stte
H-Wing:


(2=6)r3c8 - (6=3)r3c3 - r6c3 = (3)r6c8 => -2 r6c8; stte (Phil's chain)

[rjamil]

Code: Select all

 +--------------+--------------+---------------+
 | 28  1    68  | 5    7   3   | 26     4    9 |
 | 7   9    5   | 4    6   2   | 18     18   3 |
 | 4   23  (36) | 8    9   1   | 5     (26)  7 |
 +--------------+--------------+---------------+
 | 5   7    89  | 2    3   68  | 169    169  4 |
 | 28  23   1   | 69   4   678 | 679    369  5 |
 | 6   4   (39) | 1-9  15  57  | 27-9  (239) 8 |
 +--------------+--------------+---------------+
 | 1   5    7   | 3    2   4   | 89     89   6 |
 | 9   8    4   | 16   15  56  | 3      7    2 |
 | 3   6    2   | 7    8   9   | 4      5    1 |
 +--------------+--------------+---------------+

Almost Locked Set move: 2369 @ r6c38 r3c38 => -9 @ r6c47; stte

R. Jamil

[Cenoman]

As a wink to Robert :

Code: Select all

 +-----------------+------------------+-------------------+
 |  28   1    68   |  5    7    3     |  26    4     9    |
 |  7    9    5    |  4    6    2     |  18    18    3    |
 |  4   b23   36   |  8    9    1     |  5     26    7    |
 +-----------------+------------------+-------------------+
 |  5    7    89   |  2    3    68    |  169   169   4    |
 |  28  c23   1    |  69   4    678   |  679   369   5    |
 |  6    4    39   |  19   15   57    |  279 da39-2  8    |
 +-----------------+------------------+-------------------+
 |  1    5    7    |  3    2    4     |  89    89    6    |
 |  9    8    4    |  16   15   56    |  3     7     2    |
 |  3    6    2    |  7    8    9     |  4     5     1    |
 +-----------------+------------------+-------------------+

(2)r6c8 -> (2)r3c2 -> (3)r5c2 -> (3)r6c8 =>contradiction; -2r6c8; ste
...more or less the same as phil's and SpAce's

[SpAce]

Hi rjamil,

Almost Locked Set move: 2369 @ r6c38 r3c38 => -9 @ r6c47; stte

Nice move! If you want to know a more specific name, I see a couple of options depending on how the logic is seen:

Overlapping ALS-XY-Wing:


(9=36)r63c3 - (6=2)r3c8 - (2=39)r6c83 => -9 r6c47

...or:

AALS-XZ:


(9=36)r63c3 - (3|6=29)r36c8 => -9 r6c47

I prefer the latter.

[rjamil]

Hi SpAce,

Many thanks for providing the Sudoku encyclopedia.

I see lot of moves based on the same four cells but different exclusions/eliminations and logics.

Are these moves merged together and produced combined exclusions in single move?

R. Jamil
------------
(Finally, got similar definition with Sudoku Eureka notation. )
A Plan for the Improvement of Spelling in the English Language
By Mark Twain

For example, in Year 1 that useless letter “c” would be dropped to be replased either by “k” or “s”, and likewise “x” would no longer be part of the alphabet. The only kase in which “c” would be retained would be the “ch” formation, which will be dealt with later. Year 2 might reform “w” spelling, so that “which” and “one” would take the same konsonant, wile Year 3 might well abolish “y” replasing it with “i” and iear 4 might fiks the “g/j” anomali wonse and for all.

Generally, then, the improvement would kontinue iear bai iear with iear 5 doing awai with useless double konsonants, and iears 6-12 or so modifaiing vowlz and the rimeiniing voist and unvoist konsonants. Bai iear 15 or sou, it wud fainali bi posibl tu meik ius ov thi ridandant letez “c”, “y” and “x”—bai now jast a memori in the maindz ov ould doderez —tu riplais “ch”, “sh”, and “th” rispektivili.

Fainali, xen, aafte sam 20 iers ov orxogrefkl riform, wi wud hev a lojikl, kohirnt speling in ius xrewawt xe Ingliy-spiking werld.

[SpAce]

I see lot of moves based on the same four cells but different exclusions/eliminations and logics.

Are these moves merged together and produced combined exclusions in single move?

Not as any normal pattern or chain, at least without a lot of redundancy, but it doesn't matter because they all solve the puzzle. If you really want to get them all at the same time, a limited 3D-Medusa will do the trick:

Code: Select all

.----------------.-------------.----------------.
| 28  1    68    | 5   7   3   | 26   4       9 |
| 7   9    5     | 4   6   2   | 18   18      3 |
| 4   23   6'-3" | 8   9   1   | 5    2'-6"   7 |
:----------------+-------------+----------------:
| 5   7    89    | 2   3   68  | 169  169     4 |
| 28  23   1     | 69  4   678 | 679  369     5 |
| 6   4    3'-9" | 19  15  57  | 279  9-2"3"  8 |
:----------------+-------------+----------------:
| 1   5    7     | 3   2   4   | 89   89      6 |
| 9   8    4     | 16  15  56  | 3    7       2 |
| 3   6    2     | 7   8   9   | 4    5       1 |
'----------------'-------------'----------------'

3D-Medusa: "-contradiction in r6c8 => +6 r3c3, +2 r3c8, +3 r6c3, -23 r6c8

However, the coloring can be extended to get a lot more:

Code: Select all

.---------------------.---------------.------------------.
| 2'-8"  1      8'-6" | 5   7   3     | 6'-2"  4       9 |
| 7      9      5     | 4   6   2     | 18     18      3 |
| 4      3'-2"  6'-3" | 8   9   1     | 5      2'-6"   7 |
:---------------------+---------------+------------------:
| 5      7      9'-8" | 2   3   8'-6" | 19-6   169     4 |
| 8'-2"  2'-3"  1     | 69  4   67-8" | 679    3'-69   5 |
| 6      4      3'-9" | 19  15  57    | 2'-79  9-2"3"  8 |
:---------------------+---------------+------------------:
| 1      5      7     | 3   2   4     | 89     89      6 |
| 9      8      4     | 16  15  56    | 3      7       2 |
| 3      6      2     | 7   8   9     | 4      5       1 |
'---------------------'---------------'------------------'

3D-Medusa

Wrap: "-contradiction in r6c8 => 13 '-placements, 3 other "-eliminations
Trap: -6 r4c7

Not much to clean up after that. Of course coloring is more of a solving method than a presentable pattern. I find most of my solutions with coloring (this too -- the above is exactly what I found). Then I just figure out a way to present it more simply. (This puzzle got solved with just 3D-Medusa, which is the second simplest type of coloring after Simple Coloring. Usually more advanced methods are needed.)

[Mauriès Robert]

As a wink to Robert :

Code: Select all

 +-----------------+------------------+-------------------+
 |  28   1    68   |  5    7    3     |  26    4     9    |
 |  7    9    5    |  4    6    2     |  18    18    3    |
 |  4   b23   36   |  8    9    1     |  5     26    7    |
 +-----------------+------------------+-------------------+
 |  5    7    89   |  2    3    68    |  169   169   4    |
 |  28  c23   1    |  69   4    678   |  679   369   5    |
 |  6    4    39   |  19   15   57    |  279 da39-2  8    |
 +-----------------+------------------+-------------------+
 |  1    5    7    |  3    2    4     |  89    89    6    |
 |  9    8    4    |  16   15   56    |  3     7     2    |
 |  3    6    2    |  7    8    9     |  4     5     1    |
 +-----------------+------------------+-------------------+

(2)r6c8 -> (2)r3c2 -> (3)r5c2 -> (3)r6c8 =>contradiction; -2r6c8; ste

Thanks Cenoman, I'm less alone like this!
On peut aussi éviter la contradiction directe en procédant avec une anti-piste :
P'(3r6c8) : -3r6c8 -> 3r6c3 -> 6r3c3 -> 2r3c8 => -2r6c8
Robert