The New Sudoku Players' Forum

[hrcjcr]

Started with this puzzle:

Code: Select all

 *-----------*
 |.6.|...|...|
 |3.9|..5|...|
 |.45|2.9|..7|
 |---+---+---|
 |97.|.2.|...|
 |6..|5.1|..9|
 |...|.8.|.12|
 |---+---+---|
 |7..|6.2|15.|
 |...|4..|9.3|
 |...|...|.6.|
 *-----------*

 

and got to here

Code: Select all

 
 *-----------------------------------------------------------------------------*
 | 12      6       7       | 8       134     34      | 2345    9       15      |
 | 3       128     9       | 17      1467    5       | 2468    248     16      |
 | 18      4       5       | 2       136     9       | 368     38      7       |
 |-------------------------+-------------------------+-------------------------|
 | 9       7       1       | 3       2       46      | 4568    48      56      |
 | 6       28      28      | 5       47      1       | 347     347     9       |
 | 45      35      34      | 9       8       67      | 67      1       2       |
 |-------------------------+-------------------------+-------------------------|
 | 7       389     348     | 6       39      2       | 1       5       48      |
 | 15      125     6       | 4       157     8       | 9       27      3       |
 | 2458    123589  2348    | 17      13579   37      | 27      6       48      |
 *-----------------------------------------------------------------------------*



Is there an ALS or Jellyfish that I am just not seeing? Thanks.

[daj95376]

No Jellyfish. I don't know about an ALS. You apparently found an XY-Chain, but missed the subsequent one from [r1c1]..[r9c7]. I found two Unique Rectangles, but they didn't seem to help.

Code: Select all

(48) UR [r79c39] => [r9c3]<>4
(39) UR [r79c25] => [r9c2]<>12


Note: the second UR is more like a forcing net.

Code: Select all

[r7c5]=9 + X-Wing => [r9c2]=9 => [r9c2]<>12358
[r7c5]=3 => [r9c6]=7 => [r9c4]=1,[r9c7]=2 => [r9c2]<>12


Actually, the last net can be extended to where [r9c2]<>8 is derived. Bottom Line: I needed ...

Code: Select all

 -2r1c1  1r1c1  5r1c9  6r4c9  7r6c7  2r9c7  [XY-Chain] <> 2 [r1c7],[r9c1]
 -1r2c9  6r2c9  6r3c5  1r3c1                [chain__5] <> 1 [r2c2]


[Luke]

Code: Select all

(39) UR [r79c25] => [r9c2]<>12

Same x-wing plus UR also means [r9c2]<>3.

Code: Select all

(48) UR [r79c39] => [r9c3]<>4

I think you meant to say [r9c3]<>8.

From there a few XY chains will take it home.

[daj95376]

Code: Select all

(39) UR [r79c25] => [r9c2]<>12

Same x-wing plus UR also means [r9c2]<>3.

Code: Select all

(48) UR [r79c39] => [r9c3]<>4

I think you meant to say [r9c3]<>8.

From there a few XY chains will take it home.

Nice catch on [r9c2]<>3. I missed it.

As for the second UR:

Code: Select all

[r7c3]=  3 => [r6c3]=4 => [r9c3]<>4   -or-
[r9c3]=2|3             => [r9c3]<>4


I missed:

Code: Select all

[r7c3]=  3 => [r7c3]<>4 => [r7c9]=4 => [r9c9]=8 => [r9c3]<>8
[r9c3]=2|3                                      => [r9c3]<>8


[hrcjcr]

daj95376 wrote:

No Jellyfish. I don't know about an ALS. You apparently found an XY-Chain, but missed the subsequent one from [r1c1]..[r9c7]. I found two Unique Rectangles, but they didn't seem to help.

Code:
(48) UR [r79c39] => [r9c3]<>4
(39) UR [r79c25] => [r9c2]<>12


Note: the second UR is more like a forcing net.

Code:
[r7c5]=9 + X-Wing => [r9c2]=9 => [r9c2]<>12358
[r7c5]=3 => [r9c6]=7 => [r9c4]=1,[r9c7]=2 => [r9c2]<>12


Actually, the last net can be extended to where [r9c2]<>8 is derived. Bottom Line: I needed ...

Code:
-2r1c1 1r1c1 5r1c9 6r4c9 7r6c7 2r9c7 [XY-Chain] <> 2 [r1c7],[r9c1]
-1r2c9 6r2c9 6r3c5 1r3c1 [chain__5] <> 1 [r2c2]

Hadn't taken a UR to that degree of depth before as on the (39) UR.
Only needed [r9c2]<>12. The extra numbers from UR (39) and UR (48) were nice though not needed.
After this, the xy-chain above, and xy-chain [r2c9]......[r6c7] it was all down to singles and doubles.
Thanks!

[daj95376]

Actually, XY-Chains are not needed.

Code: Select all

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

   c9b9  Locked Pair                     <> 48   [r8c8],[r9c7]
   c9b9  cloned Pair                     <> 48   [r124c9]
 r6  b4  Locked Triple                   <> 345  [r5c23]
 r6  b4  cloned Triple                   <> 345  [r6c67]
 r5  b4  Naked  Pair                     <> 28   [r5c78]
 r38     X-Wing    finned                <> 1    [r9c1]
 r19     X-Wing    finned                <> 2    [r8c1]
 r69     X-Wing    finned                <> 7    [r8c6]

 +--------------------------------------------------------------------------------+
 |  128     6       7       |  18      134     34      |  23458   9       15      |
 |  3       128     9       |  178     1467    5       |  2468    248     16      |
 |  18      4       5       |  2       136     9       |  368     38      7       |
 |--------------------------+--------------------------+--------------------------|
 |  9       7       1       |  3       2       46      |  4568    48      56      |
 |  6       28      28      |  5       47      1       |  347     347     9       |
 |  45      35      34      |  9       8       67      |  67      1       2       |
 |--------------------------+--------------------------+--------------------------|
 |  7       389     348     |  6       39      2       |  1       5       48      |
 |  15      125     6       |  4       157     8       |  9       27      3       |
 |  2458    123589  2348    |  17      13579   37      |  27      6       48      |
 +--------------------------------------------------------------------------------+
 # 79 eliminations remain

 (48) UR [r79c39] => [r9c3]<>48   (Luke451 and my results combined)

 +--------------------------------------------------------------------------------+
 |  128     6       7       |  18      134     34      |  23458   9       15      |
 |  3       128     9       |  178     1467    5       |  2468    248     16      |
 |  18      4       5       |  2       136     9       |  368     38      7       |
 |--------------------------+--------------------------+--------------------------|
 |  9       7       1       |  3       2       46      |  4568    48      56      |
 |  6       28      28      |  5       47      1       |  347     347     9       |
 |  45      35      34      |  9       8       67      |  67      1       2       |
 |--------------------------+--------------------------+--------------------------|
 |  7       389     348     |  6       39      2       |  1       5       48      |
 |  15      125     6       |  4       157     8       |  9       27      3       |
 |  2458    123589  23      |  17      13579   37      |  27      6       48      |
 +--------------------------------------------------------------------------------+
 # 77 eliminations remain

 r9      Naked  Triple                   <> 237  [r9c1245]
   c58   X-Wing                          <> 7    [r5c7]
         XY-Wing  [r4c8]/[r3c8]+[r5c7]   <> 3    [r13c7],[r5c8]
         XY-Wing  [r2c9]/[r2c2]+[r3c7]   <> 8    [r2c78],[r3c1]


[Luke]

Code: Select all

 
 *-----------------------------------------------------------------------------*
 | 12      6       7       | 8       134     34      | 2345    9       15      |
 | 3      -128     9       | 17      1467    5       | 2468    248    #16      |
 |*18      4       5       | 2       136     9       |*368    *38      7       |
 |-------------------------+-------------------------+-------------------------|
 | 9       7       1       | 3       2       46      | 4568    48      56      |
 | 6       28      28      | 5       47      1       | 347     347     9       |
 | 45      35      34      | 9       8       67      | 67      1       2       |
 |-------------------------+-------------------------+-------------------------|
 | 7       389     348     | 6       39      2       | 1       5       48      |
 | 15      125     6       | 4       157     8       | 9       27      3       |
 | 2458    123589  2348    | 17      13579   37      | 27      6       48      |
 *-----------------------------------------------------------------------------*


Is there an ALS or Jellyfish that I am just not seeing? Thanks.

To me an ALS pattern is a needle/haystack proposition. The only ones I ever find are the most basic, ones that work off of a single bivalue cell like [r2c9].

The [6] is the "restricted" and the [1] is the "other."

[hobiwan]

Is there an ALS or Jellyfish that I am just not seeing? Thanks.

I can't see a single ALS that does the trick. The shortest solution with ALS I can find is:

Code: Select all

Almost Locked Set XY-Wing: A=r3c78 - {368}, B=r146c6 - {3467}, C=r6c7 - {67}, Y,Z=6,7, X=3 => r1c7,r3c5<>3
Almost Locked Set XY-Wing: A=r1c1 - {12}, B=r69c7 - {267}, C=r14c9 - {156}, Y,Z=1,6, X=2 => r1c7,r9c1<>2
Hidden Single: r1c1=2
W-Wing: 6/1 in r2c9,r3c5 connected by 1 in r1c59 => r2c5,r3c7<>6
Singles

A little bit longer, but with ALS-XZ instead of ALS-XY:

Code: Select all

Almost Locked Set XZ-Rule: A=r69c7 - {267}, B=r2c78,r3c78 - {23468}, X=6, Z=2 => r1c7<>2
Almost Locked Set XZ-Rule: A=r3c8 - {38}, B=r23569c7 - {234678}, X=8, Z=3 => r1c7<>3
Hidden Single: r1c1=2
Locked Candidates Type 1 (Pointing): 3 in b3 => r3c5<>3
W-Wing: 6/1 in r2c9,r3c5 connected by 1 in r1c59 => r2c5,r3c7<>6
Singles

A "pure" ALS solution would be (bit out of scope for a human player though):

Code: Select all

Almost Locked Set XY-Chain: A=r1c1569 - {12345}, B=r4c69 - {456}, C=r5c5 - {47}, D=r8c125 - {1257}, E=r25c2 - {128}, F=r2c789,r3c78 - {123468}, RCs=1,2,4,5,7, X=2,3,4 => r1c7<>2, r1c7,r3c5<>3, r1c7,r2c5<>4
Singles

Is there a possibility to write that in Nice Loop Notation? Especially how would you see the RCs between the ALS. Weak inferences? Strong inferences?
A try for cell r1c7:

Code: Select all

r1c7 -2|3|4- ALS:r1c1569 -5- ALS:r4c69 -4- r5c5 -7- ALS:r8c125 -2- r25c2 -1- r2c789,r3c78 -2|3|4- r1c7 -> r1c7<>234