The New Sudoku Players' Forum

[daj95376]

Hopefully, I haven't already posted this puzzle and PM. (my recordkeeping is terrible!)

Code: Select all

 +-----------------------+
 | . . 3 | 7 . 5 | . . 6 |
 | . 8 7 | . . 9 | . 3 . |
 | 2 6 . | . . . | . . . |
 |-------+-------+-------|
 | 8 . . | . . 7 | . . . |
 | . . . | . 8 4 | . 6 7 |
 | 6 7 . | 3 1 . | 8 . . |
 |-------+-------+-------|
 | . . . | . . 3 | 5 . . |
 | . 2 . | . 7 . | . 9 . |
 | 5 . . | . 9 . | . . . |
 +-----------------------+   # P_Set_A: 20


Code: Select all

 +-----------------------------------------------------------------------+
 |  9      1      3      |  7      24     5      |  24     8      6      |
 |  4      8      7      |  12     6      9      |  12     3      5      |
 |  2      6      5      |  148    3      18     |  1479   147    149    |
 |-----------------------+-----------------------+-----------------------|
 |  8      34     149    |  6      5      7      |  1349   124    12349  |
 |  13     5      2      |  9      8      4      |  13     6      7      |
 |  6      7      49     |  3      1      2      |  8      5      49     |
 |-----------------------+-----------------------+-----------------------|
 |  7      9      6      |  248    24     3      |  5      12     128    |
 |  13     2      148    |  5      7      168    |  346    9      348    |
 |  5      34     148    |  128    9      168    |  67     247    238    |
 +-----------------------------------------------------------------------+


[submacrolize]

You can view the solution here.

Click on the gray squares that you want to see. Right click to view the whole solution

[Steve R]

Code: Select all

+-------------------------------------------------------------+
|  9    1    3    |  7      24   5    | *24     8      6      |
|  4    8    7    |  12     6    9    | *12     3      5      |
|  2    6    5    |  148    3    18   |  1479   147    149    |
|-----------------+-------------------+-----------------------|
|  8    34   149  |  6      5    7    | *1349   124    12349  |
|  13   5    2    |  9      8    4    | *13     6      7      |
|  6    7    49   |  3      1    2    |  8      5      49     |
|-----------------+-------------------+-----------------------|
|  7    9    6    |  248    24   3    |  5     †12    †128    |
|  13   2    148  |  5      7    168  |  346    9     †348    |
|  5    34   148  |  128    9    168  |  67     247   †238    |
+-------------------------------------------------------------+

It’s ugly but you could:

1 Eliminate 3 from r8c7 using the ALS loop
r8c7 -3- {r1c7, r2c7, r4c7, r5c7} -9- r6c9 -4- {r7c8, r7c9, r8c9, r9c9} -3- r8c7.
2 Eliminate 3 from r5c1 using the XY loop
r5c1 -3- r5c7 -1- r2c7 -(2- r2c4 -1- r3c6 -8)(2- r1c7 -4- r8c7 -6)- r8c6 -1- r8c1 -3- r5c1.

Steve

[hobiwan]

1 Eliminate 3 from r8c7 using the ALS loop
r8c7 -3- {r1c7, r2c7, r4c7, r5c7} -9- r6c9 -4- {r7c8, r7c9, r8c9, r9c9} -3- r8c7.

If you see it as an ALS XY-Wing it eliminates 3 in r4c9 as well:
Almost Locked Set XY-Wing: A=r1245c7 - {12349}, B=r7c89,r89c9 - {12348}, C=r6c9 - {49}, Y,Z=4,9, X=3 => r4c9,r8c7<>3

Another possibilitiy with ALS is:
Almost Locked Set XY-Wing: A=r3c469 - {1489}, B=r47c8 - {124}, C=r6c9 - {49}, Y,Z=4,9, X=1 => r3c8<>1

Aside from that I have some Forcing Chains, but daj95376 probably has them already.

When starting with one of the above ALS moves, my solver needs another Forcing Chain, an X-Wing, XYZ-Wing and W-Wing.

[daj95376]

Thanks Steve.

A nice solution that my solver should have caught. You ALS Loop helped me track down a setting that restricted the reporting of forcing chains to only the shortest ones at a time. This caused many good forcing chains to be delayed in the solution for this PM.

Thanks again!

Danny

[Steve K]

An ugly possible alternate path:
aur aaic using kraken cell (348)r8c9: aur 12 r47c89 => sis[(8)r7c9=(1)r45c7] using np12-hp12=>
(1)r45c7=[(1=als849*3)r3678c9-(3=1)r8c1-(1)r5c1=(1)r5c7] => r23c7<>1 some singles
(7=1)r3c8-(1=9r3c9-(9=4)r6c9-(4)r4c8=(4)r9c8 => r9c8<>7 singles to end
also: (als12=4)r47c8-(4=9)r6c9-(9=1)r3c9 => r3c8<>1 singles to end