The New Sudoku Players' Forum

[ArkieTech]

Code: Select all

 *-----------*
 |..1|.5.|2..|
 |6..|...|..3|
 |29.|4.3|.87|
 |---+---+---|
 |...|.7.|...|
 |.7.|6.5|.1.|
 |8..|1.2|..5|
 |---+---+---|
 |7..|8.6|..4|
 |...|.2.|...|
 |..8|.1.|3..|
 *-----------*


Play/Print this puzzle online

[tlanglet]

Code after basics:

Code: Select all

*-----------------------------------------------------------*
 | 34    348   1     | 79    5     789   | 2     469   69    |
 | 6     48    7     | 2     89    1     | 49    5     3     |
 | 2     9     5     | 4     6     3     | 1     8     7     |
 |-------------------+-------------------+-------------------|
 | 1     5     2349  | 39    7     89    | 6     349   28    |
 | 349   7     2349  | 6     3489  5     | 49    1     28    |
 | 8     346   3469  | 1     349   2     | 7     349   5     |
 |-------------------+-------------------+-------------------|
 | 7     1     39    | 8     39    6     | 5     2     4     |
 | 3459  346   3469  | 3579  2     479   | 8     79    1     |
 | 459   2     8     | 579   1     479   | 3     679   69    |
 *-----------------------------------------------------------*


This solution can be viewed in multiple ways; I post it as a Kraken row.
9r7c3-r456c3=r5c1-r5c7=r2c7-(9=8)r2c5
9r7c5-(9=8)r2c5 => r2c5=8

[ArkieTech]

Code: Select all

 
 *-----------------------------------------------------------*
 | 34    348   1     | 79    5     789   | 2     469   69    |
 | 6     48    7     | 2    *89    1     |*49    5     3     |
 | 2     9     5     | 4     6     3     | 1     8     7     |
 |-------------------+-------------------+-------------------|
 | 1     5     2349  | 39    7     89    | 6     349   28    |
 | 349   7     2349  | 6     3489  5     | 4-9   1     28    |
 | 8     346  *3469  | 1    *349   2     | 7    f349   5     |
 |-------------------+-------------------+-------------------|
 | 7     1    *39    | 8    *39    6     | 5     2     4     |
 | 3459  346   3469  | 3579  2     479   | 8     79    1     |
 | 459   2     8     | 579   1     479   | 3     679   69    |
 *-----------------------------------------------------------*
finned swordfish
(9r6c8=r2c7)sf:r267c357 => -9r5c7; stte

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[ronk]

This solution can be viewed in multiple ways; I post it as a Kraken row.
9r7c3-r456c3=r5c1-r5c7=r2c7-(9=8)r2c5
9r7c5-(9=8)r2c5 => r2c5=8

Nice stte solution, but I think you mean Double Implication Chain ("DIC"). A kraken-row would have three or more ungrouped candidates in r7.

ArkieTech, in case you're not aware, dailysudoku's discussion forum has been operational since 10/23.

[ArkieTech]

ArkieTech, in case you're not aware, dailysudoku's discussion forum has been operational since 10/23.

I am aware and have decided to post here. Unless there is objection.

[ronk]

ArkieTech, in case you're not aware, dailysudoku's discussion forum has been operational since 10/23.

I am aware and have decided to post here. Unless there is objection.

No objection from me. That's a decision for the admin and moderators.

[tlanglet]

This solution can be viewed in multiple ways; I post it as a Kraken row.
9r7c3-r456c3=r5c1-r5c7=r2c7-(9=8)r2c5
9r7c5-(9=8)r2c5 => r2c5=8

Nice stte solution, but I think you mean Double Implication Chain ("DIC"). A kraken-row would have three or more ungrouped candidates in r7.

Ron, thanks for the homework assignment. I need to review my understanding of a Kraken row, and I have only seen references to a DIC.

[Marty R.]

Code: Select all

*-----------------------------------------------------------*
 | 34    348   1     | 79    5     789   | 2     469   69    |
 | 6     48    7     | 2     89    1     | 49    5     3     |
 | 2     9     5     | 4     6     3     | 1     8     7     |
 |-------------------+-------------------+-------------------|
 | 1     5     2349  | 39    7     89    | 6     349   28    |
 | 349   7     2349  | 6     3489  5     | 49    1     28    |
 | 8     346   3469  | 1     349   2     | 7     349   5     |
 |-------------------+-------------------+-------------------|
 | 7     1     39    | 8     39    6     | 5     2     4     |
 | 3459  346   3469  | 3579  2     479   | 8     79    1     |
 | 459   2     8     | 579   1     479   | 3     679   69    |
 *-----------------------------------------------------------*

Skyscraper (9) in rows 27 with transport of 9 from r7c3 to r5c1; r5c7<>9.

I have been trying to learn notation (with generous help from Ted) and here's my attempt, critique welcome, as always.

(9=4)r2c7-(8=9)r2c5-(9=3)r7c5-(3=9)r7c3-r456c3=9r5c1-->r5c7<>9.

[JC Van Hay]

I think you wanted to write : (9=4)r2c7-(4=8)r2c2-(8=9)r2c5-(9=3)r7c5-(3=9)r7c3-r456c3=9r5c1-->r5c7<>9.
As you did it in the last SL, you can drastically shorten the chain :

Instead of (9=4)r2c7-(4=8)r2c2-(8=9)r2c5, you can directly write 9r2c7=9r2c5.
Idem for (9=3)r7c5-(3=9)r7c3 : 9r7c5=9r7c3.

The shortened chain reads now : 9r2c7=9r2c5-9r7c5=9r7c3-9r456c3=9r5c1.

Further comment : 9B4R7 is an Empty rectangle eliminating 9r5c5. With 9R2, the resulting Swordfish eliminates 2 candidates : r5c57<>9

[Marty R.]

I think you wanted to write : (9=4)r2c7-(4=8)r2c2-(8=9)r2c5-(9=3)r7c5-(3=9)r7c3-r456c3=9r5c1-->r5c7<>9.
As you did it in the last SL, you can drastically shorten the chain :

Instead of (9=4)r2c7-(4=8)r2c2-(8=9)r2c5, you can directly write 9r2c7=9r2c5.
Idem for (9=3)r7c5-(3=9)r7c3 : 9r7c5=9r7c3.

The shortened chain reads now : 9r2c7=9r2c5-9r7c5=9r7c3-9r456c3=9r5c1.

Further comment : 9B4R7 is an Empty rectangle eliminating 9r5c5. With 9R2, the resulting Swordfish eliminates 2 candidates : r5c57<>9

Thank you JC. I never considered using r2c2 because that was never a part of the Skyscraper. What I was trying to say in the first step was that if r2c7<>9 then r2c5=9.

[ArkieTech]

Double implication chain..?

9r7c3-r456c3=r5c1-r5c7=r2c7-(9=8)r2c5
9r7c5-(9=8)r2c5 => r2c5=8

I call it a discontinuous loop

Code: Select all

  *-----------------------------------------------------------*
 | 34    348   1     | 79    5     789   | 2     469   69    |
 | 6     48    7     | 2    *89    1     |a49    5     3     |
 | 2     9     5     | 4     6     3     | 1     8     7     |
 |-------------------+-------------------+-------------------|
 | 1     5    d2349  | 39    7     89    | 6     349   28    |
 |c349   7    d2349  | 6     3489  5     |b49    1     28    |
 | 8     346  d3469  | 1     349   2     | 7     349   5     |
 |-------------------+-------------------+-------------------|
 | 7     1    e39    | 8    f39    6     | 5     2     4     |
 | 3459  346   3469  | 3579  2     479   | 8     79    1     |
 | 459   2     8     | 579   1     479   | 3     679   69    |
 *-----------------------------------------------------------*


(8=9)r2c5-r2c7=r5c7-r5c1=r456c3-r7c3 = r7c5-(9=8)r2c5 => 8r2c5


[7b53]

Double implication chain..?

9r7c3-r456c3=r5c1-r5c7=r2c7-(9=8)r2c5
9r7c5-(9=8)r2c5 => r2c5=8

I call it a discontinuous loop

can we also call it a forcing chain..?
as r25c7 will do the same.