## December 31, 2019

Post puzzles for others to solve here.

### December 31, 2019

Code: Select all
`+-------+-------+-------+| . . 4 | . . . | 7 . . || 3 . . | . 9 . | . . 8 || . 9 . | . . . | . 5 . |+-------+-------+-------+| . . . | 8 . 6 | . . . || 2 3 . | . 4 . | . 8 1 || . . . | 7 . 2 | . . . |+-------+-------+-------+| 8 . . | 3 7 1 | . . 9 || 4 . . | 9 . 8 | . . 5 || . 1 3 | . . . | 8 7 . |+-------+-------+-------+..4...7..3...9...8.9.....5....8.6...23..4..81...7.2...8..371..94..9.8..5.13...87.`

Apologies but this one apears to be more difficult than the planned scope of the daily sudoku by a notch or 2
ER=7.3 with a few forcing chains
If I'm still posting these puzzles after this batch of puzzles finish then I'll select them more carefully.

Play this puzzle online at the Daily Sudoku site

tarek

Posts: 3366
Joined: 05 January 2006

### Re: December 31, 2019

2 steps.
Code: Select all
`+-------------------+--------------------+-------------------+| 16    268   4     | 126   d2568 c35    | 7     9    b236   || 3     256   1256  | 1246   9     7     | 124   146   8     || 7     9     1268  | 1246 d#26+8  34    | 1234  5   a#26+34 |+-------------------+--------------------+-------------------+| 15    4     19    | 8      3     6     | 59    2     7     || 2     3     7     | 5      4     9     | 6     8     1     || 56    68    689   | 7      1     2     | 59    34   a34    |+-------------------+--------------------+-------------------+| 8    #256  #256   | 3      7     1     |#24   #46    9     || 4     7    #26    | 9     #26    8     | 13    13    5     || 9     1     3     | 246    256   45    | 8     7    #26    |+-------------------+--------------------+-------------------+`

7-link oddagon 26 in #-marked cells, guardians 8r3c5, 34r3c9
34r36c9 - 3r1c9 = (3-5)r1c6 = 58r13c5
=> 8r3c5, solves with (grouped) skyscraper 2.

HNY to all.

eleven

Posts: 2239
Joined: 10 February 2008

### Re: December 31, 2019

Can't compete with eleven's solution !
Here is a slight variation:
I had the following two "parallel" krakens (plus the skyscraper) and wondered how to merge them into one step.
Hidden Text: Show
Kraken (2)r139c9
(2-3)r1c9 = (358)b2p238
(2)r3c9
(2)r9c9 - r9c45 = (2)r8c5
=>-2r3c5

Kraken (6)r139c9
(6-3)r1c9 = (358)b2p238
(6)r3c9
(6)r9c9 - r9c45 = (6)r8c5
=>-6r3c5

The result:
Code: Select all
` +--------------------+---------------------+----------------------+ |  16   268   4      |  126   b2568  b35   |  7      9    a236    |  |  3    256   1256   |  1246   9      7    |  124    146   8      |  |  7    9     1268   |  1246  b8-26   34   |  1234   5    A2346X  |  +--------------------+---------------------+----------------------+ |  15   4     19     |  8      3      6    |  59     2     7      |  |  2    3     7      |  5      4      9    |  6      8     1      |  |  56   68    689    |  7      1      2    |  59     34    34     |  +--------------------+---------------------+----------------------+ |  8    256   256    |  3      7      1    |  24     46    9      |  |  4    7     26     |  9     Z26C    8    |  13     13    5      |  |  9    1     3      | Y246B  Y256B   45   |  8      7    X26A    |  +--------------------+---------------------+----------------------+`

1. Almost hidden pair (26)r39c9, considering each of its two configurations:
(2|6-3)r1c9 = (358)b2p238
(2)r3c9^ & (6)r9c9 - r9c45 = (6)r8c5
(6)r3c9^ & (2)r9c9 - r9c45 = (2)r8c5
=> -26 r3c5; 11 placements and basics

2. Skyscraper (2)r1c5 = r1c9 - r9c9 = r9c45 => -2 r8c5; ste
Cenoman
Cenoman

Posts: 1235
Joined: 21 November 2016
Location: Paris, France