dailysudoku.com Forum Index dailysudoku.com
Discussion of Daily Sudoku puzzles
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Super Hard 062718

 
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Other puzzles
View previous topic :: View next topic  
Author Message
immpy



Joined: 06 May 2017
Posts: 235

PostPosted: Wed Jun 27, 2018 9:17 pm    Post subject: Super Hard 062718 Reply with quote

This one took me quite a while to solve, and indeed almost stumped me.
Maybe the 1-step solvers can crack it more rapidly. I post it because it is simply one of THE hardest puzzles I ever completed. Enjoy all...

Code:

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

Play this puzzle online at the Daily Sudoku site

cheers...immp
Back to top
View user's profile Send private message
ZeroAssoluto



Joined: 05 Feb 2017
Posts: 394
Location: Rimini, Italy

PostPosted: Wed Jun 27, 2018 11:03 pm    Post subject: Reply with quote

Hi everyone,

Code:

+--------------+--------+--------------+
| 246  49  5   | 7 8  1 | 3   269 269  |
| 1    78  28  | 6 3  9 | 27  4   5    |
| 367  379 39  | 2 5  4 | 679 8   1    |
+--------------+--------+--------------+
| 348  1   348 | 9 6  5 | 248 7   248  |
| 78   789 6   | 4 1  2 | 5   3   89   |
| 5    2   49  | 3 7  8 | 469 1   469  |
+--------------+--------+--------------+
| 24   5   1   | 8 9  3 | 246 26  7    |
| 9    6   248 | 1 24 7 | 248 5   3    |
| 2348 348 7   | 5 24 6 | 1   29  2489 |
+--------------+--------+--------------+

Play this puzzle online at the Daily Sudoku site

Discontinuos Nice Loop (?) from r1c2;
if r1c2=9 r3c3=3 r9c2=3 and no number 4 in c2;
so r1c2=4 and basic.

Ciao Gianni
Back to top
View user's profile Send private message
immpy



Joined: 06 May 2017
Posts: 235

PostPosted: Thu Jun 28, 2018 1:38 am    Post subject: Reply with quote

Elegant solution Gianni. Beautiful. I was unable to spot the Discontinuous Nice Loop. I was forced to resort to a finned XY-Wing at this stage, on the 248.
The pivot is located at r8c3 and contains the fin (extra candidate) 2. The pincers are located at r2c3 (28) and r7c1 (24).

In this instance the fin proved true with r8c3=2! I know there are some in the community who frown on this approach, equating it with guessing, but when I have nothing else to grasp onto, as was my dilemma here, I will use it gladly.

As a refresher....EITHER the fin (in this case 2) is true; OR the XY-Wing
(-248) is true. The eliminations that would be made via the XY-Wing eventually lead to a contradiction, thus it is false.

cheers all...immp
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    dailysudoku.com Forum Index -> Other puzzles All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group