SudoCue Users

Posted: **Thu Dec 28, 2006 6:12 pm**

This is the position in the 28 Dec 2006 Nightmare, after initial eliminations from basic techniques:

.------------------.-------------------.------------------.
| 1237  4    *236  | 9     56     8    | 567   27    137  |
| 237  *267   9    | 56    4      1    | 5678  278   378  |
| 5    *16    8    | 3     2      7    | 69    4     19   |
&#58;------------------+-------------------+------------------&#58;
| 18   *156   4    | 56    13567  35   | 78    9     2    |
|-289  *256  *26   |-24    5679  -2459 | 3     1     78   |
| 1-29  3     7    | 8     19     29   | 4     56    56   |
&#58;------------------+-------------------+------------------&#58;
| 4     8     1    | 7     59     6    | 2     3     59   |
| 6     27    5    | 1     389    2349 | 789   78    4789 |
| 237   9     23   | 24    58     245  | 1     5678  45678|
'------------------'-------------------'------------------'

After eliminations from the following chain (cells marked with "*" in the diagram), the solution is completed with singles only:

(2=6)r5c3 - (6)r1c3 = (6)r2c2 - (6=152)r345c2 => r5c146, r6c1 <> 2

Posted: **Fri Jan 05, 2007 1:16 am**

Hate to spoil your fun, Ron; but if your grid is correct, there is no obvious (6)r1c3 = (6)r2c2 strong link. The 6 in r3c2 messes you up.

There is a nice little 56-UR in r69c89 which can only be escaped via the 5 in r7c9. Might as well hit the low hanging fruit.

Posted: **Mon Jan 08, 2007 12:57 am**

Ugh! No excuse for that. I think I had one too many (puzzles at one stretch).

Posted: **Tue Jan 09, 2007 7:16 pm**

Once you do the simple eliminations from the UR, there is a strong chain on 7 at r9c9->r9c1->r8c2->r2c2 that eliminates 7 from r2c9

followed by a strong/weak chain on value 2 at r5c2->r5c4->r9c4->r8c6->r8c2 eliminating 2 from r5c2

after another cople of simple steps there's a strong/weak chain on 5 at r1c5->r2c4->r2c7->r3c7->r3c9->r3c2->r5c2 removing 5 from r5c5

There are then a couple of real tricky to spot chains
r5c9->r4c7->r4c1->r4c2->r3c2->r3c9->r3c7->r2c7->r2c4->r1c5->r9c5 removing 8 from r9c9

then (1)r1c1->(1)r1c9->(3)r1c9->(3)r2c9->(8)r2c9->(8)r2c8->(2)r2c8->(2)r1c8 removing 2 from r1c1 and 1 from r1c8

then (1)r1c1->(1)r1c9->(3)r1c9->(3)r2c9->(8)r2c9->(8)r2c8->(8)r8c8->(7)r8c8->(7)r8c2->(7)r2c2 removing 7 from r1c1 and 1 from r2c2

finally r1c1->r3c2->r4c2->r4c1->r4c7->r5c9->r2c9 3 from r1c9 r2c1

after that, it's singles

SudoCue Users

28 Dec 2006 Nightmare: Quick Solution

28 Dec 2006 Nightmare: Quick Solution

Guilty as Charged