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Free Press, February 27, 2009

 
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
PostPosted: Sat Feb 28, 2009 8:14 pm    Post subject: Free Press, February 27, 2009 Reply with quote
Code:
Puzzle: FP022709
+-------+-------+-------+
| . . . | . 4 . | . . . |
| . . 3 | . 6 . | . 7 9 |
| . 7 . | . . . | 8 6 . |
+-------+-------+-------+
| 1 . . | . . 7 | . . . |
| 2 . . | . . . | 3 . 4 |
| . . . | 5 . . | . . 2 |
+-------+-------+-------+
| . 1 9 | . . . | . 2 . |
| . 8 2 | . 1 . | 9 . . |
| . . . | . 3 . | . . . |
+-------+-------+-------+

Quote:
I'd love to see a solution that does not use the UR!!
Keith
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storm_norm



Joined: 18 Oct 2007
Posts: 1741
PostPosted: Sat Feb 28, 2009 11:45 pm    Post subject: Reply with quote
Code:
.------------------.------------------.------------------.
| 689   69    168  | 7     4     39   | 2     35    135  |
| 5     2     3    | 18    6     18   | 4     7     9    |
| 49    7     14   | 29    5     239  | 8     6     13   |
:------------------+------------------+------------------:
| 1    U459   458  | 3     2     7    | 56   U589   568  |
| 2    U59    7    | 16    89    16   | 3    U589   4    |
| 689   3     68   | 5     89    4    | 7     1     2    |
:------------------+------------------+------------------:
| 346   1     9    | 468   7     568  | 56    2     356  |
| 3467  8     2    | 46    1     56   | 9     345   3567 |
| 467  -456   456  | 29    3     29   | 1    *48    678  |
'------------------'------------------'------------------'

the UR on {5,9} r45c28 says that either the 4 is true in r4c2 or the 8's are true in r45c8. and the chain extends down to r9c8 (8=4) eliminates the 4 from r9c2.
like this...
UR59[(4)r4c2 = (8)r45c8] - (8=4)r9c8; r9c2 <> 4

Code:
.------------------.------------------.------------------.
| 689   69    168  | 7     4     39   | 2     35    135  |
| 5     2     3    | 18    6     18   | 4     7     9    |
|*49    7    *14   | 29    5     239  | 8     6     13   |
:------------------+------------------+------------------:
| 1     4     58   | 3     2     7    | 56    9     568  |
| 2    *59    7    | 16    89    16   | 3     58    4    |
|68-9   3     68   | 5     89    4    | 7     1     2    |
:------------------+------------------+------------------:
| 346   1     9    | 468   7     568  | 56    2     356  |
| 3467  8     2    | 46    1     56   | 9     345   3567 |
| 467  *56   *456  | 29    3     29   | 1     48    678  |
'------------------'------------------'------------------'

the shortest chain I could find to finish it was...
(9=5)r5c2 - (5)r9c2 = (5-4)r9c3 = (4)r3c3 - (4=9)r3c1; r6c1 <> 9
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
PostPosted: Sun Mar 01, 2009 12:15 am    Post subject: Reply with quote
Medusa solves it. So does the UR on 56. Either r4c9 = 8 or r7c9 = 3. Each possibility results in 6 & 8 in r4c7 and r4c9.
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Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA
PostPosted: Sun Mar 01, 2009 12:21 am    Post subject: Reply with quote
Keith,

I couldn't find a non-DP solution that didn't involve a chain. Without too much difficulty, I found an ALS chain that includes an ER:
(9)r1c12|r3c46 - (9=3)r1c6 - (3=5)r1c8 - ALS(5=8)r45c8 - (8=4)r9c8 - ER[(4)r9c123=(4)r789c1] - (4=9)r3c1 - (9)r1c12|r3c46; r1c12|r3c46<>9
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
PostPosted: Sun Mar 01, 2009 12:22 am    Post subject: Reply with quote
Norm,

The Type-1 23(9) UR in R39C46 blows it wide open.

If you do not use Uniqueness arguments, this is a very difficult puzzle!

Keith
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daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Sun Mar 01, 2009 1:34 am    Post subject: Reply with quote
keith wrote:
If you do not use Uniqueness, this is a very difficult puzzle!

Code:
 prior to UR Type 1
 +--------------------------------------------------------------+
 |  689   69    168   |  7     4     39    |  2     35    135   |
 |  5     2     3     |  18    6     18    |  4     7     9     |
 |  49    7     14    |  29    5     239   |  8     6     13    |
 |--------------------+--------------------+--------------------|
 |  1     459   458   |  3     2     7     |  56    589   568   |
 |  2     59    7     |  16    89    16    |  3     589   4     |
 |  689   3     68    |  5     89    4     |  7     1     2     |
 |--------------------+--------------------+--------------------|
 |  346   1     9     |  468   7     568   |  56    2     356   |
 |  3467  8     2     |  46    1     56    |  9     345   3567  |
 |  467   456   456   |  29    3     29    |  1     48    678   |
 +--------------------------------------------------------------+
 # 66 eliminations remain

                    (4=1)r3c3 - (1=3)r3c9 - (3)r1c8 = (3-4)r8c8 = (4)r9c8 => [r9c3]<>4
(4)r4c2 = (4)r4c3 - (4=1)r3c3 - (1=3)r3c9 - (3)r1c8 = (3-4)r8c8 = (4)r9c8 => [r9c2]<>4
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storm_norm



Joined: 18 Oct 2007
Posts: 1741
PostPosted: Sun Mar 01, 2009 2:30 am    Post subject: Reply with quote
keith wrote:
Norm,

The Type-1 23(9) UR in R39C46 blows it wide open.

If you do not use Uniqueness arguments, this is a very difficult puzzle!

Keith

keith, I did skip the type 1
as you proposed in your comment.
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daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Sun Mar 01, 2009 5:53 pm    Post subject: Reply with quote
Code:
 prior to UR Type 1
 +--------------------------------------------------------------+
 |  689   69    168   |  7     4     39    |  2     35    135   |
 |  5     2     3     |  18    6     18    |  4     7     9     |
 | @49    7     14    |  29    5     239   |  8     6     13    |
 |--------------------+--------------------+--------------------|
 |  1     459   458   |  3     2     7     |  56    589   568   |
 |  2     59    7     |  16    89    16    |  3     589   4     |
 |  689   3     68    |  5     89    4     |  7     1     2     |
 |--------------------+--------------------+--------------------|
 | *346   1     9     | *468   7     568   |  56    2     356   |
 | *3467  8     2     | *46    1     56    |  9    *345   3567  |
 | *467   56-4  56-4  |  29    3     29    |  1    *48    678   |
 +--------------------------------------------------------------+
 # 66 eliminations remain

How about Kraken Swordfish c148\r789 w/kraken cell [r3c1] (ala Mike Barker approach)?

Code:
1a) Swordfish c148\r789                                             => [r9c23]<>4

1b) (4)r3c1 - (4=1)r3c3 - (1=3)r3c9 - (3)r1c8 = (3-4)r8c8 = (4)r9c8 => [r9c23]<>4
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keith



Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA
PostPosted: Sun Mar 01, 2009 6:47 pm    Post subject: Reply with quote
storm_norm wrote:
keith wrote:
Norm,

The Type-1 23(9) UR in R39C46 blows it wide open.

If you do not use Uniqueness arguments, this is a very difficult puzzle!

Keith

keith, I did skip the type 1
as you proposed in your comment.


Norm, you are correct. Sorry about that.

Keith Embarassed
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