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Puzzle 11/08/23: ~ Advanced (BBDB)

 
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daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Tue Aug 23, 2011 2:04 pm    Post subject: Puzzle 11/08/23: ~ Advanced (BBDB) Reply with quote
Code:
 +-----------------------+
 | 3 . . | . 5 . | . . 9 |
 | . 2 . | . 9 . | 7 6 4 |
 | . . 6 | . . 7 | . . 5 |
 |-------+-------+-------|
 | . . . | 9 . . | . 7 1 |
 | 6 1 . | . . . | . 5 . |
 | . . 2 | . . 5 | . . . |
 |-------+-------+-------|
 | . 3 . | . . . | . 2 6 |
 | . 6 . | 3 2 . | 9 . 7 |
 | 2 9 7 | 5 . . | 3 4 . |
 +-----------------------+

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Luke451



Joined: 20 Apr 2008
Posts: 310
Location: Southern Northern California
PostPosted: Tue Aug 23, 2011 8:12 pm    Post subject: Reply with quote
Found as an "almost" remote pair, presented as an oddagon:
Code:
*-----------------------------------------------------------*
 | 3     7     14    | 1246  5     16    | 12    8     9     |
 | 158   2     158   | 18    9     3     | 7     6     4     |
 | 9    *48    6     | 1248 *48+1  7     | 12    3     5     |
 |-------------------+-------------------+-------------------|
 |*48    5     3     | 9    *48+6  2     | 468   7     1     |
 | 6     1     9     | 7     3     48    | 48    5     2     |
 | 7    *48    2     | 1468  1468  5     | 468   9     3     |
 |-------------------+-------------------+-------------------|
 | 148   3     148   | 48    7     9     | 5     2     6     |
 | 458   6     458   | 3     2     48    | 9     1     7     |
 | 2     9     7     | 5     16    16    | 3     4     8     |
 *-----------------------------------------------------------*

oddagon(48*) [(6)r4c5=(1)r3c5]-(1)r6c5=(1)r6c4 =>r6c4<>6

There's also an "at a glance" solution if one utilizes the QNP (quantum naked pair) in column 5 Idea

(edit: changed QNT to QNP. There are three kinds of people...those who can count and those who can't.)
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
PostPosted: Thu Aug 25, 2011 1:01 am    Post subject: Reply with quote
Examining the potential 58 DP in boxes 17. Either:

r2c13=1-->r2c4=8 or

r8c13=4-->r8c6=8

With pincers, r7c4<>8

Code:

+------------+--------------+---------+
| 3   7  14  | 1246 5    16 | 12  8 9 |
| 158 2  158 | 18   9    3  | 7   6 4 |
| 9   48 6   | 1248 148  7  | 12  3 5 |
+------------+--------------+---------+
| 48  5  3   | 9    468  2  | 468 7 1 |
| 6   1  9   | 7    3    48 | 48  5 2 |
| 7   48 2   | 1468 1468 5  | 468 9 3 |
+------------+--------------+---------+
| 148 3  148 | 48   7    9  | 5   2 6 |
| 458 6  458 | 3    2    48 | 9   1 7 |
| 2   9  7   | 5    16   16 | 3   4 8 |
+------------+--------------+---------+

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daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Thu Aug 25, 2011 2:17 am    Post subject: Reply with quote
Marty, and excellent find based on internal UR constraints. You could have also used external constraints and derived r2c4=8 and/or r8c6=8 directly.
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