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Puzzle 11/04/08: ~ Difficult++

 
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daj95376



Joined: 23 Aug 2008
Posts: 3854
PostPosted: Fri Apr 08, 2011 6:11 am    Post subject: Puzzle 11/04/08: ~ Difficult++ Reply with quote
Code:
 +-----------------------+
 | . . . | . . . | . 2 . |
 | . . 8 | . . 3 | . 7 . |
 | . 6 1 | 2 . . | . 8 3 |
 |-------+-------+-------|
 | . . 3 | 4 . 5 | . . 7 |
 | . . . | . . 7 | . 5 . |
 | . 7 . | 6 2 . | . 3 9 |
 |-------+-------+-------|
 | . . . | . . . | 3 . . |
 | 5 3 6 | . 9 2 | . . . |
 | . . 7 | 3 . 6 | . . 8 |
 +-----------------------+

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JC Van Hay



Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium
PostPosted: Fri Apr 08, 2011 10:31 am    Post subject: Reply with quote
Quote:
The bivalues in C3, C7\NP(19), R3, B6, B9 form a huge boolean variable. By colouring these bivalues, it is observed that for one of the colour the DP(18)R57C12 is obtained. The other colour solves the puzzle.
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peterj



Joined: 26 Mar 2010
Posts: 974
Location: London, UK
PostPosted: Fri Apr 08, 2011 10:46 am    Post subject: Reply with quote
Two steps - could be combined into an 'almost'..
Quote:
AIC ; (9=4)r1c3 - r5c3=r5c9 - r6c7=r3c7 - (4=5)r3c5 - (5=1)r2c4 - (1=9)r2c7 ; r1c7<>9
w-wing(29) (2=9)r4c2 - r1c2=r1c3 - (9=2)r7c3 ; r5c3<>2, r79c2<>2
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JC Van Hay



Joined: 13 Jun 2010
Posts: 494
Location: Charleroi, Belgium
PostPosted: Fri Apr 08, 2011 10:48 am    Post subject: Reply with quote
Eureka notation (or "solution" for some)
Quote:
6r5c1=2r7c123(because of UR subset)-2r7c9=2r5c9-(2=68)r45c7 => -6r5c7
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peterj



Joined: 26 Mar 2010
Posts: 974
Location: London, UK
PostPosted: Fri Apr 08, 2011 11:38 am    Post subject: Reply with quote
JC Van Hay wrote:
Eureka notation (or "solution" for some)

JC, nice UR move. Just out of interest why the als at the end?
I read your move from the description as (in a longer hand)...
Code:
ur(18)r57c12[(6)r5c1=qnp(29)r7c123] - (2)r7c9=r5c9 - (2=6)r4c7 ; r4c1<>6
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Marty R.



Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA
PostPosted: Sun Apr 10, 2011 12:33 am    Post subject: Reply with quote
XY-Wing (249); r12c2<>9
X-Wing (5); r127c5<>5
UR (18), boxes 47. R5c1=6 or r7c12 forms pseudo cell 29; common outcome, r5c7=8
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