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Sydney Morning Herald 20/08/09 - Diabolical

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ledzepxx

Joined: 03 Jun 2008
Posts: 3

Posted: Thu Aug 20, 2009 6:12 am Post subject: Sydney Morning Herald 20/08/09 - Diabolical

Can anyone help me out with this?
No idea where they get them from

Original puzzle

Code:

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

This is where I and this site could get up to

Code:

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

keith

Joined: 19 Sep 2005
Posts: 3355
Location: near Detroit, Michigan, USA

Posted: Thu Aug 20, 2009 6:38 am Post subject:

After basics:

Code:

+-------------------+-------------------+-------------------+
| 489 7 5 | 1 6 2 | 48 489 3 |
| 489 3 6 | 459 7 49 | 2458 1 2489 |
| 2 49 1 | 459 3 8 | 45 7 6 |
+-------------------+-------------------+-------------------+
| 3 189 2 | 7 145 149 | 6 4589 1489 |
| 5 6 4 | 89 12 3 | 12 89 7 |
| 19 189 7 | 489 1245 6 | 3 4589 12489 |
+-------------------+-------------------+-------------------+
| 14 2 8 | 3 14 7 | 9 6 5 |
| 6 5 9 | 2 8 14 | 7 3 14 |
| 7 14 3 | 6 9 5 | 148 2 148 |
+-------------------+-------------------+-------------------+

There is an extended XY-wing 49-14-14-14-19 that takes out <9> in R2C1.

Then, there is a W-wing 4-9 that eliminates <9> in R3C4. The W-wing strong links are <14> in B78.

Nice one!

Keith

strmckr

Joined: 18 Aug 2009
Posts: 66

Posted: Thu Aug 20, 2009 6:44 am Post subject:

after ss:

Code:

.-------------.----------------.-----------------.
| 489 7 5 | 1 6 2 | 48 489 3 |
| 48 3 6 | 5-4 7 49 | 248-5 1 2489 |
| 2 49 1 | 49-5 3 8 | 5-4 7 6 |
:-------------+----------------+-----------------:
| 3 18 2 | 7 145 149 | 6 458 1489 |
| 5 6 4 | 89 12 3 | 12 89 7 |
| 19 189 7 | 48 1245 6 | 3 458 1248 |
:-------------+----------------+-----------------:
| 14 2 8 | 3 14 7 | 9 6 5 |
| 6 5 9 | 2 8 14 | 7 3 14 |
| 7 14 3 | 6 9 5 | 148 2 148 |
'-------------'----------------'-----------------'

Uniqueness Test 6: 4/5 in r2c47,r3c47 => r2c7,r3c4<>5
Hidden Rectangle: 4/5 in r2c47,r3c47 => r3c7<>4,r2c4<>4

ss solves to the end using:

Simple Colors: 4 (r2c6,r3c2,r6c4,r7c1,r8c6) / (r3c4,r7c5,r8c9,r9c2) => r2c69,r46c5,r6c9,r8c6<>4

Earl

Joined: 30 May 2007
Posts: 677
Location: Victoria, KS

Posted: Thu Aug 20, 2009 6:13 pm Post subject: brain

You can finish it with Keith's extended xy-wing if you extend it so as to remove the 9 from R6C2. Earl

tlanglet

Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

Posted: Thu Aug 20, 2009 10:24 pm Post subject: Re: brain

Earl wrote:

You can finish it with Keith's extended xy-wing if you extend it so as to remove the 9 from R6C2.

Earl

Earl, I also started with the xy-wing 14-9. I then transported the 9 in r6c1 to r1c8 via r1c1 to delete the 9 in r2c9 and complete the puzzle.

In looking back, I could not see how to extend the xy-wing to delete the 9 in r6c2. Please help.

Ted

storm_norm

Joined: 18 Oct 2007
Posts: 1741

Posted: Thu Aug 20, 2009 10:46 pm Post subject:

Code:

+----------------+-------------------+-------------------+
| 489 7 5 | 1 6 2 | 48 489 3 |
| 489 3 6 | 459 7 (49) | 2458 1 2489 |
| 2 -4(9) 1 | 45(9) 3 8 | 45 7 6 |
+----------------+-------------------+-------------------+
| 3 189 2 | 7 145 149 | 6 4589 1489 |
| 5 6 4 | 89 12 3 | 12 89 7 |
| 19 189 7 | 489 1245 6 | 3 4589 12489 |
+----------------+-------------------+-------------------+
| 1(4) 2 8 | 3 1(4) 7 | 9 6 5 |
| 6 5 9 | 2 8 1(4) | 7 3 14 |
| 7 1(4) 3 | 6 9 5 | 148 2 148 |
+----------------+-------------------+-------------------+

(4)r9c2 = (4)r7c1 - (4)r7c5 = (4)r8c6 - (4=9)r2c6 - (9)r3c4 = (9)r3c2; r3c2 <> 4

Marty R.

Joined: 12 Feb 2006
Posts: 5770
Location: Rochester, NY, USA

Posted: Fri Aug 21, 2009 3:55 am Post subject:

Quote:

In looking back, I could not see how to extend the xy-wing to delete the 9 in r6c2. Please help.

It can be easily extended to take out the 9 from r3c4 which finishes it off.

tlanglet

Joined: 17 Oct 2007
Posts: 2468
Location: Northern California Foothills

Posted: Fri Aug 21, 2009 1:54 pm Post subject:

Marty R. wrote:

Quote:

In looking back, I could not see how to extend the xy-wing to delete the 9 in r6c2. Please help.

It can be easily extended to take out the 9 from r3c4 which finishes it off.

Thanks Marty. It is the most obvious that bites you in the butt.

Ted

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