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Tough Sudoku for 18/February/2007


Choose a number, and place it in the grid above.

  1 2 3 4 5 6 7 8 9
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Submitted by: sudoku lover

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Nice photo Karen (if it is yours). I didn't get close up to the palace, only saw it at a distance.
A proof for tough sudoku of 02 18 2007:

1) Start at 22 filled - the given puzzle. Unique Possibilities to 27 filled. (UP 27).
2) Pair 36 at e79 forbids df9,e35=3 and forbids d89=6 UP 30
3) Hidden pair 39 at a9c7 forbids a9=456 and c7=478 UP 31
4) Locked 7's at c13 forbids b13=7 More...
mAen! 29 minutes
13:57 - not so tough?
10:39..but one mistake.
Nice pic. Wasn't too tough. Usual bag of tricks. xy-chain found the 6 I needed to unravel the puzzle. Steve got to an early start this morning :) U.S. residents: Enjoy your Saturday and potentially 3 day weekend. Everyone else: Warm regards
It is really a nice palace,but who live in this palace ? Is Mr. Monaco lives there? If sure 'not'because Monaco is not a person so who live there ? or is it governmental offices ?
Realy wonderful building.
Nice maEn to all.
Wagdy, Prince Albert Rainier is now the reigning monarch of Monaco, I'm pretty sure.
steve -keep posting the extended version of proofs, some of us dont have all the time to find the unique possibilities
Thank you Anne! yes it's mine. Wagdy, jp is right, it's the same family that's ruled Monaco for over 900 years.

I didn't find this puzzle that hard either... as long as you don't make stupid mistakes filling in all the possibilities.
Sorry Gath! But the caption to my Brrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr picture from a few days ago has messed up the picture galley spacing! The word needs to be broken into three parts!
1. Up 33-(h9=1,c8=8,b7=1,b6=8,c5=4,c3=7,g3=3,h3=8,c2=1,e1=1,f6=9)

2. If h5=5 forbids h2=5. If e5=5 again forbids h2=5.
3. locked 2s at a4,a6 forbids a1,a3=2.
4. If h5=5 then eventually i4,i7=8 which is impossible. Therefore h5=2 e5=5. Up 81
Sorry Gaby I don't understand that. Probably why it took me nearly 19 minutes.
Dec. 16, 2007.
17/Dec/07 10:56 AM

05/Sep/10 11:40 PM
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