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Tough Sudoku

for 2/December/2006

                 
                 
                 
                 
                 
                 
                 
                 
                 

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: basscom4life

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   Anne  From Albany W Australia    Supporting Member
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Wow, I didn't realise I had put this photo on tough.
A bit of reflection at the top as it was taken through the coach window. A beautiful place to visit and a boat ride in the bay is a must.
kevin  From Utah
great picture
Dan  From Puyallup, WA
22:46 MAEN Long time to do that one, but well worth it for that great picture!
   Anne  From Albany W Australia    Supporting Member
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fi - I don't think you've visited me yet in my place. I've been waiting for you with a drink to join the party. You'd better hurry, it's nearly over.
fi  From NT
Great picture of Bay of Islands Anne. I remember being there (such a delectable place)way back when I was a teenager... I have no idea how I managed to save enough for a fare whilst a uni student despite the various jobs and baby sitting. I guess it was the Whitlam years. I checked out your page on the first day. I'm not sure what happened to my comment.
Nick  From Toronto
20:35
HalT  From S Carolina
Nice pic. Where was it taken from? It looks like it was taken thru a window; I can see a reflection in it. A hotel room, maybe??
Steve  From Ohio    Supporting Member
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Possible proof of barely tough sudoku of 12 02 06:
1) Start at 22 filled - the given puzzle. Unique Possibilities to 26 filled. (UP 26).
2a) Locked 1's at de2 forbids a2=1
2b) Locked 2's at gh2 forbids a2=2
2c) Locked 5's at ef2 forbids aghi2=5
2d)i8=5 == ab8=5 -- a9=5 =={pair 36 at a29} -- a7=36 == a7=8 -- ab8=8 == i8=8 forbids:
i8=147,a56=6,a35=3,b7=8 UP 81
Sets: 3(1)+5=8. Max depth 5. Rating:.34
Steve  From Ohio    Supporting Member
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There are some depth 4 chains and depth 3 steps that advance this puzzle. I did not research whether or not they will fully solve it.

Step 2d above can be represented also as follows:

S1={a2=36,a7=368, a9=356} ALS with 1 degree of freedom
S2={abi8=5, abi8=8} HALS with 1 degree of freedom (in cells)
Clearly forbids hidden pair 58 at ab8 and forbids 36 outside of S1 in row a



Clark  From Michigan
Here's something that's slightly different from Steve's:

1) Start 22, Unique Possibilities to (UP) 26.
2) Naked triplet d2=17, e2=157, f2=57 forbids a2=15, def2=57.
3) Locked 2s at gh2 forbid a2=2.
4) The wraparound chain i8=1 == i5=1 -- c5=1 == c3=1 -- a3=1 == {a239=356} -- a7=36 == a7=8 -- gh7=8 == i8=8 forbids i8=457, ah5=1, b7=8.
5) Locked 5s at gh9 forbid a9=5.
6) Naked pair 36 at a29 forbids a3=3, a5=36, a6=6, a7=36. UP 81.

The chain is longer than Steve's but I don't consider that a weakness on wraparound chains.
as  From Finland
10:14
New Zealand have to be a very beautiful country!
I would like to go there one day....
Stuie  From St. Louie
Steve,
Thanks. You're the best!
JH  From icy Champaign
Nice NZ pic - Thanks, Anne! This puzzle took me forever... almost one hour - and now I notice Steve/Ohio says it's 'barely tough'! Guess I missed something fairly obvious. Good Maen, all.
HalT  From S Carolina
Re: I don't normally do this, but here is a chance for us all to make some money.
AGLOCO requires you to add a tool bar your browser that spies on you and anyone you recruit. Before you sign up for this, I recommend you read the following article: go to http://www.futurelooks.com and click on the fifth article ‘Getting Paid to Surf…’.
Trevor  From Southern Ontario
Hi Everyone
I'm going to Cuba for New Years Eve, any suggestions on the best handheld sudoku machine for under $100? Do any of them let you see multiple possibilities? I'll do my best to take a picture worthy of the site.
Thanks

rugram  From India
Nice and easy.
Bio teacher  From New York
10:07...first time I've felt a time worth posting.
   Lizbaby4  From NJ    Supporting Member
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Nice picture!

Easy puzzle.
   Canuk Greg  From Ottawa, Canada    Supporting Member
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Good afternoon to all! That's a great picture to take from a moving vehicle. Well done Anne.
Karen  From Monaco
Yeah, it helps if you don't screw up the setup and place 9's all over the place in a box where a big fat 9 is already sitting. I'm an idiot. I think this one merits a rework.
   Deb  From Brisbane    Supporting Member
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Okay....ATTENTION...ATTENTION

All guesses for the competition have been lost!!!!

You will need to redo them if you wish to be a part of the competition.
   Deb  From Brisbane    Supporting Member
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Competition.....Competition.......Competition

Guess the weight and date of arrival of my Grandbaby. Click on 'competition' and be in the running for 6 months free membership that Gath has so graciously offered.
   Deb  From Brisbane    Supporting Member
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To all who wish to take part in the competition...

If you go to 'check out my page' after my name you will see a photo of Nicole at 37 weeks. This may help in your guess. Some of you may wish to revise your guess...lol....Maybe the 'BIG CRASH' was a good thing
passerby  From on his way
Hi, possible proof with two depth4 fcs.
1) bc1=2 forbids a2=2
2) i8=1==i5=1--h6=1==a6=1--a6=9==a5=9--d5=9==d8=9 forbids d8=1, UP 27.
3) df8=79 forbids ib8=7, ef9=7, e7=7, ec8=7, UP 28.
4)e8=1==i8=1--i8=5==ab8=5--a9=5==a9=6--e9=6==e9=4 forbids e8=4, UP 81.
Steve  From Ohio    Supporting Member
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Nice work passerby! Hopefully, you will pass by again! As a point of possible interest, the rating system I use would rate your proof as:
.01+.15+.03+.15=.34.
Thus, it would rate your depth 4 proof, using (1) depth 1 step,(1) depth 2 step, and (2) depth 4 steps exactly the same as the one I provided with (3) depth 1 steps and (1) depth 5 step. I would love to hear opinions as to whether or not this equivalence is warranted.
   bluey  From Port Kembla    Supporting Member
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Nice pic Anne, and finally a place that I have actually been too!!
Fidel Castro  From Havana
Why would anyone want to support this COMMUNIST STATE by spending their $$ on tourism here?
   Anne  From Albany W Australia    Supporting Member
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17:01
david  From texas
04/11/2007 poss , 4 guesses - one wrong
12/Apr/07 12:55 PM
mb  From delaware
Oct. 30, 2007.
31/Oct/07 10:06 AM
sotir  From New York
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SE=7.3
05/Sep/10 11:09 PM
tom  From vancouver    Supporting Member
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21:03.
10/Jun/20 11:06 PM
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