Sudoku Puzzles

I've had my siesta but its still too hot and sunny so I'm going to exercise my brain only.

Good mAen all

Is that one of your photos fi from NT

Too long and a couple of guesses, oh well

20:50 - Not bad for me! Hey Anne, where's your next trip?

Maen everyone!

9:51 one good guess

I thought this was easier than the hard one today!

Half a metre high - judging by the scale, does the river rise all the way to 2 meters?

15.56 Think I'd have to wait a little longer till the water recedes.

Good Maento all! You can always try fishing while you wait!

6:28

fdgdb

34:15

1) Start 22, unique possibilities to (UP) 25.
2) Hidden pair 58 at d46 forbids d4=129, d6=249, d7=8, d9=8. UP 39.
3) Locked 1s at df9 forbid de7=1, ef8=1. UP 47.
4) g1=3 == g8=3 -- f8=3 == d7=3 forbids d1=3. UP 48.
5) Locked 3s at gh1 forbid h23=3, i23=3.
6) Naked pair 29 at df5 More...

12:38...Think I would just turn around and go have a cold beer somewhere!!!

10:10 Good mAen! Anyone got a good raft? :)

to Steve - thank you for the response from yesterday. I retire the end of this week and plan to spend my first few days (weeks/months?) learning this stuff. Gotta keep the brain working.

PLEEEESE don't anyone suggest that this was an easy one. After many many months I have finally done a Toughie without mistakes in setting up and without having to guess !! Enjoy the comments but still have difficulty following the solutions - somewhat above my head.

to Clark

nice! step (10) uncovers a good heuristic for finding useful
forbidding chains. Starting with a locked pair, try
to chain from one to the other, each number on each
end of the chain. Forbids the unused start number.

step (11) generalizes the technique.

1) Start at 22 filled - the given puzzle. Unique Possibilities to 25 filled. (UP 25).
2) Hidden pair 58 at d46 forbids d6=249 and d4=129 and d79=8 UP 39
3) Locked 1's at df9 forbids d7,e78,f8=1 UP 47
4) fc on 3's: d7 == i7 -- g8 == g1 forbids d1=3 UP 48
5) i4=7 == a4=7 -- b5=7 === More...

Often I get mono-focused, and decided that today's puzzle was weak in 7's, although there are perhaps dozens of depth 5 and depth 6 fc's available at UP 57, many not focused on 7's.

Hi Everyone,

I've started a new area - The Parent's Page. You can access it from the top right. You can submit all your baby/grandchild/kid photos here, and they will show up quicker than the other sections. This is also the 'home' for the guess-the-baby comps (though you can still post anywhere).


Gath

BTW - there are also some depth 3 fc's available at UP 57, but I was unable to find a combination of these that still did not require at least a depth 5 fc to solve the puzzle. Perhaps someone can find such an improvement to the proofs posted...

I can not follow you friends!I search to establish impossibilities,instead by fc,better by try and error,which actually is a demostration of a fc.Of course this method is time consuming,but that is not that important with difficult puzzles....

Thanks for the solve easy- saves an awful lot of 'routine' time-wasting!

14:57 a little slow today. Not too deep, but looks like it's moving fairly quickly.( The water, that is!)

Am I cheating, guessing or legitimately solving the puzzle when, at 57 completed, I temporarily adopt a6=9 for instance and follow this through until an impossibillity is reached thus making a6=8. Discovering a useful fc is a similar matter of trial and error isn't it?(if it isn't why isn't it oh More...

re guessing

Of course a guess is a legitimate path to solution,
but the point is that it requires absolutely no
thought. There is a vast gulf between throwing a die
and blindly lurching forward - or looking at what
information you have and discovering the clues and
links More...

YES Anne!! That is one of my photos - taken at the Daly River about 5-6 weeks ago a few days after it had finally opened after the wet season. I waited around for about half an hour and then headed over. I was in a troopie so had fairly high clearance. For SS from England. The river actually was More...

Sorry Jean from Champaign - I have only just read your comment and I wish I knew where my next trip will be. I have to start saving all over again. I really would love to go back to Peru, but there are so many other places out there in the big wide world to see.

today's tough was actually pretty easy. i know im only 15, but if i finish it in 5:02 i know this one is easy!

Aug. 25, 2007.

SE=6.8