Sudoku Puzzles

Good photo Keyan

EAsiest day ever. Mornin'

8:28 Maen

5:04

Fun photo. This was an easy tough. Did I make a fortuitous mistake?

Thanks, Anne! It was quite surreal - we were riding the London Eye, and suddenly saw this troupe of taiko drummers in another car. Drumming.

Needed two guesses - one fairly early in the setup, and then again near the end.

20:25

Another interesting photo from Keyan.

sudoku has me hooked:)

Not too difficult today:

1) Start 22, Unique Possibilities to (UP) 27.
2) Naked pair 69 at d12 forbids f3=6, d7=69. UP 31.
3) Naked pair 39 at gh7 forbids h8=39, i8=3. UP 35.
4) Naked pair 36 at h23 forbids g1=6, g2=6, g3=6, h1=6, i2=3, h4=36.
5) Naked triplet g2=148, g3=148, More...

my max depth 4 solution to tough 8/24/06

1) Start with 22
2) UP 27
3) Locked: a98=8 => ~c98=8
4) Locked: a654=2 => ~a98=2
5) Locked: d21=9 => ~d7=9
6) Locked: g654=9 => ~g97=9
7) Naked Pair: d21=69 => ~d7=6
8) UP 35
9) Locked: a654=6 => More...

Good mAen to all! Good shot to catch Keyan. Is the band in the bubble or on the bubble?

just noticed I can chop the front off my step 24 FC.

24) FC: a9=8 == g9=8 -- g2=8 == g2=1 -- g6=1 == a6=1
=> ~a9=1

so its one depth 4 and 2 depth 3 chains.

I actually completed a tough one first time ever, was too easy

5.03

It looks like they are up pretty high.

Another Similar Solution to tough sudoku of 08 24 06:

1) Start at 22 filled - the given puzzle. Unique Possibilities to 27 filled. (UP 27).
2) Pair 69 at d12 forbids d7f3=6 and d7=9. UP 31
3) Locked 9's at g56 forbids g7=9. UP 35
4) e2=8 == e1=8 -- c1=8 == c3=8 -- c3=6 == gh3=6 More...

hmmm - have to watch what I capitalize.....

Interestingly enough, a pair of sort of remote pairs in last two steps knocks two candidates out of the same cell to finish off the puzzle.

18:00.. nice pic Keyan

Guess I should have reversed the order of one of my last two fc's to expose the symetry...

Good mAen

9.09
interesting photo
have a great day/night one and all

Great luck Keyan! This puzzle went the same for me two. Ane early guess then a late one to mop up.

Done.

Steve (or Pat or Clarke) I used a different approach at 49 filled. I think it is a tad more complex in total, but nonetheless I'm curious about the best way to record the proof. In 3 simple steps we can prove that i2 cannot be 8, then UP to 81.We have to assume that i2 =8.
Step 1: =>g2=1 so More...

Hi Everyone,

A post from yesterday gave me an idea - and now you can play any picture you see here as a jigsaw puzzle. Just click the 'Play this pic as a jigsaw' link above the sudoku puzzle.

Hope you enjoy it!


Gath

HI Meg - I could represent your argument with a Matrix, but I believe that would not be what you are looking for. First I take the hidden pair eliminations(Hidden pair 26,, if you have not taken it yet) Here is another way:
Consider the strong set: g6=179
g6=1 -- g2=1 == i2=1
g6=1 -- g2=1 More...

BTW Meg. The latter uses a total of 6 sets, just in one step, while Pat and I used 6 sets, just in two steps, to accomplish the same thing. This is not unusual in a case like this, where the lexus of all our arguments is the g6 cell with three values in it. Albeit I choose to pare g6 down to 1 value, there is really no advantage of what I did over what proposed, except less depth in each step.

over what you proposed... above

16:43

Not too difficult today. Mostly solved during set-up and picking out hidden pairs/triplets.

One day I may attempt to record proofs, but that step is still above me.

Thankyou once again Steve for your clear explanation. I'm delighted when I find one path to the solution. You seem to see all the pathways. Working through your explanations gives us a few more tools to work with.

to Steve:
thought you might be interested in some marginalia:
new proof for 8/1/06 (posted in archive) max depth 3 (best posted was 5)

have been trying to come up with optimal proofs, quite a challenge since yours are almost always near
optimal.

Sept. 28, 2007.

SE=4.2