The New Sudoku Players' Forum

[Hud]

I'm pretty new to Suboku but have had good luck with all the average puzzles from my newspaper. Lately, I've gotten stuck on puzzles that I have reduced to this sort of point. I'll try to recreate where I'm stuck the best that I can:

3 6 7 18 4 18 5 9 2
9 5 2 3 7 6 4 1 8
8 1 4 2 5 9 6 3 7

14 39 8 6 2 13 7 5 49
5 37 6 4 9 37 2 8 1
147 2 19 17 8 5 3 6 49

6 4 3 9 1 2 8 7 5
17 78 15 578 3 4 9 2 6
2 789 59 578 6 78 1 4 3

I hope this is clear but bear with me.
Tom

[emm]

You have an xy wing at r4c1, r6c3, r4c9 that removes the 9 from r4c2, r6c9.

If you don't know about xy wings look here -

http://www.simes.clara.co.uk/programs/sudokutechnique11.htm

[Hud]

em,
Thanks for the tip. I'm a bit fuzzy on it, but I believe I see it. I bookmarked the XY link you gave me and will be studying it a lot from now on. By the way, as you probably know your tip is correct. It seems to almost stretch the limits of my abilities though (we'll see?).

[Ganesan]

Beginners are best advised to learn basic concepts from a 2 x 2 x 2 Sudoku. You'll always find it easier to extend it to the regular 3 x 3 x 3 Sudoku.

You can subscribe to the free newseltter that teaches you from the basics using 2 x 2 x 2 Sudoku at http://www.howtosolvesudokupuzzles.com .

Coming to the problem at hand, em's method is effective but somewhat cerebral; however, thankfully, we have a method that is less cerebral though it may consume slightly more time. With practice, you can learn to solve faster even with this method.

You resort to this simpler solution when you can go no farther. Just take one of the cells with multiple possible values, assume one value & try to resolve. If there is any row or column or major square of 3x3 where you have a conflict, then this assumption must be wrong. Make the other assumption, and try to solve.

For example, take Cell (1,4), i.e., r1c4. Try with the value '1' and it solves the puzzle. You've got the answer. Try with the other value '8' and you get a conflict. Sometimes, you may get answers in both cases, and then you know it has 2 (or more) possible answers.

Hope it helps.

[emm]

however, thankfully, we have a method that is less cerebral though it may consume slightly more time.

You cannot be serious! Why in the world would we want a less cerebral method that takes more time? We’re trying to solve the puzzles by beautiful means not beat them into submission with a sledge hammer. Aren't we?

[emm]

Hud, I got distracted. This is what I was going to say.

Yes, I do know my tip is probably correct because I got it off the solver!

Here's another good place to look - tso's diktat on finding xy wings

[Brendan]

however, thankfully, we have a method that is less cerebral though it may consume slightly more time.

You cannot be serious! Why in the world would we want a less cerebral method that takes more time? We’re trying to solve the puzzles by beautiful means not beat them into submission with a sledge hammer. Aren't we?

em wrote:

Hud, I got distracted. This is what I was going to say.

Yes, I do know my tip is probably correct because I got it off the solver!

lol. Such beautiful irony.

Brendan

[Cec]

lol. Such beautiful irony.

I agree with em's above response (both of them!) but what does "IoI" mean?. This jargon is all new to me such as not knowing "sez" means "says".

Cec

[PaulIQ164]

'lol' is "laugh(ing) out loud".

[NorwegianViking]

lol - Laughing Out Load (or Lots Of Laughs)

If something is extremly funny, you could use
ROFL - Rolling On Floor Laughing
ROTFWL - Rolling On The Floor With Laughter
ROTFLOL- Rolling On The Floor Laughing Out Loud
ROFLMAO - Rolling On the Floor Laughing My Ass Off

[NorwegianViking]

lol

[Cec]

Thanks Paul. I'm a bit late but congratulations on passing 400 posts - you've gone past Brian Lara's Test record highest score.

Cec

[Cec]

Thanks also NorwegianViking. By the way, you people sure spell "Ass" a funny way!

Cec

[Hud]

I've been going through some very hard puzzles that I'd gotten stuck on awhile back. Using the "naked" and "hidden" tricks I've had better luck with them. One puzzle continued to thwart me everytime I tried it after going back to start at the point where I'd placed the pencil marks after getting the obvious ones done. This morning, I finally started it "from scratch" and zipped through it in about 15 minutes. I really have to be more careful placing the pencil marks.
I haven't run into anymore "XY Wing" possibilities yet.
Tom

[emm]

If you really want XY wing possibilities here’s a link to a whole bunch of them from young Nick.

PS : Are you sick of LOL being used to signpost every single scrap of humour on the planet? In the interests of versatility and out of a passion for the subtle nuances of the English language, I’m offering a few alternatives.

1. SOA - snort of approval
2. CQTM - chuckling quietly to myself
3. GO - guffawing outrageously
4. SMS - splitting my sides
5. WMP - wetting my pants

Feel free to use them as you will.