About Untouch Sudoku, can identical digits touch each other "diagonally"?
I can understand it's not allowed (by observing the Example), but I think some "beginner"s can't.

Yes, it's meant that they can't touch each other diagonally.

Well ... "diagonally" is the only way identical digits can touch each other in a Sudoku

[ Added the missing word in link for types. It was already present in pdf. ]

Heading of the contest page needs an update. It reads date in Dec.

Why it doesn't let me to print variants??

@TiiT, please check my messages

I would like to know if anyone has attempted correctly the 'Killer' sudoku in variants in LMI beginners' test, january. If yes, can anyone tell me the correct solution for the 'Killer' sudoku in variants. I have attempted it and think my answer is correct. But the server is showing the answer to be wrong. My answer is O-564782391 and P-327941865

Edited by huisouvik 2013-01-20 2:59 AM

@huisouvik, Please check your inbox for solution to killer.

hii is it valid to claim points for mistyping a number...when i first submitted the solution to answer for killer ,under time pressure ,in the second row of the answer solution i typed the wrong number as the first digit..i could not check again ..i had only 10 seconds remaining..after i completed i realised that i had lost 5 points for mistyping a single digit..not sure if it is valid to claim here...can the admin check my submission pls and see if it is a vaild claim....

Since we introduced the Instant Grading system with the lenient penalty, we decided that the only time we will remove the penalty is when an answer key is incomplete (has blank spaces). We have a system to notify us of these cases so the claiming button seemed redundant. Hence, we decided to remove it.

Obviously, we are aware that the rare case of someone making a slight mistake within time and then correcting it after time is possible, but we still don't think its a valid enough claim. If we award points there, its a disadvantage to people who are careful, submit just after time and don't have a typo just before time to show for it.

Not a problem.I know computing bonus would be a bit of a headache in the event that you decide to award points.. not that i would be getting much bonus anyway.It would not have felt right to me too if you had awarded for a mistake on my part.It is just that 6 points go down the drain because of a single typo that my heart forced me to claim.Thnks for looking into the claim......

Thanks Richard, the classics in particular were very elegant!

The January contest is now over. Passwords removed from booklets.

Congratulations to the players who took the top spots, both in Seasoners category (Jaku111, Timothy, Janoslaw) as well as in Beginners (zbych, elena_tens, affpuzz) category.

I am happy to see almost 270 participants!

I am also happy to see that a lot of Beginners were able to solve all Classics within the time limit and also that seven Beginners managed to solve all Variants in time. Well done!

When Deb asked me if I was willing to write a Beginners Sudoku Contest for LMI, I didn’t hesitate for a split second. It meant two challenges for me: First of all, I have never written a classic sudoku before. Second, writing interesting but EASY variants, sounds like a contradiction in itself to me.

Classics
I just started with the classics as I lack experience. It was fun to look for nice patterns of given digits with good solvable sudokus. I wanted the maximum number of given digits to be 27, use different kinds of symmetry and use some unusual patterns.
There is not much to say about it; no dirty tricks, no naked singles (I am not so good in spotting those, and that might be the reason I am not so fond of this technique, and thus don’t put it often in my own puzzles.) Only speed solving skills are required to tackle all four classics. And a lot of you managed to do so.

Variants
When I start making a sudoku variant, one of my goals is to reduce the number of clues to an absolute minimum. Especially for the puzzles I create for the puzzle portal in Germany I do this very often. The only exception to this rule is when symmetry is broken by removing a clue.

But for the puzzles that are part of a Beginners Contest, I had to let go this rule pretty soon; the puzzles would have become too hard that way. For example: the irregular didn’t have the 6 and 4 in the centre in the First version and the killer had the two cages of 6 combined to one of 12 in rows 2/3 and cages 10 and 9 combined to one of 19 in rows 3/4/5. Both puzzles were too hard, so I repaired the difficulty level by placing extra givens and by splitting the cages.

Some notes to some of the variants:
Untouch: the untouch rule is necessary only a few times. Mainly normal sudoku solving techniques are used.

XV: For this puzzle the 3 centre columns can be filled very quick. The blocks 1 and 9 provide a lot of information so you can proceed very fast after that. Especially when using the information where there is no X or V.

Killer: I am fond of larger cages and I love diagonal symmetry. I think eight cages of size two is pretty much the minimum for keeping it a quickly and smoothly solving puzzle. In my original puzzle there was a bigger role for the cage 28/7 in the center in combination with the cages 11/3 and 16/3 sticking out of the 3x3-block bottom right. Incredible to see that the fastest solvers tackled this one in around three-and-a-half minute!

It was my pleasure to create this Beginners Contest for you. I hope you all enjoyed it!

The 3rd Sudoku, XV has 2 good results, please check ! :)
326914578
497865123
158732649
814659237
735281496
962473851
689547312
243196785
571328964

Completely clueless about which Sudoku XV you are referring to. Please provide a link.

Pretty sure this is the XV Sudoku from the last WPF GP.

Frantz, all instances of X and V are given, so there can't be any digits adding to 10 or 5 anywhere in the grid except where the X's and V's are given. Because there are numerous places two adjacent digits add to 5 and 10 in your solution, where no X or V is given, you solution is not valid.

I hope this helps.

Nice Tough sudokus.Thankful that Grand prix Indian round got completed just before this.Could carry on the momentum comfortably .I could almost feel instinctively where the numbers would be hidden.Ah Hidden singles again all over the place!!!Lovely construction
Some very really narrow points in the sudokus.Thankfully i found them sooner without wasting much time.
Overall CLASSIC classics!!!!!

The instructions on the "Frame Sudoku" for the on-screen solving (not the pdf) are wrong.
They're instructions for a Killer rather than a Frame.
It could definitely cause confusion for anyone who is expecting the instructions to remind them how Frame works.

I liked this test very much esp. the Classic puzzles. Each classic puzzle was very well created to give the minimum required hints. Extra Region Sudoku was nothing but Windoku itself. I think we could have introduced this type in this test instead of saying it as Extra Region Sudoku. I also liked the Frame Sudoku. Rest Sudoku XV and Irregular were easy ones. Overall very enjoyable Test. Thanks to Deb, Prassanna and LMI for this great test.

That is an interesting observation. Not sure if Prasanna designed it that way.