Logic Masters India announces Snake Variations Contest 2011

Dates : 26^th and 27^th November

Length : 120 minutes + 10 Extra minutes

IB and Submission Link : http://logicmastersindia.com/SVC2011/

Author : Serkan Yurekli

I look forward to the contest. I have a few questions:

In Graffiti Snake the rules saying "without touching itself", but in the example there is a diagonally contact at one point. Is it allowed?
And maybe two stupid questions. In Easy As Snake it's not written that head and tall are given by circles, but it should be. Am I right? And in Serpentine there is no letters in the left grid, I hope this is just a omission and that we will see it in the regular puzzle.

Nikola

:) You are right i missed the touching. I will fix the example. Yes snake cannot touch even diagonally.

Yes these two circles are head and tail, and i think i should mention in the instruction.

I marked only solutions in every puzzles to avoid making confusion. So of course all puzzles have arrows and the puzzle has letters.

Is there any option to specify whether a user need the extra 10 minutes. Example if a user solves five or six puzzles in the given 120 minutes, the user won't wish to lose 120 points for just 10 extra minutes where he is not sure whether he ll be able to finish any extra puzzle.

This seems such an obvious loophole so I'm sure you must have a check for that ..............................


Deb edited this post and added : This has got nothing to do with Snake Variation Contest

Edited by debmohanty 2011-11-23 9:46 AM

Is there any chance there can be an optimalisation used like they have on logic masters deutschland for late submissions? That way you always get your maximum score and don't have to worry about calculating how many points you lost by submitting late and then comparing it to the score of the puzzle. Because in the calculating of that you might lose another 12 points while verifying if it's worth submitting or not.

I don't exactly understand what your point is. Everyone is free to use or not to use the Extra time. After you start the test, your timer will be as shown in the attachment.

It is completely upto you to determine if you should be using the Extra time.

I can see two usages of the extra time.
1) If you check Janoslaw's submissions in Fusion test, it looks like he was engrossed in solving, almost forgot to submit. But when he started submitting, he didn't have enough time to submit all. Having extra time would have enabled him to submit all his solved ones with a minor penalty
2) If your 120 minutes is up, but you are may be 1 or 2 minutes away from finishing a puzzle, you should continue solving and submit asap. This works like a tie breaker in this case.

Since the point value per minute is around 10 and penalty is around 12, one probably won't gain much if they start solving a fresh puzzle after 120 minutes.





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Agree with that. The LMD optimisation system is good. It's always a bit frustating when you submit after the time, and you notice that you lose points because of that.

Fred

I like the idea of extra time. But I think the 10 minutes is too much time.
If the aim of this system is what you wrote 5 minutes is more than enough.

About Extra time
===========

For this contest, we will make few minor changes to extra time concept.
1) Penalty will be .2 points per second
2) In the submission page, you can see the amount of penalty when 'Extra Time' is running. This will help you determine easily if you should submit any puzzle or not. See attachment.







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2011-11-24 20 19 56.png (8KB - 3 downloads)

Password protected puzzle booklet added. It has 13 pages, including a cover page. As noted earlier, example grids are not present in the puzzle booklet.

Link to score page - http://logicmastersindia.com/SVC2011/score.asp
Note that the score page can be viewed only after the Extra time is over.

Is there still going to be a claim bonus button? Not that I expect it will apply to me, but as I saw it said score won't be available till Extra time is over.

If you claim bonus, you can see the scores instantaneously. For claiming bonus, it is required to submit all puzzles.

Does this test affect your ratings?

No, this is already answered in "About Annual Competitions" thread.

Yet another quick note about Penalty points
The time of your submission will be the time the server received your answer, not the time you clicked on submit button. In most cases the difference will be couple of seconds.

Great puzzles. Thanks to the organizers and Author for this great test.

If length of a segment is more than 10, how to write the answer?

We'll accept answers with unit digit, if that is what you are asking about.

Serkan: I think you forgot to write this in the answer key. Thanks for a fun and challenging test.

:) No, actually I didn't forget. This issue is a specific condition, so I didn't want to consider a general case in this contest, so I ignored that. Because we can easily give points to both answer formats, not a big deal. Main idea in my mind is that don't make confusion for competitors with more details in answer format

Thanks

Beautiful puzzles. I did terribly but liked the puzzles a lot, especially the snake egg puzzle.

Edited by mucha 2011-11-26 11:14 PM

To get bonus points all puzzles must be solved, so if a competitor solve 15 + half of Spiral Snake puzzle he/she cannot get bonus points, he should solve whole Spiral Snake puzzle.

Edited by yureklis 2011-11-27 4:58 AM

Thanks for the excellent Snake puzzles, and hoping my one bit of stupidity can be forgiven. I particularly enjoyed Graffiti and Sigma.

Thank you, Serkan, for amazing snakes. The last two tests here were definitely great!

Nikola

Very beautiful puzzle! Thanks!

Great puzzles. Bad typos from me. If only some method of instant grading existed....

As announced earlier, this contest will be open till Monday midnight GMT (approximately 20 hours from now)

Terrific work, Serkan! I will spend many hours on the ones I did not finish, and really enjoyed the ones I did (except maybe that one I got SO CLOSE to finishing!!).

Thank you for generously offering your time to write these puzzles for all of us to enjoy.

JZ

Thanks for the puzzles.

I would recommend consistent wording for whether or not snakes can diagonally touch. Some instructions refer to "points", others "diagonally", and others make no mention of diagonal touching.

Trayton

Great job Serkan, thank you. But I didn' find a solution for Masyu Snake. Was it possible that the snake touches itself diagonally? It wasn't specified in the PB. Otherwise I miss something. (May I have a visual solution?)

Alberto

It has a solution, probably you missed something. For Masyu Snake in the IB says that the snake cannot touch itself, so I think it is clear about diagonally touching.

Snake Variations Contest 2011 is now over. uvo won the contest, as he did last year. MellowMelon takes the second place. Nikola is other only other player to have solved all puzzles within 120 minutes.

A total of 168 players participated from 32 countries, of which 131 players got 0+ scores.

A little early for Serkan now, but I think he will soon post his views about the puzzles and the competition as a whole.

Thank you everyone for participating.

I'm not a big fan of Classic Snake puzzles (I probably have some aversion to the fact that the length is specified), but most of the puzzles in this contest uses several other logic. I especially liked the second part of the puzzles (snakes without lengths). Not a snake-puzzle-lover yet, but I think I like them more than I used to.

An unrelated note : Another test where "Claim Bonus" button had a role determining the top ranks. uvo spent close to 4 minutes before hitting Claim Bonus, MellowMelon caught his mistake before hitting the button (lucky?), motris had 2 typos which he probably could have caught if there were no Claim Bonus button.

I did not participate in the Snake Variations Contest last year. After this year's contest, I do not think I'll miss one again :-)

All the puzzles were excellent. Creating good and tricky puzzles, yet not very tough, is clearly an art, that not many possess. Serkan definitely does have it and after every test of his, there is 'satisfying' factor that I feel irrespective of my performance.

I liked Masyu and Sigma the best of the set. It never struck me that the snake could begin from one of the 'adjacent white circles' until a few minutes into solving. What really disappointed me is the Serpentine Sea Serpent. 54 pointer 64 pointer implies relatively easy in this test, but I guess I missed something. I solved it later, after the test, with a lot of erasing and tweaking, so if someone has some logic to it, please enlighten me.

Congrats to Ulrich, Palmer and Nikola. Thanks Serkan for the wonderful contest.

Edited by Rohan Rao 2011-11-29 12:58 PM

Serpentine was certainly easy, or may be I was lucky. The key was to find the two dead ends. One of the dead end was easy to find at R2C2. There are a bunch of white circles in top right corner, and I figured that one of them had to the other dead-end. Once you figure R4C9, it was all about how fast you can move your pencil.

Eh... Sorry, typo. I meant 'Sea Serpent'.

Sea Serpent: The key (at least for me) was to realize that the snake needs both R8C9 and R8C10, otherwise the 2 and 4 in column 8 can't be both satisfied. After that, look at the 7 and 8 in column 10.

Solution to Masyu Snake



Edited by debmohanty 2011-11-29 3:50 PM

Thank you Deb for the picture,
I found the correct solution this morning. A ridiculous blind point was working. :-)

Alberto

Really enjoyed the test. I used to think I'm horrible at snake, and leave it whenever it appeared in competitions. Not gonna do that from now, found these solvable and fun and got quite a morale boost. :)

Hi,

You were very kind about my puzzles, thank you very much.

Last year I wanted to organise a Snake puzzle competition. I don’t know why, or I don’t remember exact reason in my mind, I asked some puzzlers from LM Deutschland, and Jörg Reitze agreed to help me about holding Snake competition under LMD. Because there are some rules, that only LMD members can hold a competition under LMD title. By the help of Jörg I had a chance to show my Snake puzzles. After the competition I was sure that I would make again, and this year Deb and LMI give me a chance to hold Snake contest 2. Thanks a lot!

About Instructions: From my side, the most boring thing in preparing a competition is arranging a proper instruction booklet. So mostly I try to use available instructions which I used in previous contests. So most of the examples and explanations in this contest are coming from previous one. So this is the reason of diagonally/at a point differences in explanations.

Answer Format: I remember that last year, some competitors (I remember Nils’ comments, and he was right) mentioned that some puzzles’ answer formats are annoying, it is easy to make a mistake. So this year I wanted to be clear about answer formats. First idea in my mind was to use Tapa answer format. But after Thomas Decathlon 2011, his answer format seemed better to me. So I used it. I tried to make submitting answers easier for competitors. Of course I had to be sure that all arrows referred to last solving steps. So some competitors made tiny mistakes (one or two wrong digits) even if they almost solved the puzzle; like Masyu Snake, Sea Serpent, Calculusnake.

Instant Grading: If I remembered the availability of this system before the competition, I’d surely want to use in this competition.

Congratulations to Ulrich! He is a great snake solver. Also last year he got the first place, he solved 16 snake puzzles in 90 minutes (1.31.27 exact time) [2nd Michael Ley 1.32.45, and 3rd Philipp Weiß 1.45.21]. This year Ulrich has solved 16 snake puzzles in 95 minutes. As last year, 2nd and 3rd top solvers finished all puzzles in 120 minutes. Congratulations to Palmer and Nikola!

Some statistics:
- The puzzle solved by least competitors was Serpentine. It was solved by 31 competitors.
- The puzzle solved by most competitors was First Seen Snake. It was solved by 109 competitors.
- The puzzle with the highest rating was Calculusnake (9.0) and the puzzle with the lowest rating was Serpentine (6,69).
- The puzzle submitted with the highest accuracy was Schlange (%100, 59 competitors), lowest was Masyu Snake ( %76.2, 32/42 competitors)

Thanks a lot for participation,

Best,

Serkan

Thanks Serkan. That was fun, even though I had been a bit dumb for most of the solves. I don't know what it is with me and extra time, but somehow it brings out the best in me. I pushed out the 2 highest rated puzzles in the last 10 minutes. This seems to keep happening whenever there is extra time. Guess I work better under pressure.

I hope more contests will include the Mondays, it's usually an easier time for me to find the free time to enter. (unfortunately I missed that announcement this time)

Is there a solution booklet available?

Just going through these old tests for fun, but found the solution for "The Persistence of Memory" is not unique, which makes me think I may have something wrong? The two grey shapes on bottom right i'll call 'd' and 'NE arrow' can seem to have a number of routes through, and since there's no other shapes like them on board, doesn't seem to constrain this?

Here is my solution. I haven't verified that it's correct but I believe so. I think those two areas were the last to be placed, starting with the bottom left square of the 'd' as an x, as it is touched by the snake, and then the whole path is constrained.





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