Competition: "Sampler Platter"

Hey everyone!

How many of you are quick solvers? Ever want to enter a sudoku competition?

On 7th and 8th August, Logic Masters India will be having their August Sudoku Test. Augusts test will feature sudoku variants created by me that have up to 6 clue types per puzzle.

If you're interested, head to their site and grab the Instruction Booklet to prepare for this test!

http://logicmastersindia.com/M201008S1/

David

Hi David

Well I definitely don't think I'm a particurly quick or expert solver, but couldn't resist having a look at your sample platter and I must say, these are really fun little puzzles. Lucky for me I was familiar with all the variations (just not the lot mixed together) and so I was able to solve all the 6 x 6 ones without too much difficulty - I just wouldn't be able to match most people for speed! However I really did enjoy these (and have just noticed the 9 x 9 ones posted on the Griddle so am going to download these in a minute and see how much more difficult they are in a larger grid).

You never know, if it is a rainy weekend and I am stuck indoors I might just have a go (under a very unrecognisable username!!!!) just out of curiosity to see what I could get done in the 100 minutes. Just one question. I much prefer to solve puzzles on paper rather than gaze at a screen continuously (am also a bit quicker with a pencil than a mouse!) Is there any facility for printing off the puzzles and then just typing the numbers in on completion if this is done in the time?

It seems to be a site aimed at finding an indian champion, but presumably all nationalities are welcome to participate?

P.S. Since posting the above I have now completed the 9 x 9s! I wouldn't win any prizes for time but I thoroughly enjoyed them.



Edited 1 time(s). Last edit at 07/27/2010 11:07PM by Christine.

Hey Christine,

When the actual competition starts, a full PDF will be available for solving offline. However, you will have to enter the digits into the Flash component to officially enter. I know that the organizers have a provision for offline solvers but I'm not entirely sure how it works.

As for champions, there's nothing official, but they provide rankings on their site for 1st-3rd worldwide and then 1st-3rd in India specifically.

I'm glad you liked the samples from the instruction booklet though, and at least once the competition is over you can give the puzzles a try at your own pace if you'd like.

Hi Christine,

In fact, we encourage players to solve on paper because lot of actual championships are paper-based.

For solving on paper, here is what you have to do

1. Download the Puzzle pdf (will be available to download at least 24 hours before the test starts). This pdf will be password protected.
2. When you know you can spend 100 minutes continuously, you can visit the submission link. Login and click "Start". Your time starts after you click "Start". The password for the pdf will be shown below a timer.
3. Open the pdf using the password, print the pdf and start solving. [keep your printer, paper etc ready beforehand so that you don't lose seconds :-) ]
4. You have to submit all Sudokus before your time ends (100 minutes). Since you will be taking the test for the first time, I suggest you take a break from solving, after say, 50 minutes. Submit all the Sudokus you have solved by them. This will give you a feel for how much time you might need to submit per Sudoku. There is nothing worse that solving a Sudoku correctly, but not able to submit because of lack of time.
5. Note that, you don't have to enter the full grid in the online system. You can click on the button "Show Cells to Fill". Some cells will be highlighted. You only have to enter those selected cells. [Around 12 cells in a 6X6 grid or 18 in a 9X9 grid ]. This button "Show Cells to Fill" will be activated 35 minutes after you start the test.

Hope that clarifies. Should you have further questions, please post here or in the lmi forum where more members will read and answer your questions.


Yes, players from all around the world are invited and as you will see, most of the players are from other nationalities.

Cheers,
Deb
Logic Masters India

Hi Deb

Thanks very much for the info. That has certainly clarified matters. I still haven't decided yet whether to have a go at the actual timing, or whether to do the puzzles at my own leisure after the contest has ended. I will see how the mood takes me over the weekend!!

Well I had a go just now, since they were David's puzzles and they looked so inviting! And they were - the first three rounds are 6x6 which personally I found really enjoyable. The logic for me is much more pleasurable to spot at a smaller size - less searching, more thinking. Then there are two rounds of 9x9 puzzles, which for the first round of those at least I actually solved at the same speed as the 6x6 ones. I think that tells you more about me than about the puzzles however! I didn't have time to do the high-value ones in the final round, so while I'll have a pretty poor score that wasn't why I took part. In summary I thoroughly recommend the puzzles, even if you just download the PDF and save it for later.

Or try and beat my score! It's not hard to do so!

Well I also decided to give it a go, but have to say did very badly indeed!!!! I think the timer put me off a bit and for some reason I couldn't even solve the second two of the 10 point ones (I'm sure if I go back to them now I'd do them without any trouble!). Anyway I plodded my way through the rest of the 6 x 6s and then stupidly decided that as I had about 40 minutes left I would just try and solve one of the 60 point ones only to discover I'd done one of those "fatal final hurtles" Sue talked about and made a mistake towards the end! Aaagh. Back to square one and I ran out of time. So needless to say I know I won't have many points, but I still enjoyed the experience and will have to try do one or two more puzzles against the clock to try and become a bit more immune to the time pressure!

Still, great puzzles Dave, and I have saved the ones I didn't get done to do at my leisure.

Glad to hear you both enjoyed the puzzles!

I think the timer and the mix of clue types throws everyone off a bit. I tried adding lots of examples to the instructions book and on The Griddle to help with practicing and familiarizing with the clue types, but I'm not sure it was enough.

Still glad you enjoyed the puzzles and hope that trying them at your leisure will lead to a more fun experience for you both.

Christine, I found the same thing too - I couldn't do the bottom puzzle in the first round at all, and I spent as long on that first round as the next three rounds put together. I definitely found the first round harder than the following three, although I didn't try the fifth round so in fact that was probably the hardest of all. Of course it's also probably to some extent I spent the first round learning what to do, but then I had done the puzzles on the sample sheet first which I didn't find tricky in the same way.

The logic on that last 10 point puzzle is, I think, more involved than on any of the other puzzles I tried - for a start you get almost no eliminations from the inequalities right away, and virtually nothing at all from the consecutives, whereas all the other puzzles have at least a few obvious eliminations that result in givens that come immediately and clearly from the clues. Perhaps that is actually the hardest puzzle in the entire competition, complexity of logic-wise?!

For the ones with the 'difference' markers I found you could see there was either a fixed solution or one of two alternate solutions for each set, and so in those latter cases the easiest way to solve each puzzle was just to guess one option and see if it worked out - you generally saw a contradiction immediately if you picked the wrong one. I only did this when I got stuck, but if you had done it first up I imagine you could have rattled through the puzzles with those in much more quickly.

Really good puzzles anyway, so I'm going to print out the other ones from The Griddle and give the remaining 9x9 ones from the competition a go this afternoon.

I still can't solve that bottom 6x6 one. I am stuck, and just made the same mistake I made in the competition - thinking the bottom consecutive sequence was 1234 when in fact it can't be. I've now spent over half an hour on that one puzzle!



Edited 8 time(s). Last edit at 08/09/2010 03:24PM by gareth.

That bottom 6x6 is definitely a toughy.

It takes some thought to get this revelation, but (SPOILERS!)

highlight here to begin:
The bottom left section has a string of 4 consecutive digits and 2 digits that are non-adjacent - so the leftovers MUST be 1 and 6, then a string of 2-5 in some direction.

In the bottom right box, you can now place 1 and 6. The 3rd digit in that half-row must be either 2 or 5 based on the string of 4 digits in the bottom left box. Based on the greater-than symbol in the bottom right box, the 2/5 box must be larger than the cell above it. Since the cell above it can't be 1 (1 is already placed), the cell below it cannot be 2 - it must be 5.

Now you should be able to complete the bottom two boxes based on the consecutive bit and the greater-than symbols.

The middle-left box can be split into a chain of 4 and a chain of 2: 1-2 and 3-6 or 1-4 and 5-6. Since the chain of two cannot contain a 5 (since there's a 5 below it) it must be 1/2 and the other chain must be 3-6. The 6 in the bottom left box dictates the way the chain of 4 must be placed.
end highlight here.

From here... I'll stop spoiling the answer

Awesome logic... I feel entirely dumb for not noticing that! More particularly, though, I failed to remember that the 'non-consecutive' rule applied at all. I also didn't apply the 'even-pair' anti-rule either!

I think it's the mix of types that makes it hard to keep track of all the subtleties, or at least that's my excuse and I am clinging on to it!