Diogen IPST. 23-30 September 2011

Information and discussion on Puzzle Competitions
Post Reply
PuzzleScot
Site Admin
Posts: 2740
Joined: Fri 18 Jun, 2010 10:45 pm
Location: Edinburgh, Scotland

Diogen IPST. 23-30 September 2011

Post by PuzzleScot » Fri 16 Sep, 2011 5:55 pm

Dear puzzle friends,

Septembers contest by Riad Khanmagomedov will start at September 23.
The contest will contain 12 puzzles, which you will have one week to solve.
The test file will be available at
http://diogen.h1.ru/cgi-bin/contest/contest.pl?id=43

Good luck!

Andrey Bogdanov
For newbies, this is a set of 12 (traditionally) very hard puzzles, including a couple of optimisers, with what appears to be no time limit. However, you will (almost certainly) find that one week is still not long enough to solve them all!
Some of the most beautiful puzzles I have ever seen have appeared in the Diogen quarterly puzzle contests.

Highly recommended!

kiwijam
Posts: 700
Joined: Wed 01 Jun, 2011 10:03 am

Re: Diogen IPST. 23-30 September 2011

Post by kiwijam » Thu 22 Sep, 2011 11:41 pm

Thanks for pointing this out, I downloaded the previous test for a look and am now eagerly awaiting the start of this one. A change of pace to the normal speed runs, and the puzzles are very good quality.

PuzzleScot
Site Admin
Posts: 2740
Joined: Fri 18 Jun, 2010 10:45 pm
Location: Edinburgh, Scotland

Re: Diogen IPST. 23-30 September 2011

Post by PuzzleScot » Sun 02 Oct, 2011 12:04 am

I didn't finish my last puzzle until this afternoon. Some really nice puzzles in there as usual. Thanks to Riad (and Andrey) for organising this 8-)

PuzzleScot
Site Admin
Posts: 2740
Joined: Fri 18 Jun, 2010 10:45 pm
Location: Edinburgh, Scotland

Re: Diogen IPST. 23-30 September 2011

Post by PuzzleScot » Mon 03 Oct, 2011 4:26 pm


detuned
Posts: 1875
Joined: Mon 21 Jun, 2010 2:25 pm
Location: London, UK
Contact:

Re: Diogen IPST. 23-30 September 2011

Post by detuned » Mon 03 Oct, 2011 4:55 pm

Wow, nice going guys, I make that 3 of us from the forums in the top 10!

PuzzleScot
Site Admin
Posts: 2740
Joined: Fri 18 Jun, 2010 10:45 pm
Location: Edinburgh, Scotland

Re: Diogen IPST. 23-30 September 2011

Post by PuzzleScot » Mon 03 Oct, 2011 6:30 pm

detuned wrote:Wow, nice going guys, I make that 3 of us from the forums in the top 10!
I prefer "2 of us in the top 4", or "3 in the top 7", but yeah, cool...

There were a couple of problems in the optimisers.
10. "There may be only one king in this part". This was meant to mean "If you only have one king in this part, that's not a problem".
12. Design a tapa - There is an inifinite solution, that James, Hideaki and myself spotted.

Still, great contest, with some very challenging puzzles. Most enjoyable!
#5 - Polymino is the stand-out puzzle, if you're just going to do one puzzle. (hint: do not attempt without a ruler!)

AndreyBogdanov
Posts: 33
Joined: Tue 10 Aug, 2010 5:49 pm
Location: Moscow

Re: Diogen IPST. 23-30 September 2011

Post by AndreyBogdanov » Tue 04 Oct, 2011 1:22 pm

PuzzleScot wrote:There were a couple of problems in the optimisers.
Riad worries about this very much. He cannot decide what to do with puzzle 10. The first variant is to consider results as final and the second is to give maximum points for the solutions with only one king and 52 cells.

PuzzleScot
Site Admin
Posts: 2740
Joined: Fri 18 Jun, 2010 10:45 pm
Location: Edinburgh, Scotland

Re: Diogen IPST. 23-30 September 2011

Post by PuzzleScot » Tue 04 Oct, 2011 9:04 pm

AndreyBogdanov wrote:
PuzzleScot wrote:There were a couple of problems in the optimisers.
Riad worries about this very much. He cannot decide what to do with puzzle 10.
Discussing with Stefano earlier, he suggested you separate the solutions into 2 groups:
- The ones that included both kings, and the ones with one king.
For EACH group, award the points as if the other group did not compete.
This seems reasonably fair, although I realise this will knock me down a few places.

kiwijam
Posts: 700
Joined: Wed 01 Jun, 2011 10:03 am

Re: Diogen IPST. 23-30 September 2011

Post by kiwijam » Sun 09 Oct, 2011 9:41 pm

Looks like there's been a rescoring of puzzle 10, which has bumped me up to the top. Very happy with the result, not necessarily so much with the actual process. And we still have 2 in the top 4 and 3 in the top 7.
The first 9 puzzles were great. Tough and innovative, and possible to work through over a week. Worth downloading definitely.

Then I was hoping for three good optimizers to sort out the field. Unfortunately they all had 'difficulties'.
Puzzle 10 had an ambiguous instruction, which meant Russian readers got higher scores than English readers. This has since been fixed, but I also wonder if too much chess knowledge is required for it.
Puzzle 11 annoyed me. You had to find as many distinct symbols as possible, in groups of 4. But I think the maximum number of symbols was 23, meaning finding 20 was easy, and most people did, but you could only get tantalizingly close to the next band of 24. So 'everyone' got full points and no spreading of the field occurred here.
And finally puzzle 12, which did not have enough restrictions. It was possible to get infinite solutions in different ways, using a mostly-full infinite 1xn strip, or a mostly-empty 10xn strip or an mxn 2D-grid. Maybe it needed a maximum size, like the previous competition had (an 8x8 maximum slitherlink). The puzzle writer adjusted the rules during the week to ban the mostly-empty solutions, but not the mostly-full one. So the top score was given to a mathematical curiosity, rather than to the puzzlers who genuinely constructed some good solutions. I was really worried how this might get treated, so I submitted my answers 4 days early to give me time to create a different solution if they didn't like it.

Anyway, can't wait til next time, hopefully these wrinkles will be ironed out.

Post Reply