Search found 129 matches

by Feadoor
Mon 22 Feb, 2021 1:46 am
Forum: General Puzzle Discussions
Topic: Some puzzles for your solving pleasure
Replies: 27
Views: 16638

Re: Some puzzles for your solving pleasure

I made a linked set of 27 puzzles; they should keep you busy for quite a long time. The file is too large to attach directly to this post but you can download the PDF from this link:

https://drive.google.com/file/d/1MHtqW_ ... sp=sharing
by Feadoor
Sat 20 Feb, 2021 10:50 am
Forum: Puzzle Competitions
Topic: 2021 WPF Sudoku and Puzzle GPs
Replies: 48
Views: 3070

Re: 2021 WPF Sudoku and Puzzle GPs

Note that this is version 2 of the IB; the difference from version 1 is that three puzzles worth 150+ points have been removed and the total points reduced from nearly 1300 to a "mere" 841 :D
by Feadoor
Thu 18 Feb, 2021 2:11 am
Forum: Puzzle (incl. Sudoku) Rules & Tips
Topic: Masyu
Replies: 5
Views: 152

Re: Masyu

The second of those follow-up examples appears broken!
by Feadoor
Tue 16 Feb, 2021 10:36 am
Forum: Puzzle Competitions
Topic: 2021 WPF Sudoku and Puzzle GPs
Replies: 48
Views: 3070

Re: 2021 WPF Sudoku and Puzzle GPs

Yes, Classic 6 needed either advanced techniques or a well-chosen *ahem* bifurcation *ahem*. I don't 100% agree that Killer Arrows is just a gimmick - the fact that the arrow sum is forced for any given cage total doesn't necessarily make it a bad variant for me. But I don't think it was showcased p...
by Feadoor
Sun 14 Feb, 2021 2:56 pm
Forum: Puzzle Competitions
Topic: Killer Sudoku Contest 13/02/21
Replies: 3
Views: 376

Re: Killer Sudoku Contest 13/02/21

If I were nit-picking slightly then I might say that our creators have sometimes veered over into the computer-assisted line whilst setting these - I don’t think anyone sets anything like this entirely by hand - but all in all this is easily the most remarkable set of killer sudoku in existence tha...
by Feadoor
Fri 12 Feb, 2021 9:05 am
Forum: Puzzle Competitions
Topic: Divisions A and B 2020-2021
Replies: 36
Views: 3926

Re: Divisions A and B 2020-2021

If it's helpful, here's how I saw the same deduction that Freddie describes, in picture form: sending R6C6 up and right causes problems for the white pearl marked with an X.
masyuallcells.PNG
masyuallcells.PNG (98.99 KiB) Viewed 419 times
by Feadoor
Wed 10 Feb, 2021 9:36 pm
Forum: Puzzle Competitions
Topic: Divisions A and B 2020-2021
Replies: 36
Views: 3926

Re: Divisions A and B 2020-2021

Yeah, this was a surprisingly tricky round. There were a few low-pointer puzzles with relatively advanced deductions, most notably the first slitherlink and regional yajilin. By "first Slitherlink" do you mean the first of the S&W ones? Because I had no problem with the standard ones but that S&W k...
by Feadoor
Mon 08 Feb, 2021 7:55 am
Forum: Puzzle Competitions
Topic: Killer Sudoku Contest 13/02/21
Replies: 3
Views: 376

Killer Sudoku Contest 13/02/21

If anyone's looking for something to do this Saturday afternoon, here's a Sudoku contest that isn't quite your usual fare. https://logic-masters.de/Wettbewerbe/CE/wettbewerb.php?id=159 In a nutshell, 27 themed Killer Sudoku, fixed starting time, first to finish them all wins. I tested the puzzles (a...
by Feadoor
Thu 04 Feb, 2021 8:16 am
Forum: Puzzle Competitions
Topic: 2021 WPF Sudoku and Puzzle GPs
Replies: 48
Views: 3070

Re: 2021 WPF Sudoku and Puzzle GPs

Is there a way to get into puzzle 1 - I've not had a massive look at it yet. I solved it after time. My way into it was to subtract away cunningly-chosen disjoint clumps of areas from the entire total to leave behind only two region. Doing that in a few different ways gave me enough pairs with appr...
by Feadoor
Tue 02 Feb, 2021 3:17 pm
Forum: Puzzle Competitions
Topic: 2021 WPF Sudoku and Puzzle GPs
Replies: 48
Views: 3070

Re: 2021 WPF Sudoku and Puzzle GPs

There's been an update to the results to reflect the issue with puzzles 4/5. James climbs a few places and Freddie slips into 3rd and will have to wait a little longer for an individual victory.

3. Freddie Hand 752
9. James McGowan 685
19. Neil Zussman 577
by Feadoor
Thu 28 Jan, 2021 2:52 pm
Forum: Puzzle Competitions
Topic: Puzzle Ramayan and Sudoku Mahabharat 2021
Replies: 4
Views: 426

Re: Puzzle Ramayan and Sudoku Mahabharat 2021

Results for PR Round 1 are out, the UK top three are: 7. Freddie Hand (139.98) 16. James McGowan (126.6) 34. Sam Cappleman-Lynes (111.83) I thought the puzzles were of extremely high quality, although I did somehow manage to spend 18 minutes solving Hitori (and I told Prasanna I'd never forgive him ...
by Feadoor
Tue 26 Jan, 2021 6:58 pm
Forum: Puzzle Competitions
Topic: 2021 WPF Sudoku and Puzzle GPs
Replies: 48
Views: 3070

Re: 2021 WPF Sudoku and Puzzle GPs

Sorry to sound silly, but by parity properties you mean like a checkerboard and it has to go white black white black? The observation I used for the example was that if you colour the grid as you say, all of the tens digits of the primes share a colour, and all of the units digits share a colour. A...
by Feadoor
Mon 25 Jan, 2021 3:38 pm
Forum: Puzzle Competitions
Topic: 2021 WPF Sudoku and Puzzle GPs
Replies: 48
Views: 3070

Re: 2021 WPF Sudoku and Puzzle GPs

Oh no, I hope you have better luck for the puzzle GP. Thanks for the tips! I was wondering, though, what is the no battenburg rule? In Cave, you have two things to keep in mind: - The white cells must be connected - The black cells must all connect to the edge of the board Imagine you had a 2x2 squ...
by Feadoor
Fri 22 Jan, 2021 9:18 pm
Forum: Puzzle Competitions
Topic: Puzzle Ramayan and Sudoku Mahabharat 2021
Replies: 4
Views: 426

Puzzle Ramayan and Sudoku Mahabharat 2021

In the same vein as the GP thread, let's combine these two threads this year. The first Puzzle Ramayan round has started, and runs throughout the weekend.

https://logicmastersindia.com/live/?contest=PR202101
by Feadoor
Tue 19 Jan, 2021 9:39 am
Forum: Puzzle Competitions
Topic: 2021 WPF Sudoku and Puzzle GPs
Replies: 48
Views: 3070

Re: 2021 WPF Sudoku and Puzzle GPs

Preliminary results are out, the UK top 3 are: 32. Sam Cappleman-Lynes - 495 41. Jeremy Kong - 468 58. Tom Collyer - 412 The overall top 3 (Kota, Tantan and Tiit) are well clear of the rest of the field. Puzzles-wise, I did not regret my decision to just keep guessing at the endpoints of the lines i...
by Feadoor
Thu 14 Jan, 2021 9:15 pm
Forum: Puzzle Competitions
Topic: 2021 WPF Sudoku and Puzzle GPs
Replies: 48
Views: 3070

Re: 2021 WPF Sudoku and Puzzle GPs

Yes - that's essentially all there is to it. Any clue in the range 1-4 must start with a 1, in the range 5-8 a 2 and so on. The rest is standard Sudoku and comparing the values within each range of four to get further restrictions. It can be a lot to keep track of so I strongly suggest crossing a cl...
by Feadoor
Thu 14 Jan, 2021 10:03 am
Forum: Puzzle Competitions
Topic: 2021 WPF Sudoku and Puzzle GPs
Replies: 48
Views: 3070

Re: 2021 WPF Sudoku and Puzzle GPs

Sudoku Round 1 starts tomorrow, and the instruction booklet is available here: https://gp.worldpuzzle.org/content/instruction-booklet
by Feadoor
Thu 10 Dec, 2020 7:35 pm
Forum: General Puzzle Discussions
Topic: Some puzzles for your solving pleasure
Replies: 27
Views: 16638

Re: Some puzzles for your solving pleasure

As an aside, for us that are not great at solving Sudoku it would help if the grids were larger to give us more space for having to put candidates in etc. Thanks Liane, I'll bear that in mind in future. Tom/David, I'm glad you enjoyed them. They were a lot of fun to create. I am intrigued which one...
by Feadoor
Thu 10 Dec, 2020 9:32 am
Forum: Puzzle Competitions
Topic: Division C 2020-2021
Replies: 15
Views: 3451

Re: Division C 2020-2021

I'm only just getting round to looking at the examples for these: the diagonal fillomino example has two solutions, I believe (you can swap R2C3 and R3C2 in the given solution).
by Feadoor
Fri 27 Nov, 2020 11:53 am
Forum: General Puzzle Discussions
Topic: Some puzzles for your solving pleasure
Replies: 27
Views: 16638

Re: Some puzzles for your solving pleasure

I've been making some more puzzles. A whole bunch of Classic Sudoku this time. Enjoy!
by Feadoor
Mon 23 Nov, 2020 8:12 am
Forum: General Puzzle Discussions
Topic: Printing puzzles for contests
Replies: 3
Views: 1138

Re: Printing puzzles for contests

This is an interesting question which as far as I know does not have a common consensus. There is some discussion and food for thought here: https://hausigel.de/blog/2020/03/08/screen-vs-paper/ Personally, if a contest is designed to be solved on paper, I think it's cheating. Not just because of fun...
by Feadoor
Tue 20 Oct, 2020 8:19 pm
Forum: Puzzle Competitions
Topic: Divisions A and B 2020-2021
Replies: 36
Views: 3926

Re: Divisions A and B 2020-2021

I haven't used the site so this is pure speculation, but my intuitive feeling is that anyone with a mouse is likely to be able to make accurate movements significantly more quickly than me using a trackpad.
by Feadoor
Mon 19 Oct, 2020 6:39 pm
Forum: Puzzle Competitions
Topic: Divisions A and B 2020-2021
Replies: 36
Views: 3926

Re: Divisions A and B 2020-2021

Regarding Puzzle Duel, I don’t see an issue with giving everyone the same solving medium. After a very interesting discussion about writing speeds and notations, I like the idea of levelling that particular playing field. If it doesn’t work well, we can change it for 2021-2022. It's only level if I...
by Feadoor
Sat 04 Jul, 2020 10:03 pm
Forum: Welcome!
Topic: Hello
Replies: 6
Views: 4539

Re: Hello

Don't worry, everyone else is baffled by that too.