Instruction Booklet is available now.

Looks VERY nice!
(Small note about IB: the example for puzzle #2 (kropki) is missing a couple of dots in column 2..)
Denis

My bad, missed those dots :(
Re-checking the competition grids to make sure I've made no more mistakes :)

A few questions:

3. Cornerless Snake
Can the missing half of turning cells, be on the inner side instead?

5. Triangular Battleships
"Numbers outside the grid indicate to product of all lengths occupied by the ships in the corresponding rows/columns."
I don't understand this.

10. Unknown Calendar
"Each pair of consecutive numbers should have at least one digit in common and has to be placed
in either same row or same column of the bottom table"
Is this two requirements or just one needed to be satisfied?
In the example, you have 29 and 18 in the same column, can they be consecutive in the puzzle grid?

"For example, 15 can be followed by 11 or 25, but not by 10 (different rows) or 17 (difference is less
than 4)."
But there is no 10 in the table.

11. Unknown Diginet
Can the lines be diagonal?

I have following questions:
1) What is the duration of the contest? (No time limit?)

2) Cornerless Snake - I don't understand the meaning of "On every turn half the cell is cut away." What is a turn defined here?
For e.g. R3c1 to R2c1 is it defined as turn?

100 minutes

"Numbers outside the grid indicate THE product of all lengths occupied by the ships in the corresponding rows/columns."

In the IB example,
- In row 2, the product is (1/2) x (3/2) = (3/4)
- In row 3, it is (1/2) x (1/2) x (1./2) = (1/8)
- In column 5, it is (1/2) x (5/2) = (5/4)

Past winners of forsmarts anniversary contests:

Can't see any point in leaving outer half as it'll make the puzzle no different to a usual Snake.
So the answer would be "no".


For example, there's two segments occupied by the ships in a row: 1/2 and 3/2 (1+1/2). Then the clue outside would be: 1/2*3/2=3/4.


There might be in an actual puzzle.


As long as they connect the numbers, they can go whatever direction you wish.

The picture shows how the snake looked like before the corners were cut off. I hope now it's clearer.

11. Unknown Diginet
Can we use the inserted digits for new crossings?

I'm not sure I understand the question.
If you're asking whether the inserted digit can be a start for a new line then the answer is "no". The lines should connect the originally given numbers only.

Yes, that is what I thought. Thanks!

Thanks. Got it.

The test is active now. The test can be started till 23:59 IST / 18:29 GMT on Monday (19th).

Good luck to all participants!

What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Which set of puzzles did you like the most?	Incorrect Products
What was your opinion about the answer key extraction?	Perfect answer keys
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little
What was your opinion of the booklet formatting and printing?	Just right

What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Fairly Nice
Which set of puzzles did you like the most?	Incorrect Products
What was your opinion about the answer key extraction?	Mostly perfect answer keys
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

A good mix of puzzles -- with a mix of quality, too. But most puzzles are good. Let's see:

- Non-Integer Kakuro: This is just Missing Digits Kakuro (or something like that). The non-integer part isn't utilized much. And honestly I don't think you can do much with Non-Integer Kakuro that you can't do with Kakuro with nonstandard set.
- Non-Integer Kropki: You can just multiply by 2 to get normal Kropki except white circles have difference 2. But at least this one changes the meaning of the circles, and so is a more interesting application.
- Cornerless Snake: This is actually a very interesting design, even if I ended up intuiting it. Still need to figure out a more logical approach, but this puzzle was good. Answer key was less good though; I'm not sure if H, F, - make the best answers, but I feel like it could have been better.
- Triangular Minesweepers: Both puzzles were incredible, although I think the large one ended up needing a few "I think this must go this way" reasoning near the end. Very good showcase of these puzzles. Answer key was... weird; could have gone with all letters (Mine / Empty, for example), or something that involves orientations of the mines too.
- Triangular Battleships: I also mostly intuited it, but I think it has a nice logical solution. And even though its name is Battleships, its logic has nearly nothing in common with it.
- Incorrect Easy As ABC: Somehow this one doesn't seem quite penetrable and I had to resort to guessing a lot. My first opinion is that this type is kinda brute-forcy, but if someone can show a logical solution...
- Incorrect Products: This one, though, is way fairer. I identified the two conflicting clues right away. These liar puzzles seem to be best if there's a clear set of contradicting clues, which I don't believe I find in Easy As ABC.
- Incorrect Calcudoku: Same as above, although the contradicting clues aren't as clear. But still very reasonable.
- Incorrect Spiral Galaxies: Ehhh, I intuited this through like usual Spiral Galaxies. I'm sure it's possible to do it logically, but most Spiral Galaxies fall through with intuition easier.
- Unknown Calendar: Oops I skipped this. But "sharing a digit" and "in the same row/column" are two different things and the instructions should have exactly stated which one. At the current state, 2 and 10 may or may not be adjacent.
- Unknown Diginet: Okay this is an incredibly weird genre and I'm not sure whether I like it or not. I ended up intuiting it and I'm not sure what logical solution I can possibly obtain from this genre. The answer key is also not something I'm sure I like.
- Unknown Pentomino: This one falls through fairly, and nothing particularly notable.
- Instructionless Alpha: This is a pretty good genre idea, although the logic falls through very easily once you get the tricks. Answer key was a big mess though; should have gone with the same symbols instead of translating to B and F.
- Instructionless Beta: Oops I still can't figure this out.
- Instructionless Gamma: Region borders might have been better clearer, but otherwise this lends itself to easy puzzles. Not certain the answer key was the best (could have gone with the standard "longest/all segments in marked rows/columns").

So, all in all: interesting puzzles, some less-than-perfect applications but mostly good, some less-than-perfect answer keys as well, but I enjoyed the interesting genres.

What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Which set of puzzles did you like the most?	Instructionless Gamma
What was your opinion about the answer key extraction?	Mostly perfect answer keys
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

I was able to answer both Alphas without finishing the puzzle, due to the answer keys pointing to easy rows.
Not sure why rightmost lines were used, leftmost feels more 'normal'.
Alpha Small felt like it had 2 solutions?
Don't like the Beta example.
I solved the first two as integer puzzles, which I think is a nicer presentation.
Gamma, Unknown Pentomino, and Alpha were my favourite new types.

What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Which set of puzzles did you like the most?	Non-Integer Kropki
What was your opinion about the answer key extraction?	Perfect answer keys
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Which set of puzzles did you like the most?	Non-Integer Kakuro
What was your opinion about the answer key extraction?	Perfect answer keys
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Which set of puzzles did you like the most?	Incorrect Products
What was your opinion about the answer key extraction?	Mostly perfect answer keys
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

"Contest extended by 24 hours" post is not visible when I'm not logged in.

Edited by kiwijam 2018-02-20 4:22 AM

What was your opinion of the distribution of easy/hard puzzles?	Too many medium difficult puzzles
What did you think about the puzzle quality of the test?	Very nice
Which set of puzzles did you like the most?	Unknown Calendar
What was your opinion about the answer key extraction?	Perfect answer keys
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

Well interesting set of puzzles. Wasted lot of time in switching between puzzles and couldn't complete lots of them. Have to solve remaining.
Thanks for the test.

What was your opinion of the distribution of easy/hard puzzles?	Too many hard puzzles
What did you think about the puzzle quality of the test?	Very nice
Which set of puzzles did you like the most?	Triangular Minesweeper
What was your opinion about the answer key extraction?	Perfect answer keys
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Many puzzles were worth too much or too little
What was your opinion of the booklet formatting and printing?	Just right

What was your opinion of the distribution of easy/hard puzzles?	Too many medium difficult puzzles
What did you think about the puzzle quality of the test?	Fairly Nice
Which set of puzzles did you like the most?	Unknown Diginet
What was your opinion about the answer key extraction?	Mostly perfect answer keys
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

What was your opinion of the distribution of easy/hard puzzles?	Just right
What did you think about the puzzle quality of the test?	Very nice
Which set of puzzles did you like the most?	Unknown Calendar
Of the puzzles you solved/attempted, how well did the point values reflect the difficulty?	Most puzzles were worth the right amount
What was your opinion of the booklet formatting and printing?	Just right

My first ever podium finish that I can remember, and this is done when I'm half-asleep. Clearly I should do contests while half-asleep. :P

I've come to a similar conclusion recently. I make more mistakes when I'm solving fresh -_- There's probably a weird theory explaining it somewhere even if I can't think of one now.

Big thanks to all the competitors and congratulations to Endo, Ivan and Kota, who made it to a top-3.
I would also like to thank my co-authors:
Olga Shut, who created all Unknown puzzles and Instructionless Gamma
and Andrey Bogdanov, author of all Triangular puzzles.

Edited by forsmarts 2018-02-21 3:37 PM

I think that Unknown digits have second possible solution: 1234. Connecting: 1-6, 2-7, 3-5, 3-9, 4-5. Am I wrong?

Also, can we know rules for instructionless puzzles? For example when I solve alpha I get multiple solutions (but proper answer keys nevertheless).

EDIT: I just figured out proper alpha rules that don't give multiple solutions.

Edited by skrzypl1 2018-02-21 4:04 PM

Seems like you're right :( Confirmed with Olga.
I'll ask an administrator to give full points for this one as well.

Thank you Vladimir and all your helpers for an entertaining and challenging set of puzzles. I never know how such creative people come up with new puzzle types but I am grateful that you do!

Will there be a solution pdf published? Man oh man I do not see what I did wrong on Gamma -- at least the first one seems like it follows a perfectly unique set of rules.

I'm sure the solutions will be posted a bit later on a contest page. Meanwhile you can get it from here: https://drive.google.com/open?id=1-WA0Yld3B-L_d-CzrC-nBNj13kdc0eiw

Great puzzles and a lot of new ideas!
Is there a way to see the puzzles from the aforementioned Moscow Cup ?

They'll be posted shortly on http://diogenclub.com/, but it will be in Russian.

Isn’t this a valid solution for Incorrect Products too?

42513
31452
23145
54231
15324

Para: The 6 is replaced by a 18; that's not a change of one digit.

And to the puzzle: It's a shame to know that Unknown Diginet has multiple solutions. That must be why I was wondering how you can possibly approach this logically.

Edited by chaotic_iak 2018-02-23 6:56 AM

Solution Booklet available now.

Ah, okay. I didn’t really read the rules carefully enough. I just went with, they all work the same as the first, which was one incorrect clue.

For beta, also the line has to turn at each dot? Otherwise the example seems not unique.

The alpha rules are nice, unfortunately some Slalom-like rules were too promising for me (no loops, then no crosses: seemed to work fine for the example and the first puzzle, but the second one is contradictory quite late).

You're right, it should also make a turn at each dot!

Example is not unique for slalom-like solution, there's one cell that may contain either slash.

Thank you for the solutions, Vladimir. I solved Gamma as "Path must alternate going through circle-wall-circle-wall..." but did not realize the additional constraint. It solved the example uniquely but obviously not uniquely for the puzzles themselves. Which might explain why I had to guess and was happy (at the time!) to reach a conclusion! :)

I thought it was a great contest. I did have one question about the incorrect products puzzle. I got an answer of 45213 and 23541 doing this the 36 was the incorrect product. Maybe I am missing something but after checking many times this seems to be a possible alternative solution.

The rules say there's just one incorrect digit. If you have a solution with 36 turning into, say, 16 or 35, please share, but I still think the solution is unique.