Riad Khanmagomedov's April Contest — 20th to 28th April 2016
@ 2016-04-11 7:02 AM (#21482) (#21482) Top

Administrator



2000100050020
Country : India

Administrator posted @ 2016-04-11 7:02 AM




@ 2016-04-15 5:06 AM (#21515 - in reply to #21482) (#21515) Top

kiwijam



Posts: 183
10020202020
Country : New Zealand

kiwijam posted @ 2016-04-15 5:06 AM

Yay! :D
@ 2016-04-17 12:02 PM (#21518 - in reply to #21482) (#21518) Top

mikeylyk



Posts: 16

Country : United States

mikeylyk posted @ 2016-04-17 12:02 PM

always interesting and innovative, an annual highlight for me
@ 2016-04-19 9:16 AM (#21522 - in reply to #21482) (#21522) Top

Administrator



2000100050020
Country : India

Administrator posted @ 2016-04-19 9:16 AM

Some notes about April Contest

Please note this contest will have a slightly different format than regular LMI tests.

Key differences from regular LMI tests:
• There is no IB (i.e. no Instructions Booklet). If you have any questions about any puzzle, please ask here.
• The PB (Puzzle Booklet) does not have any password
• You can download the pdf and start solving. Login at the contest page to start submitting.
• There is no time limit. You can submit until the contest ends.
• There will be some optimizer puzzles. Other puzzles will be very hard (compared to regular LMI tests)
• Same scores will have same rank (i.e. early submissions do not count towards rank)

@ 2016-04-20 12:53 AM (#21523 - in reply to #21482) (#21523) Top

Plucky



Posts: 8

Country : United Kingdom

Plucky posted @ 2016-04-20 12:53 AM

Trying to access puzzles from http://www.diogen.h1.ru/cgi-bin/contest/start.pl brings up the error page http://err.h18.ru/error404.shtml in all cases it seems - could this be fixed please, or another website given where these puzzles/examples can be accessed?
@ 2016-04-20 3:13 AM (#21524 - in reply to #21482) (#21524) Top

auroux



Posts: 145
1002020
Country : France

auroux posted @ 2016-04-20 3:13 AM

I don't think I understand the answer format for puzzle #1, or else I'm not sure I understand why my submission triggers the red message "pentomino letters, + or -" as if it were malformed.
Could an organizer check whether my submission for Pentobattle is well-formed? (answer key contents are valid and of the correct length to match expected answers?)
(I also happen to think that I have solved the puzzle correctly but understand that you'd rather not comment on that).
Thanks in advance!
Denis
@ 2016-04-20 3:57 AM (#21525 - in reply to #21482) (#21525) Top

Administrator



2000100050020
Country : India

Administrator posted @ 2016-04-20 3:57 AM

April Contest has started

• Puzzle booklet (without password) is available.
• This thread will remain open (unrestricted) throughout the contest - which will allow players to ask questions about the puzzles.
• The red warnings for optimizer puzzles are not always correct. You can ignore them, if you are fairly sure that your answer keys are in correct format;
• Potential Score page - http://logicmastersindia.com/2016/04Contest/score.asp

@ 2016-04-20 5:45 AM (#21526 - in reply to #21482) (#21526) Top

Plucky



Posts: 8

Country : United Kingdom

Plucky posted @ 2016-04-20 5:45 AM

For Trid-Fir, it says "Digits in one line should be different." - does this mean only horizontal lines within each triangle, or also diagonal lines within each triangle?
@ 2016-04-20 5:54 AM (#21527 - in reply to #21524) (#21527) Top

debmohanty




1000500100100100202020
Country : India

debmohanty posted @ 2016-04-20 5:54 AM

auroux - 2016-04-20 3:13 AM

I don't think I understand the answer format for puzzle #1, or else I'm not sure I understand why my submission triggers the red message "pentomino letters, + or -" as if it were malformed.
Could an organizer check whether my submission for Pentobattle is well-formed? (answer key contents are valid and of the correct length to match expected answers?)
(I also happen to think that I have solved the puzzle correctly but understand that you'd rather not comment on that).
Thanks in advance!
Denis

The red warnings are not correct for this puzzle. Will have them fixed.
@ 2016-04-20 5:59 AM (#21528 - in reply to #21526) (#21528) Top

debmohanty




1000500100100100202020
Country : India

debmohanty posted @ 2016-04-20 5:59 AM

Plucky - 2016-04-20 5:45 AM

For Trid-Fir, it says "Digits in one line should be different." - does this mean only horizontal lines within each triangle, or also diagonal lines within each triangle?
Each diagonal too, even if the length of some of the diagonals could be less than "N"
See section C of Puzzle Jackpot contest for a classic Trid puzzle
@ 2016-04-20 8:22 AM (#21529 - in reply to #21482) (#21529) Top

chaotic_iak




Posts: 241
1001002020
Country : Indonesia

chaotic_iak posted @ 2016-04-20 8:22 AM

Pentobattle: Just to warn, these use unusual letters (J and S instead of N and Z).
Mirrored Sudokus: Can a number from a grid on the left be mirrored twice to a grid on the right with the same orientation?
@ 2016-04-20 9:29 AM (#21530 - in reply to #21529) (#21530) Top

debmohanty




1000500100100100202020
Country : India

debmohanty posted @ 2016-04-20 9:29 AM

chaotic_iak - 2016-04-20 8:22 AM

Pentobattle: Just to warn, these use unusual letters (J and S instead of N and Z).
We will accept any of the conventions
@ 2016-04-20 9:29 AM (#21531 - in reply to #21527) (#21531) Top

debmohanty




1000500100100100202020
Country : India

debmohanty posted @ 2016-04-20 9:29 AM

debmohanty - 2016-04-20 5:54 AM

auroux - 2016-04-20 3:13 AM

I don't think I understand the answer format for puzzle #1, or else I'm not sure I understand why my submission triggers the red message "pentomino letters, + or -" as if it were malformed.
Could an organizer check whether my submission for Pentobattle is well-formed? (answer key contents are valid and of the correct length to match expected answers?)
(I also happen to think that I have solved the puzzle correctly but understand that you'd rather not comment on that).
Thanks in advance!
Denis

The red warnings are not correct for this puzzle. Will have them fixed.

Fixed.
@ 2016-04-20 10:12 AM (#21532 - in reply to #21482) (#21532) Top

deu



Posts: 69
202020
Country : Japan

deu posted @ 2016-04-20 10:12 AM

In Puzzle 9, red warning for the first box still remains even after entering a positive integer.
@ 2016-04-20 11:32 AM (#21533 - in reply to #21532) (#21533) Top

debmohanty




1000500100100100202020
Country : India

debmohanty posted @ 2016-04-20 11:32 AM

deu - 2016-04-20 10:12 AM

In Puzzle 9, red warning for the first box still remains even after entering a positive integer.
Fixed.
@ 2016-04-20 12:48 PM (#21534 - in reply to #21482) (#21534) Top

chaotic_iak




Posts: 241
1001002020
Country : Indonesia

chaotic_iak posted @ 2016-04-20 12:48 PM

In The Citadels: Is it allowed to use 6D twice (because it's split into two)?
Borderless Sextet: "so that each yellow cell was occupied by a white cell of the grid. Should appear the connected yellow region (possibly only with black cells inside)." I can't understand this portion.
@ 2016-04-20 1:35 PM (#21535 - in reply to #21534) (#21535) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-20 1:35 PM

chaotic_iak - 2016-04-20 12:48 PM

In The Citadels: Is it allowed to use 6D twice (because it's split into two)?
Borderless Sextet: "so that each yellow cell was occupied by a white cell of the grid. Should appear the connected yellow region (possibly only with black cells inside)." I can't understand this portion.

IN THE CITADEL: 6D can be used only once.
BORDERLESS SEXTET: Inside the yellow area may be black cells, but not white cells.
@ 2016-04-20 2:06 PM (#21536 - in reply to #21482) (#21536) Top

chaotic_iak




Posts: 241
1001002020
Country : Indonesia

chaotic_iak posted @ 2016-04-20 2:06 PM

Borderless Sextet:
- Must all cells in the loop region be used in the loop? Is the loop's length 16? By "touching", does it mean Snake-like touching (being on adjacent cells while not being consecutive cells in the loop) or Masyu-like touching (using the same cell twice)?
- Do the diagonal clues for packing count multiple cells of the same region only once or as many times as the cells? (That is, do they add up regions' numbers or cells'?)
@ 2016-04-20 2:35 PM (#21537 - in reply to #21536) (#21537) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-20 2:35 PM

chaotic_iak - 2016-04-20 2:06 PM

Borderless Sextet:
- Must all cells in the loop region be used in the loop? Is the loop's length 16? By "touching", does it mean Snake-like touching (being on adjacent cells while not being consecutive cells in the loop) or Masyu-like touching (using the same cell twice)?
- Do the diagonal clues for packing count multiple cells of the same region only once or as many times as the cells? (That is, do they add up regions' numbers or cells'?)

1. The loop region consists of 16 cells, the length of the loop 16. Everything else you determine by solving a puzzle.
2. The sum of the numbers in the yellow cells are indicated along the two diagonals. For example, if along the diagonal 6 yellow cells, that indicated the sum of the numbers in this 6 cells.
@ 2016-04-20 5:53 PM (#21538 - in reply to #21482) (#21538) Top

Para



Posts: 315
100100100
Country : The Netherlands

Para posted @ 2016-04-20 5:53 PM

In "In the Citadel", I assume there is only a restriction on using stairs once and not on the paths between the stairs?
@ 2016-04-20 6:19 PM (#21539 - in reply to #21527) (#21539) Top

forcolin




Posts: 172
100202020
Country : ITALY

forcolin posted @ 2016-04-20 6:19 PM

debmohanty - 2016-04-20 5:54 AM

auroux - 2016-04-20 3:13 AM

I don't think I understand the answer format for puzzle #1, or else I'm not sure I understand why my submission triggers the red message "pentomino letters, + or -" as if it were malformed.
Could an organizer check whether my submission for Pentobattle is well-formed? (answer key contents are valid and of the correct length to match expected answers?)
(I also happen to think that I have solved the puzzle correctly but understand that you'd rather not comment on that).
Thanks in advance!
Denis

The red warnings are not correct for this puzzle. Will have them fixed.

I had the same problem as Denis. will wait to see when it's fixed
@ 2016-04-20 7:13 PM (#21540 - in reply to #21538) (#21540) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-20 7:13 PM

Para - 2016-04-20 5:53 PM

In "In the Citadel", I assume there is only a restriction on using stairs once and not on the paths between the stairs?

Yes, there is only a restriction on using stairs once. This is evident from the example in the Answer format.
@ 2016-04-20 8:27 PM (#21541 - in reply to #21482) (#21541) Top

forcolin




Posts: 172
100202020
Country : ITALY

forcolin posted @ 2016-04-20 8:27 PM

a question about 4.BRICKS.
the brick fragment which must be filled with the length of the brick will always occur at one of the ends of the brick or it can occur also in the middle?
@ 2016-04-21 5:34 AM (#21542 - in reply to #21482) (#21542) Top

kiwijam



Posts: 183
10020202020
Country : New Zealand

kiwijam posted @ 2016-04-21 5:34 AM

"Borderless Sextet" questions:

- Is every cell of the grid in one of the 6 regions? Or can there be cells which are not used?
- Packing Figures are only on white cells, Battleships only on blue cells, the other 4 regions can be white or blue. Correct?
- The Battleships region must include empty cells between ships, but can other regions include empty cells also? e.g. can the Snake region be larger than 19 cells, or can the Scrabble region include cells without letters?
I think in the other three regions, every cell must be part of a loop/tetromino/yellow figure?
@ 2016-04-21 10:05 AM (#21543 - in reply to #21482) (#21543) Top

Para



Posts: 315
100100100
Country : The Netherlands

Para posted @ 2016-04-21 10:05 AM

In Opti Pentobattle, if I input the wrong K+1.5N because I didn't count the number of solutions correctly, will my solution be counted as wrong or will it count as the correct K+1.5N?
@ 2016-04-21 10:29 AM (#21544 - in reply to #21543) (#21544) Top

debmohanty




1000500100100100202020
Country : India

debmohanty posted @ 2016-04-21 10:29 AM

Para - 2016-04-21 10:05 AM

In Opti Pentobattle, if I input the wrong K+1.5N because I didn't count the number of solutions correctly, will my solution be counted as wrong or will it count as the correct K+1.5N?
In previous years, Riad has corrected the "optimized value", if it is wrong. It will be done similarly for Opti-Pentobattle.

The purpose of asking optimized value is to sort the solutions quickly.
@ 2016-04-21 12:48 PM (#21545 - in reply to #21544) (#21545) Top

marred



Posts: 12

Country : Poland

marred posted @ 2016-04-21 12:48 PM

Just to clarify: in Pentobattle do I have to separate each cell with comma?
@ 2016-04-21 12:50 PM (#21546 - in reply to #21545) (#21546) Top

debmohanty




1000500100100100202020
Country : India

debmohanty posted @ 2016-04-21 12:50 PM

marred - 2016-04-21 12:48 PM

Just to clarify: in Pentobattle do I have to separate each cell with comma?
Commas not required.
@ 2016-04-21 1:42 PM (#21547 - in reply to #21541) (#21547) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-21 1:42 PM

forcolin - 2016-04-20 8:27 PM

a question about 4.BRICKS.
the brick fragment which must be filled with the length of the brick will always occur at one of the ends of the brick or it can occur also in the middle?

Length is always stated at the end of the brick.
@ 2016-04-21 1:51 PM (#21548 - in reply to #21542) (#21548) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-21 1:51 PM

kiwijam - 2016-04-21 5:34 AM

"Borderless Sextet" questions:

- Is every cell of the grid in one of the 6 regions? Or can there be cells which are not used?
- Packing Figures are only on white cells, Battleships only on blue cells, the other 4 regions can be white or blue. Correct?
- The Battleships region must include empty cells between ships, but can other regions include empty cells also? e.g. can the Snake region be larger than 19 cells, or can the Scrabble region include cells without letters?
I think in the other three regions, every cell must be part of a loop/tetromino/yellow figure?

1. Each cell belongs to one of 6 regions.
2. Correct.
3. Yes.
@ 2016-04-21 5:25 PM (#21549 - in reply to #21482) (#21549) Top

rob



Posts: 170
100202020
Country : Germany

rob posted @ 2016-04-21 5:25 PM

In the Citadel stair codes answer code is marked red, although my format seems correct as far as I can tell.
@ 2016-04-21 10:58 PM (#21550 - in reply to #21482) (#21550) Top

Mihalich



Posts: 25
20
Country : Ukraine

Mihalich posted @ 2016-04-21 10:58 PM

??????? 6 - ?. 4 ?????? ?????????? ? ??????? ??????. ??? ????? ?????????? 4?
@ 2016-04-21 11:01 PM (#21551 - in reply to #21482) (#21551) Top

Mihalich



Posts: 25
20
Country : Ukraine

Mihalich posted @ 2016-04-21 11:01 PM

Zadanije 6 - C. 4 dolgno nahoditsa tolko v zelenoy kletke. Kak i kuda moget otrazitsa 4?
@ 2016-04-22 1:15 PM (#21552 - in reply to #21551) (#21552) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-22 1:15 PM

Mihalich - 2016-04-21 11:01 PM

Zadanije 6 - C. 4 dolgno nahoditsa tolko v zelenoy kletke. Kak i kuda moget otrazitsa 4?

4, chto v pole C, otrazitsya v 4 v pole A, esli sootvetstvuyushchie kletki zelyonye.
@ 2016-04-22 2:37 PM (#21553 - in reply to #21482) (#21553) Top

Administrator



2000100050020
Country : India

Administrator posted @ 2016-04-22 2:37 PM

Tie-breaker for Puzzle 10 - OPTI-PENTOBATTLE

Announcement from Riad - Tie-breaker for solutions with same value of K + 1.5N

If two solutions have same value of K + 1.5N, the solution which has smallest rectangular Pentomino area will be considered as better solution.

@ 2016-04-22 5:29 PM (#21554 - in reply to #21553) (#21554) Top

Para



Posts: 315
100100100
Country : The Netherlands

Para posted @ 2016-04-22 5:29 PM

Administrator - 2016-04-22 2:37 PM

Tie-breaker for Puzzle 10 - OPTI-PENTOBATTLE

Announcement from Riad - Tie-breaker for solutions with same value of K + 1.5N

If two solutions have same value of K + 1.5N, the solution which has smallest rectangular Pentomino area will be considered as better solution.



What does smallest rectangular Sea Area mean exactly? Is that the smallest rectangle the pentomino shape could be fitted in (with max dimensions 10 by 10)? Is this purely by size (9x4=6x6)?
@ 2016-04-22 5:57 PM (#21555 - in reply to #21554) (#21555) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-22 5:57 PM

Para - 2016-04-22 5:29 PM
What does smallest rectangular Sea Area mean exactly? Is that the smallest rectangle the pentomino shape could be fitted in (with max dimensions 10 by 10)? Is this purely by size (9x4=6x6)?

The best, where Pentamino area limited by the rectangle of smaller area. For example, the area bounded by the rectangle 8x10 better that by the rectangle 9x9.
The length of the rectangle cannot be more than 10.
@ 2016-04-22 6:01 PM (#21556 - in reply to #21482) (#21556) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-22 6:01 PM

Deb, please change places K and N in the Tie-breaker. Must be K + 1.5N.
@ 2016-04-22 9:06 PM (#21557 - in reply to #21556) (#21557) Top

chaotic_iak




Posts: 241
1001002020
Country : Indonesia

chaotic_iak posted @ 2016-04-22 9:06 PM

To clarify, it's the Pentomino area that's on the tiebreaker, not the Sea area, right?
@ 2016-04-22 10:19 PM (#21558 - in reply to #21557) (#21558) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-22 10:19 PM

chaotic_iak - 2016-04-22 9:06 PM

To clarify, it's the Pentomino area that's on the tiebreaker, not the Sea area, right?

In our case Pentamino area is the Sea area.
@ 2016-04-22 11:55 PM (#21559 - in reply to #21558) (#21559) Top

chaotic_iak




Posts: 241
1001002020
Country : Indonesia

chaotic_iak posted @ 2016-04-22 11:55 PM

So it's the area that's not covered by pentomino, the area that doesn't contain the ships?
@ 2016-04-23 4:31 AM (#21560 - in reply to #21559) (#21560) Top

kiwijam



Posts: 183
10020202020
Country : New Zealand

kiwijam posted @ 2016-04-23 4:31 AM

So it's the area that's not covered by pentomino, the area that doesn't contain the ships?


The area not covered by pentominoes is "land". The pentominoes are the "sea". The ships are placed into the sea somewhere. So then the pentominoes contain ship cells and empty sea cells.

You need to find the smallest rectangle (max 10x10) that will hold all your pentominoes.
@ 2016-04-23 10:28 AM (#21561 - in reply to #21560) (#21561) Top

chaotic_iak




Posts: 241
1001002020
Country : Indonesia

chaotic_iak posted @ 2016-04-23 10:28 AM

Oh, right, ships are placed on sea. I instinctively translate regions left without pieces as sea.

I also misread the tiebreaker, thinking that the tiebreaker is to minimize the area of the largest rectangular region that is entirely inside the pentominoes.
@ 2016-04-24 2:43 AM (#21562 - in reply to #21482) (#21562) Top

forcolin




Posts: 172
100202020
Country : ITALY

forcolin posted @ 2016-04-24 2:43 AM

question about 9 ACCORDANCES

Is the question solvable only with logic/algebraic calculations or does it require knowledge in a particular field? (music, sport, astronomy etc.)
@ 2016-04-26 1:26 AM (#21565 - in reply to #21482) (#21565) Top

Igor_Aipkin



Posts: 3

Country : Uzbekistan

Igor_Aipkin posted @ 2016-04-26 1:26 AM

Sorry for repeating the question, that was above, but nevertheless - my answers for puzzles 1 and 12 are considered in wrong format, though I checked it many times. Deb said that it would be fixed, but it's still not. Is there a way to be sure that the format of the answer is right? Maybe a pm from someone? I'm not asking to check the answer itself, only format.
One more question - about puzzle 8 - how do you write the content of a cell with a number, if it has more than one digit - for example 19 - should I write 19 or 9, for example, or somehow else?

Edited by Igor_Aipkin 2016-04-26 1:27 AM
@ 2016-04-26 1:49 AM (#21566 - in reply to #21482) (#21566) Top

forcolin




Posts: 172
100202020
Country : ITALY

forcolin posted @ 2016-04-26 1:49 AM

I have used the notation in parenthesis - for example (19). i know the length of the input string is longer and the format alarm goes on but i believe this is a warning for the player rather than a physical limitation to the length. If i am wrong pls administrator let me know and i will change the format
@ 2016-04-26 5:22 AM (#21567 - in reply to #21565) (#21567) Top

Administrator



2000100050020
Country : India

Administrator posted @ 2016-04-26 5:22 AM

Igor_Aipkin - 2016-04-26 1:26 AM

Sorry for repeating the question, that was above, but nevertheless - my answers for puzzles 1 and 12 are considered in wrong format, though I checked it many times. Deb said that it would be fixed, but it's still not. Is there a way to be sure that the format of the answer is right? Maybe a pm from someone? I'm not asking to check the answer itself, only format.
One more question - about puzzle 8 - how do you write the content of a cell with a number, if it has more than one digit - for example 19 - should I write 19 or 9, for example, or somehow else?

Fixed red warnings for 1 (again)
Red warnings for 12 can not be fixed. Please ignore them and submit carefully.
About 8 : Riad expects to type 19. You can follow forcolin's advice above, if you want.
@ 2016-04-26 2:09 PM (#21568 - in reply to #21562) (#21568) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-26 2:09 PM

forcolin - 2016-04-24 2:43 AM

question about 9 ACCORDANCES

Is the question solvable only with logic/algebraic calculations or does it require knowledge in a particular field? (music, sport, astronomy etc.)

Accepted any answer.
@ 2016-04-26 2:13 PM (#21569 - in reply to #21565) (#21569) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-26 2:13 PM

Igor_Aipkin - 2016-04-26 1:26 AM
One more question - about puzzle 8 - how do you write the content of a cell with a number, if it has more than one digit - for example 19 - should I write 19 or 9, for example, or somehow else?

Only one solver gave the last digits of the numbers, but I'll count this answer as correct.
@ 2016-04-26 2:21 PM (#21570 - in reply to #21482) (#21570) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-26 2:21 PM

In the puzzle VOYAGE five solvers have indicated a certain number once (instead of having to do it twice). I think to count such answers as correctly, because the solvers could be difficulties with the translation of the text.
@ 2016-04-26 4:24 PM (#21571 - in reply to #21482) (#21571) Top

Igor_Aipkin



Posts: 3

Country : Uzbekistan

Igor_Aipkin posted @ 2016-04-26 4:24 PM

Riad, I'd like to know your personal opinion about the way to solve optimizers - how do you think, is it ok to write programs to solve them, or they should be solved by a human alone? I know you can't check how everyone does it, but how are they intended to be solved? Can a solution, found by a program, be "true"?
@ 2016-04-26 6:20 PM (#21572 - in reply to #21571) (#21572) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-26 6:20 PM

Igor_Aipkin - 2016-04-26 4:24 PM

Riad, I'd like to know your personal opinion about the way to solve optimizers - how do you think, is it ok to write programs to solve them, or they should be solved by a human alone? I know you can't check how everyone does it, but how are they intended to be solved? Can a solution, found by a program, be "true"?

Igor, I am not a programmer. In the years of study at University, I have relied on pure math, and now regret that I ignored the programming. 16 years since I quit math and do editorial work. As a solver I don't use programs. Are programmers other solvers? I don't know. I know that Kiwijam, won in the April Contest in past years, reported in detail on their strategies for optimization puzzles and without programming.
@ 2016-04-26 11:08 PM (#21573 - in reply to #21482) (#21573) Top

Mihalich



Posts: 25
20
Country : Ukraine

Mihalich posted @ 2016-04-26 11:08 PM

Zadanije 7. Nugno perechislat vse cisla v geltoy linii (primer 12) - 12,12,10,8,11 ili tolko po odnoy - 12,10,8,11
@ 2016-04-27 12:17 AM (#21574 - in reply to #21482) (#21574) Top

auroux



Posts: 145
1002020
Country : France

auroux posted @ 2016-04-27 12:17 AM

I generally don't think it would be fair to use programming in this contest, and in fact I am very pleased with Riad's ideas for optimizer puzzles, which in general are fairly accessible to logical reasoning + taking educated guesses, and wouldn't be trivial at all to do by computer. (Of course the computer software, if you manage to write it, would find the optimal solution. In this year's contest my impression is that optimal solutions to both optimizer puzzles are achievable purely by logical deduction, but we'll only know once my scores on those puzzles become known. In previous year contests the optimizers involved a lot more guesswork for me and I didn't get optimal solutions or see a way to reason entirely logically to find those (even after seeing the optimal solution).
@ 2016-04-27 2:07 AM (#21575 - in reply to #21482) (#21575) Top

sduran



Posts: 7

Country : Turkey

sduran posted @ 2016-04-27 2:07 AM

for question 7; voyage:
for example some portion of loop is white cell-10-10-white cell...
answer format should be which: 10 or 10,10 ?
example given does not clarify this.
@ 2016-04-27 2:51 AM (#21576 - in reply to #21482) (#21576) Top

Kithyane



Posts: 49
2020
Country : France

Kithyane posted @ 2016-04-27 2:51 AM

About programming for optimizer, I agree that it's not the spirit of this test to allow programming. I fail to see how "opti-pentobattle" could be programmed, but "in the citadel" can be modelized by a very classical optimisation problem (I'll probably code it for fun at one point). But despite the tentation, I was happy to notice that for "in the citadel", there was a purely logical way to know if a path is optimal or not (well, until answers are checked, I hope I'm right). I've yet to do opti-pentobattle, so I can't comment on this one.

For now, I'm quite happy to have solved Mirrored Sudoku and Voyage today, afer breaking both of them twice this week-end !
@ 2016-04-27 3:59 AM (#21577 - in reply to #21482) (#21577) Top

Kithyane



Posts: 49
2020
Country : France

Kithyane posted @ 2016-04-27 3:59 AM

Question for "Borderless Sextet" : that's probably me overthinking, but can the battleships region contain black cells ? I ask only because other types mention it specifically ("possibly with black cells"...) and not battelships. If so, I understand that ships can't go on black cells, so black cells are necessarily water ?
@ 2016-04-27 4:30 AM (#21578 - in reply to #21577) (#21578) Top

kiwijam



Posts: 183
10020202020
Country : New Zealand

kiwijam posted @ 2016-04-27 4:30 AM

sduran - 2016-04-27 9:07 AM

for question 7; voyage:
for example some portion of loop is white cell-10-10-white cell...
answer format should be which: 10 or 10,10 ?
example given does not clarify this.


Answer should be just 10. Each block of numbers between white cells gets one number written only.
But if there is a white cell between them, you write one number for every block: e.g. for "white cell-10-10-10-white cell-10-10-white cell..." you will write "10,10".


Kithyane - 2016-04-27 10:59 AM

Question for "Borderless Sextet" : that's probably me overthinking, but can the battleships region contain black cells ? I ask only because other types mention it specifically ("possibly with black cells"...) and not battelships. If so, I understand that ships can't go on black cells, so black cells are necessarily water ?


Yes, the Battleship region can contain black cells. Nothing can be written in any black cell.
@ 2016-04-27 2:24 PM (#21579 - in reply to #21573) (#21579) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-27 2:24 PM

Mihalich - 2016-04-26 11:08 PM

Zadanije 7. Nugno perechislat vse cisla v geltoy linii (primer 12) - 12,12,10,8,11 ili tolko po odnoy - 12,10,8,11

Po odnoy. Vsyakiy raz pri vhode linii v zhyoltuyu figuru.
@ 2016-04-27 2:36 PM (#21580 - in reply to #21575) (#21580) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-27 2:36 PM

sduran - 2016-04-27 2:07 AM

for question 7; voyage:
for example some portion of loop is white cell-10-10-white cell...
answer format should be which: 10 or 10,10 ?
example given does not clarify this.

If 10-10-10-white cell-10, the answer should be: 10, 10. The line has twice been recognized as a yellow figure, so 10 twice.
I was originally offered other answer format, but he admitted long. The current format I think difficult to grasp, but this proposal of my Indian friends.
@ 2016-04-27 2:42 PM (#21581 - in reply to #21577) (#21581) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-27 2:42 PM

Kithyane - 2016-04-27 3:59 AM

Question for "Borderless Sextet" : that's probably me overthinking, but can the battleships region contain black cells ? I ask only because other types mention it specifically ("possibly with black cells"...) and not battelships. If so, I understand that ships can't go on black cells, so black cells are necessarily water ?

Ships can be only in the blue cells, symbolizing water.
@ 2016-04-27 2:45 PM (#21582 - in reply to #21578) (#21582) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-27 2:45 PM

kiwijam - 2016-04-27 4:30 AM

sduran - 2016-04-27 9:07 AM

for question 7; voyage:
for example some portion of loop is white cell-10-10-white cell...
answer format should be which: 10 or 10,10 ?
example given does not clarify this.


Answer should be just 10. Each block of numbers between white cells gets one number written only.
But if there is a white cell between them, you write one number for every block: e.g. for "white cell-10-10-10-white cell-10-10-white cell..." you will write "10,10".


Kithyane - 2016-04-27 10:59 AM

Question for "Borderless Sextet" : that's probably me overthinking, but can the battleships region contain black cells ? I ask only because other types mention it specifically ("possibly with black cells"...) and not battelships. If so, I understand that ships can't go on black cells, so black cells are necessarily water ?


Yes, the Battleship region can contain black cells. Nothing can be written in any black cell.

Thank you James for the answers! I did not immediately drew attention to it.
@ 2016-04-27 11:41 PM (#21583 - in reply to #21482) (#21583) Top

tamz29



Posts: 225
10010020
Country : Thailand

tamz29 posted @ 2016-04-27 11:41 PM

The warning box is still visible in my Opti-pentomino answer. Should I ignore this?
@ 2016-04-28 9:13 AM (#21584 - in reply to #21583) (#21584) Top

Para



Posts: 315
100100100
Country : The Netherlands

Para posted @ 2016-04-28 9:13 AM

tamz29 - 2016-04-27 11:41 PM

The warning box is still visible in my Opti-pentomino answer. Should I ignore this?


I don't have any error warnings. Do all your rows have 10 characters, even rows that have no pentominos in them?
@ 2016-04-28 9:23 AM (#21585 - in reply to #21583) (#21585) Top

Administrator



2000100050020
Country : India

Administrator posted @ 2016-04-28 9:23 AM

tamz29 - 2016-04-27 11:41 PM

The warning box is still visible in my Opti-pentomino answer. Should I ignore this?
The pentominos have different set of symbol than what you have submitted (for example J for N). Your submission will be accepted.
@ 2016-04-29 3:01 AM (#21586 - in reply to #21482) (#21586) Top

David McNeill



Posts: 63
202020
Country : United Kingdom

David McNeill posted @ 2016-04-29 3:01 AM

Check out my answer to In the Citadel!! This is why I will never be the World Puzzle Champion. Thanks for the puzzles Riad. Never thought I would get so many done.
@ 2016-04-29 3:15 AM (#21587 - in reply to #21586) (#21587) Top

kiwijam



Posts: 183
10020202020
Country : New Zealand

kiwijam posted @ 2016-04-29 3:15 AM

David McNeill - 2016-04-29 10:01 AM

Check out my answer to In the Citadel!!


Haha, I'm hoping you thought it said 'maximise' instead of 'minimise'.

Edited by kiwijam 2016-04-29 3:41 AM
@ 2016-04-29 3:19 AM (#21588 - in reply to #21482) (#21588) Top

rob



Posts: 170
100202020
Country : Germany

rob posted @ 2016-04-29 3:19 AM

Would someone be willing to spoil the Accordances puzzle?


Edited by rob 2016-04-29 3:24 AM
@ 2016-04-29 3:32 AM (#21589 - in reply to #21482) (#21589) Top

David McNeill



Posts: 63
202020
Country : United Kingdom

David McNeill posted @ 2016-04-29 3:32 AM

Check out Cordelia's "wrong" answer for a clue
@ 2016-04-29 3:33 AM (#21590 - in reply to #21482) (#21590) Top

David McNeill



Posts: 63
202020
Country : United Kingdom

David McNeill posted @ 2016-04-29 3:33 AM

And thanks James for your sympathy.
@ 2016-04-29 3:35 AM (#21591 - in reply to #21589) (#21591) Top

rob



Posts: 170
100202020
Country : Germany

rob posted @ 2016-04-29 3:35 AM

David McNeill - 2016-04-29 3:32 AM

Check out Cordelia's "wrong" answer for a clue


So close, I had considered both ingredients.
@ 2016-04-29 3:46 AM (#21592 - in reply to #21590) (#21592) Top

kiwijam



Posts: 183
10020202020
Country : New Zealand

kiwijam posted @ 2016-04-29 3:46 AM

David McNeill - 2016-04-29 10:33 AM

And thanks James for your sympathy.


Sorry David, I hadn't noticed that the rest of your answers and your other optimiser were perfect, and this alone was keeping you from being 1st=. (You know I think you're wonderful.)
@ 2016-04-29 4:34 AM (#21593 - in reply to #21592) (#21593) Top

kiwijam



Posts: 183
10020202020
Country : New Zealand

kiwijam posted @ 2016-04-29 4:34 AM

Opti-Pentobattle

In the original version of this puzzle it was too easy to find an optimal solution. With the added challenge to minimise the grid size it became a very good optimiser puzzle. Here are my thoughts on the steps needed to solve it.

(On an earlier discussion, I'm not against people using a computer to solve an optimising problem. It is usually very slow to do though. Writing a computer program to solve Opti-Pentobattle is probably a bad idea. There are vast numbers of cases to check, and any insights to speed up the program would also allow you to solve it on paper 10x faster. Although if anyone did successfully write a program I would love to talk to you more about it)

Q1: How many pentominoes are needed?
Two ships always need at least one extra sea cell to join between them.
Three ships would always need two+ extra sea cells.
Ten ships need nine extra cells. So the area must be at least 29 cells, so 6 pentominoes are needed.

Q2: How small can the grid be?
Any 2x2 square can never contain pieces from two different ships.
The fleet contains 7 ships that can fit on one 2x2 square, and 3 ships that fit on two 2x2 squares.
So the whole grid must include at least 13 different 2x2 squares (or pieces of squares).
A 9x5 grid contains 5x3=15 squares, a 7x7 grid contains 4x4=16 squares, anything smaller will not fit the whole fleet.
Of these two, 9x5=45 is better than 7x7=49.

Q3: How can the fleet fit into a 9x5 grid?
At first I could not fit 10 ships into this grid size. But consider this:
Maths: [Imagine the grid has an extra row and column (right and below), it is 6x10.
And imagine each ship has an extra row and column (right and below) of empty space where another ship cannot go.
So a 1-ship "occupies" 4 cells, and a 4-ship occupies 10 cells.
The whole fleet occupies 4x4+3x6+2x8+1x10 = 60 cells, the same size as the 6x10 grid.
So _every_ cell must be used.]
=> Rule for 9x5 grid only: Every 2x2 square that covers some of the 9x5 grid must include a piece of ship. (even overlapping an edge or corner)
Therefore:
- Every corner cell has a ship piece.
- The 4-ship must be horizontal (parallel to the 9-edge) in row 1 or 3 or 5.
There are different ways to do this, e.g. I just created three horizontal rows containing 421, 331, and 2211 ships.

Q4: How do I join the fleet to have a unique solution?
There are some cases you cannot have:
- You cannot join a 1 directly to another 1. Because "1.1" can be swapped with a "3" elsewhere.
- You cannot join two different sizes in a straight line. Because "2.3" might also be "3.2", etc.
- You cannot join a 1 to the end of a 3. Because a V-pentomino containing a 1.3 could also be 3.1.

So this should lead you to a shape that has a unique Battleships solution.
The final step is to find a combination of 6 different pentominoes to cover this shape.
Because only 29 cells are needed for the unique solution, you have one 'spare' cell that can be added anywhere, which should make this step easier.

Also, if you want to solve one of the contestant's 9x5 solutions, use the rules "Every 2x2 square must include a piece of ship" and "Every ship cell cannot diagonally touch another ship cell" will make it much faster.
Most solutions use one of these approaches early on:
- After placing initial pieces there is only one location that the 4-ship can fit.
- After placing initial pieces the four 1-ships have been found, so all other ship pieces are 2+ long.

Edited by kiwijam 2016-04-29 4:41 AM
@ 2016-04-29 6:47 AM (#21594 - in reply to #21482) (#21594) Top

debmohanty




1000500100100100202020
Country : India

debmohanty posted @ 2016-04-29 6:47 AM

We have compiled the submissions of Opti-PentoBattle in a pdf. Here is the link. The submissions are not checked for correctness.
@ 2016-04-29 7:52 AM (#21595 - in reply to #21482) (#21595) Top

kiwijam



Posts: 183
10020202020
Country : New Zealand

kiwijam posted @ 2016-04-29 7:52 AM

All twelve solutions with (Area=45, K=6, N=1) are good.
@ 2016-04-29 10:18 AM (#21596 - in reply to #21482) (#21596) Top

Para



Posts: 315
100100100
Country : The Netherlands

Para posted @ 2016-04-29 10:18 AM

I seem to have written GOGOGOV instead of GOGOVOV. I think that is my error in the Sextet at least.

I misplaced one Cloud stupidly.

And I had found the 44, but counted it as 42 so didn't submit it.

Not my contest clearly.

Edited by Para 2016-04-29 10:45 AM
@ 2016-04-29 12:50 PM (#21597 - in reply to #21482) (#21597) Top

forcolin




Posts: 172
100202020
Country : ITALY

forcolin posted @ 2016-04-29 12:50 PM

my solution to puzzle 1 seems all right to me.
I noticed the same solution has also been submitted by two other players
here is the solution. Is it possible that the puzzle had multiple solutions?

http://web.freepass.it/sf2l/mysoln1.JPG

are the solutions to be posted somewhere soon?
stefano

Edited by forcolin 2016-04-29 1:19 PM
@ 2016-04-29 1:41 PM (#21599 - in reply to #21595) (#21599) Top

forcolin




Posts: 172
100202020
Country : ITALY

forcolin posted @ 2016-04-29 1:41 PM

kiwijam - 2016-04-29 7:52 AM

All twelve solutions with (Area=45, K=6, N=1) are good.


It looks to me that some may have multiple solutions.
@ 2016-04-29 3:20 PM (#21600 - in reply to #21482) (#21600) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-29 3:20 PM

I congratulate the winners - Ken, Hideaki, Tomoya and James!


Several solvers were caught in the step of victory, but were prevented by the puzzle Accordances. I invented it few years ago, but did not dare to include in the Contest. I didn't want to hear claims in its incorrectness. So in the last two April Contests (2014 and 2015) I suggested puzzles, where some of the letters match the Roman numbers (see Roman XO and Roman COOL-L-L). Only after that I included the puzzle in the Contest.
@ 2016-04-29 3:24 PM (#21601 - in reply to #21482) (#21601) Top

debmohanty




1000500100100100202020
Country : India

debmohanty posted @ 2016-04-29 3:24 PM

Final score page, with puzzle ratings - http://logicmastersindia.com/2016/04Contest/score.asp

VOYAGE was voted as the best puzzle, with a near-10 rating.
@ 2016-04-29 4:17 PM (#21603 - in reply to #21596) (#21603) Top

forcolin




Posts: 172
100202020
Country : ITALY

forcolin posted @ 2016-04-29 4:17 PM

Para - 2016-04-29 10:18 AM

I seem to have written GOGOGOV instead of GOGOVOV. I think that is my error in the Sextet at least.

I misplaced one Cloud stupidly.

And I had found the 44, but counted it as 42 so didn't submit it.

Not my contest clearly.


It seems typos are not penalized.I also had one (typed 3 instead of 2)
@ 2016-04-29 4:29 PM (#21604 - in reply to #21482) (#21604) Top

Puzlifouk



Posts: 62
202020
Country : France

Puzlifouk posted @ 2016-04-29 4:29 PM

Congratulations to the champions , and to Riad.
I had less time this year to look for the problems, but they seemed harder than last year.
For Mirrored sudokus, I only answered to puzzle B, but it seems my answer is correct : why don't I get 1.5 points ? (which will not change anything...)
@ 2016-04-29 5:27 PM (#21605 - in reply to #21600) (#21605) Top

Para



Posts: 315
100100100
Country : The Netherlands

Para posted @ 2016-04-29 5:27 PM

Riad Khanmagomedov - 2016-04-29 3:20 PM

I congratulate the winners - Ken, Hideaki, Tomoya and James!


Several solvers were caught in the step of victory, but were prevented by the puzzle Accordances. I invented it few years ago, but did not dare to include in the Contest. I didn't want to hear claims in its incorrectness. So in the last two April Contests (2014 and 2015) I suggested puzzles, where some of the letters match the Roman numbers (see Roman XO and Roman COOL-L-L). Only after that I included the puzzle in the Contest.


Accordances just clicked when I tried Roman Numerals. 51(Li) was key for me. Got some use out of remembering HHeLiBeBCNOF as a mnemonic when I was in high school.
@ 2016-04-29 5:47 PM (#21606 - in reply to #21605) (#21606) Top

tamz29



Posts: 225
10010020
Country : Thailand

tamz29 posted @ 2016-04-29 5:47 PM

Solved these on an 11hr flight and still couldn't finish it!
Mirrored Sudoku, Borderless Sextet and Voyages alone took me about 6-7 hours combined.
As someone who also solve word and lateral puzzles, I got Accordances in about 5 seconds (high fives self).

I've never tried optimizing puzzles seriously before so its nice to see I can still score well there.
Also eager waiting to see the solutions for Crossmind, love the idea a lot but did anyone else find the individual Mastermind puzzles having too many multiple solutions?
Which translated to having to trial and error the criss-cross portion a little too much for it to be as enjoyable as other puzzles in the set.

The flight attendant told me I had to put the tray-table back up cause we're about to land so I couldn't go back to finish Bricks ;)

Thanks Riad!
Will you be doing this in September as well?
@ 2016-04-29 6:07 PM (#21607 - in reply to #21603) (#21607) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-29 6:07 PM

forcolin - 2016-04-29 4:17 PM

Para - 2016-04-29 10:18 AM

I seem to have written GOGOGOV instead of GOGOVOV. I think that is my error in the Sextet at least.

I misplaced one Cloud stupidly.

And I had found the 44, but counted it as 42 so didn't submit it.

Not my contest clearly.


It seems typos are not penalized.I also had one (typed 3 instead of 2)

The typos have been to several solvers. I recognized correct those solutions that had a long answer.
@ 2016-04-29 6:11 PM (#21608 - in reply to #21604) (#21608) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-29 6:11 PM

Puzlifouk - 2016-04-29 4:29 PM

Congratulations to the champions , and to Riad.
I had less time this year to look for the problems, but they seemed harder than last year.
For Mirrored sudokus, I only answered to puzzle B, but it seems my answer is correct : why don't I get 1.5 points ? (which will not change anything...)

I thought that the points for Mirrored Sudokus is done automatically. I'm with Deb now you will add 1.5 points, thank you.
@ 2016-04-29 6:35 PM (#21609 - in reply to #21606) (#21609) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-29 6:35 PM

tamz29 - 2016-04-29 5:47 PM

Solved these on an 11hr flight and still couldn't finish it!
Mirrored Sudoku, Borderless Sextet and Voyages alone took me about 6-7 hours combined.
As someone who also solve word and lateral puzzles, I got Accordances in about 5 seconds (high fives self).

I've never tried optimizing puzzles seriously before so its nice to see I can still score well there.
Also eager waiting to see the solutions for Crossmind, love the idea a lot but did anyone else find the individual Mastermind puzzles having too many multiple solutions?
Which translated to having to trial and error the criss-cross portion a little too much for it to be as enjoyable as other puzzles in the set.

The flight attendant told me I had to put the tray-table back up cause we're about to land so I couldn't go back to finish Bricks ;)

Thanks Riad!
Will you be doing this in September as well?

These puzzles I made in 2104-15, and in January I tested at the time. The fastest I solved Mirrored Sudokus – for 72 minutes, the longest – Crossmind – for 100 minutes. This despite the fact that I am very fast in solving verbal puzzles. In the preparation of each of Mastermind I used word meaning the same thing in different languages. I am from a small Tabasaran ethnic groups, compactly living in Dagestan. In addition I speak Azerbaijani and Turkish languages. So the idea to make a multilingual puzzle using 5-letter words.
This year I plan to meet with you at LMI twice. I promise a lot of innovation in the September Sudoku Contest and the Moscow Puzzle Cup. I have the booklets ready, so it remains only to discuss dates.
@ 2016-04-29 7:59 PM (#21610 - in reply to #21482) (#21610) Top

-.ferchx.-



Posts: 12

Country : Spain

-.ferchx.- posted @ 2016-04-29 7:59 PM

Hello. No solutions for accordances? I would like know the solution.
@ 2016-04-29 8:12 PM (#21611 - in reply to #21610) (#21611) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-29 8:12 PM

-.ferchx.- - 2016-04-29 7:59 PM

Hello. No solutions for accordances? I would like know the solution.

If you write the left numbers at the Roman way, they will resemble the symbols of chemical elements. On the right indicate the atomic numbers of these elements.
@ 2016-04-29 9:10 PM (#21612 - in reply to #21611) (#21612) Top

-.ferchx.-



Posts: 12

Country : Spain

-.ferchx.- posted @ 2016-04-29 9:10 PM

Thanks. I wrote the left numbers at the Roman way, but I not seen the chemical elements... Very interesting. Congratulations for all the puzzles. Very funny.
@ 2016-04-29 10:51 PM (#21613 - in reply to #21482) (#21613) Top

chaotic_iak




Posts: 241
1001002020
Country : Indonesia

chaotic_iak posted @ 2016-04-29 10:51 PM

So, feedback about the contest.

Not particularly enjoyable. This contest just reiterates the reason I dislike large puzzles. (Even though I authored NEW, HUGE, AND CHALLENGING! and one puzzle in Puzzle Marathon, yes.) The puzzles are so tough that you don't know where to look. While this is not a very big problem for the earlier puzzles (Pentobattle and the Clouds variant were nice), I particularly dislike Borderless Sextet and Crossmind. The former is probably because of the rules being terribly unclear, even after clarifications in-thread (where some went unanswered). The latter because it looks like pretty much all work, with no logic visible. I bruteforced the Mastermind puzzles by programming, and even after getting all possible answers for each, I couldn't even start putting any to the grid; too many letters that cross each other in all positions. And of course I loathe Accordances just like I loathe similar inductive puzzles. Yes, I got the expected answer for that, but I still dislike it anyway.

Puzzles that I solved, besides Accordances above... Pentobattle was a nice, easy puzzle. In Terms of Area, despite being big, is actually manageable, because that's approximately the size of medium-large Clouds puzzles. Both are my favorites for the contest. Coded Arrows wasn't very memorable; I think there were a few trial and error, testing whether a number works for a letter. Bricks was fine during solving, although it's a rather awful idea; I don't know why, I just don't like that genre in general. Probably because the positions of the clues are already given, so finding the sums can be independent from placing the bricks. I distinctly recall Trid-Fir requiring quite a lot of casework, putting a certain number here to find a contradiction about 10-20 numbers later. Mirrored Sudokus were actually quite fine; the large-scale logic of placing the 4s and the 3s early is interesting, although I think that's pretty common in Mirrored Sudokus in general. Opti-Pentobattle was a fun one. In The Citadels was just messy; the first thing I did was to convert it to a graph, then blindly trying things until I stumbled on a solution.

So, yes, I don't know why I keep doing these April Contests even though I don't particularly enjoy some of them. Maybe just because they are puzzle tests that are otherwise rare here on LMI nowadays.
@ 2016-04-30 3:43 AM (#21614 - in reply to #21482) (#21614) Top

forcolin




Posts: 172
100202020
Country : ITALY

forcolin posted @ 2016-04-30 3:43 AM

The feedback about the contest from me is the opposite... one of the best contests of the year.
People believe we are good because we solve difficult puzzle.
But what about those persons who SET the difficult puzzles? they are even more genial in my opinion.
I enjoy particularly this contest because traditionally I have my best results. A bit unconventional, speed does not count that much..... This contest is the Paris-Roubaix of puzzling. If it wasn't for a stupid typing mistake I could have been in the top five, in excellent company. Will try again next year.
These puzzles in general are very well constructed and with the right type of twist. The best for me was the borderless sextet, very deceptive with that double black cell on which I lost hours. Believe it or not, I started solving it from the Scrabble. Also very good the Voyage; I also liked the Coded Arrows for its simple and very logical solving path (couldn't see it, Chaotic?).The least beautiful the mirrored sudokus (ended up cross-eyed... you know, at my age......) and the Crossmind. And yes, I did not like too much Accordances, which requires more intuition than logic. The first optimizer, in the modified variant, has turned out to be very good, while the Citadel could have been a bit larger thus offering more possible options. As it has been pointed out before in the discussion, for both optimizers it was possible to demonstrate at a certain (early) stage that no better solutions were possible.
Thanks Riad for yet another very enjoyable week.
Stefano

Edited by forcolin 2016-04-30 3:48 AM
@ 2016-04-30 5:12 AM (#21615 - in reply to #21482) (#21615) Top

Para



Posts: 315
100100100
Country : The Netherlands

Para posted @ 2016-04-30 5:12 AM

The Crossmind puzzle was really enjoyable to me. I could get to all Mastermind puzzles logically, Even with the non-uniqueness. It helped me reinforce some of the logic involved as I hadn't really done many recently.
The secong part of the puzzle relied very much on uniqueness. Knowing that certain words had multiple solutions, they would have to go cross with other words to fix uniqueness. This actually made the Crossword very solvable. This might not be the favourite logic for many, but it's the kind of creative thinking that is expected in this contest. Think outside the box, find ways to approach the problem differently. That's what to expect in this contest.

The same could be said about the Bordeless Sextet. I actually constructed almost the whole crossword, except for LQQ on a separate piece of paper and then tried to fit it in. It's a bit like optimising. How can I use this space optimally, so that I expect everything to fit? You know in advance there's going to be relatively little space to use, so you start recognising how things fit together. It's not necessarily, "oh this 9 shape has to go there", but "oh this would be a perfect spot for this 9 shape; it is like it's made for it". It's good to train these skills too, to have a feeling what the author did, instead of what the author wants you to do.

That thinking also comes into place in the optimisers. First you figure out you need an even number of steps to get to 0, then you work out how to get this as high as possible. The highest possible Even Steps path doesn't have a 0 solution though. That took me a while to prove. So then lose 2 steps and try again.
The other optimiser turned from easy to, how do I get these 10 ships in as small a shape as possible. And then, which cells should remain blank to have a possibility to ever be unique. And then can I cover the rest with pentominos. With the last step being, make sure it's unique. This can be annoying.

I get that this contest isn't for everyone, which is why it gets these low competitor totals. But for those who enjoy it, they are always fun.
@ 2016-04-30 6:34 AM (#21616 - in reply to #21615) (#21616) Top

tamz29



Posts: 225
10010020
Country : Thailand

tamz29 posted @ 2016-04-30 6:34 AM

In general, I have the same mindset as Ivan (Chaotic). Large puzzles are boring (we're talking 25x25 sudoku "large" and not some other creative "large" eg. some of the puzzles in LMI marathon).
However, I will make the case for the Borderless Sextet and Voyages.
Who would think Borderless Sextet starts from the Scrabble? The weird letter patterns in the word list should prompt you create a draft of the grid - which only had about 3-4 possible alternatives and ruling out each one wasn't so guessy. Packing in numbers and tetrominoes were very logical. So I felt this puzzle required initial insight and mostly logic. Defitinitely not blind stumbling like the Crossmind (I don't think using uniqueness should be a job for solvers).

Voyages was also procedural. Start with the biggest piece and work your way from the maximum values 21-20-19-18-17.. Etc.
The solving path may have been a little too narrow that one mistake can ruin hours of work.
But the bottom line is you can see that it is logical.

@ 2016-04-30 9:25 AM (#21617 - in reply to #21482) (#21617) Top

chaotic_iak




Posts: 241
1001002020
Country : Indonesia

chaotic_iak posted @ 2016-04-30 9:25 AM

My complaint about Borderless Sextet is that I can't understand the instructions, so I didn't even attempt to solve it. For example, I've been understanding Loop that "touching" means Snake-like touching; if adjacent cells are both part of the loop, then the loop must also go through them consecutively. The regions are also said to be contiguous, so I wondered what could fit inside the hole that the Loop region had to make. (Although I haven't seen the solution, I'm pretty sure that the loop simply had to not cross each other, so the "touching" is Masyu-like touching; going in adjacent cells is okay.)

While that alone isn't a big complaint, my issue is that I asked for clarification, but it went unanswered. I believe rule questions should be answered, because otherwise it's an unfair disadvantage for people that interpreted the ambiguous instruction incorrectly (for having an immediate contradiction like above).

For Crossmind, the fact that you need to use uniqueness metalogic also means that it's a bad puzzle. If Riad created this puzzle by also using uniqueness, I wonder how many solutions were missed; if Riad created it purely with logic, I'm interested to know the intended path.
@ 2016-04-30 11:27 AM (#21618 - in reply to #21617) (#21618) Top

tamz29



Posts: 225
10010020
Country : Thailand

tamz29 posted @ 2016-04-30 11:27 AM

chaotic_iak - 2016-04-30 9:25 AM

My complaint about Borderless Sextet is that I can't understand the instructions, so I didn't even attempt to solve it.

For Crossmind, the fact that you need to use uniqueness metalogic also means that it's a bad puzzle. If Riad created this puzzle by also using uniqueness, I wonder how many solutions were missed; if Riad created it purely with logic, I'm interested to know the intended path.


I agree on both points. I also had to rereard the instructions several times over before solving. In the past (and this time) well-intentioned early finishers help answer questions in the forums. But surely, having a test solver reword some of the instructions beforehand would be quite productive.

Also eager to hear other people's experience with the Crossmind.

@ 2016-04-30 11:44 AM (#21619 - in reply to #21482) (#21619) Top

Kithyane



Posts: 49
2020
Country : France

Kithyane posted @ 2016-04-30 11:44 AM

Hi, just checked why I had no points for Borderless Sextet. For the first column, the offcial answer is FXLLDVD99LQQ--B-B and mine is FXLLDVD99LQQ--B-- (only difference is a ship or not in the last cell). In my grid, I have on the last row for battleship a BBB-B- pattern which could be switched to B-BBB- to get the official solution. Could it be that the aswer is not completely unique ? Or I have made an error elsewhere that I fail to see. Could someone enlighten me ?
http://i.imgur.com/WJqx96W.jpg
@ 2016-04-30 1:47 PM (#21621 - in reply to #21619) (#21621) Top

tamz29



Posts: 225
10010020
Country : Thailand

tamz29 posted @ 2016-04-30 1:47 PM

Kithyane - 2016-04-30 11:44 AM

Hi, just checked why I had no points for Borderless Sextet. For the first column, the offcial answer is FXLLDVD99LQQ--B-B and mine is FXLLDVD99LQQ--B-- (only difference is a ship or not in the last cell). In my grid, I have on the last row for battleship a BBB-B- pattern which could be switched to B-BBB- to get the official solution. Could it be that the aswer is not completely unique ? Or I have made an error elsewhere that I fail to see. Could someone enlighten me ?
http://i.imgur.com/WJqx96W.jpg


You missed ZY from Scrabble - that changes the Battleship regions.
@ 2016-04-30 2:41 PM (#21622 - in reply to #21482) (#21622) Top

Kithyane



Posts: 49
2020
Country : France

Kithyane posted @ 2016-04-30 2:41 PM

Arg, such a stupid error... thanks tamz29 !
@ 2016-04-30 6:33 PM (#21623 - in reply to #21617) (#21623) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-30 6:33 PM

chaotic_iak - 2016-04-30 9:25 AM
While that alone isn't a big complaint, my issue is that I asked for clarification, but it went unanswered. I believe rule questions should be answered, because otherwise it's an unfair disadvantage for people that interpreted the ambiguous instruction incorrectly (for having an immediate contradiction like above).

Your questions, I gave a clear answer - the 16-length loop to be accommodated in the 16-cell region (see under your question).
@ 2016-04-30 6:40 PM (#21624 - in reply to #21617) (#21624) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-04-30 6:40 PM

chaotic_iak - 2016-04-30 9:25 AM

My complaint about Borderless Sextet is that I can't understand the instructions, so I didn't even attempt to solve it. For example, I've been understanding Loop that "touching" means Snake-like touching; if adjacent cells are both part of the loop, then the loop must also go through them consecutively. The regions are also said to be contiguous, so I wondered what could fit inside the hole that the Loop region had to make. (Although I haven't seen the solution, I'm pretty sure that the loop simply had to not cross each other, so the "touching" is Masyu-like touching; going in adjacent cells is okay.)

While that alone isn't a big complaint, my issue is that I asked for clarification, but it went unanswered. I believe rule questions should be answered, because otherwise it's an unfair disadvantage for people that interpreted the ambiguous instruction incorrectly (for having an immediate contradiction like above).

For Crossmind, the fact that you need to use uniqueness metalogic also means that it's a bad puzzle. If Riad created this puzzle by also using uniqueness, I wonder how many solutions were missed; if Riad created it purely with logic, I'm interested to know the intended path.

The Contest must be surprised for solvers, otherwise it is not interesting for me, as for the author. 90-minute contests with a focus on well-known genres, with hundreds of fans, I am able to spend each week. Actually, I do it regularly for magazines published in Russia.
I can only say that I propose handmake puzzles. All of them are solved logically.
Ivan, you thought that the crossword grid can be constructed to eliminate the options? Do you think that I was not able to provide unique solutions for each Mastermind? The ambiguity of some Mastermind was intentional. You kidding me, it seems.

If you have any questions, I'll answer after 4 May.
@ 2016-04-30 7:19 PM (#21625 - in reply to #21618) (#21625) Top

prasanna16391



Posts: 1775
1000500100100202020
Country : India

prasanna16391 posted @ 2016-04-30 7:19 PM

tamz29 - 2016-04-30 11:27 AM


But surely, having a test solver reword some of the instructions beforehand would be quite productive.



I feel I should answer this since I've been test solving Riad's contests for the past few times.

All of these times, I have reworded the instructions. This time too, I reworded them for the ones I solved. Even some of the answer keys have been reworded and edited, both this time and in the past. For whatever reasons (time, capabilities, other commitments, etc.) I couldn't complete some of the puzzles, including Borderless Sextet. I tried them for a significant amount of time and couldn't do much. I'm just generally weak at word puzzles, so maybe that's part of the problem. Since there are so many variables in those rules I decided it best to leave them unchanged, since I might put in something wrong, having not solved it.

Its still true that I failed to do a complete job this time as the test solver, but I just wanted to share this because the suggestion made has already been implemented over the years, and this year too for some of the puzzles.

As for the contest itself, my thoughts are it is a special attraction contest which has its own unique value in the puzzle community. I think solvers should realize that sometimes a puzzle might have a logical path which is just beyond their prowess, as I found out with the Borderless Sextet's Scrabble start and the Crossmind's crossword part. If this happened in a 90 minute timed contest it is definitely up for debate whether the puzzle should have been on the contest or not. But as a special attraction contest making it clear at the outset that these are difficult puzzles without a time limit, I think its important to go in with a mindset that you may not be able to spot everything no matter how good a solver you are in other contests. Its just more space to improve, or an area to ignore, depending on individual perspective.
@ 2016-05-01 12:02 AM (#21626 - in reply to #21482) (#21626) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-05-01 12:02 AM

Prasanna, thank you for your help in testing and translation of texts into English!
Before leaving, I found time on a detailed response about Crossmind.
I'll start with history. In Russia it is published a series of magazines "Handmade". They content are Keywords, Fillwords, Tetris and other word puzzles. From the first issues they published Crossmind’s invented by me. Typically several pages using words of different lengths.
Ivan, I advise you to make a Crossmind with 4-6 words, as in our magazines. When you feel the puzzle, then make more difficult tasks:
1. In each Mastermind given words should denote the same thing in different languages.
2. Crossmind should not be split into two independent puzzles – Mastermind and Crossword. Therefore, some Mastermind must be solved at the expense of crossword intersections. That is, it is necessary to construct a crossword grid, which guarantees uniqueness Crossmind.
3. Black crossword cells must draw the letters L, M, I.
I spent several days creating Crossmind. I was engulfed in a process so that refused lunch.
I will come back to the discussion on 4 May.
@ 2016-05-01 1:22 AM (#21627 - in reply to #21623) (#21627) Top

chaotic_iak




Posts: 241
1001002020
Country : Indonesia

chaotic_iak posted @ 2016-05-01 1:22 AM

Riad Khanmagomedov - 2016-04-30 9:33 PM

chaotic_iak - 2016-04-30 9:25 AM
While that alone isn't a big complaint, my issue is that I asked for clarification, but it went unanswered. I believe rule questions should be answered, because otherwise it's an unfair disadvantage for people that interpreted the ambiguous instruction incorrectly (for having an immediate contradiction like above).

Your questions, I gave a clear answer - the 16-length loop to be accommodated in the 16-cell region (see under your question).


The second part of the question was not answered, whether the loop may touch itself. I do know that the region is made of 16 cells, but I don't know how the loop works. My question was something like this. Left part is a correct Masyu-like loop, while right part is an incorrect Snake-like loop. Which of them is the rule in the puzzle?
@ 2016-05-01 1:25 AM (#21628 - in reply to #21482) (#21628) Top

chaotic_iak




Posts: 241
1001002020
Country : Indonesia

chaotic_iak posted @ 2016-05-01 1:25 AM

Re Crossmind: That's why I'm interested to know the intended logical path to solve Crossmind, because it just looks completely beyond any approach I can think of.
@ 2016-05-01 4:43 AM (#21629 - in reply to #21628) (#21629) Top

rob



Posts: 170
100202020
Country : Germany

rob posted @ 2016-05-01 4:43 AM

chaotic_iak - 2016-05-01 1:25 AM

Re Crossmind: That's why I'm interested to know the intended logical path to solve Crossmind, because it just looks completely beyond any approach I can think of.


I would guess that you missed some of the Mastermind deductions. If my notes are correct, there are just 7 ambiguous words, of which only two have more than two options.
@ 2016-05-01 9:35 AM (#21630 - in reply to #21629) (#21630) Top

chaotic_iak




Posts: 241
1001002020
Country : Indonesia

chaotic_iak posted @ 2016-05-01 9:35 AM

No, I'm very confident my "solves" for Mastermind were right (because I just used programming to brute force each combination). But even with all of that, I still can't figure out where to start placing any of them.
@ 2016-05-01 3:43 PM (#21631 - in reply to #21482) (#21631) Top

dm_litv



Posts: 1

Country : Russia

dm_litv posted @ 2016-05-01 3:43 PM

About the "Crossmind" discussion:
The crossword part of this puzzle is completely logically solvable without using of uniqueness.
You should start with second "left-to-right" word (middle top of the grid).
The first and the last letters of this word must be 4th letters in some pair of words.
There are only 3 possible words, 2 of them very quickly lead to the contradiction.
Next - everything goes without problems.

On the competition as a whole - it is exactly as it should be.


Edited by dm_litv 2016-05-01 3:46 PM
@ 2016-05-01 8:19 PM (#21633 - in reply to #21631) (#21633) Top

forcolin




Posts: 172
100202020
Country : ITALY

forcolin posted @ 2016-05-01 8:19 PM

dm_litv - 2016-05-01 3:43 PM

On the competition as a whole - it is exactly as it should be.


I fully agree.

[a bit OT, a question for admin] Is there scope for competitions dedicated to optimization puzzles only?

Stefano

Edited by forcolin 2016-05-01 8:19 PM
@ 2016-05-02 4:38 PM (#21634 - in reply to #21625) (#21634) Top

hsaa509



Posts: 1

Country : India

hsaa509 posted @ 2016-05-02 4:38 PM

I am unable to understand about it, could you reply me with proper or actual question?
@ 2016-05-04 4:58 AM (#21638 - in reply to #21633) (#21638) Top

kiwijam



Posts: 183
10020202020
Country : New Zealand

kiwijam posted @ 2016-05-04 4:58 AM

forcolin - 2016-05-02 3:19 AM

Is there scope for competitions dedicated to optimization puzzles only?

Stefano


I think the optimization puzzles are the highlight of Riad's tests.
This time there were only 2, and they were 'solvable', but I'd like to see more too!
@ 2016-05-04 8:33 PM (#21641 - in reply to #21482) (#21641) Top

Riad Khanmagomedov



Posts: 218
100100
Country : Russia

Riad Khanmagomedov posted @ 2016-05-04 8:33 PM

Thanks to all the participants! Next year it will be necessary to return to the format with three optimization puzzles.
@ 2016-05-04 9:40 PM (#21642 - in reply to #21482) (#21642) Top

forcolin




Posts: 172
100202020
Country : ITALY

forcolin posted @ 2016-05-04 9:40 PM

I agree with both the last posts. However I miss a bit the good old DOM.
@ 2017-08-27 5:04 AM (#23059 - in reply to #21482) (#23059) Top

Eugene Porter



Posts: 11

Country : United States

Eugene Porter posted @ 2017-08-27 5:04 AM

Does anyone have a solution for the Trid-Fir? I keep getting stuck.
@ 2017-08-28 8:01 AM (#23060 - in reply to #23059) (#23060) Top

Eugene Porter



Posts: 11

Country : United States

Eugene Porter posted @ 2017-08-28 8:01 AM

This is a very tough contest. I am also struggling with the Voyage puzzle. Even after looking at the answer string I am not sure how to do this puzzle. Is there a solutions page somewhere. After spending several days on these and getting nowhere it would be nice to know what it is I am not getting. Any help would be great.
@ 2017-08-28 10:24 AM (#23061 - in reply to #21482) (#23061) Top

kiwijam



Posts: 183
10020202020
Country : New Zealand

kiwijam posted @ 2017-08-28 10:24 AM

It was a tough contest, much harder than other contests because you have a week instead of an hour to solve them.
Perhaps show us an image of where you are up to and we can suggest some next steps?