ISC Report & Results

IPC Report & Results

SM - Junior 2025 Cumulative results
Riad Khanmagomedov's April Contest — 18th to 27th April 202551 posts • Page 1 of 3 • 1 2 3
@ 2025-04-23 7:15 PM (#33767 - in reply to #33716) (#33767) Top

anurag



Posts: 140
1002020
Country : India

anurag posted @ 2025-04-23 7:15 PM

Names Hitori: I think words like Sarayu and Joeri cannot be used. It is confusing that they are on the list.
@ 2025-04-23 8:08 PM (#33768 - in reply to #33716) (#33768) Top

giorgia



Posts: 1

Country : ITALY

giorgia posted @ 2025-04-23 8:08 PM

I can't fully understand the rules of 9. Mosaic with digits:
- the "diagonal direction" pointed by an arrow is always a 45° directions, regardless of the cell's shape? Or is it perpendicular to the diagonal of the arrow's cell?
- "number of diagonals parallel" means "parallel" or "of the same type"? I mean: two diagonals "/" in a 1x1 cell and in a 2x1 cell should be considered "parallel"?
@ 2025-04-23 11:17 PM (#33769 - in reply to #33767) (#33769) Top

Riad Khanmagomedov



Posts: 249
1001002020
Country : Russia

Riad Khanmagomedov posted @ 2025-04-23 11:17 PM

anurag - 2025-04-23 7:15 PM



Names Hitori: I think words like Sarayu and Joeri cannot be used. It is confusing that they are on the list.


These are the names of the participants of April Contest 2024. Everyone decides for themselves which words to use and which not to use.
@ 2025-04-24 10:15 AM (#33770 - in reply to #33716) (#33770) Top

alamgirsudoku



Posts: 1

Country : Bangladesh

alamgirsudoku posted @ 2025-04-24 10:15 AM

🌟
@ 2025-04-24 12:10 PM (#33771 - in reply to #33716) (#33771) Top

anurag



Posts: 140
1002020
Country : India

anurag posted @ 2025-04-24 12:10 PM

Do overlapping words attract disqualification of the solution?
@ 2025-04-24 1:18 PM (#33772 - in reply to #33771) (#33772) Top

Riad Khanmagomedov



Posts: 249
1001002020
Country : Russia

Riad Khanmagomedov posted @ 2025-04-24 1:18 PM

anurag - 2025-04-24 12:10 PM



Do overlapping words attract disqualification of the solution?


Yes.
@ 2025-04-26 2:58 AM (#33781 - in reply to #33716) (#33781) Top

kiwijam



Posts: 190
10020202020
Country : New Zealand

kiwijam posted @ 2025-04-26 2:58 AM

A question for LMI:

On this discussion page I see "27 posts - Page 1 of 2". (After my post, it will probably say 28 posts.)

On page 1 I see 25 posts, all is good.

But when I click to page 2 I see nothing (no posts) at all. I have tried this in different devices and different browsers.

Is something wrong, preventing posts 26+ from displaying?



[Edit: I now see this post at the top of page 2. Perhaps 2 posts were deleted and the website was confused. But I still count 26 posts, not 28.)

Edited by kiwijam 2025-04-26 3:01 AM

@ 2025-04-26 3:57 AM (#33782 - in reply to #33716) (#33782) Top

kiwijam



Posts: 190
10020202020
Country : New Zealand

kiwijam posted @ 2025-04-26 3:57 AM

A question for Riad:



After reading Anurag's question, I think there are 2 ways to understand Name Hitori.

1) Are the words chosen by the contestant, using parentheses? 2) Or are the words chosen by wordlist only?



For example, my row is "KENDOWXYZ". This includes the letters "KEN" and "ENDO".

1) I know I am only allowed one word here. In the answer key I enter (KEN)DOWXYZ or K(ENDO)WXYZ. The other word is ignored, and I do not count it for my score.

or 2) This row breaks the rules. Even if I enter (KEN)DOWXYZ, the puzzle is invalid and I get no score.



So we all use the same rule, do you think 1) or 2) is correct?
@ 2025-04-26 12:23 PM (#33783 - in reply to #33782) (#33783) Top

Riad Khanmagomedov



Posts: 249
1001002020
Country : Russia

Riad Khanmagomedov posted @ 2025-04-26 12:23 PM

kiwijam - 2025-04-26 3:57 AM



A question for Riad:



After reading Anurag's question, I think there are 2 ways to understand Name Hitori.

1) Are the words chosen by the contestant, using parentheses? 2) Or are the words chosen by wordlist only?



For example, my row is "KENDOWXYZ". This includes the letters "KEN" and "ENDO".

1) I know I am only allowed one word here. In the answer key I enter (KEN)DOWXYZ or K(ENDO)WXYZ. The other word is ignored, and I do not count it for my score.

or 2) This row breaks the rules. Even if I enter (KEN)DOWXYZ, the puzzle is invalid and I get no score.



So we all use the same rule, do you think 1) or 2) is correct?


James, example 1) using the name KEN ENDO is correct. If you specify only one word in parentheses, the answer will be accepted. It is not allowed to use parentheses like this: (K(EN)DO)WXYZ.
@ 2025-04-26 4:05 PM (#33785 - in reply to #33716) (#33785) Top

krasnosulinec1797



Posts: 4

Country : Russia

krasnosulinec1797 posted @ 2025-04-26 4:05 PM

Здравствуй,Риад
Вопрос по головоломке 11.
Обязательно ли в сетке должны все слова пересекаться по правилам кроссворда?
Возможно ли такое заполнение строки без пересечений ( ARTHEJOYU)-ART-HE-JO-YU = 4 слова и разрешается ли в сетке отсутствие черных клеток?
Дмитрий.
@ 2025-04-26 6:33 PM (#33786 - in reply to #33716) (#33786) Top

anurag



Posts: 140
1002020
Country : India

anurag posted @ 2025-04-26 6:33 PM

LOL, this is a debacle. Admin: please delete my submission. I do not want to enter anymore. Thank you. BTW, the reply is still unclear and does not help. The last reply (to me) meant something diametrically opposite. Things need to be made explicit as this is only a test of logic.
@ 2025-04-26 10:24 PM (#33787 - in reply to #33786) (#33787) Top

Carlos



Posts: 10

Country : France

Carlos posted @ 2025-04-26 10:24 PM

@anurag The example of "Name Hitori" contains the name "AOKI" without counting it among the valid words, since it overlaps "NAOKI". Nevertheless, the grid is considered to be valid. Hence, I guess that a valid grid can contain words overlapping other words, as long as they are not counted. At least, that is what I understand from the example.

Unfortunately, you're not the only one who misunderstood the first answer of Riad: this is my case too, so I understand your frustration.
@ 2025-04-27 12:51 AM (#33788 - in reply to #33785) (#33788) Top

Riad Khanmagomedov



Posts: 249
1001002020
Country : Russia

Riad Khanmagomedov posted @ 2025-04-27 12:51 AM

krasnosulinec1797 - 2025-04-26 4:05 PM

Здравствуй,Риад
Вопрос по головоломке 11.
Обязательно ли в сетке должны все слова пересекаться по правилам кроссворда?
Возможно ли такое заполнение строки без пересечений ( ARTHEJOYU)-ART-HE-JO-YU = 4 слова и разрешается ли в сетке отсутствие черных клеток?
Дмитрий.

Дима, в моём примере XIU (см. последний столбец) не пересекается с прочими горизонтальными словами. Правила классического кроссворда здесь не обязательно соблюдать.
В твоём заполнении скобки следует расставить иначе: (ART)(HE)(JO)(YU). В таком виде строка приемлема.
Чёрных клеток быть не должно, ведь по условию "неиспользованные клетки надо заполнить любыми английскими буквами".
@ 2025-04-27 12:59 AM (#33789 - in reply to #33787) (#33789) Top

Riad Khanmagomedov



Posts: 249
1001002020
Country : Russia

Riad Khanmagomedov posted @ 2025-04-27 12:59 AM

Carlos - 2025-04-26 10:24 PM



@anurag The example of "Name Hitori" contains the name "AOKI" without counting it among the valid words, since it overlaps "NAOKI". Nevertheless, the grid is considered to be valid. Hence, I guess that a valid grid can contain words overlapping other words, as long as they are not counted. At least, that is what I understand from the example.

Unfortunately, you're not the only one who misunderstood the first answer of Riad: this is my case too, so I understand your frustration.


Paul, thanks for your detailed answer to Anurag. The example is eloquent.
@ 2025-04-27 4:45 AM (#33790 - in reply to #33716) (#33790) Top

krasnosulinec1797



Posts: 4

Country : Russia

krasnosulinec1797 posted @ 2025-04-27 4:45 AM

Прошу администратора ОТМЕНИТЬ мою заявку.
@ 2025-04-28 5:02 AM (#33792 - in reply to #33781) (#33792) Top

prasanna16391



Posts: 1909
1000500100100100100
Country : India

prasanna16391 posted @ 2025-04-28 5:02 AM

kiwijam - 2025-04-26 2:58 AM



A question for LMI:





Simple explanation here I think, unless I misunderstood the question. Two posts were pending approval as they were first time posts from people, and some of us were away for the weekend and slow to approve it.
@ 2025-04-28 7:05 AM (#33793 - in reply to #33716) (#33793) Top

debmohanty




Posts: 1869
1000500100100100202020
Country : India

debmohanty posted @ 2025-04-28 7:05 AM

Optimizer Submissions

Submissions to Optimizer puzzles here.

Puzzles are not checked for correctness. If you notice any incorrect submissions, please help Riad by reporting them.



Puzzle 10 : S not cross checked

Puzzle 11 : N not cross checked, Hitori not solved

Puzzle 12 : S, L not cross checked. puzzle not solved.

@ 2025-04-28 10:41 PM (#33795 - in reply to #33716) (#33795) Top

Riad Khanmagomedov



Posts: 249
1001002020
Country : Russia

Riad Khanmagomedov posted @ 2025-04-28 10:41 PM

Preliminary results have been published.
I ask Christian to check his Hitori.
Nikola and Duс, please check your answers to puzzle 12. The lines should not overlap.
@ 2025-04-29 4:02 PM (#33797 - in reply to #33716) (#33797) Top

kiwijam



Posts: 190
10020202020
Country : New Zealand

kiwijam posted @ 2025-04-29 4:02 PM

Oh wow, thank you for a great contest Riad! The puzzles were hard, but they are always hard. And thank you to all the contestants with short names. 😎
I don't think anybody has got 100 points before. If it is useful for others, I will share some thoughts on how I approached them.

Opti-Sumdoku:
The first step was to find a grid with a high Samedoku score. I looked at patterns for each digit separately. It is not possible to place a digit in 9 cells so that it counts 18 times to the sum (when every digit can see another digit in both diagonal directions). The best possible is 16 times (see the 9s in my solution). But not all digits can be 16 - the best grid overall has {16, 15, 15, 14, 14, 14, 14, 14, 14} for the Samedoku. I think Carlos has the same grid as me.
The second step is to take away as many digits as possible. Check for uniqueness, try another digit. Eventually you will get down to ~22 clues.
The last step is to choose which digit goes in each part of the grid pattern. Calculate 16/15/14 minus the number of hints remaining (e.g. 9 gets the best place = 16-1, 8 gets the 14-0, 7 gets 15-2).
Please don't try to solve my classic sudoku! It is unique, but it needs a lot of Xwings, Ywings, chains... 😭

Name Hitori:
I decided to use all the 2-letter and 3 words, and many 4s, and I ignored all 5+ words.
It is easy to have too many blacks, or not enough blacks, so I started by trying to intersect many 4-words together.
I found a 4x4 with 6 4-words inside, I put that in the bottom-left corner. I found another 4x4 with 6 words inside. When I put that in the bottom-right, the common letters (e.g. ADEM-ENDO) helped fill 90% of those cells with black or white. I filled the top-right with 4-words too, sometimes choosing letters for Hitori, sometimes choosing for intersection. At the end I put the final 2- and 3-words in the gaps. I had two empty cells. One I used to finish the Hitori, and one was a bonus point.

Threads With Knots:
I wanted to start with long diagonal lines for the 1st, 3rd, 5th, 7th sections to get a high length. I put small numbers near the corners. The 8,5,3,7 clues define knots 1 to 7. The 2 clue is not needed, but it did give lots of empty squares on the long diagonal.
Then I switched to finding a unique solution with small clues. Thread length was less important now. Putting clues on the same parity/colour diagonals helped too. I found two medium numbers (9, 13) to finish.
SP1 and EKBM both had much better clues than me, but my long thread was important. It is possible to have length > 100, but then you need too many big clues to make it unique.
@ 2025-04-29 10:12 PM (#33798 - in reply to #33716) (#33798) Top

SP1



Posts: 12

Country : Japan

SP1 posted @ 2025-04-29 10:12 PM

Riad, thanks for organizing a great contest!

And congratulations to kiwijam for a perfect win!!!

Thanks also to the LMI team for running the event.

I had not participated in this contest for a few years, but I really enjoyed it.



I especially like prob. 7 and 12.

I didn't have time to fix my solution for 12 because it was the last day of the contest when I realized that the length of lines was important.I regret that.

Anyway, I think prob.12 is a really good optimization setup!



I like optimization puzzles very much, and I am very happy to see the April Contest where I can enjoy them.

I'm planning to hold an optimization contest at a local site in Japan.

I hope that the fun of optimization will spread more and more.

Edited by SP1 2025-04-29 10:13 PM

@ 2025-04-30 12:43 AM (#33799 - in reply to #33716) (#33799) Top

Riad Khanmagomedov



Posts: 249
1001002020
Country : Russia

Riad Khanmagomedov posted @ 2025-04-30 12:43 AM

Thanks a lot to everyone!

Congratulations to James, Takuma and Paul!

Success in optimization problems in 2025 earned more points than ever. James had a very impressive victory. Only two participants managed to score points in all optimizations. Takuma, great result! Interestingly written in the two posts above. I wish Takuma success in organizing the optimization contest in Japan.

There were questions like: Why ban word overlapping in Hitori? I think through the answer format so that it is convenient for the organizers. A lot of parentheses can prevent Deb from forming grids with solutions. For clarity, it is better to place the parentheses sequentially. Thanks to the LMI team, Deb and Prasanna, and a special thanks to Kota for the long-term support!
@ 2025-05-03 4:09 PM (#33805 - in reply to #33716) (#33805) Top

pinkagape



Posts: 19

Country : United Kingdom

pinkagape posted @ 2025-05-03 4:09 PM

Thanks Riad and well done James! Are there solutions available to the puzzles? I had a tough time with some of them and was hoping to work through them with the solutions.
Riad Khanmagomedov's April Contest — 18th to 27th April 202551 posts • Page 1 of 3 • 1 2 3
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