SM 2024 R3 - Math & Neighbours (5th - 11th Apr) Score Discuss
Riad's April Contest 2024 (13th - 21st April) has started Discuss
Riad Khanmagomedov's April Contest — 16th to 23nd April 202389 posts • Page 2 of 4 • 1 2 3 4
@ 2023-04-17 9:26 PM (#31479 - in reply to #31435) (#31479) Top

jeff10



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Country : United States

jeff10 posted @ 2023-04-17 9:26 PM

For the Bubbles Puzzle (Puzzle 2), do bubbles have to circle completely around an NxN (N=1,2,3) square of cells, or can a bubble of "size 3" only circle 3 of the leftmost cells while the center of the bubble is outside the grid?
@ 2023-04-18 12:06 AM (#31480 - in reply to #31477) (#31480) Top

Riad Khanmagomedov



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Riad Khanmagomedov posted @ 2023-04-18 12:06 AM

auroux - 2023-04-17 8:54 PM

On puzzle 10, does a circular equality loop "all around" with equal signs separating equal terms (in particular there must be at least two = signs), or do we get to "break the circle" where we want (not necessarily at an equality sign, and not necessarily in the same place in both directions) to form equalities that can be read clockwise or counterclockwise?

Concretely, if for some digits A,B,C,D,E one had the identities A_PLUS_BC=DEF and ED=CB_PLUS_AF, where the latter can be formed by writing the former around a circle, cutting in a different place, and reading in the other direction, would this be a valid solution ? Or is the only legal way to write the identity A_PLUS_BC=DEF to actually write "A_PLUS_BC=DEF=" around the circle (with an extra equal sign) and both expressions must be formed by cutting the circle at an "=" sign ?

You can't break the expression wherever you want. If you write down your expressions many times in a row (or read in a circle an infinite number of times), then you should get the right equality. In the example , you can write 68=45_PLUS_23=68=45_PLUS_23=68= etc.
@ 2023-04-18 12:14 AM (#31481 - in reply to #31478) (#31481) Top

Riad Khanmagomedov



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Riad Khanmagomedov posted @ 2023-04-18 12:14 AM

auroux - 2023-04-17 8:59 PM

After more thinking, I assume the correct interpretation is that we can break the circle anywhere we want (not necessarily at an = sign, and not necessarily in the same place in both directions), and that the example I gave would be a valid solution. Otherwise, it would have been easier to state the problem as producing an equality which is valid when read forwards and backwards (no need to use a circle).

The circle is used in the construction of letter palindromes, which are read an infinite number of times clockwise and counterclockwise, but sometimes giving different phrases. In Russia, such constructions are called cyclodromes.
@ 2023-04-18 12:21 AM (#31482 - in reply to #31480) (#31482) Top

auroux



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auroux posted @ 2023-04-18 12:21 AM

Riad Khanmagomedov - 2023-04-17 11:06 AMYou can't break the expression wherever you want. If you write down your expressions many times in a row (or read in a circle an infinite number of times), then you should get the right equality. In the example , you can write 68=45_PLUS_23=68=45_PLUS_23=68= etc.

Ok, thanks. But, uh, wait. Now I am concerned. Is there, then, a requirement to have at least two equal signs?
Otherwise, something like '98765*43210=' around the circle produces a valid equality when reading around the circle infinitely many times: 98765*43210=98765*43210=98765*43210=...
But this seems to violate the spirit of the puzzle, or at least there isn't much optimization left to do in this version.

And for completeness, can you clarify what exactly you expect in the answer key? The example given for the answer format only has one = sign given for each direction, even though there are two reading around the circle, so do we answer by giving what you get by cutting the circle open at an '=' sign and reading everything from just after that '=' sign to just before it, but not including the '=' sign along which we cut?

Sorry to be picky about details, but I think people spending time on this puzzle want to make sure that they are working on the correct version of it...


Thanks,Denis
@ 2023-04-18 2:57 AM (#31483 - in reply to #31479) (#31483) Top

prasanna16391



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prasanna16391 posted @ 2023-04-18 2:57 AM

jeff10 - 2023-04-17 9:26 PM

For the Bubbles Puzzle (Puzzle 2), do bubbles have to circle completely around an NxN (N=1,2,3) square of cells, or can a bubble of "size 3" only circle 3 of the leftmost cells while the center of the bubble is outside the grid?


The former.
@ 2023-04-18 2:59 AM (#31484 - in reply to #31435) (#31484) Top

prasanna16391



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prasanna16391 posted @ 2023-04-18 2:59 AM

A new puzzle booklet has been uploaded to address some of the issues discussed in the previous page (puzzle 9 wording and puzzle 2 example's key)
@ 2023-04-18 11:26 AM (#31488 - in reply to #31482) (#31488) Top

Riad Khanmagomedov



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Riad Khanmagomedov posted @ 2023-04-18 11:26 AM

auroux - 2023-04-18 12:21 AM

Riad Khanmagomedov - 2023-04-17 11:06 AMYou can't break the expression wherever you want. If you write down your expressions many times in a row (or read in a circle an infinite number of times), then you should get the right equality. In the example , you can write 68=45_PLUS_23=68=45_PLUS_23=68= etc.

Ok, thanks. But, uh, wait. Now I am concerned. Is there, then, a requirement to have at least two equal signs?
Otherwise, something like '98765*43210=' around the circle produces a valid equality when reading around the circle infinitely many times: 98765*43210=98765*43210=98765*43210=...
But this seems to violate the spirit of the puzzle, or at least there isn't much optimization left to do in this version.

And for completeness, can you clarify what exactly you expect in the answer key? The example given for the answer format only has one = sign given for each direction, even though there are two reading around the circle, so do we answer by giving what you get by cutting the circle open at an '=' sign and reading everything from just after that '=' sign to just before it, but not including the '=' sign along which we cut?

Sorry to be picky about details, but I think people spending time on this puzzle want to make sure that they are working on the correct version of it...


Thanks,Denis

You must have 2, 3 or more equal signs. You can also get the equality 1 = 3-2 = 5-4 = with three equal signs and write it out endlessly in a circle. But at the same time, in the opposite direction, it must also be true.
@ 2023-04-18 11:40 AM (#31489 - in reply to #31435) (#31489) Top

auroux



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auroux posted @ 2023-04-18 11:40 AM

Ok thank you! Now it is clear.
@ 2023-04-18 2:31 PM (#31493 - in reply to #31489) (#31493) Top

Riad Khanmagomedov



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Riad Khanmagomedov posted @ 2023-04-18 2:31 PM

auroux - 2023-04-18 11:40 AM

Ok thank you! Now it is clear.

It is allowed to use arithmetic signs on both sides of the equal sign.
@ 2023-04-18 5:01 PM (#31494 - in reply to #31435) (#31494) Top

Leonardo024



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Country : The Netherlands

Leonardo024 posted @ 2023-04-18 5:01 PM

For puzzle 5 (Navigation), the instruction says to form 8 connected areas along the grid lines, however only 6 letters are given. Does this imply that the other two regions do not occur in the 2 columns of the answer format (column 4 and 9)? Since the answer page also asks for digits and/or letters A-F (rather than A-H for 8 areas instead of 6).
@ 2023-04-18 10:43 PM (#31495 - in reply to #31435) (#31495) Top

Administrator



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Administrator posted @ 2023-04-18 10:43 PM

If you try the puzzle your question will be answered.
@ 2023-04-19 3:20 PM (#31497 - in reply to #31435) (#31497) Top

Nikola



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Nikola posted @ 2023-04-19 3:20 PM

Puzzle 10

Can we create equality without directly expressed result? For the example, is 32_PLUS_54=86_PLUS_0= allowed? Maybe this is a bad example because of zero but I hope you understand the question.
@ 2023-04-19 3:55 PM (#31498 - in reply to #31435) (#31498) Top

auroux



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auroux posted @ 2023-04-19 3:55 PM

Nikola: I think the answer is yes, and this is exactly what Riad meant when he wrote to me that "It is allowed to use arithmetic signs on both sides of the equal sign." What I am not sure about, though, is whether the answer key should include the final "=" (even though it is there when writing around the circle) - my current understanding based on the PB example is that the circular identity "32_PLUS_54=86_PLUS_0=..." is entered as "32_PLUS_54=86_PLUS_0" for the answer key.

Edited by auroux 2023-04-19 3:57 PM
@ 2023-04-19 4:27 PM (#31499 - in reply to #31435) (#31499) Top

Nikola



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Nikola posted @ 2023-04-19 4:27 PM

Okay, but in his example he still got a result 1 (in one direction). Another example: 9x2=6x3= ... I don't want to put =18 because it would give 81 in the opposite direction. Maybe confirmation would be useful.

Edited by Nikola 2023-04-19 4:35 PM
@ 2023-04-19 4:47 PM (#31502 - in reply to #31435) (#31502) Top

L00ping007



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Country : France

L00ping007 posted @ 2023-04-19 4:47 PM

In puzzle 10, there is a digit missing in the "Answer key" sentence
"68=45_PLUS_23, 32_PLUS_54=8" should be ", 68=45_PLUS_23, 32_PLUS_54=86" ;-)
@ 2023-04-19 6:36 PM (#31504 - in reply to #31497) (#31504) Top

Riad Khanmagomedov



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Riad Khanmagomedov posted @ 2023-04-19 6:36 PM

Nikola - 2023-04-19 3:20 PM

Puzzle 10

Can we create equality without directly expressed result? For the example, is 32_PLUS_54=86_PLUS_0= allowed? Maybe this is a bad example because of zero but I hope you understand the question.

Yes
@ 2023-04-19 6:40 PM (#31505 - in reply to #31498) (#31505) Top

Riad Khanmagomedov



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Riad Khanmagomedov posted @ 2023-04-19 6:40 PM

auroux - 2023-04-19 3:55 PM

Nikola: I think the answer is yes, and this is exactly what Riad meant when he wrote to me that "It is allowed to use arithmetic signs on both sides of the equal sign." What I am not sure about, though, is whether the answer key should include the final "=" (even though it is there when writing around the circle) - my current understanding based on the PB example is that the circular identity "32_PLUS_54=86_PLUS_0=..." is entered as "32_PLUS_54=86_PLUS_0" for the answer key.

In this case, write the answer as follows: 32_PLUS_54=86_PLUS_0 and 0_PLUS_68= 45_PLUS_23.
@ 2023-04-19 6:44 PM (#31506 - in reply to #31499) (#31506) Top

Riad Khanmagomedov



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Riad Khanmagomedov posted @ 2023-04-19 6:44 PM

Nikola - 2023-04-19 4:27 PM

Okay, but in his example he still got a result 1 (in one direction). Another example: 9x2=6x3= ... I don't want to put =18 because it would give 81 in the opposite direction. Maybe confirmation would be useful.

I gave an example with 1 to demonstrate three equal signs. This example is more successful: 7-6=5-4=3-2=7-6=5-4=3-2= etc.
@ 2023-04-19 6:47 PM (#31507 - in reply to #31502) (#31507) Top

Riad Khanmagomedov



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Riad Khanmagomedov posted @ 2023-04-19 6:47 PM

L00ping007 - 2023-04-19 4:47 PM

In puzzle 10, there is a digit missing in the "Answer key" sentence
"68=45_PLUS_23, 32_PLUS_54=8" should be ", 68=45_PLUS_23, 32_PLUS_54=86" ;-)

I'll correct it, thank you!
@ 2023-04-19 10:22 PM (#31509 - in reply to #31435) (#31509) Top

Barbitos



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Barbitos posted @ 2023-04-19 10:22 PM

On Puzzle 11; does the minesweeper part in itself have to be unique or can it have multiple solutions but only one mine-loops pairing?
@ 2023-04-19 11:39 PM (#31510 - in reply to #31509) (#31510) Top

Riad Khanmagomedov



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Riad Khanmagomedov posted @ 2023-04-19 11:39 PM

Barbitos - 2023-04-19 10:22 PM

On Puzzle 11; does the minesweeper part in itself have to be unique or can it have multiple solutions but only one mine-loops pairing?

Quote from the text: "Create a Minesweeper puzzle with a unique solution".
@ 2023-04-19 11:47 PM (#31511 - in reply to #31510) (#31511) Top

Barbitos



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Barbitos posted @ 2023-04-19 11:47 PM

thanks :) i figured that was probably the case but wanted to make sure

also thanks for hosting this contest, i'm having a blast solving those devilish puzzles
@ 2023-04-20 12:54 AM (#31512 - in reply to #31510) (#31512) Top

auroux



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auroux posted @ 2023-04-20 12:54 AM

Riad Khanmagomedov - 2023-04-19 10:39 AM
Barbitos - 2023-04-19 10:22 PMOn Puzzle 11; does the minesweeper part in itself have to be unique or can it have multiple solutions but only one mine-loops pairing?
Quote from the text: "Create a Minesweeper puzzle with a unique solution".
Oh, that's so disappointing. It would have been more elegant to have to create a puzzle whose solution is unique when one takes into account the requirement that there should exist a loop (but which may have multiple solutions as a pure minesweeper puzzle) -- so much so that I assumed that it was actually the task. Oh well, I shall redo it to make something that is also unique as a minesweeper puzzle. I was so happy with my submission, but it's definitely not unique at all as a minesweeper.
@ 2023-04-20 10:57 AM (#31516 - in reply to #31435) (#31516) Top

pinkagape



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Country : United Kingdom

pinkagape posted @ 2023-04-20 10:57 AM

In Puzzle 6, I'm a bit confused by the "vice versa" in the instructions for Turns. Is it saying that if the loop doesn't turn and enters a cell without a circle, then it must turn in the next cell (so you can't have more than one straight in a row)?
@ 2023-04-20 11:35 AM (#31518 - in reply to #31512) (#31518) Top

Riad Khanmagomedov



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Riad Khanmagomedov posted @ 2023-04-20 11:35 AM

auroux - 2023-04-20 12:54 AM

Riad Khanmagomedov - 2023-04-19 10:39 AM
Barbitos - 2023-04-19 10:22 PMOn Puzzle 11; does the minesweeper part in itself have to be unique or can it have multiple solutions but only one mine-loops pairing?
Quote from the text: "Create a Minesweeper puzzle with a unique solution".
Oh, that's so disappointing. It would have been more elegant to have to create a puzzle whose solution is unique when one takes into account the requirement that there should exist a loop (but which may have multiple solutions as a pure minesweeper puzzle) -- so much so that I assumed that it was actually the task. Oh well, I shall redo it to make something that is also unique as a minesweeper puzzle. I was so happy with my submission, but it's definitely not unique at all as a minesweeper.

Denis, I will check the uniqueness of the Minesweeper puzzle, and then watch a loop.
Riad Khanmagomedov's April Contest — 16th to 23nd April 202389 posts • Page 2 of 4 • 1 2 3 4
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