Substitution and Neighbours - 19th - 25th Mar 2021 - Sudoku Mahabharat & ISC Qualifier 2021
@ 2021-03-12 8:45 AM (#29000) (#29000) Top

Administrator



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Administrator posted @ 2021-03-12 8:45 AM




Link for rules and other details about Sudoku Mahabharat: http://logicmastersindia.com/SM/2021sm.asp
The Instruction booklet is available on the contest page: https://logicmastersindia.com/live/?contest=SM202103



@ 2021-03-17 9:25 PM (#29009 - in reply to #29000) (#29009) Top

Administrator



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Administrator posted @ 2021-03-17 9:25 PM

Points Table


Points table shall be updated on 19th March 2021.

@ 2021-03-17 9:26 PM (#29010 - in reply to #29000) (#29010) Top

Administrator



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Country : India

Administrator posted @ 2021-03-17 9:26 PM

Penpa Tabs


Please use the "Sudoku" tab for all sudokus.
Sometimes the modes reset to something else but are easily changeable as per convenience.
You can also "resize" the grid based on your device and your solving convenience.

@ 2021-03-18 4:01 AM (#29011 - in reply to #29000) (#29011) Top

Timjamiller



Posts: 54
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Timjamiller posted @ 2021-03-18 4:01 AM

Question for True or Lie: "given clues" refer specifically to the small numbers, and we should trust the large numbers to be accurate, yes?
@ 2021-03-19 9:03 AM (#29014 - in reply to #29011) (#29014) Top

rakesh_rai




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rakesh_rai posted @ 2021-03-19 9:03 AM

Timjamiller - 2021-03-18 4:01 AM

Question for True or Lie: "given clues" refer specifically to the small numbers, and we should trust the large numbers to be accurate, yes?

Yes. Good point. The rules will be modified to reflect this.
@ 2021-03-19 4:32 PM (#29015 - in reply to #29014) (#29015) Top

Administrator



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Administrator posted @ 2021-03-19 4:32 PM

(Updated) Instructions Booklet


An updated version of the IB is now available at the contest page: https://logicmastersindia.com/live/?contest=SM202103

1) Points table has been updated.
2) True or Lie sudoku - Rule has been updated based on the comment in this thread.

@ 2021-03-19 7:07 PM (#29016 - in reply to #29000) (#29016) Top

Administrator



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Administrator posted @ 2021-03-19 7:07 PM

Sudoku Booklet


The password-protected Sudoku Booklet is now available at the contest page: https://logicmastersindia.com/live/?contest=SM202103

@ 2021-03-21 2:25 PM (#29017 - in reply to #29000) (#29017) Top

TiiT



Posts: 139
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TiiT posted @ 2021-03-21 2:25 PM

Thank you for the enjoyable puzzles. I even don't have favourites. They all were equally good. Although the letters in coded were hard to see when solving and I think I struggeled too much with True or Lie sudoku. There was probably something I missed.

About this visibility:
The gray in fortress vs. renban/coded was different. The fortress seemed a bit darker. Coded and Renban was still a bit too light in my opinion. But it was already a little bit better than last time. I didn't have to redraw anything this time, but I was far from comfort-zone in coded, because I really had to double check everything to be sure I didn't get a letter wrong. Luckily the coded sudoku was easy enough and the coding part wasn't the main part (thank you for that actually for making sudoku part more important than coding part).
@ 2021-03-21 2:57 PM (#29018 - in reply to #29000) (#29018) Top

dhruvarajsinhpuwar06



Posts: 5

Country : India

dhruvarajsinhpuwar06 posted @ 2021-03-21 2:57 PM

I did not expect such easy sudokus from Mr. Rakesh Rai Sir. In excitement, I made an error in entering the answer key in one of the sudokus. Like Mr. Tiit Vunk Sir mentioned, I also found difficulty in visibility in 9x9 coded sudoku and 9x9 fortress was darker. But, after all, I am very happy to complete this SM-3 round fully with bonus points which is the first ever SM round I finished.
@ 2021-03-21 4:57 PM (#29019 - in reply to #29017) (#29019) Top

Feadoor



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Feadoor posted @ 2021-03-21 4:57 PM

TiiT - 2021-03-21 9:25 AM
Coded and palindrome was still a bit too light in my opinion.


I had the exact opposite problem. The letters in Coded were so dark that I could barely see what I had written on top of them.
@ 2021-03-21 5:43 PM (#29020 - in reply to #29000) (#29020) Top

rakesh_rai




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rakesh_rai posted @ 2021-03-21 5:43 PM

Thanks for bringing out the shading printing issues. We did change the shading from SM1 based on Tiit's comments but there are still issues. Will explore Penpa further to see how this experience can be improved.

Also I am puzzled how the same puzzle is darker for one participant and lighter for another participant (assuming no local issues).
@ 2021-03-21 5:44 PM (#29021 - in reply to #29018) (#29021) Top

rakesh_rai




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rakesh_rai posted @ 2021-03-21 5:44 PM

dhruvarajsinhpuwar06 - 2021-03-21 2:57 PM

I did not expect such easy sudokus from Mr. Rakesh Rai...

Why?
@ 2021-03-21 5:48 PM (#29022 - in reply to #29020) (#29022) Top

Feadoor



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Feadoor posted @ 2021-03-21 5:48 PM

Also I am puzzled how the same puzzle is darker for one participant and lighter for another participant (assuming no local issues).


It could be a number of things: printer differences, a difference in personal preference, maybe one of us is using a darker pen/pencil than the other (I used HB pencil). It's difficult to please everyone :) Next time I'll know to bring a pen or a darker pencil.
@ 2021-03-21 11:27 PM (#29023 - in reply to #29022) (#29023) Top

TiiT



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TiiT posted @ 2021-03-21 11:27 PM

It's interesting you pointed that out. I'm using pen (blue), which is really well visible when I write something down. Cannot agree more that this is probably the reason why nothing is too dark for me. Pencil is something I just don't like using.
I also agree that there might be printer issues, although I haven't configured any settings there. Just printers are different.

But really it was better this time. You (organizers) already have done something for of me and I really appreciate it. I also don't want to say that I would have done 5 minutes faster if the gray was darker. No, I'm talking about some seconds here which probably didn't affect my result.

The fair thing would be to keep everything more or less similar than this time.


Feadoor - 2021-03-22 2:48 PM

Also I am puzzled how the same puzzle is darker for one participant and lighter for another participant (assuming no local issues).


It could be a number of things: printer differences, a difference in personal preference, maybe one of us is using a darker pen/pencil than the other (I used HB pencil). It's difficult to please everyone :) Next time I'll know to bring a pen or a darker pencil.
@ 2021-03-22 12:07 AM (#29024 - in reply to #29000) (#29024) Top

swaroop2011




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swaroop2011 posted @ 2021-03-22 12:07 AM

@TiiT @Feadoor
Thanks for your feedback regarding the shades. One thing we can probably do in the future for coded/substitution alphabets is to provide in the top left corner in black color (similar to True or Lie), this will keep the centre space empty and also make alphabets clearly visible. In regards to shading, we hope the below test will help to further improve.

@Everyone - If you don't mind, can you please print the following puzzle and share your feedback regarding which shade you feel is very light, very dark or appropriate/suitable. That would help us to further improve the choice of color.
Thanks in advance to all.
https://git.io/Jmd7K (Use "Screenshot" button at the top to download the image with default settings as is (i.e. High Quality and PNG))
You can either share your feedback here or send it to penpaplus@gmail.com, your time is very much appreciated.

Edit: Added alphabets to each shade and option for easier reference and feedback.

Edited by swaroop2011 2021-03-22 12:18 AM
@ 2021-03-22 6:29 AM (#29025 - in reply to #29000) (#29025) Top

bakpao



Posts: 15

Country : The Netherlands

bakpao posted @ 2021-03-22 6:29 AM

For me, it would break down into the following:

Shaded
Ideal - C
Workable - B,D,K
Too dark - A,S

Thermo
Ideal - E
Workable - F,G
Too dark - H,I,J

Line
Ideal - R
Workable - L,M,Q
Too dark - N,O,P

Arrow
Ideal - U
Workable - T,V
Too dark - W,X

What seems to work best for me is as light as possible (since the shapes are large enough to be distinctive), except for lines perhaps take 1 shade darker than the very lightest since they can be easier to miss. But honestly anything within the workable range is perfectly fine for me

Edit: Standard printer settings, wrote some pencil marks and digits in each cell with a regular HB pencil. I also want to add that I think moving coding information etc to the cell corner is a great idea

Edited by bakpao 2021-03-22 6:40 AM
@ 2021-03-22 2:12 PM (#29026 - in reply to #29021) (#29026) Top

dhruvarajsinhpuwar06



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Country : India

dhruvarajsinhpuwar06 posted @ 2021-03-22 2:12 PM

Sir, I did not expect that SM-3 round would be easy because generally your genius sudokus and puzzles are tough and require more time to solve but in this round all were easy. My favourites in this round were 9x9 Fortress Sudoku and 9x9 Consecutive Pairs Sudoku.
@ 2021-03-22 10:25 PM (#29027 - in reply to #29000) (#29027) Top

Anu G



Posts: 17

Country : India

Anu G posted @ 2021-03-22 10:25 PM

What an interesting contest. My laptop gave trouble so I got stressed out and lost my focus.in general I get a little demoralised when contests are very tough, Thus has brought back my confidence and enthusiasm in solving contests. Thanks very much Mr, Rakesh for a very enjoyable SM. I wish my score proved it.
@ 2021-03-23 12:27 PM (#29028 - in reply to #29000) (#29028) Top

vopani



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vopani posted @ 2021-03-23 12:27 PM

Fantastic set. Didn't expect anything lesser.
Great example of how easy sudokus can be of high quality.

Favourites:
True or Lie 6x6
Consecutive Pairs 9x9
True or Lie 9x9

Thanks Rakesh!
@ 2021-03-23 1:18 PM (#29029 - in reply to #29000) (#29029) Top

ravilp



Posts: 10

Country : India

ravilp posted @ 2021-03-23 1:18 PM

As Dhruv had earlier mentioned, I too was surprised by the much easier set. I started the set remembering Rakesh's mean mini set. But found easier and so made an error in 9×9 Fortress which ate my time. Eventhough I didn't finish the set, this was my best effort in SM and a BIG thankyou for that Rakesh.
@ 2021-03-23 1:25 PM (#29030 - in reply to #29000) (#29030) Top

ravilp



Posts: 10

Country : India

ravilp posted @ 2021-03-23 1:25 PM

Very apt password.
My favourite was the 9×9 Fortress and the True or Lie
@ 2021-03-23 5:36 PM (#29031 - in reply to #29025) (#29031) Top

Veronika



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Country : Slovakia

Veronika posted @ 2021-03-23 5:36 PM

For me the best shading is:

Shaded - C, K
Thermo - E, F
Line - Q, R
Arrow - U, V

Shading A is not usable for me at all.

Thank you for asking this feedback.
@ 2021-03-23 10:38 PM (#29032 - in reply to #29000) (#29032) Top

TiiT



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TiiT posted @ 2021-03-23 10:38 PM

I have to be honest. I printed it out and basically everything is workable (with only few exceptions). If you have used some of these in competitions, then there must me something else, which affects this (maybe the quality of pdf file, the pdf itself or resolution).

I first recommend to create an actual pdf and not put these different variants next to each other. Like this C feels fine only because it has darker areas on it's sides.

So:
Shaded:
C - Cannot tell for sure, it seems fine, but maybe a bit too light.
K, D - Perfect for me
B, S - workable
A - A bit too much

Thermo:
E - Would say workable, but not sure
F, G, H - totally fine
I, J - workable

Line:
L - workable in here
R, Q - Perfect for me
M, N, O - workable
P - maybe too much, but would be workable for me

Arrow:
U - seems workable
V, T - perfect
W, X - Also totally fine

numbers 1 and 2. I can see them clearly in here. They are definitely not the same as they were in coded sudoku. In here both are fine.
@ 2021-03-24 9:33 AM (#29033 - in reply to #29000) (#29033) Top

aashay



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2020
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aashay posted @ 2021-03-24 9:33 AM

Great set of Sudokus, relatively on the easier side. I echo Tiit's views that the Fortress was too dark and the Coded alphabets were too large, which made the solve slightly uncomfortable. I also found the True or Lie 9x9 to be tougher than the Fortress 9x9, though it was worth lesser.

Overall, a fantastic set. Thanks Rakesh!
@ 2021-03-24 10:59 AM (#29034 - in reply to #29000) (#29034) Top

Nityant



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Nityant posted @ 2021-03-24 10:59 AM

What a Great set of Sudokus! Loved all of them. I had some issues with reading the numbers in coded Sudokus(penpa), But didn't have much problem as they were not hard to solve. Consecutive pairs Sudoku 9x9 increased my time by a large margin.
Amazing set. Expected nothing less from you sir. Thank you
@ 2021-03-24 3:58 PM (#29035 - in reply to #29034) (#29035) Top

Administrator



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Administrator posted @ 2021-03-24 3:58 PM

Contest Extension


Like some recent contests, this contest is also extended by 24 hours and shall be open till Thursday 11:59 PM IST (25th March) - based on requests from some participants.
(Participants must start the test before 11:59 PM on 25th March.)

@ 2021-03-25 2:49 PM (#29036 - in reply to #29000) (#29036) Top

akash.doulani



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akash.doulani posted @ 2021-03-25 2:49 PM

A very enjoyable set of sudokus. My favourites were consecutive pairs 9x9 , Fortress 9x9 and consecutive pairs 6x6. Classics were enjoyable as well
@ 2021-03-25 11:35 PM (#29037 - in reply to #29000) (#29037) Top

pranavmanu



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pranavmanu posted @ 2021-03-25 11:35 PM

Enjoyable set of sudokus. I just quickly saw the variants in a hurried rush before taking the test. After finishing it at a stroll, I remembered to check who the author was, and had to do a double take after seeing it was Rakesh, never would have expected this level of difficulty from him :)
Favourites were Consecutive Pairs 1 and 2, and Classic 3. Thank you, Rakesh.
@ 2021-03-26 12:17 AM (#29038 - in reply to #29037) (#29038) Top

rakesh_rai




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rakesh_rai posted @ 2021-03-26 12:17 AM

TiiT - 2021-03-21 2:25 PM

Thank you for the enjoyable puzzles. I even don't have favourites. They all were equally good. Although the letters in coded were hard to see when solving and I think I struggeled too much with True or Lie sudoku. There was probably something I missed.
Thanks Tiit! Perhaps True or Lie was slightly undervalued in terms of points, as noted by Aashay too.

dhruvarajsinhpuwar06 - 2021-03-22 2:12 PM

Sir, I did not expect that SM-3 round would be easy ...My favourites in this round were 9x9 Fortress Sudoku and 9x9 Consecutive Pairs Sudoku.
Thanks Dhruva!

Anu G - 2021-03-22 10:25 PM

What an interesting contest. My laptop gave trouble so I got stressed out and lost my focus.in general I get a little demoralised when contests are very tough, Thus has brought back my confidence and enthusiasm in solving contests. Thanks very much Mr, Rakesh for a very enjoyable SM. I wish my score proved it.
I also wish the score would have been better. But we cannot control external factors. Hope to see you do better in the next round.

vopani - 2021-03-23 12:27 PM

Fantastic set. Didn't expect anything lesser. Great example of how easy sudokus can be of high quality. Favourites: True or Lie 6x6, Consecutive Pairs 9x9, True or Lie 9x9
Thanks Rakesh!
Thanks Rohan!

ravilp - 2021-03-23 1:18 PM

As Dhruv had earlier mentioned, I too was surprised by the much easier set. I started the set remembering Rakesh's mean mini set. But found easier and so made an error in 9×9 Fortress which ate my time. Eventhough I didn't finish the set, this was my best effort in SM and a BIG thankyou for that Rakesh.
Congratulations for your best effort. I was hoping for a century too. Personally, I think rank is more important than absolute score. I hope this would be one of your better ranks too!
@ 2021-03-26 12:27 AM (#29039 - in reply to #29037) (#29039) Top

rakesh_rai




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rakesh_rai posted @ 2021-03-26 12:27 AM

ravilp - 2021-03-23 1:25 PM

Very apt password.
My favourite was the 9×9 Fortress and the True or Lie
Glad that you noticed and mentioned it (the password).

aashay - 2021-03-24 9:33 AM

Great set of Sudokus, relatively on the easier side. I echo Tiit's views that the Fortress was too dark and the Coded alphabets were too large, which made the solve slightly uncomfortable. I also found the True or Lie 9x9 to be tougher than the Fortress 9x9, though it was worth lesser.

Overall, a fantastic set. Thanks Rakesh!
Thanks Aashay! Agree with your points on Fortress and Coded. True or Lie may indeed have been trickier. One of the reasons it had lesser points is that it had less variant part and was almost a classic/pencilmarks sudoku.
Nityant - 2021-03-24 10:59 AM

What a Great set of Sudokus! Loved all of them. I had some issues with reading the numbers in coded Sudokus(penpa), But didn't have much problem as they were not hard to solve. Consecutive pairs Sudoku 9x9 increased my time by a large margin.
Amazing set. Expected nothing less from you sir. Thank you
Thanks Nityant! Consecutive pairs 9x9 was a straightforward solve (unless you unnecessarily bring the converse rules into play)

akash.doulani - 2021-03-25 2:49 PM

A very enjoyable set of sudokus. My favourites were consecutive pairs 9x9 , Fortress 9x9 and consecutive pairs 6x6. Classics were enjoyable as well
Thanks Akash! Not surprising as Consecutive Pairs is one of your favourite variants as I can see on your blog.

pranavmanu - 2021-03-25 11:35 PM

Enjoyable set of sudokus. I just quickly saw the variants in a hurried rush before taking the test. After finishing it at a stroll, I remembered to check who the author was, and had to do a double take after seeing it was Rakesh, never would have expected this level of difficulty from him :) Favourites were Consecutive Pairs 1 and 2, and Classic 3. Thank you, Rakesh.
Thanks Pranav! You were the co-author of this round last year. So I guess these variants would be familiar to you anyway.
@ 2021-03-26 1:43 AM (#29040 - in reply to #29039) (#29040) Top

Administrator



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Administrator posted @ 2021-03-26 1:43 AM

Thanks to the 357 participants.

Congratulations to Tantan Dai, Seungjae Kwak, Tiit Vunk, Jakub Ondrousek and Kota Morinishi for taking the top 5 spots - finishing in less than 36 minutes.

Also, Congratulations to Prasanna Seshadri, Rohan Rao and Kishore Kumar for taking the top 3 spots from India - finishing in less than 50 minutes.

A high number of finishers in this round- 125 overall, and 21 from India.

Thanks to Rakesh Rai for authoring this round!

The Solutions Booklet is now available.

Those who missed taking part in this test can still take this test unofficially.

@ 2021-03-26 1:45 AM (#29041 - in reply to #29000) (#29041) Top

swaroop2011




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swaroop2011 posted @ 2021-03-26 1:45 AM

Wonderful contest. Thanks Rakesh and testers and LMI.
Feels Good to finish an SM round.
@ 2021-03-26 1:07 PM (#29042 - in reply to #29000) (#29042) Top

harmeet



Posts: 87
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harmeet posted @ 2021-03-26 1:07 PM

Fun filled and well balanced set for SM. Favorites were True-Lie-2 and Fortress-2. Thanks Rakesh!
@ 2021-03-26 11:45 PM (#29043 - in reply to #29042) (#29043) Top

rakesh_rai




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rakesh_rai posted @ 2021-03-26 11:45 PM

swaroop2011 - 2021-03-26 1:45 AM

Wonderful contest. Thanks Rakesh and testers and LMI.
Feels Good to finish an SM round.
Thanks Swaroop!

harmeet - 2021-03-26 1:07 PM

Fun filled and well balanced set for SM. Favorites were True-Lie-2 and Fortress-2. Thanks Rakesh!
Thanks Harmeet! I think this set was not that "balanced" as all sudokus were on the easier side (except maybe some classics)
@ 2021-03-26 11:53 PM (#29044 - in reply to #29000) (#29044) Top

rakesh_rai




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rakesh_rai posted @ 2021-03-26 11:53 PM

I am glad this round did take place as per the schedule. Thanks everyone who took part, and everyone who posted their feedback!

I tried to keep the sudokus "not difficult" in this round. And we have a record number of finishers this time! Happy to see 21 finishers from India.

Personally I would have liked to make some of the sudokus more elegant - less clues in renban 9x9, more "true or lie" clues in True or Lie 9x9 and lesser shaded clues in fortress 9x9. Coded and Consecutive Pairs were exactly as I had planned. For Coded, I came up with the "The charm of March" initially and luckily got a neat "Home craft" from these letters. This helped to make the decoding part very easy. (Pleasantly) Surprised to see many "pure" sudoku players attempt and solve coded sudoku in this contest.

Nice to see Kartik, Shambo, Harsh, Poonam, James Peter, Dhruva, Nityant and Harmeet in the 100s! Congratulations all!
And a very impressive timing from Tantan - significantly ahead of everyone else. Congratulations!

Looking forward to the next round - Math.
@ 2021-03-28 5:56 PM (#29045 - in reply to #29024) (#29045) Top

Kithyane



Posts: 49
2020
Country : France

Kithyane posted @ 2021-03-28 5:56 PM

My opinion on the grayscale benchmark, although I never had a real problem in a competition with this :

Shaded
Ideal - K
Workable - C,D
Too dark - B,S
Impossible to see my writing : A

Thermo
Ideal - F
Workable - E,G
Too dark - H,I
Impossible to see my writing : J

Line
Ideal - M,Q
Workable - N,O
Too light/dark - L,P,R

Arrow
Ideal - U
Workable - T,V,X
Too dark - W


I think overall, I prefer lines (and arrows) darker than shading/thermo.
Also for clues (like coded), I'd rather they were small and in a corner rather than big and center (it also gives the advantage of printing them black instead of grey).

@ 2021-03-28 9:19 PM (#29046 - in reply to #29000) (#29046) Top

swaroop2011




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swaroop2011 posted @ 2021-03-28 9:19 PM

Thanks Bakpao, Veronika, TiiT, Kithyane for your inputs on the grayscale and others for their feedback.
More or less combining Ideal and Workable choices, it overlaps for all of you. We will take this into our consideration and implement these choices in the next round whenever applicable.

Thats a good point TiiT, it may be possible PDF rendering is impacting some way, hopefully not too much. We will see if there is any resolution setting that can be improved while generating pdf.
@ 2021-04-08 2:28 AM (#29086 - in reply to #29000) (#29086) Top

EctoPlasma




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EctoPlasma posted @ 2021-04-08 2:28 AM

I'd say I'm in complete agreement with bakpao, would prefer as light as possible. (Saying this now because of Double Chocos on Puzzle Ramayan round that recently concluded. Shading of them felt so dark that I had trouble extracting solution codes.)