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LMI Spring Sudoku Test (26th/27th March)91 posts • Page 3 of 4 • 1 2 3 4
What is your opinion about the new 'Paper Submission Mode'?
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The new "Paper Submission Mode" is very useful and LMI must continue it.16 Votes - [100%]
The new "Paper Submission Mode" is good, but needs improvement (Please specify in forum)0 Votes - [0%]
The new "Paper Submission Mode" is not any useful, and should be dropped0 Votes - [0%]

@ 2011-03-28 2:01 AM (#3858 - in reply to #3740) (#3858) Top

Ours brun




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Ours brun posted @ 2011-03-28 2:01 AM

motris - 2011-03-26 6:26 PM

Really fun test with some great puzzles. Lots of creativity with great theming and a few phenomenal variations. My only possible complaint is that the dark green is a hard color to write on/read but it was still nice to see so many different ways to welcome Spring.

The new answer submission system was also a great improvement, so thumbs up all around.

detuned - 2011-03-27 2:46 AM

I thought the paper submission thing worked very well. Sadly as I was waiting for everything to print out I did the classic in the web interface and somehow managed to lose my answer by the end of the test. Never mind.

For what it's worth I thought the set was set at just about the right level. From a designers point of view, everything was very pleasing. Sundoku is a lovely idea, the classic solved really nicely (remarkably so for a classic), and the Sudokurve was very creative. This is without mentioning the excellent challenging puzzles at the end of the test haha!

rakesh_rai - 2011-03-27 4:04 AM

[...] But the overall experience from the test was a very positive one.

neerajmehrotra - 2011-03-27 1:35 PM

Mind blowing.........great test..........
This new submission system is excellent.

purifire - 2011-03-27 9:20 PM

A great set of puzzles.... after a long time something which made me think for a long time... A few of the puzzles were simply superb... great job Authors...

rishi


What can I say ? A big thank you for these kind comments.

=> Thomas : My bad about the dark green. I am the one who designed the puzzles and I couldn't access to a printer before the test, so I couldn't exactly figure out what the color would look like. I keep the remark in mind for future tests with colored puzzles.

=> Tom : We went through several doubts concerning the overall difficulty of the test ; before the start, I was a bit afraid that it could be "too easy" ; then I saw the first results and it appeared that, on the contrary, it was probably slightly too hard. So it is good to read that some top solvers have found it well estimated.

=> Rakesh, Neeraj, Rishi : I am really happy that you liked the test. It is always difficult, when you build puzzles according to a "theme", not to fall into the trap of sacrificing quality for aesthetic. But of course, that is what makes the construction of such puzzles interesting.

Yet a few hours before the complete results...
@ 2011-03-28 3:20 AM (#3859 - in reply to #3740) (#3859) Top

detuned



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detuned posted @ 2011-03-28 3:20 AM

Ah - well that'd certainly be my advice to any would-be test creators. Your own puzzles are almost certainly harder to other people, and so any test you put together will be harder than you think it is :). (Unsurprisingly) if you'd taken my test times for the UKPA sudoku I'd have ended up significantly quicker than far better solvers than myself.

Besides, I think if you concentrate on making hard puzzles, rather than creative puzzles, you won't end up with anything particularly good. I believe the author has to have some fun too!
@ 2011-03-28 3:34 AM (#3860 - in reply to #3859) (#3860) Top

Fred76




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Fred76 posted @ 2011-03-28 3:34 AM

detuned - 2011-03-28 3:20 AM

Ah - well that'd certainly be my advice to any would-be test creators. Your own puzzles are almost certainly harder to other people, and so any test you put together will be harder than you think it is :). (Unsurprisingly) if you'd taken my test times for the UKPA sudoku I'd have ended up significantly quicker than far better solvers than myself.

Besides, I think if you concentrate on making hard puzzles, rather than creative puzzles, you won't end up with anything particularly good. I believe the author has to have some fun too!


We applied a little different method for testing than usual, for this test, I'll explain that tomorrow if you want
@ 2011-03-28 3:50 AM (#3861 - in reply to #3859) (#3861) Top

Ours brun




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Ours brun posted @ 2011-03-28 3:50 AM

detuned - 2011-03-27 11:20 PM

Ah - well that'd certainly be my advice to any would-be test creators. Your own puzzles are almost certainly harder to other people, and so any test you put together will be harder than you think it is :). (Unsurprisingly) if you'd taken my test times for the UKPA sudoku I'd have ended up significantly quicker than far better solvers than myself.

I am well aware of that ; each time I organize a tournament, I take this fact into account... and every time I realize, once it is over, that I nonetheless underestimated the difficulty. Fortunately, we were six authors this time, so we had a more global vision (and yet, the test was a bit hard...). And I just see that Fred proposed to tell you some more tomorrow, so I am gonna shut up now.
@ 2011-03-28 3:56 AM (#3862 - in reply to #3861) (#3862) Top

Fred76




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Fred76 posted @ 2011-03-28 3:56 AM

Ours brun - 2011-03-28 3:50 AM

detuned - 2011-03-27 11:20 PM

Ah - well that'd certainly be my advice to any would-be test creators. Your own puzzles are almost certainly harder to other people, and so any test you put together will be harder than you think it is :). (Unsurprisingly) if you'd taken my test times for the UKPA sudoku I'd have ended up significantly quicker than far better solvers than myself.

I am well aware of that ; each time I organize a tournament, I take this fact into account... and every time I realize, once it is over, that I nonetheless underestimated the difficulty. Fortunately, we were six authors this time, so we had a more global vision (and yet, the test was a bit hard...). And I just see that Fred proposed to tell you some more tomorrow, so I am gonna shut up now.


Bastien, if you want to talk about that now, don't hesitate
I'm just a bit tired and my English is very poor, so that each message I post is a real effort. That's why I planned to speak more tomorrow

Fred
@ 2011-03-28 4:09 AM (#3863 - in reply to #3862) (#3863) Top

Ours brun




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Ours brun posted @ 2011-03-28 4:09 AM

Fred76 - 2011-03-27 11:56 PM

Bastien, if you want to talk about that now, don't hesitate
I'm just a bit tired and my English is very poor, so that each message I post is a real effort. That's why I planned to speak more tomorrow

Fred

No, precisely I am also a bit tired so I welcomed with great joy your message. Right now I just need to get away from screen, grab some book and read until the test is over (I definitely won't be able to sleep till I know the final results, so...).
@ 2011-03-28 4:14 AM (#3864 - in reply to #3863) (#3864) Top

Fred76




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Fred76 posted @ 2011-03-28 4:14 AM

Ours brun - 2011-03-28 4:09 AM

Fred76 - 2011-03-27 11:56 PM

Bastien, if you want to talk about that now, don't hesitate
I'm just a bit tired and my English is very poor, so that each message I post is a real effort. That's why I planned to speak more tomorrow

Fred

No, precisely I am also a bit tired so I welcomed with great joy your message. Right now I just need to get away from screen, grab some book and read until the test is over (I definitely won't be able to sleep till I know the final results, so...).


Ah, so you're not creating grids now ???
@ 2011-03-28 5:05 AM (#3865 - in reply to #3740) (#3865) Top

Ziti



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Ziti posted @ 2011-03-28 5:05 AM

Thank you to the authors of these puzzles. This was a wonderful set -- I think it rates as highly as any I've ever played.
@ 2011-03-28 5:10 AM (#3866 - in reply to #3864) (#3866) Top

Ours brun




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Ours brun posted @ 2011-03-28 5:10 AM

Fred76 - 2011-03-28 12:14 AM

Ah, so you're not creating grids now ???

Are you suggesting that I may be addicted to puzzle creation ? Look, we have met several times by now, we begin to know each other. I ask you, during one of those times we met, did you ever see me, even once, creating puzzles ?

Rhetorical question, you don't have to answer.

Please, do not answer.


By the way, you just reminded me about an idea of a puzzle I had last night and forgot to put down on paper.
@ 2011-03-28 5:25 AM (#3867 - in reply to #3865) (#3867) Top

Fred76




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Fred76 posted @ 2011-03-28 5:25 AM

Ziti - 2011-03-28 5:05 AM

Thank you to the authors of these puzzles. This was a wonderful set -- I think it rates as highly as any I've ever played.


Thank you, Jason !
@ 2011-03-28 5:59 AM (#3868 - in reply to #3867) (#3868) Top

Fred76




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Fred76 posted @ 2011-03-28 5:59 AM

The test is over. You can view the results here

Congratulations to Thomas, Michael and Jason who take the places on the podium ! Thank you all for participating, I hope you had fun doing this test. We will post more detailed comments tomorrow, after a good night's sleep. (It was tiring to watch you playing )

Also thanks to LMI team and especially Deb for the great work he does for these tournaments. It's enormous !

Fred

Edited by Fred76 2011-03-28 6:00 AM
@ 2011-03-28 8:53 AM (#3869 - in reply to #3740) (#3869) Top

rakesh_rai




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rakesh_rai posted @ 2011-03-28 8:53 AM

From the results I can see that Double sum Sudoku had the least number of solvers, and the lowest %correct answers. I find this a bit intriguing, as, in my opinion, this puzzle was fairly straightforward with well defined starting points (columns/rows marked with 'E'). In fact, this was probably one puzzle which was over-valued, and definitely easier than some of the other high-pointers.

All killers were very good.
@ 2011-03-28 9:23 AM (#3870 - in reply to #3740) (#3870) Top

debmohanty




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debmohanty posted @ 2011-03-28 9:23 AM

Thanks to all authors for such a nice welcome to Spring ( i know we are 1 week late in welcoming, but we had some scheduling problems :-)

Very satisfying to see good Indian results as well, 3 positions in Top 20 (Rohan, Rishi and Rakesh - all Rs). Rohan did a mistake and lost the highest pointer sudoku (he mentioned that he wanted to write something about the test after it is over, may be about this).

Also good to know that the "Paper Submission Mode" is appreciated by all. We'll continue using it. In fact, I think we missed the trick by continuing the 'old method' for such a long time.

Thank you everyone for participating. Please leave any other feedback/suggestion you may have.
@ 2011-03-28 9:26 AM (#3871 - in reply to #3855) (#3871) Top

debmohanty




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debmohanty posted @ 2011-03-28 9:26 AM

Fred76 - 2011-03-27 6:47 PM

rakesh_rai - 2011-03-27 8:04 AM

If anything, the killer was a bit problematic for me at some places, as the '0' candidate in some cells was overlapping with killer clues. I had to restart the grid from scratch as I missed reading a zero while solving.


We identify this little problem with Deb, that appears on each test including a killer sudoku.
If someone has an idea to improve the system for killer sudoku, you can speak we Deb, he'll be happy

Fred


Yes, this was an issue which Fred and Rakesh pointed out during pretesting. Unfortunately, there was not much we could do.
Without spending significant effort, we thought we'll show the pencil marks in different color, but we dropped the idea in the end.
@ 2011-03-28 9:32 AM (#3872 - in reply to #3740) (#3872) Top

debmohanty




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debmohanty posted @ 2011-03-28 9:32 AM

A small note about Paper Submission Mode
From the database, I found that as many as 6 players submitted same Sudoku using both modes. Fortunately for them, both the answers were correct.
But please remember that, it is not necessary and definitely a waste of time (and error-prone) to submit same Sudoku using both modes.

Well, I do know that some players don't read forum, and might make the same mistake next time :-)
@ 2011-03-28 1:18 PM (#3876 - in reply to #3872) (#3876) Top

Nikola



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Nikola posted @ 2011-03-28 1:18 PM

Great test, as I predicted. Thanks to all authors! Please, repeat this before the start of each season.

Nikola
@ 2011-03-28 1:31 PM (#3877 - in reply to #3876) (#3877) Top

purifire




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purifire posted @ 2011-03-28 1:31 PM

Nikola - 2011-03-28 1:18 PM

Great test, as I predicted. Thanks to all authors! Please, repeat this before the start of each season.

Nikola


Great test indeed... my personal Favorites were the 0-8 Killer and the Inequality Killer.... The puzzles opened up beautifully and very logical....

made a complete mess of the last puzzle in the last 20 minutes... :(

Rishi
@ 2011-03-28 3:47 PM (#3878 - in reply to #3740) (#3878) Top

reesylou



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reesylou posted @ 2011-03-28 3:47 PM

I made the mistake of trying to do this puzzle late at night and very tired - but it was the only chance I had. I really enjoyed the puzzles, but stopped after about one hour when I (after solving the first two) got almost to the end of the jigsaw wordoku and realised I had stuffed it up.

It is hard for me - with a four year old, the only time I get to work on things is late at night when she is asleep.

Loved the look of the test and will add them to the pile of puzzles to solve on the train.
@ 2011-03-28 4:16 PM (#3879 - in reply to #3740) (#3879) Top

David McNeill



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David McNeill posted @ 2011-03-28 4:16 PM

Aesthetically beautiful puzzle set. Congratulations to the setters.

Puzzles 1-6 went smoothly for me - logical solves and appropriate points values.

Puzzle 7 (Sundoku) is where things started to go off the rails. I couldn't solve this puzzle logically and had to resort to guessing. Same for puzzle 8 (Extra Regions). Such a beautiful grid design it seems a shame not to find a logical solve. Would love to know how other people cracked this one. Puzzle 9 (Jigsaw) was just horrible and I couldn't finish it. Jumped to puzzle 11 (0-8 Killer). Unlike what other people have said, I cannot see how this can be solved logically. If it really is a beautiful solve, please share your insights.

What really annoys me, though, is that the two puzzles I never looked at were really easy. Puzzle 10 (Mixed) is a lovely puzzle with a very simple logical solution. Puzzle 12 (Double Sum) is easy to solve quickly by a mixture of logic and trial and error.

I think I will enjoy solving some of these again without the time pressure.
@ 2011-03-28 5:34 PM (#3880 - in reply to #3879) (#3880) Top

Fred76




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Fred76 posted @ 2011-03-28 5:34 PM

A few words about the tournament.

1. Preparation.
When we got in touch with Deb in late December asking when we could organize a monthly test, he told us that the months of January and February were already taken. We decided to organize the test in March.
Therefore we had the idea of ??building grids on the theme of spring. We made a brief glimpse of what could be done: use letters (puzzle 1, 9 and 12), date (20 March) (puzzle 3 and 11), and try to symbolize, to image the wildlife , plants, sun, etc... inside grids.
Then we worked on our own and we sent grids to each other when they were created.
2. Testing.
Since we were 6 authors, no need to seek external testers. Everyone can test the grids of other authors. But, usually, with testers that solve all the grids, we can make a mean time and compare the difficulty of all grids. Here, each author does not test its own creations. Therefore, we thought that the best time of us for each grid would be an excellent reference time and comparison to assign points.
Thus, the sum of our best times for each grid reached the total of 1h50. We thought it was a good estimate of the time it would take for some better players to complete the test, and that 4-5 people would be able to do so.
We failed to take into account the fact that, although some are better than us, it is not possible to beat or approaching the reference time on each grid, and during the 2 hours of tournament, even being at the best level, there are grids that can be solved optimally, and others where you can lose several minutes compared to the ideal time would be done in theory.
Thus the grids were a little too hard for a 2 hours tournament, nobody could fix everything in time.
3. The tournament.
Hideaki Jo, David Jones and Thomas Snyder were the first of the favorites to play and thus give give us a good reference about the difficulty of the test. Seeing none has succeeded in solving all the grids, we realized that the test was a little too hard and it would be difficult to find someone who could do anything (but may not be impossible?). Thomas was very close to doing so. He still had 8 minutes to solve the sudokurve. Unfortunately the code he gave was false. Throughout the weekend, we waited to see if anyone was going to beat Thomas by passing the entire grid. Sunday, Deb sent us a link telling us that there was a puzzle weekend in Germany, and that one should not hope too that the best German players taked part. 5 minutes later he was denied by Michael Ley, who entered the tournament. And he very nearly created a small surprise, making all the codes, but also with an error on the sudokurve. Thomas and Michael have dominated the tournament with a fairly comfortable lead on the 3rd. 3 hours from the end of the tournament, when we thought everything was played for the first places we saw Jakub Hrazdira and Jason Zuffranieri get into the tournament. The latter manages to stand on the podium. At 13 minutes remaining, he had not made the consecutive and jigsaw Wordoku. He fails completed one of these two grids (the jigsaw Wordoku would have placed him at 950 pts without the time bonus).
4. Conclusion
With 12 grids, none of which really easy for beginners, there were many zero scores. We realize that this was not an easy test for beginners or people unfamiliar with variants. However, we hope everybody had fun solving some grids and that you will take time to try to solve others in the coming days / weeks. We thank all participants, without whom these events would not be what they are and Deb for his wonderful work. It was really a pleasure to work with someone who shows his commitment and desire to constantly improve everything that can be.

On behalf of the team,
Fred
@ 2011-03-28 5:43 PM (#3881 - in reply to #3879) (#3881) Top

Fred76




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Fred76 posted @ 2011-03-28 5:43 PM

David McNeill - 2011-03-28 4:16 PM

Puzzle 7 (Sundoku) is where things started to go off the rails. I couldn't solve this puzzle logically and had to resort to guessing. Same for puzzle 8 (Extra Regions). Such a beautiful grid design it seems a shame not to find a logical solve. Would love to know how other people cracked this one.


David, I'll post step by step explanation for sundoku and extraregions, which were not so difficult, but they are some steps that are not so easy to find, especially under time pressure.

David McNeill - 2011-03-28 4:16 PM

Puzzle 12 (Double Sum) is easy to solve quickly by a mixture of logic and trial and error.


rakesh_rai - 2011-03-28 8:53 AM

From the results I can see that Double sum Sudoku had the least number of solvers, and the lowest %correct answers. I find this a bit intriguing, as, in my opinion, this puzzle was fairly straightforward with well defined starting points (columns/rows marked with 'E'). In fact, this was probably one puzzle which was over-valued, and definitely easier than some of the other high-pointers.


It's nice to see that there is no unanimity about difficulty of some grids . When I tested Double sum, I must say I found it very hard, and I could not find a strategy to solve it in a good time. I think all testers found it hard (best of us solved it in 17'), this is why it had so many points.

Fred
@ 2011-03-28 6:44 PM (#3886 - in reply to #3740) (#3886) Top

detuned



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detuned posted @ 2011-03-28 6:44 PM

To continue my mini discussion with Bastien and Fred - another thing to take into account is that each puzzle author inevitably has his/her own style. I imagine that as a group you are well accustomed to each other's puzzles. Of course you also have the extra factors of time-pressure, printing time, answer-entry time and all the rest as you rightly say.

Very strange re the double sum. During the test itself I must have spent that last ~45 minutes on the 0-8 killer. I got about a third to a half way in, thinking to myself this will now fall very quickly, like most killers do when you get a few digits placed. Except I didn't. In comparison, solving afterwards, the double sum was quite gentle. It definitely didn't take longer than 10 minutes and was probably closer to 5. My explanation is that the 0-8 killer didn't feel very constrained at all (I'm probably missing something), and the double sum most certainly did - to the point where I thought I'd gone wrong a couple of times only to spot that actually I had made the sum elsewhere in the row/column.

I'm glad I'm in good company with the sudokurve. I thought I had it solved, but as I was entering I saw the mistake. I then decided to put it aside, and thanks to the 0-8 killer never managed to get back round to it!
@ 2011-03-28 6:48 PM (#3887 - in reply to #3763) (#3887) Top

Administrator



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Administrator posted @ 2011-03-28 6:48 PM

purifire - 2011-03-16 9:53 PM

I have the images for solution ready but I am getting a server error when trying to upload...

Rishi

This problem is fixed now.



(text3428.png)



Attachments
----------------
Attachments text3428.png (6KB - 4 downloads)
@ 2011-03-28 10:03 PM (#3888 - in reply to #3740) (#3888) Top

Para



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Para posted @ 2011-03-28 10:03 PM

I enjoyed this test. Best sudoku finish so far for me. But that is probably partly because it was only a small set of puzzles. I generally fair better with a smaller number of harder sudoku puzzles than a lot of easier sudoku puzzles.

My favourites during competition were the extra regions and 0-8 killer sudoku. I didn't need to guess for the extra regions, found the logic path quite nicely.
I spent a bit too much time on the Jigsaw Wordoku as I had at first missed the "repeated letters can't be adjacent" rule. I got pretty far with it till I realised that one.
The first time I did the Sudokurve I messed it up too, till I noticed 2 6's in a long bent row. I found the outside lines a bit too hard to follow.
The Sundoku was tricky and I messed it up twice in competition. I thought the opening was really nice, just too bad I kept breaking it.
The mixed was also very nice, although I missed the opening during competition. The inequalities did feel a little as an afterthought, as in we set up this really nice thermometer/arrows path except it's not unique yet. I thought the double sum was very hard and when solving it afterwards it didn't really feel like a solid logic path, always felt like I was doing it a bit intuively, constantly finding things that work and assuming i'm still on the right path, not being 100% sure my deductions were right.

All in all, thanks for a fun test. Now if only I can not make an entry error next time. Dumb 4.
@ 2011-03-28 11:09 PM (#3889 - in reply to #3888) (#3889) Top

Fred76




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Fred76 posted @ 2011-03-28 11:09 PM

About extraregions:



We can easily place every 9 (region 2 & 9, then 5, 4 and finally 6):



Then, we see pairs 38 and 27 in region 9:



That leads to other easy placement:



We now can view a pair 35 in the extra yellow region:



What about the cell R9C6? We can have 1 or 2... but the 2 doesn't fit, otherwise we couldn't place a 2 in blue extra region. So it's a 1 !
And the 35 pair implies a pair 34 in region 1 (by the placement of the 3 in column 3), and of course then a 16 pair in region 1 and another pair 34 in row 3. Then we can place the 5 in region 3. Here we are:



There is only one possible placement for the 1 in blue extraregion, that leads to:






What about the 7 in R6C3? impossible, otherwise there will be two 7's in the red extra region !

So it's a 2 !

Further, looking at placement of the 1 in red region leads to place 1 and 4 in region 6 !

Another extraregion analysis: 5 in Row 7 is in the green region, so there is only one possibility for the 5 in column 4: R2C4. Which leads to:



On R7C1, there is only one possibilty: the 1. Then only one possibility for the 1 in green region: R6C4. Then a few easy placements:



3 is in red region in region 1, in blue region in region2, so the only placement in region 5 is R6C5, which leads to:



We can then place the 5 in region 5, then 4 in region 5 and some easy placements:



Place the 3 in green region, then all the rest are easy placements

Solution:



Fred
LMI Spring Sudoku Test (26th/27th March)91 posts • Page 3 of 4 • 1 2 3 4
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