(First Solver) Howdy,

I think the solution for the magic sudoku puzzle is

843 275 961
579 681 324
216 439 785

765 318 492
491 752 638
328 964 157

184 596 273
932 847 516
657 123 849

If not... then that's due to typos. :)
Best regards,
--
Oliver Runge

---------------------------- Various Solvers ---------------------------------

Mark Ingram -- Awesome puzzle, as usual. I really enjoyed it.
Joseph McDermott -- Ouch!
M.A. Uri Guzman -- You are right, only one possible answer.
Jorge N. G. -- Here is the solution. Congratulation for this sudoku, it is really amusing.
Bryce Lewis
Andy Flatley -- I used a spreadsheet to work the solution.
Paul Cleary
Steve Tregidgo
Rohit Seksaria
Stan N. Isaacs --That was both interesting and difficult. I doubted the possibility of solving it without guesswork, but it seemed to have enough information (barely.) Good Puzzle!
Alex Fink
Alberto Chacon -- It was a really fun challenge, thanks.
Juan Pablo Fuentes
Alberto & Sebastián Araque
Alberto Cid -- Interesting Puzzle.
Roland Studer -- Having experience in solving a great number of "normal" sudoku’s, it was a pleasure to find the solution of this magic sudoku.
HomoTrivens
Markus Götz -- that was really difficult!!! and fun ;-)
Szeman, Attila
Alan O'Donnell -- That is a truly wonderful Sudoku variation created by Alexandre!
Odette De Meulemeester
Dewitt, Jeffrey Ryan -- Please post my name up on the list of people who have solved it. Thank you! P.S. Great puzzle! I'm addicted to Sudokus now.
Andrew Liat
Four --Thank you for posting the Magic Sudoku. It was fun. Thank you.
Alan & Margaret Cuthbertson -- Rather cute problem... well done!
Warren Phillips -- First 26 moves were straightforward. After investigating a couple of false trails, the rest of it sorted out without too much difficulty.
Bob Clarke
Alan O'Donnell
Patrick Masterson -- This was quite the challenge, but I'm glad I decided to try it. Nice mental workout. :)
Eric Fuller
Al Stanger -- By hand, pencil and paper.
M P Young
Elisa
grif sims -- This was certainly interesting to solve. In any case I wanted to send the solution and let you know that I very much enjoy your mathpuzzle.com site. Thanks for maintaining it.
Leonella H Liu
Junjie Liang -- Nice puzzle there.
pascal esper -- it's a great puzzle
Susan Hoover -- No guessing or computation required.
Mark Michell -- Also attached is a staged solution document. I have not annotated it, but I think the layout is more or less self-explanatory.
Matt Jones -- Finally, one I can get!
Alastair Cuthbertson -- A corker of a puzzle!!
Jose Climent -- Thank you. That was fun.
John Dalbec
Brown, Christopher Duane
Robert Reid -- An ingenious variation, not too difficult but sufficiently hard to provide a workout.
Jeff Wanko -- Thanks for the hardest sudoku I've run across yet--three evening spent on it, but not wasted!
Brian Carnes -- Excellent puzzle, a nice twist on the regular number game.
Martin Doublesin
Jeff Smith
Evgeni Lukin
DataPacRat
Jordi Domèmech
ssteffes
Neeraj Bankar
Tom Boppart -- Great Puzzle!
Jan Merolant
Bryce Herdt
Will Smith

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Hi the answer of the M-suduko is as following

8 4 3 2 7 5 9 6 1
5 7 9 6 8 1 3 2 4
2 1 6 4 3 9 7 8 5
7 6 5 3 1 8 4 9 2
4 9 1 7 5 2 6 3 8
3 2 8 9 6 4 1 5 7
1 8 4 5 9 6 2 7 3
9 3 2 8 4 7 5 1 6
6 5 7 1 2 3 8 4 9

This is very good puzzle.
Can we tell me the logic of construction
(How to desige it)
Can any normal suduko with diagonal property
(i.e having 1 to 9 numbers) puzzlelied in such
puzzle
Vibhav Gandre

--------------------------------------------------------------

Hi there,

I saw the Magic Sudoku through your site, and noticed your invitation to
send the solution. Hoping that you'll be able to confirm or deny that I
got the answer right (looks okay to me, but given the number of times I
stared at the half-finished grid missing some really obvious
connections, I may have messed it up), here's what I make it:

843 275 961
579 681 324
216 439 785

765 318 492
491 752 638
328 964 157

184 596 273
932 847 516
657 123 849

It was a nice puzzle -- no applications of "reductio ad absurdum" (if
you like) necessary, if I remember correctly. I'll be looking through
your Sudoku Variations page later, which also looks really interesting.

I don't know if you've already covered them, but there are some other
number-related puzzles I've seen of Japanese origin; they were published
in sudoku magazines in the UK, presumably to add some variety.

One was called "Bridges" (probably not the original name), and there's a
brief description here (I've not seen anything else about it on the web):
http://www.nikoli.co.jp/puzzles/14/index-e.htm.

Others are probably more well known, such as Slither Link and Cross Sum;
there are a few listed here:
http://www.nikoli.co.jp/puzzles/index-e.htm.

Whether any of them hold any mathematical interest is another matter; I
haven't considered it personally, but thought you may like the link.

Looking forward to checking out the rest of your site.

Cheers,
Steve Tregidgo

---------------------------------------------------------------------

Hey, Ed!

My father Dale C. Krause is obsessed with Sudoku right now. He just
got back from a conference in Australia and I handed him your
challenge. Jetlagged he finished in 36 hours. He wanted me to attach
his solution, plus the kaput one. Note that you increased the bar --
he had been doing the ones in newspapers in ink. Great fun, thanks.

Hope that this summer's school went well. Did you get involved in any
interesting projects?

And that you also had some time to kick back and relax.

Best to you,
Tara Krause

P.S. I just went onto the ringtones sneak preview and was thrilled by
your all's work. WOW! I messed with some 1599's and down loaded them
for my cell phone. Congrats to the team!

-----------------------------------------------------------

Hi Mr. Pegg,

Here's my solution. I was able to initially place the red digits
without guessing. The green digits represent a branch I took
in the search tree. Initially I placed 1 to the right of the
central 5, instead of above it. This led to an elaborate dead
end which almost filled the puzzle. I was surprised a dead
end could last that long. So, I had to blank out all the green
digits and start over. I believe this correct solution was the
only other possible branch to take, so it looks like this is
indeed a unique solution.

David J Bush

--------------------------------------------------------------

8 4 3 2 7 5 9 6 1
5 7 9 6 8 1 3 2 4
2 1 6 4 3 9 7 8 5

7 6 5 3 1 8 4 9 2
4 9 1 7 5 2 6 3 8
3 2 8 9 6 4 1 5 7

1 8 4 5 9 6 2 7 3
9 3 2 8 4 7 5 1 6
6 5 7 1 2 3 8 4 9

All done through logic; what I mean is no trial and error is necessary.

Doing the obvious/easier steps leaves:

X X X X 7 X 9 6 X
X X 9 X 8 X X X X
2 1 X X X 9 7 8 X

X X X X X 8 X 9 X
X 9 X 7 5 X X X X
X X X 9 6 X 1 X X

X 8 4 X 9 X X X X
9 X X X X X X X X
6 X X X X 3 8 4 9

Then everything slowly falls into place, mostly through elimination;
like the "8" is forced in top left corner because the remaining 8 spots
of its diagonal cannot take a "8". Similarly, only a "3" is possible
in row4, column4.

I'm sure everyone that tries it will agree that the most "headachy"
part is handling the "2,3" remains that pop up all over!

To Alexandre: very nice puzzle, Sir Muniz :)

Note: after getting my 1st part done, I got a 10by10 sheet of paper
and made myself a 9by9 grid with 1inch squares, in order to have
enough room to "clearly" enter the possible numbers in each square;
believe me, that's a good part of the battle!!

Denis Borris