Logic Masters India announces January 2012 Sudoku Test — Shapes and Sizes

Dates : 7^th and 8^th January

Length : 120 minutes

IB and Submission Link : http://logicmastersindia.com/M201201S/

Author : Richard Stolk

Irregular.. eek! Well there goes my rise in the rankings. On the other hand, good practice to improve my irregular sudoku solving capability, if thats indeed possible!

Since I do not have my own website, I consider my user page at Logic Masters Germany (LMD) as my homepage. Every Friday at noon (CET) I publish a puzzle in the puzzle portal. (It is not always a sudoku variant by the way). A lot of these puzzles have instructions in both German and English language. I am still busy to write the English instructions for the remaining puzzles.
I noticed that a lot of the participants in the monthly tests here at LMI are also a regular visitor of LMD. They are familiair with my puzzles. To give everybody the opportunity to get used to my puzzles (apart from the IB), I have prepared a list of links to my puzzles that are the most relevant for the coming test. Please note: Some of these puzzles are more suitable for leisure solving; being too hard to use in a test.

Here is the list (all of these puzzles have proper English instructions):

Plain chaos sudoku:
Easy
Medium
Hard

Chaos windoku:
Very hard
Easy

Twin chaos sudoku:
Very hard

Low-digits chaos sudoku:
Medium

Nonconsecutive chaos sudoku:
Medium

Chaos sudoku with other constraints:
Very easy, odd/even
Medium, diagonals
Hard, consecutive

Scattered sudoku plain:
Medium
Medium

Scattered non consecutive:
Hard
Hard

Scattered sudoku with (outside) sums:
Easy
Medium

Scattered sudokuro:
Medium

Scattered sudoku with other constraints:
Diagonal, hard
Kropki-like, hard
Kropki, hard
Kropki, hard
Kropki, small, easy

Irregular sudokus with added clues:
Medium
Hard
Very hard

Overlapping irregular sudoku:
Hard
Medium, 2010 - 2011 specialty; digits 0,0..7
Hard, Xmas 2010 specialty; replace letters first
Hard

Toroidal/cylindrical plain:
Medium
Medium
Medium
Hard, 0~9

Toroidal with other constraints:
Easy, consecutive
Medium, kropki

Chain sudoku:
Easy

After preparing the test I had a few spare puzzles unused. Those puzzles will be published today in the puzzle portal of LMD. I will provide a link to these puzzles later today.

Have fun with the puzzles!

Best regards, Richard

Edited by Richard 2011-12-30 6:08 PM

As promised earlier, here are the links to the 'Leftover'-puzzles that I published today:

Scattered outside sums
Cylindrical
Chaos windoku
Scattered overlapping

Have fun!

Irregular sudoku: A big challenge for me ! I have great difficulty in being fast on these grids. I face to this problem: trying to increase speed makes me do a lot of mistakes , more than on other variations...

However, I look forward to this test , and have no doubt that it will be very useful for me !

Fred

YEAH !!!!!
First test in NEW YEAR..2012
hope to have good start..
Nice selection of sudokus.. IT's really chaos !!! :)

Thanks Richard for the links to extra practice puzzles.
I've a question. In terms of difficulty, how do you rate the 'leftover' puzzles with respect to the actual puzzles in the test?

Sorry Deb, I forgot to mention that.
All four 'leftover' puzzles are harder than the ones in the real test. That's the reason why I didn't use them in the test.

That's too bad. I really liked the difficulty of 3 of the 4. Only the smallest had me stumped, till I remembered it was your puzzle and I figured I should look in one place and the next step was exactly there. Opposed to Fred i´m a big fan of chaos sudokus. Any sudoku that doesn´t have 3 by 3 regions is preferred by me.

We are making a small change to the image of Sudokuro - the clue cells are made more gray. Here is how the new image looks like.

Updated IB uploaded, but this is the only change.

Is it possible the online solving in this test?

Yes. We'll put all examples online for practicing. May be in next 24 hours.

All examples can now be solved online.

This test has lot of non 9X9 sudokus. So we needed to tweak the flash interface a bit.
Request to online solvers : please report any issues while solving/testing the examples before the test starts. It is unlikely that we'll make any changes after the test starts.

Is it correct, that in Scattered non-consecutive sudoku, 0 and 1 ARE consecutive and 9 and 0 ARE NOT consecutive?

@TiiT: Yes, that is correct.

hey can anyone help me out with scattered non-consecutive sudoku..
just got a "0" at r9c10..
and also with scattered sudoku with added clues...
in this got few numbers like 1 and 2 at few places but not able to proceed further..

Check 13 = 6+7
After that in left grid, R2C2=4
and then R1C1 = 3, R6C4=5
It is really smooth solve, so I guess you are not focusing on all the given sums.

Edit : Wrong steps

Edited by debmohanty 2012-01-05 10:21 AM

how can left grid r2c2 be 4 ?

because it will make r2c2 = 6 in right grid.
that makes r3c3 = 7 and r2c6 =7 in right grid..
which in turn makes r3c3 = 6 and r2c6 = 6 in left grid. This contradicts that grey cells must contain 1-7 only once

i think after concentrating on what u said about 13..
the r2c2 should be 5.
then r1c1 = 3 as you said..

and i cant believe that i got the opening of scattered non-consecutive..IT was really very hard to find it out took literally more than 3-4 hours but got it just now..
thanks for the help.

Since there are not much given digits in the grid and they are concentrated in four areas, one of those areas must provide the start.
After the 0 you found in R9C10 the real start of the puzzle can be found in R1C8 + R1C10. What digits can go there?

Since I am the author, I hesitate to give more detailed answers.

Best regards, Richard

nope
thanks for it
:)

After several attempts, that zero is the only digit I have as well. However, only now, after reading here, do I realize that the puzzle is non-consecutive. That may have been the source of my problem.

So yeah, I should really enter answer keys when i finish a puzzle. after not leaving enough time last sudoku test, this time I just totally forget to put in an answer key of the cylindrical, which was one of the first I finished.

What I observe over many tests is that, many players submit as soon as they are done with a 'page'. So typically 2 puzzles or so.