Thread - A or B — LMI October Sudoku Test

@ 2011-09-21 6:59 AM (#5664) (#5664) Top

Administrator

Country : India

Administrator posted @ 2011-09-21 6:59 AM

@ 2011-09-24 9:13 PM (#5675 - in reply to #5664) (#5675) Top

Administrator

Country : India

Administrator posted @ 2011-09-24 9:13 PM

Logic Masters India announces October 2011 Sudoku Test — Sudoku A or B

Dates : 1^st and 2^nd October

Length : 120 minutes

IB and Submission Link : http://logicmastersindia.com/M201110S/

Author : Deb Mohanty

@ 2011-09-24 10:18 PM (#5676 - in reply to #5664) (#5676) Top

Ours brun

Posts: 148

Country : France

Ours brun posted @ 2011-09-24 10:18 PM

This looks wonderful. I can't wait to try the puzzles of the IB... but I will have to, since USSC is about to start. Damn !

@ 2011-09-24 10:23 PM (#5677 - in reply to #5676) (#5677) Top

Fred76

Posts: 337

Country : Switzerland

Fred76 posted @ 2011-09-24 10:23 PM

Ours brun - 2011-09-24 10:18 PM

This looks wonderful. I can't wait to try the puzzles of the IB... but I will have to, since USSC is about to start. Damn !

ditto

@ 2011-09-25 1:19 PM (#5682 - in reply to #5664) (#5682) Top

neerajmehrotra

Posts: 329

Country : India

neerajmehrotra posted @ 2011-09-25 1:19 PM

looks wonderful and challenging!!!

@ 2011-09-25 2:07 PM (#5683 - in reply to #5664) (#5683) Top

debmohanty

Country : India

debmohanty posted @ 2011-09-25 2:07 PM

There are 12 examples, but around 20 rules. So, there are some 'unused' rules in the IB.
Here are some links which can used for practice. Most of the Sudokus have appeared in LMI tests earlier.
Rohan's blog has examples for many of them as well. If someone wants online solving, check argio-logic.net

Sudoku Type	LMI test link	Rohan's blog link	argio-logic link
Odd Sudoku	ISC2011 finals	search/label/Odd%20Sudoku
Extra Region Sudoku	ISC2011 Qualifier, Fivefold, Spring	search/label/Extra%20Region%20Sudoku
Even Sudoku	Mock18 IB	search/label/Even%20Sudoku
Greater Sudoku	Sudoku Hotpot
Sequence Sudoku	Mock19	search/label/Sequence%20Sudoku
Palindrome Sudoku	ISC2010	search/label/Palindrome%20Sudoku	palindromo
Marked Quadro	Mastermind Twins
Multiplication Table	ISC2011 finals	search/label/Multiplication%20Table%20Sudoku
Neighbouring Sudoku			neighbours
Touchy Sudoku	Mock12, Classic Lookalikes	rules-of-touchy-sudoku.html	Touchy
Anti-Knight Sudoku	Classic Lookalikes	search/label/Anti%20Knight%20Sudoku	knight
XV Sudoku	ISC2011 Qualifier	search/label/XV%20Sudoku	xv
Kropki Sudoku	LOGIDOKU	search/label/Kropki%20Sudoku	kropkinew
Consecutive Sudoku	ISC2011 Qualifier, Spring	search/label/Consecutive%20Sudoku	consecutivo
Fiver Sudoku	Qixi Festival (Give me 5)
Skyscraper Sudoku	Sudoku City :-)	search/label/Skyscraper%20Sudoku	skyscraper
Outside Sudoku	ISC2011 Qualifier, Fivefold	search/label/Outside%20Sudoku	outside
Odd Even View Sudoku	ISC2011 Finals		evenoddview

@ 2011-09-25 7:41 PM (#5684 - in reply to #5664) (#5684) Top

debmohanty

Country : India

debmohanty posted @ 2011-09-25 7:41 PM

Point changes for XV/Kropki, Consecutive/Fiver - Updated IB uploaded.

@ 2011-09-25 8:17 PM (#5685 - in reply to #5664) (#5685) Top

akash.doulani

Posts: 157

Country : India

akash.doulani posted @ 2011-09-25 8:17 PM

JUST WANTED TO KNOW WHETHER WE CAN APPLY UNIQUENESS TEST FOR THE PUZZLES. IN THE 3RD EXAMPLE OF EVEN/SMALL NEIGHBOUR I CAME ACROSS SUCH SITUATION IN CELLS R2C1 R2C2 , R4C1 R4C2. I WASNT SURE WHETHER THE UNIQUENESS PRINCIPLE COULD BE APPLIED OR NOT. LATER AFTER SOLVING I FELT THAT IT COULD HAVE BEEN APPLIED. PLEASE CLARIFY

@ 2011-09-25 8:56 PM (#5686 - in reply to #5664) (#5686) Top

Ours brun

Posts: 148

Country : France

Ours brun posted @ 2011-09-25 8:56 PM

The general rule about uniqueness and variants is that you can apply it as long as no cell amongst the ones you are dealing with can be affected by the additional rule(s) of this variant. I can't say more about this particular puzzle but I advise you to be very careful when applying unicity to variants.

@ 2011-09-25 9:20 PM (#5687 - in reply to #5664) (#5687) Top

Ours brun

Posts: 148

Country : France

Ours brun posted @ 2011-09-25 9:20 PM

Well, I just solved the puzzle but never got in the situation you describe, so I will just examine an hypothetical case. Let's say (all this happening before you determine which is the correct rule) you have R2C1/R2C2=39 and R4C1/R4C2=359. It is tempting to say that either R4C1 or R4C2 contains a 5, but it is a wrong assertion. Indeed, there is one cell (R2C1) which can be affected by the "small neighbours" rule, so you could perfectly have a unique rectangle 39/39/39/39. If it happens that the rule is the one of "small neighbours", then there cannot be a 9 in R2C1 and the unique rectangle is broken.

I hope I made it clear enough, I wrote this a bit in a hurry.

@ 2011-09-25 9:29 PM (#5688 - in reply to #5687) (#5688) Top

debmohanty

Country : India

debmohanty posted @ 2011-09-25 9:29 PM

Thanks Bastien for clarifying. Even I didn't catch the situation Akash is describing.

As-is, it is little dangerous to apply unique rectangle to variants. In this test with 2-rules, it is probably little early if you apply unique rectangle before 'determining' the correct rule.

@Akash, to specifically answer if you can apply uniqueness rule, all I can say is all sudokus are designed to have unique solutions :-)

One side note on examples : the difficulty of examples vary a lot, and has nothing to do with difficulty of actual puzzles

@ 2011-09-25 10:39 PM (#5690 - in reply to #5664) (#5690) Top

euklid

Posts: 28

Country : Austria

euklid posted @ 2011-09-25 10:39 PM

With Sum10/Multiple, are all black marks given?
I.e., is it possible in Sum10 that two neighboring numbers sum up to 10 and have no black square between them?
Is it possible for Multiple Sudoku that two neighboring numbers are a multiple of each others but have no black square between them?

@ 2011-09-25 11:44 PM (#5692 - in reply to #5690) (#5692) Top

debmohanty

Country : India

debmohanty posted @ 2011-09-25 11:44 PM

euklid - 2011-09-25 10:39 PM

With Sum10/Multiple, are all black marks given?
I.e., is it possible in Sum10 that two neighboring numbers sum up to 10 and have no black square between them?
Is it possible for Multiple Sudoku that two neighboring numbers are a multiple of each others but have no black square between them?

All black marks are not given. So converse rule does not apply.

Edited by debmohanty 2011-09-25 11:44 PM

@ 2011-09-26 11:09 AM (#5706 - in reply to #5664) (#5706) Top

akash.doulani

Posts: 157

Country : India

akash.doulani posted @ 2011-09-26 11:09 AM

@deb and bastien. thanks a lot for clarifying my doubts.

@ 2011-09-27 11:47 PM (#5707 - in reply to #5664) (#5707) Top

TiiT

Posts: 139

Country : Estonia

TiiT posted @ 2011-09-27 11:47 PM

Is there a double solution in Greater/Lesser sudoku in Instruction Booklet? 7's & 8's in Box 6, 8 and 9.

@ 2011-09-28 1:01 AM (#5708 - in reply to #5707) (#5708) Top

caudmont

Posts: 18

Country : France

caudmont posted @ 2011-09-28 1:01 AM

TiiT - 2011-09-27 11:47 PM

Is there a double solution in Greater/Lesser sudoku in Instruction Booklet? 7's & 8's in Box 6, 8 and 9.

Not for me because of the 7 between L8C3 et L8C4.

@ 2011-09-28 10:55 AM (#5709 - in reply to #5664) (#5709) Top

TiiT

Posts: 139

Country : Estonia

TiiT posted @ 2011-09-28 10:55 AM

OH ok, now I understand the rules. I think. I got it wrong first. I should always read all the rules more carefully.

@ 2011-09-28 3:34 PM (#5711 - in reply to #5664) (#5711) Top

debmohanty

Country : India

debmohanty posted @ 2011-09-28 3:34 PM

All examples can now be solved online in the submission page ( http://logicmastersindia.com/M201110S/ )

@ 2011-09-28 7:53 PM (#5712 - in reply to #5664) (#5712) Top

debmohanty

Country : India

debmohanty posted @ 2011-09-28 7:53 PM

While testing the sudokus, Rakesh asked me if it is allowed make 2 copies of the booklet. I didn't answer his question, but I think he printed only a single copy.
There is discussion in sudokuvariante forum that one of the strategy could be printing 2 copies, and solving using different rules on separate copies.

The reasons I'm bringing it up here is
1) I want to make sure that everyone knows that this is a strategy that some player might want to follow
2) More importantly, I feel, just like an offline competition where only one set of printout is allowed, one should use only one set of printout for this test.
3) Most importantly, without revealing much about what to expect in actual sudokus, I can say that printing two copies will not help one solving faster.

Edited by debmohanty 2011-09-28 7:54 PM

@ 2011-09-30 11:00 PM (#5715 - in reply to #5664) (#5715) Top

Administrator

Country : India

Administrator posted @ 2011-09-30 11:00 PM

Announcements

1) Bonus points

So, click on "Claim Bonus" as soon as you think you are done.

2) Sudoku Booklet

3) Read the instruction booklet carefully

4) Score page

http://logicmastersindia.com/M201110S/score.asp

~~The score page will not show bonus points until the test is over~~

@ 2011-10-01 6:42 AM (#5717 - in reply to #5712) (#5717) Top

Fred76

Posts: 337

Country : Switzerland

Fred76 posted @ 2011-10-01 6:42 AM

debmohanty - 2011-09-28 7:53 PM

While testing the sudokus, Rakesh asked me if it is allowed make 2 copies of the booklet. I didn't answer his question, but I think he printed only a single copy.
There is discussion in sudokuvariante forum that one of the strategy could be printing 2 copies, and solving using different rules on separate copies.

The reasons I'm bringing it up here is
1) I want to make sure that everyone knows that this is a strategy that some player might want to follow
2) More importantly, I feel, just like an offline competition where only one set of printout is allowed, one should use only one set of printout for this test.
3) Most importantly, without revealing much about what to expect in actual sudokus, I can say that printing two copies will not help one solving faster.

I read this on Hideaki Jo's blog first. I'm not sure I understood well, because I'm not a specialist of japanese translation

. I thought it was an interesting point, so I report this on my forum. Thanks for clarifying (and for reading sudokuvariante

) !

Fred

@ 2011-10-01 6:46 AM (#5718 - in reply to #5717) (#5718) Top

debmohanty

Country : India

debmohanty posted @ 2011-10-01 6:46 AM

Fred76 - 2011-10-01 6:42 AM

I thought it was an interesting point, so I report this on my forum. !

Precisely the same reason I posted in this forum :-) and my French is probably as good as your Japanese

Edited by debmohanty 2011-10-01 6:47 AM

@ 2011-10-01 12:52 PM (#5721 - in reply to #5664) (#5721) Top

debmohanty

Country : India

debmohanty posted @ 2011-10-01 12:52 PM

Attention :
If you are solving online, you need not submit again using paper mode. It consumes time and error prone.

@ 2011-10-02 2:39 AM (#5723 - in reply to #5664) (#5723) Top

motris

Posts: 199

Country : United States

motris posted @ 2011-10-02 2:39 AM

Excellent puzzles. Thanks for the fun test!

@ 2011-10-02 12:10 PM (#5724 - in reply to #5675) (#5724) Top

davep

Posts: 43

Country : United States

davep posted @ 2011-10-02 12:10 PM

Deb - Really well done, nice set of puzzles. Enjoyed it! Cheers, Dave