Thread - Prime Exotica - LMI Jan 2011 Sudoku Test

@ 2011-01-12 4:03 PM (#3146) (#3146) Top

Administrator

Country : India

Administrator posted @ 2011-01-12 4:03 PM

Logic Masters India announces January 2011 Sudoku Test — Prime Exotica

Author: Rakesh Rai

Date: 22-23 January 2011

Sudoku Types: This test focuses on prime numbers and a few exotic variants.

Length: 101 minutes

IB and Submission Link

Instructions in Chinese - http://www.sudokufans.org.cn/forums/index.php?showtopic=195

@ 2011-01-13 10:29 AM (#3152 - in reply to #3146) (#3152) Top

rakesh_rai

Posts: 774

Country : India

rakesh_rai posted @ 2011-01-13 10:29 AM

Sudoku Types in Prime Exotica:

DNA Sudoku

MultiTab Sudoku

Poker Sudoku

Quad Sudoku

Tennisdoku

Kid Sudoku

Numerologidoku

Prime Number Sudoku

Rhombus Sudoku

Kombinance Sudoku

Peephole Sudoku

Product Sudoku

Rossini Sudoku

@ 2011-01-13 5:24 PM (#3155 - in reply to #3146) (#3155) Top

neerajmehrotra

Posts: 329

Country : India

neerajmehrotra posted @ 2011-01-13 5:24 PM

As per IB The sum of all corresponding numbers in the two strands is 10. But I think 10 is not possible in case of 6X6 grid............please confirm.

@ 2011-01-13 5:40 PM (#3156 - in reply to #3155) (#3156) Top

Fred76

Posts: 337

Country : Switzerland

Fred76 posted @ 2011-01-13 5:40 PM

neerajmehrotra - 2011-01-13 5:24 PM

As per IB The sum of all corresponding numbers in the two strands is 10. But I think 10 is not possible in case of 6X6 grid............please confirm.

I think Rakesh forgot to mention that for the DNA sudoku, 6*6 grid in the booklet: The sum of all corresponding numbers in the two strands is 6.

For tournament grid, sum is 10 but for IB grid, sum is 6

Fred

@ 2011-01-13 7:31 PM (#3157 - in reply to #3156) (#3157) Top

rakesh_rai

Posts: 774

Country : India

rakesh_rai posted @ 2011-01-13 7:31 PM

Fred76 - 2011-01-13 5:40 PM

neerajmehrotra - 2011-01-13 5:24 PMAs per IB The sum of all corresponding numbers in the two strands is 10. But I think 10 is not possible in case of 6X6 grid............please confirm.

I think Rakesh forgot to mention that for the DNA sudoku, 6*6 grid in the booklet: The sum of all corresponding numbers in the two strands is 6.For tournament grid, sum is 10 but for IB grid, sum is 6

Fred

Thanks Fred.

A few things which got missed in the IB. This is only for the examples:
- For DNA sudoku, the sum of corresponding cells is 6.
- For Kid Sudoku, the kid cannot count or add beyond 6.
- For Quad sudoku, 6 and 1 are considered consecutive.
- For Poker Sudoku, there are only 2 hand types.

For the actual grids, the given rules in the IB apply.

@ 2011-01-13 8:10 PM (#3158 - in reply to #3157) (#3158) Top

Calavera

Posts: 13

Country : Germany

Calavera posted @ 2011-01-13 8:10 PM

I've spotted a small mistake in the example for the KID Sudoku: One of the 3s in the 5th row must be a 5. Haven't solved it yet so I'm not sure which.

Also I'm not completely sure about the MULTITAB Sudoku: Is the three digit number in a cage always on the right/bottom? And is the one digit number always to the left/top of the two digit number?

@ 2011-01-13 8:18 PM (#3159 - in reply to #3146) (#3159) Top

David McNeill

Posts: 63

Country : United Kingdom

David McNeill posted @ 2011-01-13 8:18 PM

Rakesh,

Looks like a great puzzle set. The clue for the 5th row in Kid Sudoku should be 46353. Will the strands in DNA Sudoku cross each other? If so, it would be helpful to make the colours more easily distinguishable on a black and white printer. I assume that the prime numbers in Prime Number Sudoku will not necessarily be of 3 digits. Loved your 2011 fact.

Thank you,

David McNeill.

@ 2011-01-13 8:23 PM (#3160 - in reply to #3158) (#3160) Top

rakesh_rai

Posts: 774

Country : India

rakesh_rai posted @ 2011-01-13 8:23 PM

Calavera - 2011-01-13 8:10 PMI've spotted a small mistake in the example for the KID Sudoku: One of the 3s in the 5th row must be a 5. Haven't solved it yet so I'm not sure which.

You are right. It is 46353.

Also I'm not completely sure about the MULTITAB Sudoku: Is the three digit number in a cage always on the right/bottom?

Yes.

And is the one digit number always to the left/top of the two digit number?

Not necessarily. There will be one 1-digit number and one 2-digit number, whose product will be a 3-digit number. From the grid it will be clear which comes first - the 2-digit number or the 1-digit number.

@ 2011-01-13 8:37 PM (#3163 - in reply to #3159) (#3163) Top

rakesh_rai

Posts: 774

Country : India

rakesh_rai posted @ 2011-01-13 8:37 PM

David McNeill - 2011-01-13 8:18 PM

Will the strands in DNA Sudoku cross each other?

No.

I assume that the prime numbers in Prime Number Sudoku will not necessarily be of 3 digits.

You are right. The prime numbers can be of any length from 1 to 9. :)

@ 2011-01-13 11:35 PM (#3164 - in reply to #3163) (#3164) Top

rakesh_rai

Posts: 774

Country : India

rakesh_rai posted @ 2011-01-13 11:35 PM

Updated IB based on comments above is now available for download.

@ 2011-01-14 2:20 AM (#3167 - in reply to #3146) (#3167) Top

caudmont

Posts: 18

Country : France

caudmont posted @ 2011-01-14 2:20 AM

DNA : would the sum of cell A in orange strand and the same cell A in blue strand equal 10 ?

Thanks

Edited by caudmont 2011-01-14 2:21 AM

@ 2011-01-14 9:47 AM (#3168 - in reply to #3167) (#3168) Top

rakesh_rai

Posts: 774

Country : India

rakesh_rai posted @ 2011-01-14 9:47 AM

caudmont - 2011-01-14 2:20 AM

DNA : would the sum of cell A in orange strand and the same cell A in blue strand equal 10 ?

That is a good question. I would repeat the relevant portion of the rules: "The sum of all corresponding numbers in the two strands is 10 (6 in the example)." - I hope you would have got your answer.

@ 2011-01-14 10:19 AM (#3169 - in reply to #3146) (#3169) Top

tamz29

Posts: 225

Country : Thailand

tamz29 posted @ 2011-01-14 10:19 AM

Hi
Looks like a wonderful test. I value presentation almost as much as the puzzle quality and this one may very well be the first to have both.
Hopefully, I come back on Sunday night in time for it.
Well done.

@ 2011-01-14 11:12 AM (#3170 - in reply to #3146) (#3170) Top

utkaarsh

Posts: 89

Country : India

utkaarsh posted @ 2011-01-14 11:12 AM

Rakesh, very very creative set of puzzles, with my limited knowledge, i found these the best & most innovative ones, very excited for this one

@ 2011-01-14 5:14 PM (#3171 - in reply to #3168) (#3171) Top

caudmont

Posts: 18

Country : France

caudmont posted @ 2011-01-14 5:14 PM

rakesh_rai - 2011-01-14 9:47 AM

caudmont - 2011-01-14 2:20 AM

DNA : would the sum of cell A in orange strand and the same cell A in blue strand equal 10 ?

Thanks

@ 2011-01-14 5:59 PM (#3173 - in reply to #3146) (#3173) Top

akash.doulani

Posts: 157

Country : India

akash.doulani posted @ 2011-01-14 5:59 PM

one question regarding tennisdoku. in a situation where the set is given as 1:0 , does the first number have to be greater than the second one or it could be both ways ?

@ 2011-01-14 6:10 PM (#3174 - in reply to #3173) (#3174) Top

rakesh_rai

Posts: 774

Country : India

rakesh_rai posted @ 2011-01-14 6:10 PM

akash.doulani - 2011-01-14 5:59 PMone question regarding tennisdoku. in a situation where the set is given as 1:0 , does the first number have to be greater than the second one or it could be both ways ?

Thanks for asking this question, Akash.

In a "x:y" situation, x is the number of sets won and y is the number of sets lost. So, a "1:0" means 1 set won and 0 sets lost. And a set can be won in many ways: 6-1, 6-2, 6-3, 6-4, 7-5, 7-6, 8-6 and 9-7. so the two cells in question will have one of these "final scores".

To answer your question precisely, the answer is Yes. For a "1:0" situation, the first number has to be greater than the second one. I hope this helps clarify your doubt.

@ 2011-01-14 8:07 PM (#3175 - in reply to #3146) (#3175) Top

purifire

Posts: 460

Country : India

purifire posted @ 2011-01-14 8:07 PM

Very Interesting sudokus... nice twists Rakesh... Looking forward to the test.... :)

ps. Thanks for letting me know my numerological number

Rishi

@ 2011-01-14 8:25 PM (#3176 - in reply to #3146) (#3176) Top

akash.doulani

Posts: 157

Country : India

akash.doulani posted @ 2011-01-14 8:25 PM

will the clues(i.e the numbers that appear in each type ) be given for poker sudoku or we will have to find out the numbers ourselves?

@ 2011-01-14 9:30 PM (#3177 - in reply to #3176) (#3177) Top

rakesh_rai

Posts: 774

Country : India

rakesh_rai posted @ 2011-01-14 9:30 PM

akash.doulani - 2011-01-14 8:25 PM

will the clues(i.e the numbers that appear in each type ) be given for poker sudoku or we will have to find out the numbers ourselves?

Akash: This is mentioned clearly in the IB.

"The repeating number in three of a kind/ four of a kind will be given. For full house, two numbers will be given, one of which will form a “pair” and the other will represent “three of a kind”. For Two pair, again two numbers will be given, both of which will form “pair”. For sequence, the first and last number will be given as clues."

So you do not have to find out the numbers. With the given clues, you'll probably need to find out which hand type will be on which line.

@ 2011-01-16 3:32 AM (#3180 - in reply to #3146) (#3180) Top

Para

Posts: 315

Country : The Netherlands

Para posted @ 2011-01-16 3:32 AM

For Prime Number sudoku, are we provided with a list of prime numbers made up of different digits? Because to be honest I don't know all prime numbers by head between 1 and 9 digits (I don't even know them past 2 digits), or be able to figure out if for example 7142957 (which is) or 7148563(which isn't) is a prime or not on the spot. Becaused the file I found to confirm if these numbers were or weren't, contains 1 million numbers. And I don't exactly feel like sorting through it to filter out all primes that only contain different digits, just for the sake of being able to solve the sudoku.

@ 2011-01-16 12:02 PM (#3182 - in reply to #3177) (#3182) Top

purifire

Posts: 460

Country : India

purifire posted @ 2011-01-16 12:02 PM

In the Numerologidoku, can the resultant number be flipped. as in example you mentioned that when I add up the letters I get 63. So is only 63 to be used or it can be flipped to 36?

Rishi

@ 2011-01-16 3:22 PM (#3185 - in reply to #3182) (#3185) Top

rakesh_rai

Posts: 774

Country : India

rakesh_rai posted @ 2011-01-16 3:22 PM

purifire - 2011-01-16 12:02 PM

In the Numerologidoku, can the resultant number be flipped. as in example you mentioned that when I add up the letters I get 63. So is only 63 to be used or it can be flipped to 36?

Rishi: Flipping is not allowed. (also because this is not the FLIP LMI Test

)

As mentioned in the IB, All “clue numbers” in the shaded cells read from left to right. - without flipping. So, if one of the clues is RISHI, we'll have to fill 63 in two consecutive shaded cells in the same row, reading left to right.

@ 2011-01-16 3:41 PM (#3186 - in reply to #3180) (#3186) Top

rakesh_rai

Posts: 774

Country : India

rakesh_rai posted @ 2011-01-16 3:41 PM

Para: I was expecting this query and I'm glad you asked it.

Para - 2011-01-16 3:32 AM

For Prime Number sudoku, are we provided with a list of prime numbers made up of different digits?

No.

Because to be honest I don't know all prime numbers by head between 1 and 9 digits (I don't even know them past 2 digits), or be able to figure out if for example 7142957 (which is) or 7148563(which isn't) is a prime or not on the spot. Because the file I found to confirm if these numbers were or weren't, contains 1 million numbers.

From the IB: "...prime numbers are like life. They are very logical but you could never work out the rules, even if you spend all your time thinking about them."
Anyway, Prime Exotica is not a test of memory. So its perfectly alright if you do not remember a list of prime numbers. However, there are a few basic techniques to find out if a number is not a prime number (for example, one such link is here). You may like to go through these once.

And I don't exactly feel like sorting through it to filter out all primes that only contain different digits, just for the sake of being able to solve the sudoku.

I agree with you. This is not needed anyway.

In my opinion, if you approach the puzzle with an open mind and only basic knowledge of prime numbers, you should be able to solve it.

@ 2011-01-17 11:43 AM (#3192 - in reply to #3186) (#3192) Top

rakesh_rai

Posts: 774

Country : India

rakesh_rai posted @ 2011-01-17 11:43 AM

A feature being tried out this time is that of "anonymous ratings". On the score page, the average rating and number of solvers who rated will still be visible. But A cannot see ratings given by B (and vice-versa).