Henry Sudoku

aman · Posted: Thu Apr 05, 2007 12:03 am Post subject: Henry Sudoku

Some of my old dusty sudoku creations from the British math educational NRICH website were used in the recent Second World Sudoku Championship 2007 in Prague:

1. Ratio Sudoku

http://nrich.maths.org.uk/public/viewer.php?obj_id=4827&part=index&refpage=monthindex.php

2. Intersection Product Sudoku

http://nrich.maths.org.uk/public/viewer.php?obj_id=4903&part=index&refpage=monthindex.php

3. Intersection Sums Sudoku

http://nrich.maths.org.uk/public/viewer.php?obj_id=5018&part=index&refpage=monthindex.php

4. Pole Star Sudoku

http://nrich.maths.org.uk/public/viewer.php?obj_id=5433&part=index&refpage=monthindex.php

5. Twin Corresponding Sudokus

http://nrich.maths.org.uk/public/viewer.php?obj_id=5477&part=index&refpage=monthindex.php

6. Integrated Sums Sudoku

http://nrich.maths.org.uk/public/viewer.php?obj_id=5571&part=index&refpage=monthindex.php

7. Integrated Product Sudoku

http://nrich.maths.org.uk/public/viewer.php?obj_id=5596&part=index&refpage=monthindex.php

aman · Posted: Sun Jul 29, 2007 11:25 pm Post subject:

Finally, in order to complete the series, three versions of my variants from the Age of Puzzles website had been used in the Second World Sudoku Championship 2007 at Prague:

8. Duplex Sums Sudoku

http://www.ageofpuzzles.com/Collections/DuplexSumsSudoku/DuplexSumsSudoku.htm

9. Duplex Plex Sudoku

http://www.ageofpuzzles.com/Collections/DuplexPlexSudoku/DuplexPlexSudoku.htm

10. Quadruple Clue Sudoku

http://www.ageofpuzzles.com/Collections/QuadrupleClueSudoku/QuadrupleClueSudoku.htm

The last variant was also used in the Italian National Sudoku Championship 2007.

Please refer to the website http://www.nonzero.it/pdf/indizi.pdf where the variant is called "sudoku a indizi" in Italian.

aman · Posted: Fri Nov 02, 2007 7:37 pm Post subject:

My second Pole Star Sudoku variant (Differenzen-Sudoku in German) was published on the NRICH website http://nrich.maths.org/public/viewer.php?rss=1&obj_id=5724&part=index in August 2007.

Another Quadruple Clue Sudoku was published in September 2007 by NRICH http://nrich.maths.org/public/viewer.php?obj_id=5797

The first difference sudoku, Duplex Difference Sudoku (Duplex-Differenzen-Sudoku in German), was published in March 2006 by issue No 38 of Plus magazine http://plus.maths.org/issue38/puzzle/index.html

It uses more than one inequality signs as additional clues for solving the puzzle.

Minimal Difference Sudoku was published in October 2007 by NRICH http://nrich.maths.org/public/viewer.php?obj_id=5798

It uses only a single inequality sign as additional aid for getting the solution.

aman · Posted: Sat Dec 01, 2007 7:21 pm Post subject:

NRICH has created a beautiful graphic called the "Advent Calendar" on the web page http://nrich.maths.org/content/id/5905/calendar.swf for easy access to some of my past monthly Sudoku puzzles in the run-up to Christmas.

aman · Posted: Sat Dec 29, 2007 11:36 am Post subject:

I have created the first ever sudoku that requires an additional clue from a story for obtaining the solution to the puzzle. I have named my new sudoku variant "Story Sudoku".

I have posted it together with my fairy tale entitled "Fictusia" on Dr Sam Guo's website http://www.chinasudoku.com/

For those readers who like stories and sudoku variants, they will find something new and refreshing in "Story Sudoku".

aman · Posted: Sun Dec 30, 2007 5:23 pm Post subject:

My new sudoku variant, "Colour Islands Sudoku", is posted on the website http://www.ageofpuzzles.com/Collections/ColorIslandsSudoku/ColorIslandsSudoku.htm

The variant is based in part on the rules of my two board games "Henry's Houses" and "Pseudo-Go" that are sold on-line by Kadon Enterprise http://www.gamepuzzles.com/pseudocoup.htm

The rule of both board games: "No two pieces of the same colour (or number) may be next to each other in any direction -- horizontally, vertically or diagonally. Each piece must be next to all-different colours (or numbers), different from itself and different from each other. Every fully filled 3x3 area will contain 9 different colours (or numbers)."

aman · Posted: Tue Jan 01, 2008 3:56 am Post subject:

My creation "Twin Equivalent Sudoku" is posted on the Jan 2008 NRICH website http://nrich.maths.org/public/viewer.php?rss=1&obj_id=5969&part=index

aman · Posted: Sat Jan 12, 2008 9:07 pm Post subject:

Since my "Story Sudoku" is related to the difference sudoku, I take the opportunity here to make a few comments on this special variant.

As the difference sudoku has the peculiar characteristic of having two sets of solution, I jokingly called it "Blindfold Sudoku" in my article on "Corresponding Sudokus" on the NRICH website http://nrich.maths.org/public/viewer.php?obj_id=5439

I published my first difference sudoku, called Duplex Difference Sudoku (Duplex-Differenzen-Sudoku in German), in March 2006 in the issue No 38 of Plus magazine http://plus.maths.org/issue38/puzzle/index.html

The answer of that puzzle was "fixed" by the symbols 1> and 1<.

The former symbol means the answer in the cell on the left is 1 greater in value than the answer in the cell on the right. Similarly, the symbol 1< indicates that the answer in the cell on the left is 1 less than the answer in the cell on the right.

I could not find any other differerence sudoku on the web until somebody came out with another variation five months later -- in August 2006.

Later on -- in October 2007 -- I "fixed" the answer of the difference sudoku with a single inequality sign instead of multiple inequality signs. This was what I had done with another variant called Minimal Difference Sudoku in October 2007 NRICH http://nrich.maths.org/public/viewer.php?obj_id=5798

The answer of a difference sudoku can also be "fixed" with a single digit in a cell, as what I had done with a variant called "Pole Star Sudoku". There are two such examples on the NRICH website:

http://nrich.maths.org/public/viewer.php?obj_id=5433&part=index&refpage=monthindex.php

http://nrich.maths.org/public/viewer.php?obj_id=5724

Another way to "fix" the answer, as what I had done in a variant called "Constellation Sudoku", is to use a set of starting numbers (a number per star) to fill up some cells containing stars. My first example of such variant was published on the May 2007 NRICH website http://nrich.maths.org/public/viewer.php?rss=1&obj_id=5630&part=index

The same variant was first published as one of the "Puzzles to be solved in Prague -- Good practise" for the Second World Sudoku Championship 2007 on the website http://www.sudoku07.com/main/Puzzles.pdf

My second "Constellation Sudoku" was withdrawn from the Second World Sudoku Championship 2007 at Prague due to longer time required to solve it. It was later published on the website http://www.ageofpuzzles.com/Collections/ConstellationSudoku/ConstellationSudoku.htm

And finally in the "Story Sudoku", I used a clue in a fairy tale to fix the answer of the difference sudoku.

aman · Posted: Fri Feb 01, 2008 1:48 am Post subject:

Another new original creation of mine called "Equation Sudoku" on the Feb 2008 NRICH website http://nrich.maths.org/public/viewer.php?obj_id=5970

aman · Posted: Mon Mar 03, 2008 6:32 am Post subject:

One more original creation of mine called "LCM Sudoku" on the NRICH website http://nrich.maths.org/public/viewer.php?rss=1&obj_id=6018&part=index

aman · Posted: Tue Apr 01, 2008 3:47 am Post subject:

My sudoku variant called "All-variables Sudoku" published in April on NRICH website http://nrich.maths.org/public/viewer.php?rss=1&obj_id=6019&part=index

aman · Posted: Mon Aug 11, 2008 10:32 am Post subject:

Please refer to the link http://nrich.maths.org/public/viewer.php?rss=1&obj_id=6224&part=index to have a look at my latest sudoku creation for this month (August) -- Multiplication Equation Sudoku.

aman · Posted: Tue Sep 02, 2008 5:38 pm Post subject:

1. My sudoku variant for this month (September) in http://nrich.maths.org/public/viewer.phprss=1&obj_id=6225&part=index is the Quadruple Clue Sudoku.

2. Other sudoku variants published in the past few months were:

i. Colour Islands Sudoku
in the July issue of http://nrich.maths.org/public/viewer.php?obj_id=6179

ii. Quadruple Clue Sudoku
in the June issue of http://nrich.maths.org/public/viewer.php?obj_id=6113

iii. Twin Corresponding Sudokus
in the May issue of http://nrich.maths.org/public/viewer.php?obj_id=6087

3. Some of my sudoku variants were used in the Czech National Sudoku Championship 2008.

aman · Posted: Sat Oct 04, 2008 6:17 pm Post subject:

My sudoku creation for the October 2008 edition of NRICH in http://nrich.maths.org/public/viewer.php?rss=1&obj_id=6310&part=index is the Addition Equation Sudoku.

aman · Posted: Thu Nov 06, 2008 1:13 pm Post subject:

My sudoku creation for this month (November 2008) in http://nrich.maths.org/public/viewer.php?rss=1&obj_id=6311&part=index is called the "LCM Sudoku".

For the first time, NRICH uses the creative and innovative idea of flash interactivity for its puzzles.

My first version of "LCM Sudoku" in an earlier issue of NRICH in the link http://nrich.maths.org/public/viewer.php?obj_id=6018 used unknown variables and numbers.

To be more specific, that variant should be called "Algebraic LCM Sudoku".