[Kde-games-devel] Killer Sudoku / Mathdoku

[Ian Wadham]

Hi Richard,

On 06/04/2015, at 7:59 PM, Richard Llom wrote:
> Ian Wadham wrote:
>> On 25/03/2015, at 5:43 AM, Ronald Ellison wrote:
>>> 
>>> http://killersudokuonline.com/play.html?puzzle=D34b3vy2894&year=2013
>>> 
>>> This puzzle brings simple maths into Sudoku and I find it the most
>>> addictive of all.
>> 
>> I have done some Googling around re Killer Sudoku and I must say it does
>> pose an interesting design and programming challenge.  The problems are 
>> to find a Killer Sudoku generator, an accurate difficulty grader and a
>> Killer Sudoku solver.
>> 
> Actually "Killer" Soduko is just subset/variant of KenKen:
> https://en.wikipedia.org/wiki/KenKen
> Due to trademark issues this is often available as Mathdoku (which is also a 
> more fitting name, IMHO), e.g.
> https://play.google.com/store/apps/details?id=net.cactii.mathdoku
> This app is open source and the source is here:
> https://code.google.com/p/mathdoku/source/browse/

Thank you very much for this information, Richard.

Heh, heh, I always did want to learn Java… :-)

Re the relationships between Sudoku, Killer Sudoku and KenKen (which
I get in my daily newspaper): if I understand correctly, Killer Sudoku is not
a strict subset of KenKen, because Killer Sudoku has 3x3 boxes as well as
rows, columns and cages.  The three puzzles would be related by sets of
constraints.

Sudoku: Latin square 1-9, 3x3 boxes, clues to start with.
Killer Sudoku: Latin square 1-9, 3x3 boxes, additive cages, cages usually do not have duplicates.
KenKen: Latin square 1-n (n = 3 to 9[?]), cages with any operator, cages can have duplicates.

KenKen and Killer Sudoku can effectively have clues, as in Sudoku, if there
are some single-cell cages.

Please correct me if I am wrong about any of these rules.

KSudoku can handle many shapes and sizes of Sudoku, including 3-D.
And the constraints of each type of puzzle are data-driven from XML files.
So it should be relatively easy to add KenKen and Killer Sudoku layouts.
Also the Java code referred to in the link above has a puzzle generator
for Mathdoku (aka KenKen).  So there is plenty to chew on.

Killer Samurai Sudoku anyone?  Five overlapping 9x9 grids?

Thanks again, Richard.
Cheers, Ian W.