Wikipedia:Reference desk/Archives/Mathematics/2013 July 25

= July 25 =

two digit sudoku and its answer
please arrange a two digit sudoku with numbers and also its answer — Preceding unsigned comment added by 202.83.50.219 (talk) 10:56, 25 July 2013 (UTC)


 * There is a general procedure for producing an $$n^2\times n^2$$ sudoku. In the first row, list the numbers 1 thru $$n^2$$ in order.  For the next n rows, cyclically permute the first row by blocks of n.  Then for row n+1 cyclically permute the first n slots of the first row, the second n slots of the first row, etc.  For row n+2, do this to the second row, and so on.  For instance, applying this procedure for a 9x9 sudoku gives
 * 123456789
 * 456789123
 * 789123456
 * 231564897
 * 564897231
 * 897231564
 * 312645978
 * 645978312
 * 978312645
 * It's left as an exercise how to do this, eg, for whatever two digit size you had in mind (16x16, 25x25, 81x81). (Note: this clearly will not generate all possible suduko's, even if you are allowed to change the labels, but you just asked for one.)   Sławomir Biały  (talk) 12:24, 25 July 2013 (UTC)
 * To be fair, that's "only" a solution. The question how many squares are needed to make a sudoku unique hasn't been attacked above.
 * Wildly WP:ORing, I'd say it looks like that par tof the problem would be NP (complexity).
 * I guess a two-digit sudoku is one with 10 to 99 different symbols, and if you want numbers, those would be two digits per square. That would be, 3 < n < 10. (n=10 is ok if, contravening usual sudoku conventions, all combinations from 00 to 99 are used.) - ¡Ouch! (hurt me / more pain) 16:36, 27 July 2013 (UTC)