homeWelcome, sign in or click here to subscribe.login
     


 

 

News


Subscriber content preview

May 29, 2009

Strange But True!

Q. You Sudoku savants, could every person on Earth be given a different puzzle to work?

A. There are 5,472,730,538 fundamentally distinct 9-by-9 Sudoku grids, less than the global population, says computer science professor Jean-Paul Delahaye. However, from each of these grids a vast number of others can be derived by various elementary operations, such as swapping two rows or columns or systematically replacing each number with some other (1 becomes 2, 2 becomes 7, and so on). The resulting number of different grids approaches 7 sextillion (7 followed by 21 zeros), enough for everyone everywhere to be given more than a trillion (12 zeros) personal puzzles!


 
. . .


To read this story in full login or purchase a subscription.



Previous columns:



Email or user name:
Password:
 
Forgot password? Click here.