The New Sudoku Players' Forum

[Hadian]

I found a site which does not propose a grid but which résoud instantaneously statements that one proposes. http://www.i2i.fr/en/ It finds a solution even for grids empty or incomplete. I makes use of it amongst other things to check my grids finished. How a waiter can solve in one second of the statements known as difficult or diabolic? Hadrian.