I have been trying to create sudoku puzzles with the computer and am having difficulty trying to seperate the easy to hard resulting puzzles.
What I know:
The puzzles are not randomly generated, and have certain dependencies with the row, column and box numbers.
The amount of starting numbers is somewhat proportional with the difficulty level.
Any complete puzzle row can be switched with any other puzzle row as long as the switch takes place within the confines of a any boxes 3 rows. The same applies to the columns.
How important is the location of the blank cells?
How do the experts create the puzzles?
What is the algorithm that takes care of the dependicies?