Andrew's Sudoku description

Sudoku game with three level of difficulty. All sudoku schemas were generated from a java application realized by the author. It is possible to play on hint modality, in such a case color of the cells will evidence where remains only a number to choice or where remains only few.
Easy level of difficulty consist in a initial schema with 27 numbers, medium difficulty schema consist in a initial schema of 25 numbers, at last hard difficulty consist in a initial schema of 23 numbers.