Questions about Sudoku puzzles!?

Question

Does anybody know: 1] How they know they have given enough of the numbers that you can solve the puzzle? 2] How do they determine the difficulty levels? Is there some kind of computer program that determines this?

Thanks!

Answer 1

the nubers can be in any order for the game to work but they cant disobey the rules.... they must also provide enough info for the puzzle to be sovlable....so they have to test it........they rate how hard the puzzle is by....either 1 doing it and rating it personally....2 rate its difficulty by the numbers provided at the beginning....notice how advanced puzzles may have 5 numbers at the beginning and a beginners puzzle normally has like 12