Introduction - If you have any usage issues, please Google them yourself
Sudoku a) the design of a command-line interface of the game, log into the game interface, there should be rules of the game description, key instructions.
b) prior to entering the game should have difficulty options: 1 means simple, 2 for moderate, 3 for difficulty.
c) There can be recycled input Sudoku value, you can continuously play several bureau until you exit the game the main interface, test results, see the answer, features a newly opened office.
d) Information prompts: input error when prompted, the game fails or gets victory should have celebrated interface.