SUDOKU - Just for fun!

On the launch of an application user is presented with three options: Easy, Medium and Hard. Easy has 30 numbers on board, medium has 50 and hard option will have only 20 numbers on board. Once the difficulty is selected user will be presented with a Sudoku board. Below the board there will be numbers which one can select to fill the blank spaces on the board. Note that only the correct number can be placed on the specific spot. Once the user fills all the blank spots on the board, means he has correctly solved the puzzle.