Sudoku is the addictive number puzzle game that has taken the UK by storm and is now taking over the rest of the world. It is branded by many as the "hottest puzzle since the Rubiks Cube". Studies show that playing Sudoku can improve memory, mind clarity, and even stop and prevent brain illnesses such as Alzheimer and Parkinson. Therefore there are some scientists & researchers recommending playing Sudoku, as part of our regular daily activity. And the rule is as follows: fill in the grid so that every row, every column and every 3 x 3 box contains the digits l to 9, and there is no any repeat number for each row and column.