Rule of sudoku
Sudoku, also called Number Place, is a logic-based number-placement puzzle. A problem of sudoku puzzle is made of 9x9 grid with digits from 1 to 9 partially filled as in the following figure.
Objective of the sudoku is to fill in the blank cells with numbers 1 to 9, so that each row, column, and box (3x3 subgrids as indicated in bold lines in the figure) contains all of the digits from 1 to 9.
Solution of the above puzzle is as follows. Please confirm that the condition is satisfied.
Sudoku puzzle should have a unique solution.
The above mentioned rule is a standard sudoku rule adopted in Kaidoku program. There are many variant of the rule. For detail, please refer to