备注： The word Sudoku means "numbers singly" in Japanese, which is a logic-based placement puzzle. The object of the puzzle is to enter a number, usually from 1 through 9, in each cell of a grid, most frequently a 9x9 grid made up of 3x3 sub grids (called "regions"), starting with various numerals given in some cells ( the "givens"). Each row, column and region must contain only one instance of each numeral. Completing the puzzle requires patience and logical ability.
