shuziyouxi

代码说明：

  　在数独高手的规则是要将9个数字填入一个9个小九宫格组成的9×9格子里。使得每一行，每一列和每个小九宫格里都有1－9的数字，并且每个数字在它所在的行、列以及每个小九宫格里面都只出现唯一一次。(Sudoku expert in the rules is to fill a 9 digit composed of nine small squares 9 × 9 grid yard. So that each row, each column and each have 1-9 small squares in the figures, and each figure in its row, column, and each small squares appear only inside the only time.)