leetcode36 Valid Sudoku

 1 """
 2 Determine if a 9x9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules:
 3     Each row must contain the digits 1-9 without repetition.
 4     Each column must contain the digits 1-9 without repetition.
 5     Each of the 9 3x3 sub-boxes of the grid must contain the digits 1-9 without repetition.
 6 A partially filled sudoku which is valid.
 7 The Sudoku board could be partially filled, where empty cells are filled with the character '.'.
 8 Example 1:
 9 Input:
10 [
11   ["5","3",".",".","7",".",".",".","."],
12   ["6",".",".","1","9","5",".",".","."],
13   [".","9","8",".",".",".",".","6","."],
14   ["8",".",".",".","6",".",".",".","3"],
15   ["4",".",".","8",".","3",".",".","1"],
16   ["7",".",".",".","2",".",".",".","6"],
17   [".","6",".",".",".",".","2","8","."],
18   [".",".",".","4","1","9",".",".","5"],
19   [".",".",".",".","8",".",".","7","9"]
20 ]
21 Output: true
22 Example 2:
23 Input:
24 [
25   ["8","3",".",".","7",".",".",".","."],
26   ["6",".",".","1","9","5",".",".","."],
27   [".","9","8",".",".",".",".","6","."],
28   ["8",".",".",".","6",".",".",".","3"],
29   ["4",".",".","8",".","3",".",".","1"],
30   ["7",".",".",".","2",".",".",".","6"],
31   [".","6",".",".",".",".","2","8","."],
32   [".",".",".","4","1","9",".",".","5"],
33   [".",".",".",".","8",".",".","7","9"]
34 ]
35 Output: false
36 Explanation: Same as Example 1, except with the 5 in the top left corner being
37     modified to 8. Since there are two 8's in the top left 3x3 sub-box, it is invalid.
38 """
39 """
40 很考验python功底的一道题
41 """
42 class Solution:
43     def isValidSudoku(self, board):
44         for num1 in board:
45             if not self.isRep(num1):
46                 return False
47         for col in zip(*board):  # ！！！矩阵的转置
48             if not self.isRep(col):
49                 return False
50         for i in (0, 3, 6):
51             for j in (0, 3, 6):
52                 square = [board[x][y] for x in range(i, i + 3) for y in range(j, j + 3)]
53                 if not self.isRep(square):
54                     return False
55         return True
56 
57     def isRep(self, unit):
58         unit = [i for i in unit if i != '.']
59         return len(set(unit)) == len(unit)  # ！！！判断数组中有无重复值得方法。set