[LeetCode]题解（python）：036-Valid Sudoku

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题目来源

https://leetcode.com/problems/valid-sudoku/

etermine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules.

The Sudoku board could be partially filled, where empty cells are filled with the character '.'. A valid Sudoku board (partially filled) is not necessarily solvable. Only the filled cells need to be validated.

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题意分析
Input: a list means the sudoku with each element in the list is a str

Output:True or False

Conditions:看已有的数字是否满足数独的条件（每行、列、小九方格不能一样的数字）

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题目思路

此题是判断已有的矩阵块是否为有效的数独组，分别遍历每一行，每一列，每一个小九方格即可，注意下标范围

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AC代码（Python）

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 _author_ = "YE"
 # -*- coding:utf-8 -*-
 class Solution(object):
     def verifyRow(self, board):
         for i in range(9):
             L = []
             for j in range(9):
                 if board[i][j] == '.':
                     continue
                 elif board[i][j] in L:
                     return False
                 else:
                     L.append(board[i][j])
         return True

     def verifyColumn(self, board):
         for j in range(9):
             L = []
             for i in range(9):
                 if board[i][j] == '.':
                     continue
                 elif board[i][j] in L:
                     return False
                 else:
                     L.append(board[i][j])
         return True

     def verifySquare(self, board):
         for i in range(3):
             for j in range(3):
                 L = []
                 for k in range(3):
                     for x in range(3):
                         if board[3 * i + k][3 * j + x] == '.':
                             continue
                         elif board[3 * i + k][3 * j + x] in L:
                             return False
                         else:
                             L.append(board[3 * i + k][3 * j + x])
         return True

     def isValidSudoku(self, board):
         """
         :type board: List[List[str]]
         :rtype: bool
         """
         numbers = len(board[0])
         print(numbers)

         # print('row:',self.verifyRow(board))
         if not self.verifyRow(board):
             return False
         # print('column:',self.verifyColumn(board))
         if not self.verifyColumn(board):
             return False
         # print('square:',self.verifySquare(board))
         if not self.verifySquare(board):
             return False

         return True

 #test code
 s = Solution()
 board = [".87654321","2........","3........","4........","5........","6........","7........","8........","9........"]
 print(s.isValidSudoku(board))