[leetcode]Valid Sudoku @ Python

原题地址：https://oj.leetcode.com/problems/valid-sudoku/

题意：

Determine 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 partially filled sudoku which is valid.

 

Note:
A valid Sudoku board (partially filled) is not necessarily solvable. Only the filled cells need to be validated.

解题思路：判断是否为合法的数独。

代码：

class Solution:

    # @param board, a 9x9 2D array

    # @return a boolean

    def isValidSudoku(self, board):

        def isValid(x, y, tmp):

            for i in range(9):

                if board[i][y]==tmp:return False

            for i in range(9):

                if board[x][i]==tmp:return False

            for i in range(3):

                for j in range(3):

                    if board[(x/3)*3+i][(y/3)*3+j]==tmp: return False

            return True

        for i in range(9):

            for j in range(9):

                if board[i][j]=='.':continue

                tmp=board[i][j]

                board[i][j]='D'

                if isValid(i,j,tmp)==False: return False

                else:

                    board[i][j]=tmp

        return True