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