LeetCode#36 Valid Sudoku

Problem Definition:

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.

Solution: 用仨字典，一次扫描，针对n x n 的Sudoku，时间复杂度O(n^2).

 1 def isValidSudoku( board ):
 2         col,row,block={},{},{}
 3         for i in range(9):
 4             for j in range(9):
 5                 if board[i][j]=='.':
 6                     continue
 7                 d=board[i][j]
 8                 T=row.get(str(i)+d,False)
 9                 if T:
10                     return False
11                 else:
12                     row[str(i)+d]=True
13                 T=col.get(str(j)+d,False)
14                 if T:
15                     return False
16                 else:
17                     col[str(j)+d]=True
18                 T=block.get(str((i/3)*3+j/3)+d,False)
19                 if T:
20                     return False
21                 else:
22                     block[str((i/3)*3+j/3)+d]=True
23         return True

 

 

 
 
posted @ 2015-07-24 20:18  曾可爱  阅读(131)  评论(0)  编辑  收藏  举报