[leetcode] Valid Sudoku

Valid Sudoku

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.

 1 class Solution
 2 {
 3 public:
 4   bool isValidSudoku(vector<vector<char> > &board)
 5   {
 6     int i = 0, j = 0;
 7     map<char, int> count;
 8     
 9     //判断行是否合法
10     for(i = 0; i < 9; i++)
11     {
12       count.clear();
13       for(j = 0; j < 9; j++)
14       {
15         count[board[i][j]]++;
16         if(count[board[i][j]] > 1 && board[i][j] != '.')
17           return false;
18       }
19     }
20 
21     //判断列是否合法
22     for(i = 0; i < 9; i++)
23     {
24       count.clear();
25       for(j = 0; j < 9; j++)
26       {
27         count[board[j][i]]++;
28         if(count[board[j][i]] > 1 && board[j][i] != '.')
29           return false;
30       }
31     }
32 
33     // 判断九个小方块是否合法
34     for(i = 0; i < 9; i = i+3)
35     {
36       for(j = 0; j < 9; j = j+3)
37       {
38         count.clear();
39         for(int m = 0; m < 3; m++)
40         {
41           for(int n = 0; n < 3; n++)
42           {
43             count[board[i + m][j + n]]++;
44             if(count[board[i + m][j + n]] > 1 && board[i + m][j + n] != '.')
45               return false;
46           }
47         }
48       }
49     }
50 
51     return true;
52   }
53 };