LeetCode.36.Valid Sudoku

原題鏈接：Valid Sudoku

題目內容：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.
這裏不需要驗證是否有解，只要符合數獨的規則就可以。

---

C++

class Solution {
public:
    bool isValidSudoku(vector<vector<char>>& board) {
        int i,j,k,l,row[10], col[10], grid[10];  
        if(board.size()!=9 || board[0].size()!=9)return false;  
        for(i=0;i<9;i++){
            memset(row,0,sizeof(row));
            for(j=0;j<9;j++){  
                if(board[i][j]=='.')continue;  
                if(board[i][j]<'0' || board[i][j]>'9')return false;  
                int num=board[i][j]-'0';  
                if(row[num])return false;  
                row[num]=true; 
            }  
        }  
        for(i=0;i<9;i++){
            memset(col,0,sizeof(col));  
            for(j=0;j<9;j++){  
                if(board[j][i]=='.')continue;  
                if(board[j][i]<'0' || board[j][i]>'9')return false;  
                int num=board[j][i]-'0';  
                if(col[num])return false;  
                col[num]=true;  
            }  
        }  
        for(i=0;i<3;i++){  
            for(j=0;j<3;j++){ 
                memset(grid,0,sizeof(grid));  
                for(k=i*3;k<i*3+3;k++){  
                    for(l=j*3;l<j*3+3;l++){  
                        if(board[k][l]=='.')continue;  
                        int num=board[k][l]-'0';  
                        if(grid[num])return false;  
                        grid[num]=true;  
                    }  
                }  
            }  
        }  
        return true;   
    }
};

python

class Solution(object):
    def isValidSudoku(self, board):
        """
        :type board: List[List[str]]
        :rtype: bool
        """
        seen = []
        for pos_r, row in enumerate(board):
            for pos_c, value in enumerate(row):
                if value != '.':
                    seen += [(value,pos_c),(pos_r,value),(pos_r/3,pos_c/3,value)]
        return len(seen) == len(set(seen))