有效的数独

Python

class Solution:
    def isValidSudoku(self, board):
        Cell = [[] for i in range(9)]
        Col = [[] for i in range(9)]
        Row = [[] for i in range(9)]
        for i, row in enumerate(board):
            for j, num in enumerate(row):
                if num != '.':
                    k = (i//3)*3 + j//3  # //为整数除法，/为浮点除法
                    if num in Row[i] + Col[j] + Cell[k]:  # 将3个list顺序拼接
                        return False
                    Row[i].append(num)
                    Col[j].append(num)
                    Cell[k].append(num)
        return True

C++

class Solution
{
public:
    bool isValidSudoku(vector<vector<char>>& board)
    {
        if (board.empty() || board[0].empty()) return false;
        int m = board.size(), n = board[0].size();
        vector<vector<bool>> rowFlag(m, vector<bool>(n, false));
        vector<vector<bool>> colFlag(m, vector<bool>(n, false));
        vector<vector<bool>> cellFlag(m, vector<bool>(n, false));
        for (int i = 0; i < m; ++i) 
        {
            for (int j = 0; j < n; ++j) 
            {
                if (board[i][j] >= '1' && board[i][j] <= '9') 
                {
                    int c = board[i][j] - '1';
                    if (rowFlag[i][c] || colFlag[c][j] || cellFlag[3 * (i / 3) + j / 3][c]) return false;
                    rowFlag[i][c] = true;
                    colFlag[c][j] = true;
                    cellFlag[3 * (i / 3) + j / 3][c] = true;
                }
            }
        }
        return true;
    }
};