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.

思路：

思路很简单，只要检查每行、每列、每个子区域中没有重复的数字即可。

代码：

    bool isValidSudoku(vector<vector<char> > &board) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
        map<char, int> table;
        for(int i = 0; i < 9; i++){
            table.clear();
            for(int j = 0; j < 9; j++){
                if(board[i][j] != '.'){
                    if(table.find(board[i][j]) != table.end())
                        return false;
                    else
                        table[board[i][j]] = 1;
                }
            }
        }
        for(int i = 0; i < 9; i++){
            table.clear();
            for(int j = 0; j < 9; j++){
                if(board[j][i] != '.'){
                    if(table.find(board[j][i]) != table.end())
                        return false;
                    else
                        table[board[j][i]] = 1;
                }
            }
        }
        for(int i = 0; i < 9; i++){
            table.clear();
            for(int j = 0; j < 3; j++){
                for(int k = 0; k < 3; k++){
                    if(board[3*(i/3)+j][3*(i%3)+k] != '.'){
                        if(table.find(board[3*(i/3)+j][3*(i%3)+k]) != table.end())
                            return false;
                        else
                            table[board[3*(i/3)+j][3*(i%3)+k]] = 1;
                    }
                }
            }
        }
        return true;
    }