36. Valid Sudoku

解題思路

分成 row, column 以及九個 box，個別計算。 

程式碼

class Solution {
public:
    bool isValidSudoku(vector<vector<char>>& board) {
        int row[9][10] = {0}, col[9][10] = {0}, box[9][10] = {0};
        for(int i=0; i<9; i++)
        {
            for(int j=0; j<9; j++)
            {
                if(board[i][j] == '.') continue;
                row[i][board[i][j] - '0']++;
                col[j][board[i][j] - '0']++;
                box[i/3*3 + j/3][board[i][j] - '0']++;
                if(row[i][board[i][j] - '0'] > 1 || col[j][board[i][j] - '0'] > 1 || box[i/3*3 + j/3][board[i][j] - '0'] > 1)
                {
                    cout << row[i] << " " << col[j] << " " << box[i/3*3 + j/3] << endl;
                    return false;
                }    
            }
        }
        return true;
    }
};