LeetCode OJ-- Valid Sudoku

https://oj.leetcode.com/problems/valid-sudoku/

给出数独的一部分来，验证给出的这一部分是否为 valid

行上无重复的，且是从 ‘1’ 到‘9’

列上无重复的，且是从 ‘1’ 到‘9’

小的3*3 无重复的，且是从 ‘1’ 到‘9’

class Solution {
public:
    bool isValidSudoku(vector<vector<char> > &board) {
        if(board.empty() || board.size() == 0)
            return false;
        
        // store the filled to map
        for(int i = 0; i < 9; i++)
        {
            for(int j = 0; j < 9; j++)
            {
                int times = 0; // record the same 
                
                // is num
                if(board[i][j] != '.')
                {
                    // from 1 to 9
                    if(!(board[i][j] >= '1' && board[i][j] <= '9'))
                        return false;
                        
                    // small cube
                    int ith = i / 3;
                    int jth = j / 3;
                    for(int p = 0; p < 3; p++)
                    {
                        for(int q = 0; q < 3; q++)
                        {
                            if(board[ith*3 + p][jth*3 + q] == board[i][j])
                                times++;
                        }
                    }
                    
                    for(int p = 0; p < 9; p++)
                    {
                        if(board[i][j] == board[i][p])
                            times++;
                        if(board[i][j] == board[p][j])
                            times++;
                    }
                    
                }
                if(times > 3)
                    return false;
            }
        }
        
        return true;
    }
};