Valid Sudoku

Total Accepted: 57185 Total Submissions: 199536 Difficulty: Easy

 

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.

合法的数独就是每一行每一列每一个3*3小块都不能有重复的数字

class Solution {
public:
    bool isValidSudoku(vector<vector<char>>& board) {
        int row[10],col[10];
        for(int i=0;i<9;i++){
            memset(row,0,sizeof(int)*10);
            memset(col,0,sizeof(int)*10);
            for(int j=0;j<9;j++){
                if(board[i][j]!='.'){
                    if(row[board[i][j]-'0']!=0){
                        return false;
                    }
                    row[board[i][j]-'0'] = 1;    
                }
                
                if(board[j][i]!='.'){
                    if(col[board[j][i]-'0']!=0){
                        return false;
                    }
                    col[board[j][i]-'0'] = 1;    
                }
            }
        }
        for(int i=0;i<9;i+=3){
            for(int j=0;j<9;j+=3){
                memset(row,0,sizeof(int)*10);
                for(int a=0;a<3;a++){
                    for(int b=0;b<3;b++){
                        if(board[i+a][j+b]!='.'){
                            int digit = board[i+a][j+b]-'0';
                            if(row[digit]!=0){
                                return false;
                            }
                            row[digit] = 1;            
                        }
                    }
                }
            }
        }
        return true;
    }
};