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