［LeetCode］Valid Sudoku

class Solution {
public:
bool isValidSudoku(vector<vector<char>>& board) {
vector<set<char> > vertSets(9);
vector<set<char> > horiSets(9);
vector<set<char> > squaSets(9);

for (int i = 0; i < board.size(); ++i){
for(int j = 0; j < board[i].size(); ++j){
if(board[i][j] == '.'){
continue;
}
if (!vertSets[i].insert(board[i][j]).second ||
!horiSets[j].insert(board[i][j]).second ||
!squaSets[i/3 * 3 + j/3].insert(board[i][j]).second){
return false;
}

}
}
return true;
}
};