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.
玩过九宫格的都应该知道规则（没玩过的可以试玩一下九宫格）
（1）每行1~9各出现一次
（2）每列1~9各出现一次
（3）每个小的3宫格，1~9各出现一次
class Solution {
public:
bool isValidRow(vector<vector<char> >& board){
for(int row = ; row < ; ++ row){
vector<int> cnt(,);
for(int col = ; col < ; ++ col){
char item = board[row][col];
if(item != '.'){
if(cnt[item-'']!=) return false;
else cnt[item-'']++;
}
}
}
return true;
}
bool isValidCol(vector<vector<char> >& board ){
for(int col = ; col < ; ++ col){
vector<int> cnt(,);
for(int row = ; row < ; ++ row){
char item = board[row][col];
if(item != '.'){
if(cnt[item-'']!=) return false;
else cnt[item-'']++;
}
}
}
return true;
}
bool isValidBox(vector<vector<char> >& board){
for(int i = ; i < ; ++ i){
for(int j = ; j < ; ++ j){
vector<int> cnt(,);
for(int row = *i;row < *i+; ++row){
for(int col = *j; col < *j+; ++col){
char item = board[row][col];
if(item != '.'){
if(cnt[item-'']!=) return false;
else cnt[item-'']++;
}
}
}
}
}
return true;
}
bool isValidSudoku(vector<vector<char> > &board) {
return isValidRow(board)&&isValidCol(board)&&isValidBox(board);
}
};