有效的数独
请你判断一个 9x9 的数独是否有效。只需要 根据以下规则 ，验证已经填入的数字是否有效即可。
- 数字
1-9在每一行只能出现一次。 - 数字
1-9在每一列只能出现一次。 - 数字
1-9在每一个以粗实线分隔的3x3宫内只能出现一次。（请参考示例图）
数独部分空格内已填入了数字，空白格用 \'.\' 表示。
注意：
- 一个有效的数独（部分已被填充）不一定是可解的。
- 只需要根据以上规则，验证已经填入的数字是否有效即可。
示例 1：
输入：board = [["5","3",".",".","7",".",".",".","."] ,["6",".",".","1","9","5",".",".","."] ,[".","9","8",".",".",".",".","6","."] ,["8",".",".",".","6",".",".",".","3"] ,["4",".",".","8",".","3",".",".","1"] ,["7",".",".",".","2",".",".",".","6"] ,[".","6",".",".",".",".","2","8","."] ,[".",".",".","4","1","9",".",".","5"] ,[".",".",".",".","8",".",".","7","9"]] 输出：true
遍历就行了：
class Solution {
public:
bool isValidSudoku(vector<vector<char>>& board) {
int book[10];
memset(book,0,sizeof(book));
for(int i = 0; i < 9; i++){
for(int j = 0; j < 9; j++){
if(board[i][j] >= \'0\' && board[i][j] <= \'9\'){//横着的
int a = board[i][j] - \'0\';
if(book[a] == 1)return false;
else book[a] = 1;
}
}
memset(book,0,sizeof(book));
for(int j = 0; j < 9; j++){
if(board[j][i] >= \'0\' && board[j][i] <= \'9\'){//竖着的
int a = board[j][i] - \'0\';
if(book[a] == 1)return false;
else book[a] = 1;
}
}
memset(book,0,sizeof(book));
}
for(int i = 0; i < 9; i += 3){
for(int j = 0; j < 9; j += 3){
memset(book,0,sizeof(book));
for(int k = 0; k < 3; k++){//每个 3 * 3的矩形
for(int l = 0; l < 3; l++){
if(board[i + k][j + l] >= \'0\' && board[i + k][j + l] <= \'9\'){
int a = board[i + k][j + l] - \'0\';
if(book[a] == 1)return false;
else book[a] = 1;
}
}
}
}
}
return true;
}
};