请你判断一个 9 x 9 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)
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。
空白格用 '.' 表示。
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
示例 2:
输入:board =
\["8","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:false
解释:除了第一行的第一个数字从 5 改为 8 以外,空格内其他数字均与 示例1 相同。 但由于位于左上角的 3x3 宫内有两个 8 存在, 因此这个数独是无效的。
提示:
board.length == 9
board[i].length == 9
board[i][j] 是一位数字(1-9)或者 '.'
我的答案
cpp
class ValidSuduku {
public:
bool isValidSudoku(vector<vector<char>>& board) {
//本元素在3x3、行或列中是否出现过
bool isValid = true;
for (int i = 0; i < board.size(); i++)
{
for (int j = 0; j < board.size(); j++)//这个for如何省掉
{
char own = board[i][j];
if (own != '.')
{
int x = i / 3, y = j / 3;
for (int p = 0; p < 3; p++)
{
for (int q = 0; q < 3; q++)
{
if ((x * 3 + p != i && y * 3 + q != j)&&(own == board[x * 3 + p][y * 3 + q]))//先看3x3
{
isValid = false;
break;
}
int m = p*3 + q;
if ((m != i && own == board[m][j]) || (m != j && own == board[i][m]))//再看0-8的行列
{
isValid = false;
break;
}
}
}
}
if (!isValid)
break;
}
if (!isValid)
break;
}
return isValid;
}
};
int main()
{
vector<vector<vector<char>>> boards;
char arrayBoards1[][9] = {
{ '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' }
};
char arrayBoards2[][9] = {
{ '8', '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' }
};
vector<vector<char>> boards1(9,vector<char>(9));
vector<vector<char>> boards2(9, vector<char>(9));
for (int i = 0; i < 9; i++)
{//此处耗时
memcpy(&boards1[i][0], &arrayBoards1[i][0], 9 * sizeof(char));
}
for (int i = 0; i < 9; i++)
{//此处耗时
memcpy(&boards2[i][0], &arrayBoards2[i][0], 9 * sizeof(char));
}
boards.push_back(boards1);
boards.push_back(boards2);
ValidSuduku validSuduku;
for (int i = 0; i < boards.size(); i++)
{
std::cout << "已填入的数字是否有效:" << (validSuduku.isValidSudoku(boards[i])==0?"False" :"True") << std::endl;
}
boards1.clear();
boards1.shrink_to_fit();
boards2.clear();
boards2.shrink_to_fit();
boards.clear();
boards.shrink_to_fit();
}