作者：力扣 (LeetCode)
链接：https://leetcode-cn.com/leetbook/read/top-interview-questions-easy/x2ba4i/
来源：力扣（LeetCode）
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题目
题目：有效的数独
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 ‘.’
相关标签
数组
哈希表
矩阵
C++源程序：
class Solution {
public:
bool isValidSudoku(vector<vector<char>>& board) {
int row[9][10] = {0}; // 初始化二维数组 row 行 为什么第二个是10 因为想表达从1到10
int col[9][10] = {0}; // 初始化二维数组 column 列
int box[9][10] = {0}; // box里只有9个数不过同样可以 1开头不影响
for(int i = 0; i < 9; i++){
// 同时进行三个维度判断 行 列 盒子中
for(int j = 0; j < 9; j++){
if(board[i][j] == '.')
continue; // 结束这次循环，进行下一次的循环
int curNumber = board[i][j] - '0';
if(row[i][curNumber])
return false;
if(col[j][curNumber])
return false;
if(box[j/3 + (i/3) *3][curNumber])
return false;
row[i][curNumber] = 1;
col[j][curNumber] = 1;
box[j/3 + (i/3)*3][curNumber] = 1;
}
}
return true;
}
};