LeetCode 36题：有效的数独

题目

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。

1. 数字 1-9 在每一行只能出现一次。
2. 数字 1-9 在每一列只能出现一次。
3. 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 '.'

 代码

#include <stdio.h>
#include <string.h>
#include <stdbool.h>bool isValidSudoku(char **board, int boardSize, int *boardColSize);int main()
{char *board[] ={"....5..1.", ".4.3.....", ".....3..1", "8......2.", "..2.7....", ".....2...", ".6....28.", ".2.9.....", "..4......"};int t, *te;            printf("%d", isValidSudoku(board, t, te));return 0;
}bool isValidSudoku(char **board, int boardSize, int *boardColSize)//后两个参数没有用
{int rownums[10], colnums[10];memset(rownums, 0, sizeof(rownums));memset(colnums, 0, sizeof(colnums));for (int i = 0; i < 9; i++){for (int j = 0; j < 9; j++){if (board[i][j] != '.'){int number = board[i][j] - '0';if (rownums[number] == 0){rownums[number] = 1;}elsereturn false;}if (board[j][i] != '.'){int number = board[j][i] - '0';if (colnums[number] == 0){colnums[number] = 1;}elsereturn false;}}memset(rownums, 0, sizeof(rownums));memset(colnums, 0, sizeof(colnums));}int i = 0, j = 0;for (int p = 3; p <= 9; p = p + 3){for (int q = 3; q <= 9; q = q + 3){i=p-3;for (; i < p; i++){j=q-3;for (; j < q; j++){if (board[i][j] != '.'){int number = board[i][j] - '0';if (rownums[number] == 0){rownums[number] = 1;}elsereturn false;}}}memset(rownums, 0, sizeof(rownums));            }}return true;
}