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 
#include 
#include 

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;
                }
                else
                    return false;
            }
            if (board[j][i] != '.')
            {
                int number = board[j][i] - '0';
                if (colnums[number] == 0)
                {
                    colnums[number] = 1;
                }
                else
                    return 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;
                        }
                        else
                            return false;
                    }
                }
            }
        memset(rownums, 0, sizeof(rownums));            
        }
    }
    return true;
}