题目：

题目链接： https://leetcode-cn.com/problems/image-smoother/

解题思路：

主要就是边界点的判断

代码实现：

class Solution:
    def imageSmoother(self, M: List[List[int]]) -> List[List[int]]:
        def calc_sum(i, j, m, n, M):
            idx_lst = [[i - 1, j - 1], [i - 1, j], [i - 1, j + 1],[i, j - 1], [i, j], [i, j + 1],[i + 1, j - 1], [i + 1, j], [i + 1, j + 1]]
            curr_sum = curr_num = 0
            for row, column in idx_lst:
                if 0 <= row < m and 0 <= column < n:
                    curr_sum += M[row][column]
                    curr_num += 1

            return curr_sum // curr_num

        m = len(M)
        if m == 0:
            return []
        n = len(M[0])
        if n == 0:
            return []

        res = [[0 for i in range(n)] for j in range(m)]
        for i in range(m):
            for j in range(n):
                res[i][j] = calc_sum(i, j, m, n, M)

        return res