661. Image Smoother

Given a 2D integer matrix M representing the gray scale of an image, you need to design a smoother to make the gray scale of each cell becomes the average gray scale (rounding down) of all the 8 surrounding cells and itself. If a cell has less than 8 surrounding cells, then use as many as you can.

就是给二维数组做8方向均值平缓

class Solution(object):
    def imageSmoother(self, M):
        """
        :type M: List[List[int]]
        :rtype: List[List[int]]
        """
        dires = [[-1, 0], [-1, -1], [0, -1], [1, -1], [1, 0], [1, 1], [0, 1], [-1, 1]]
        matrix = []
        n = len(M)
        m = len(M[0])
        for i in range(n):
            matrix.append([0] * m)
        for i in range(n):
            for j in range(m):
                cnt = 1
                total_sum = M[i][j]
                for dire in dires:
                    new_i = i + dire[0]
                    new_j = j + dire[1]
                    if new_i >= 0 and new_i < n and new_j >= 0 and new_j < m:
                        cnt += 1
                        total_sum += M[new_i][new_j]
                matrix[i][j] = int(floor(total_sum / cnt))
        return matrix