leetcode-661-Image-Smoother

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描述

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.

Example 1:

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Input:
[[1,1,1],
 [1,0,1],
 [1,1,1]]
Output:
[[0, 0, 0],
 [0, 0, 0],
 [0, 0, 0]]
Explanation:
For the point (0,0), (0,2), (2,0), (2,2): floor(3/4) = floor(0.75) = 0
For the point (0,1), (1,0), (1,2), (2,1): floor(5/6) = floor(0.83333333) = 0
For the point (1,1): floor(8/9) = floor(0.88888889) = 0

Note:

  1. The value in the given matrix is in the range of [0, 255].
  2. The length and width of the given matrix are in the range of [1, 150].

分析

对图片进行平滑处理，这里的算法很简单，对每个点统计周围点的总数，然后除以点的总数即为该点的值。

解决方案1(Java)

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class Solution {
    public int[][] imageSmoother(int[][] M) {
        int row = M.length, col = M[0].length;
        int[][] result = new int[row][col];
        
        for (int i = 0; i < row; i++) {
            for (int j = 0; j < col; j++) {
                int count = 0;
                for (int iRow = i-1; iRow <= i+1; iRow++) {
                    for (int jCol = j-1; jCol <= j+1; jCol++) {
                        if (0 <= iRow && iRow < row && 0 <= jCol && jCol < col) {
                            result[i][j] += M[iRow][jCol];
                            count++;
                        }
                    }
                }
                result[i][j] /= count;
            }
        }
        return result;
    }
}

题目来源