Image Smoother
题目描述:
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:
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:
- The value in the given matrix is in the range of [0, 255].
- The length and width of the given matrix are in the range of [1, 150].
题目大意:
题目给定一个矩阵，更新每个元素的值，更新法则为：本身的值加上四周8个方向的元素求平均值。
题目代码:
class Solution {
public:vector<vector<int>> imageSmoother(vector<vector<int>>& M) {int dir[8][2] = {
{0,1},{0,-1},{1,0},{-1,0},{1,1},{-1,-1},{1,-1},{-1,1}};vector<vector<int>> ans(M.size(),vector<int>(M[0].size()));for(int i = 0; i < M.size(); i++){for(int j = 0; j < M[0].size(); j++){int cnt = 1; ans[i][j] += M[i][j];for(int k = 0; k < 8; k++){int xx = i+dir[k][0];int yy = j+dir[k][1];if(xx < 0 || yy < 0 || xx >= M.size() || yy >= M[0].size()){continue;}cnt++;ans[i][j] += M[xx][yy];}ans[i][j] /= cnt;}}return ans;}
};