题目:
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].
思路:
练手题目,哈哈。
代码:
class Solution {
public:
vector<vector<int>> imageSmoother(vector<vector<int>>& M) {
if (M.size() == 0) {
return {};
}
int row_num = M.size(), col_num = M[0].size();
vector<vector<int>> N(row_num, vector<int>(col_num, 0));
for (int r = 0; r < row_num; ++r) {
for (int c = 0; c < col_num; ++c) {
N[r][c] = getAverage(M, r, c);
}
}
return N;
}
private:
int getAverage(vector<vector<int>> &M, int r, int c) {
int row_num = M.size(), col_num = M[0].size();
int count = 0, sum = 0;
for (int i = r - 1; i <= r + 1; ++i) {
for (int j = c - 1; j <= c + 1; ++j) {
if (i >= 0 && i < row_num && j >= 0 && j < col_num) {
sum += M[i][j];
++count;
}
}
}
return sum / count;
}
};