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Formatted question description: https://leetcode.ca/all/661.html
661. Image Smoother (Easy)
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].
Related Topics:
Array
Solution 1.
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class Solution { public int[][] imageSmoother(int[][] M) { if (M == null || M.length == 0 || M[0].length == 0) return M; int rows = M.length, columns = M[0].length; int[][] smooth = new int[rows][columns]; int[][] directions = { {-1, -1}, {-1, 0}, {-1, 1}, {0, 1}, {1, 1}, {1, 0}, {1, -1}, {0, -1} }; for (int i = 0; i < rows; i++) { for (int j = 0; j < columns; j++) { int sum = M[i][j]; int count = 1; for (int[] direction : directions) { int newRow = i + direction[0], newColumn = j + direction[1]; if (newRow >= 0 && newRow < rows && newColumn >= 0 && newColumn < columns) { sum += M[newRow][newColumn]; count++; } } smooth[i][j] = sum / count; } } return smooth; } } ############ class Solution { public int[][] imageSmoother(int[][] img) { int m = img.length; int n = img[0].length; int[][] ans = new int[m][n]; for (int i = 0; i < m; ++i) { for (int j = 0; j < n; ++j) { int s = 0; int cnt = 0; for (int x = i - 1; x <= i + 1; ++x) { for (int y = j - 1; y <= j + 1; ++y) { if (x >= 0 && x < m && y >= 0 && y < n) { ++cnt; s += img[x][y]; } } } ans[i][j] = s / cnt; } } return ans; } } -
// OJ: https://leetcode.com/problems/image-smoother/ // Time: O(MN) // Space: O(1) class Solution { public: vector<vector<int>> imageSmoother(vector<vector<int>>& A) { int M = A.size(), N = A[0].size(); vector<vector<int>> ans(M, vector<int>(N)); for (int i = 0; i < M; ++i) { for (int j = 0; j < N; ++j) { int cnt = 0; for (int x = i - 1; x <= i + 1; ++x) { for (int y = j - 1; y <= j + 1; ++y) { if (x < 0 || x >= M || y < 0 || y >= N) continue; ans[i][j] += A[x][y]; ++cnt; } } ans[i][j] /= cnt; } } return ans; } }; -
class Solution: def imageSmoother(self, img: List[List[int]]) -> List[List[int]]: m, n = len(img), len(img[0]) ans = [[0] * n for _ in range(m)] for i in range(m): for j in range(n): s = cnt = 0 for x in range(i - 1, i + 2): for y in range(j - 1, j + 2): if 0 <= x < m and 0 <= y < n: cnt += 1 s += img[x][y] ans[i][j] = s // cnt return ans ############ class Solution(object): def imageSmoother(self, M): """ :type M: List[List[int]] :rtype: List[List[int]] """ m = len(M) n = len(M[0]) ans = [[0] * n for _ in range(m)] for i in range(m): for j in range(n): cnt = 0 sums = 0 for di in range(-1, 2): for dj in range(-1, 2): newi, newj = i + di, j + dj if 0 <= newi < m and 0 <= newj < n: cnt += 1 sums += M[newi][newj] ans[i][j] = sums / cnt return ans -
func imageSmoother(img [][]int) [][]int { m, n := len(img), len(img[0]) ans := make([][]int, m) for i, row := range img { ans[i] = make([]int, n) for j := range row { s, cnt := 0, 0 for x := i - 1; x <= i+1; x++ { for y := j - 1; y <= j+1; y++ { if x >= 0 && x < m && y >= 0 && y < n { cnt++ s += img[x][y] } } } ans[i][j] = s / cnt } } return ans } -
function imageSmoother(img: number[][]): number[][] { const m = img.length; const n = img[0].length; const locations = [ [-1, -1], [-1, 0], [-1, 1], [0, -1], [0, 0], [0, 1], [1, -1], [1, 0], [1, 1], ]; const res = []; for (let i = 0; i < m; i++) { res.push([]); for (let j = 0; j < n; j++) { let sum = 0; let count = 0; for (const [y, x] of locations) { if ((img[i + y] || [])[j + x] != null) { sum += img[i + y][j + x]; count++; } } res[i].push(Math.floor(sum / count)); } } return res; } -
impl Solution { pub fn image_smoother(img: Vec<Vec<i32>>) -> Vec<Vec<i32>> { let m = img.len(); let n = img[0].len(); let locations = [ [-1, -1], [-1, 0], [-1, 1], [0, -1], [0, 0], [0, 1], [1, -1], [1, 0], [1, 1], ]; let mut res = vec![]; for i in 0..m { res.push(vec![]); for j in 0..n { let mut sum = 0; let mut count = 0; for [y, x] in locations.iter() { let i = i as i32 + y; let j = j as i32 + x; if i < 0 || i == m as i32 || j < 0 || j == n as i32 { continue; } count += 1; sum += img[i as usize][j as usize]; } res[i].push(sum / count); } } res } }