[661. Image Smoother] #leetcode

661_0829.java

class Solution {
    public int[][] imageSmoother(int[][] M) {
        if (M == null) return null;
        
        int rows = M.length;
        if (rows == 0) return new int[0][];
        int cols = M[0].length;

        int result[][] = new int[rows][cols];

        for (int row = 0; row < rows; row++) {
            for (int col = 0; col < cols; col++) {
                int count = 0;
                int sum = 0;
                for (int incR : new int[]{-1, 0, 1}) {
                    for (int incC : new int[]{-1, 0, 1}) {
                        if (row + incR >= 0 && row + incR < rows && col + incC >= 0 && col + incC < cols) {
                            count++;
                            sum += M[row + incR][col + incC];
                        }
                    }
                }
                result[row][col] = sum / count;
            }
        }

        return result;

    }
}