Package g1301_1400.s1314_matrix_block_sum

Class Solution

java.lang.Object
g1301_1400.s1314_matrix_block_sum.Solution
public class Solution extends Object
1314 - Matrix Block Sum.

Medium

Given a m x n matrix mat and an integer k, return a matrix answer where each answer[i][j] is the sum of all elements mat[r][c] for:

  • i - k <= r <= i + k,
  • j - k <= c <= j + k, and
  • (r, c) is a valid position in the matrix.

Example 1:

Input: mat = [[1,2,3],[4,5,6],[7,8,9]], k = 1

Output: [[12,21,16],[27,45,33],[24,39,28]]

Example 2:

Input: mat = [[1,2,3],[4,5,6],[7,8,9]], k = 2

Output: [[45,45,45],[45,45,45],[45,45,45]]

Constraints:

  • m == mat.length
  • n == mat[i].length
  • 1 <= m, n, k <= 100
  • 1 <= mat[i][j] <= 100

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • matrixBlockSum

      public int[][] matrixBlockSum(int[][] mat, int k)