Practice Matrix Block Sum
Read the task, work through the examples, and check your approach against the constraints. Use the original LeetCode task for coding and submissions.
Problem Statement
For every position (i, j) in the m by n matrix mat, sum the values at positions (r, c) satisfying i - k <= r <= i + k and j - k <= c <= j + k. Include only positions inside mat. Return the matrix of these sums.
Source: Matrix Block Sum on LeetCode. Use the original task for its coding environment and submissions.
Examples
# 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
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