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Given a

`m * 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 = 1Output:[[12,21,16],[27,45,33],[24,39,28]]

**Example 2:**

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

All contents and pictures on this website come from the Internet and are updated regularly every week. They are for personal study and research only, and should not be used for commercial purposes. Thank you for your cooperation.