Problem
You are given an n x n
integer matrix grid
.
Generate an integer matrix maxLocal
of size (n - 2) x (n - 2)
such that:
maxLocal[i][j]
is equal to the largest value of the3 x 3
matrix ingrid
centered around rowi + 1
and columnj + 1
.
In other words, we want to find the largest value in every contiguous 3 x 3
matrix in grid
.
Return the generated matrix.
Example 1:
Input: grid = [[9,9,8,1],[5,6,2,6],[8,2,6,4],[6,2,2,2]] Output: [[9,9],[8,6]] Explanation: The diagram above shows the original matrix and the generated matrix. Notice that each value in the generated matrix corresponds to the largest value of a contiguous 3 x 3 matrix in grid.
Example 2:
Input: grid = [[1,1,1,1,1],[1,1,1,1,1],[1,1,2,1,1],[1,1,1,1,1],[1,1,1,1,1]] Output: [[2,2,2],[2,2,2],[2,2,2]] Explanation: Notice that the 2 is contained within every contiguous 3 x 3 matrix in grid.
Constraints:
n == grid.length == grid[i].length
3 <= n <= 100
1 <= grid[i][j] <= 100