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 the?3 x 3?matrix in?grid?centered around row?i + 1?and column?j + 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.

居然沒(méi)超時(shí)，我不理解。。。。

Runtime:?2 ms, faster than?96.57%?of?Java?online submissions for?Largest Local Values in a Matrix.

Memory Usage:?43.9 MB, less than?16.09%?of?Java?online submissions for?Largest Local Values in a Matrix.