public class Solution
extends Object
840 - Magic Squares In Grid\.
Medium
A `3 x 3` magic square is a `3 x 3` grid filled with distinct numbers **from** `1` **to** `9` such that each row, column, and both diagonals all have the same sum.
Given a `row x col` `grid` of integers, how many `3 x 3` "magic square" subgrids are there? (Each subgrid is contiguous).
**Example 1:**
**Input:** grid = \[\[4,3,8,4],[9,5,1,9],[2,7,6,2]]
**Output:** 1
**Explanation:** The following subgrid is a 3 x 3 magic square:  while this one is not:  In total, there is only one magic square inside the given grid.
**Example 2:**
**Input:** grid = \[\[8]]
**Output:** 0
**Constraints:**
* `row == grid.length`
* `col == grid[i].length`
* `1 <= row, col <= 10`
* `0 <= grid[i][j] <= 15`