# 0840. Magic Squares In Grid

https://leetcode.com/problems/magic-squares-in-grid

## Description

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:**

![](https://assets.leetcode.com/uploads/2020/09/11/magic_main.jpg)

```
**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:
![](https://assets.leetcode.com/uploads/2020/09/11/magic_valid.jpg)
while this one is not:
![](https://assets.leetcode.com/uploads/2020/09/11/magic_invalid.jpg)
In total, there is only one magic square inside the given grid.
```

**Example 2:**

```
**Input:** grid = [[8]]
**Output:** 0
```

**Example 3:**

```
**Input:** grid = [[4,4],[3,3]]
**Output:** 0
```

**Example 4:**

```
**Input:** grid = [[4,7,8],[9,5,1],[2,3,6]]
**Output:** 0
```

**Constraints:**

* `row == grid.length`
* `col == grid[i].length`
* `1 <= row, col <= 10`
* `0 <= grid[i][j] <= 15`

## ac

```java
```
