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Java Solution for LeetCode algorithm problems, continually updating

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1895\. Largest Magic Square

Medium

A `k x k` **magic square** is a `k x k` grid filled with integers such that every row sum, every column sum, and both diagonal sums are **all equal**. The integers in the magic square **do not have to be distinct**. Every `1 x 1` grid is trivially a **magic square**.

Given an `m x n` integer `grid`, return _the **size** (i.e., the side length_ `k`_) of the **largest magic square** that can be found within this grid_.

**Example 1:**

![](https://assets.leetcode.com/uploads/2021/05/29/magicsquare-grid.jpg)

**Input:** grid = [[7,1,4,5,6],[2,5,1,6,4],[1,5,4,3,2],[1,2,7,3,4]]

**Output:** 3

**Explanation:** The largest magic square has a size of 3.

Every row sum, column sum, and diagonal sum of this magic square is equal to 12.

- Row sums: 5+1+6 = 5+4+3 = 2+7+3 = 12

- Column sums: 5+5+2 = 1+4+7 = 6+3+3 = 12

- Diagonal sums: 5+4+3 = 6+4+2 = 12 

**Example 2:**

![](https://assets.leetcode.com/uploads/2021/05/29/magicsquare2-grid.jpg)

**Input:** grid = [[5,1,3,1],[9,3,3,1],[1,3,3,8]]

**Output:** 2 

**Constraints:**

*   `m == grid.length`
*   `n == grid[i].length`
*   `1 <= m, n <= 50`
*   1 <= grid[i][j] <= 10⁶