public class Solution
extends Object
2319 - Check if Matrix Is X-Matrix\.
Easy
A square matrix is said to be an **X-Matrix** if **both** of the following conditions hold:
1. All the elements in the diagonals of the matrix are **non-zero**.
2. All other elements are 0.
Given a 2D integer array `grid` of size `n x n` representing a square matrix, return `true` _if_ `grid` _is an X-Matrix_. Otherwise, return `false`.
**Example 1:**
**Input:** grid = \[\[2,0,0,1],[0,3,1,0],[0,5,2,0],[4,0,0,2]]
**Output:** true
**Explanation:** Refer to the diagram above.
An X-Matrix should have the green elements (diagonals) be non-zero and the red elements be 0.
Thus, grid is an X-Matrix.
**Example 2:**
**Input:** grid = \[\[5,7,0],[0,3,1],[0,5,0]]
**Output:** false
**Explanation:** Refer to the diagram above.
An X-Matrix should have the green elements (diagonals) be non-zero and the red elements be 0.
Thus, grid is not an X-Matrix.
**Constraints:**
* `n == grid.length == grid[i].length`
* `3 <= n <= 100`
* 0 <= grid[i][j] <= 105