2022\. Convert 1D Array Into 2D Array

Easy

You are given a **0-indexed** 1-dimensional (1D) integer array `original`, and two integers, `m` and `n`. You are tasked with creating a 2-dimensional (2D) array with `m` rows and `n` columns using **all** the elements from `original`.

The elements from indices `0` to `n - 1` (**inclusive**) of `original` should form the first row of the constructed 2D array, the elements from indices `n` to `2 * n - 1` (**inclusive**) should form the second row of the constructed 2D array, and so on.

Return _an_ `m x n` _2D array constructed according to the above procedure, or an empty 2D array if it is impossible_.

**Example 1:**

![](https://assets.leetcode.com/uploads/2021/08/26/image-20210826114243-1.png)

**Input:** original = [1,2,3,4], m = 2, n = 2

**Output:** [[1,2],[3,4]]

**Explanation:** The constructed 2D array should contain 2 rows and 2 columns. 

The first group of n=2 elements in original, [1,2], becomes the first row in the constructed 2D array. 

The second group of n=2 elements in original, [3,4], becomes the second row in the constructed 2D array.

**Example 2:**

**Input:** original = [1,2,3], m = 1, n = 3

**Output:** [[1,2,3]]

**Explanation:** The constructed 2D array should contain 1 row and 3 columns. 

Put all three elements in original into the first row of the constructed 2D array.

**Example 3:**

**Input:** original = [1,2], m = 1, n = 1

**Output:** []

**Explanation:** There are 2 elements in original. 

It is impossible to fit 2 elements in a 1x1 2D array, so return an empty 2D array.

**Constraints:**

*   <code>1 <= original.length <= 5 * 10<sup>4</sup></code>
*   <code>1 <= original[i] <= 10<sup>5</sup></code>
*   <code>1 <= m, n <= 4 * 10<sup>4</sup></code>