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.

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Example 1:

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

• 1 <= original.length <= 5 * 104

• 1 <= original[i] <= 105

• 1 <= m, n <= 4 * 104

Easy題目，做個(gè)for循環(huán)轉(zhuǎn)換一下即可。

Runtime5 ms

Beats

78.50%

Memory52.1 MB

Beats

62.21%