diff --git a/website/content/ChapterFour/2000~2099/2022.Convert-1D-Array-Into-2D-Array.md b/website/content/ChapterFour/2000~2099/2022.Convert-1D-Array-Into-2D-Array.md new file mode 100644 index 00000000..834ee99a --- /dev/null +++ b/website/content/ChapterFour/2000~2099/2022.Convert-1D-Array-Into-2D-Array.md @@ -0,0 +1,82 @@ +# [2022. Convert 1D Array Into 2D Array](https://leetcode.com/problems/convert-1d-array-into-2d-array/) + +## 题目 + +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:** + + + +``` +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:** + +- `1 <= original.length <= 5 * 104` +- `1 <= original[i] <= 105` +- `1 <= m, n <= 4 * 104` + +## 题目大意 + +给你一个下标从 0 开始的一维整数数组 original 和两个整数 m 和 n 。你需要使用 original 中 所有 元素创建一个 m 行 n 列的二维数组。 + +original 中下标从 0 到 n - 1 (都 包含 )的元素构成二维数组的第一行,下标从 n 到 2 * n - 1 (都 包含 )的元素构成二维数组的第二行,依此类推。 + +请你根据上述过程返回一个 m x n 的二维数组。如果无法构成这样的二维数组,请你返回一个空的二维数组。 + +## 解题思路 + +- 简单题。从一维数组 original 中依次取出每行 n 个元素,顺序放到 m 行中。此题中,如果 m*n 大于或者小于 original 的长度,都输出空数组。 + +## 代码 + +```go +package leetcode + +func construct2DArray(original []int, m int, n int) [][]int { + if m*n != len(original) { + return [][]int{} + } + res := make([][]int, m) + for i := 0; i < m; i++ { + res[i] = original[n*i : n*(i+1)] + } + return res +} +``` + + +---------------------------------------------- +
+ diff --git a/website/content/ChapterFour/2000~2099/_index.md b/website/content/ChapterFour/2000~2099/_index.md new file mode 100644 index 00000000..e954f087 --- /dev/null +++ b/website/content/ChapterFour/2000~2099/_index.md @@ -0,0 +1,4 @@ +--- +bookCollapseSection: true +weight: 20 +---