# 2649. Nested Array Generator

###### tags: `leetcode 30 days js challenge` `Medium`

[2649. Nested Array Generator](https://leetcode.com/problems/nested-array-generator/)

### 題目描述

Given a **multi-dimensional** array of integers, return a generator object which yields integers in the same order as **inorder traversal**.

A **multi-dimensional array** is a recursive data structure that contains both integers and other **multi-dimensional arrays**.

**inorder traversal** iterates over each array from left to right, yielding any integers it encounters or applying **inorder traversal** to any arrays it encounters.

### 範例

**Example 1:**

Input: arr = [[[6]],[1,3],[]]
Output: [6,1,3]
Explanation:
const generator = inorderTraversal(arr);
generator.next().value; // 6
generator.next().value; // 1
generator.next().value; // 3
generator.next().done; // true

**Example 2:**

Input: arr = []
Output: []
Explanation: There are no integers so the generator doesn't yield anything.

**Constraints**:

- 0 <= `arr.flat().length` <= 10⁵
- 0 <= `arr.flat()[i]` <= 10⁵
- `maxNestingDepth` <= 10⁵

### 解答

#### TypeScript

type MultidimensionalArray = (MultidimensionalArray | number)[];

function* inorderTraversal(arr: MultidimensionalArray): Generator<number, void, unknown> {
  for (let i = 0; i < arr.length; i++) {
    if (typeof arr[i] === 'number') {
      yield arr[i] as number;
    } else {
      yield* inorderTraversal(arr[i] as MultidimensionalArray);
    }
  }
}

> [name=Sheep][time=Sat, June 3, 2023]

### Reference

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