# 2649. Nested Array Generator

## Description

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

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.

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

Can you solve this without creating a new flattened version of the array?

## Solutions

• type MultidimensionalArray = (MultidimensionalArray | number)[];

function* inorderTraversal(arr: MultidimensionalArray): Generator<number, void, unknown> {
for (const e of arr) {
if (Array.isArray(e)) {
yield* inorderTraversal(e);
} else {
yield e;
}
}
}

/**
* const gen = inorderTraversal([1, [2, 3]]);
* gen.next().value; // 1
* gen.next().value; // 2
* gen.next().value; // 3
*/