[Generator, Array] Nested Array Generator (feat. flat)

https://leetcode.com/problems/nested-array-generator/description/

Nested Array Generator - LeetCode

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.

 

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

 

solution

/**
 * @param {Array} arr
 * @return {Generator}
 */
var inorderTraversal = function*(arr) {
    arr = arr.flat(Infinity);
    let i = 0;
    while(i < arr.length) {
        yield arr[i];
        i++;
    }
};

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

 

 

solution2) 재귀를 이용한 방법

var inorderTraversal = function*(arr) {
  for (const element of arr) {
    if (Array.isArray(element)) {
      yield* inorderTraversal(element);
    } else {
      yield element;
    }
  }
}