1. Can you describe the coding challenge you participated in, including the JavaScript concepts that were tested, such as currying and object flattening?
2. Design a parking lot.
3. Given the root of a binary tree, calculate the vertical order traversal of the binary tree.
4. Sum of Subarray Problem Statement Given an array of integers nums, find the sum of all possible subarrays. A subarray is a contiguous part of an array, and the sum of a subarray can be defined as the sum of its elements. Constraints: 1 ≤ nums.length ≤ 104 -109 ≤ nums[i] ≤ 109
5. What are the updates in ES6?