CodingMediumcod-g308

Subject Balanced treesLevel Entry–Mid~25 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given a strictly increasing sorted integer array nums, build a height-balanced BST and return its level-order encoding (include None for a present node's missing child, then trim trailing Nones). When a subarray has even length, choose the LEFT of the two middle elements as the root. Return [] for an empty array.

Implement

sorted_array_to_bst_levelorder(nums: list[int]) → list

Examples

in[[-10,-3,0,5,9]]out[0,-10,5,null,-3,null,9]

What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

Learn the concepts

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.