CodingEasycod-g307

Subject Binary search treeLevel Entry–Mid~15 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given a binary search tree as a level-order list (None marks a missing child; children of None are omitted) and an inclusive value range [lo, hi], return the sum of values of all nodes with value in [lo, hi]. Exploit the BST property to prune subtrees that cannot contain in-range values. An empty tree sums to 0.

Implement

bst_range_sum(level: list, lo: int, hi: int) → int

Examples

in[[10,5,15,3,7,null,18],7,15]out32

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.