CodingMediumcod-g764

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

Question

Given a binary tree as a level-order array (null for missing) where every node value is a digit 0-9, each root-to-leaf path spells a number formed by concatenating the digits from root to leaf. Return the sum of all such numbers. If the tree is empty, return 0.

Implement

sum_root_to_leaf(level: list) → int

Examples

in[[1,2,3]]out25

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.