CodingMediumcod-g582

Subject Priority queuesLevel Mid–Senior~25 minCommon in Distributed systems · Algorithms & data structures interviewsIndustries Software development, Technology

Question

You are given k sorted integer lists (a list of lists). Merge them into a single sorted list using a k-way merge with a heap so the work is O(N log k) where N is the total element count, not O(N log N). Some input lists may be empty. Return the fully merged sorted list.

Implement

kway_merge(lists: list[list[int]]) → list[int]

Examples

in[[[1,4,5],[1,3,4],[2,6]]]out[1,1,2,3,4,4,5,6]

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.