Code Room
CodingMediumcod-g1199
Subject ArraysLevel Entry–Mid~14 minCommon in Databases & SQL · Algorithms & data structures interviewsIndustries Software development

Question

Storage lockers are arranged in a ring, so the last locker sits next to the first. Given the parcel count in each locker (in ring order), return a list where position i holds the combined count of locker i's two neighbours: the one before and the one after, wrapping around the ends. With a single locker, both neighbours are that locker itself. Example: [1, 2, 3, 4] gives [6, 4, 6, 4].

Implement
ring_neighbor_sums(counts: list[int]) → list[int]
Examples
in[[1,2,3,4]]out[6,4,6,4]
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.

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.