Code Room
CodingMediumcod-g1195
Subject ArraysLevel Entry–Mid~13 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given two integer lists that may contain repeats, return the values that appear in exactly one of the two lists — present somewhere in the first or in the second, but not in both. Return each qualifying value once, in ascending order. Example: [1, 2, 3] and [2, 3, 4] give [1, 4].

Implement
exactly_one_side(a: list[int], b: list[int]) → list[int]
Examples
in[[1,2,3],[2,3,4]]out[1,4]
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.