Code Room
CodingMediumcod-g073
Subject Sliding windowLevel Mid–Senior~25 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given an integer array a and an integer k, return the length of the longest contiguous subarray that contains at most k distinct values. If k <= 0 or the array is empty, return 0.

Implement
longest_at_most_k_distinct(a: list[int], k: int) → int
Examples
in[[1,2,1,2,3],2]out4
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.