CodingHardcod-g317

Subject Sliding windowLevel Senior–Staff~32 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given an array nums of positive integers and an integer k, return the number of subarrays (contiguous) that contain exactly k distinct integers. Constraints: 1 <= len(nums) <= 2*10^4, 1 <= nums[i] <= len(nums), 1 <= k <= len(nums).

Implement

subarrays_k_distinct(nums: list[int], k: int) → int

Examples

in[[1,2,1,2,3],2]out7

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.