Code RoomLongest substring with k distinct
MediumPrep Room Coding #887

Longest substring with k distinct

CodingAlgorithms & data structuresMid–Senior~28 min

Given a string s and integer k, return the length of the longest substring that contains at most k distinct characters. If k is 0, the answer is 0. Constraints: 0 <= len(s) <= 5*10^4, 0 <= k <= 26, s is lowercase letters.

Implement
longest_k_distinct(s: str, k: int) → int
Examples
in["eceba",2]out3
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.

0:00 of about 28 min
InputExpectedGot
["eceba",2]3not run yetsample