CodingMediumcod-g393

Subject StringsLevel Mid–Senior~25 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given a string s of lowercase letters (1 <= len(s) <= 1000), return the length of the SHORTEST substring that occurs exactly once in s. Such a substring always exists for non-empty s (the whole string occurs once unless it is fully periodic, in which case a longer-but-unique length is returned). Return that minimal unique length.

Implement

shortest_unique_substring_len(s: str) → int

Examples

in["aabba"]out2

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.