Code Room
CodingHardcod-g162
Subject Suffix structuresLevel Senior–Staff~30 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Return the total number of distinct non-empty substrings of s across all lengths. For example "abab" has the 7 distinct substrings: a, b, ab, ba, aba, bab, abab. The empty string has 0. The reference handles inputs up to a few hundred characters; the optimal solution uses a suffix automaton or suffix array + LCP to count in near-linear time, which is the discussion the problem is meant to provoke.

Implement
count_distinct_substrings(s: str) → int
Examples
in["abab"]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.

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.