Question

What is a time complexity for finding the longest substring that is repeated in a string?

(a) O (log n!)

(b) Ɵ (n!)

(c) O (n^2+ n1)

(d) Ɵ (n)

This interesting question is from Suffix tree topic in chapter Trie of Data Structures & Algorithms I

This question was addressed to me during an internship interview.

Answer 1

Right choice is (d) Ɵ (n)

Easiest explanation - Suffix Tree allows fast string operation. To check if a substring is present in a string of a length of n, the time complexity for such operation is found to be O (n). The time complexity for finding the longest substring that is repeated in a string is Ɵ (n).