What is a time complexity for finding the longest substring that is common in string S1 and S2 (n1 and n2 are the string lengths of strings s1, s2 respectively)?
(a) O (log n!)
(b) Ɵ (n!)
(c) O (n^2+ n1)
(d) Ɵ (n1 + n2)
Question is taken from Suffix tree in chapter Trie of Data Structures & Algorithms I
I had been asked this question at a job interview.
The correct answer is (d) Ɵ (n1 + n2)
Easy 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 common in string S1 and S2 is Ɵ (n1 + n2).