NP-hard

Longest common subsequence problem for unoriented and cyclic strings

Given a finite set of strings X, the Longest Common Subsequence problem (LCS) consists in finding a subsequence common to all strings in X that is of maximal length. LCS is a central problem in stringology and finds broad applications in text …

Hardness of Optimal Spaced Seed Design

Speeding up approximate pattern matching is a line of research in stringology since the 80's. Practically fast approaches belong to the class of filtration algorithms, in which text regions dissimilar to the pattern are excluded (filtered out) in a …