Crucial Words and the Complexity of Some Extremal Problems for Sets of Prohibited Words
Combinatorics
2007-05-23 v1
Abstract
We introduced the notation of a set of prohibitions and give definitions of a complete set and a crucial word with respect to a given set of prohibitions. We consider 3 particular sets which appear in different areas of mathematics and for each of them examine the length of a crucial word. One of these sets is proved to be incomplete. The problem of determining lengths of words that are free from a set of prohibitions is shown to be NP-complete, although the related problem of whether or not a given set of prohibitions is complete is known to be effectively solvable.
Keywords
Cite
@article{arxiv.math/0205217,
title = {Crucial Words and the Complexity of Some Extremal Problems for Sets of Prohibited Words},
author = {A. Evdokimov and S. Kitaev},
journal= {arXiv preprint arXiv:math/0205217},
year = {2007}
}
Comments
16 pages