Pattern matching in (213, 231)-avoiding permutations
Résumé
Given permutations $\sigma \in S_k$ and $\pi \in S_n$ with $k < n$, the
pattern matching problem is to decide whether $\pi$ matches
$\sigma$ as an order-isomorphic subsequence.
We give a linear-time algorithm in case both $\pi$ and $\sigma$ avoid
the two size-$3$ permutations $213$ and $231$.
For the special case where only $\sigma$ avoids $213$ and $231$, we present a
$O(max(kn^2,n^2\log(\log(n)))$ time algorithm.
We extend our research to bivincular patterns that avoid $213$ and $231$ and present a $O(kn^4)$ time algorithm.
Finally we look at the related problem of the longest subsequence which avoids $213$ and $231$.
Origine | Fichiers produits par l'(les) auteur(s) |
---|