Sorting and preimages of pattern classes
Combinatorics
2012-03-13 v1 Data Structures and Algorithms
Abstract
We introduce an algorithm to determine when a sorting operation, such as stack-sort or bubble-sort, outputs a given pattern. The algorithm provides a new proof of the description of West-2-stack-sortable permutations, that is permutations that are completely sorted when passed twice through a stack, in terms of patterns. We also solve the long-standing problem of describing West-3-stack-sortable permutations. This requires a new type of generalized permutation pattern we call a decorated pattern.
Cite
@article{arxiv.1203.2437,
title = {Sorting and preimages of pattern classes},
author = {Anders Claesson and Henning Úlfarsson},
journal= {arXiv preprint arXiv:1203.2437},
year = {2012}
}
Comments
13 pages, 5 figures, to appear at FPSAC 2012