English

Passing through a stack $k$ times with reversals

Combinatorics 2018-08-14 v1

Abstract

We consider a stack sorting algorithm where only the appropriate output values are popped from the stack and then any remaining entries in the stack are run through the stack in reverse order. We identify the basis for the 22-reverse pass sortable permutations and give computational results for some classes with larger maximal rev-tier. We also show all classes of (t+1)(t+1)-reverse pass sortable permutations are finitely based. Additionally, a new Entringer family consisting of maximal rev-tier permutations of length nn was discovered along with a bijection between this family and the collection of alternating permutations of length n1n-1. We calculate generating functions for the number permutations of length nn and exact rev-tier tt.

Keywords

Cite

@article{arxiv.1808.04199,
  title  = {Passing through a stack $k$ times with reversals},
  author = {Toufik Mansour and Howard Skogman and Rebecca Smith},
  journal= {arXiv preprint arXiv:1808.04199},
  year   = {2018}
}

Comments

23 pages

R2 v1 2026-06-23T03:32:01.153Z