arXiv subjects

Yoong Kuan Goh

Publications and source records attributed to Yoong Kuan Goh.

2 recordsLinked to original sources

arXiv2019

$k$-pop stack sortable permutations and $2$-avoidance

We consider permutations sortable by $k$ passes through a deterministic pop stack. We show that for any $k\in\mathbb N$ the set is characterised by finitely many patterns, answering a question of Claesson and Guðmundsson. Our characterisation demands a more precise definition than in previous literature of what it means for a permutation to avoid a set of barred and unbarred patterns. We propose a new notion called \emph{$2$-avoidance}.

math.CO↗

arXiv2018

Permutations sorted by a finite and an infinite stack in series

We prove that the set of permutations sorted by a stack of depth $t \geq 3$ and an infinite stack in series has infinite basis, by constructing an infinite antichain. This answers an open question on identifying the point at which, in a sorting process with two stacks in series, the basis changes from finite to infinite.

math.CO↗