A numeral system for the middle-levels graphs

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteur principal: Dejter, Italo J.
Format: Preprint
Publié: 2010
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866929454371045376
author Dejter, Italo J.
author_facet Dejter, Italo J.
contents The middle-levels graph $M_k$ ($0<k\in\mathbb{Z}$) has a dihedral quotient pseudograph $R_k$ whose vertices are the $k$-edge ordered trees $T$, each $T$ encoded as a $(2k+1)$-string $F(T)$ formed via $\rightarrow$DFS by: {\bf(i)} ($\leftarrow$BFS-assigned) Kierstead-Trotter lexical colors $0,\ldots,k$ for the descending nodes; {\bf(ii)} asterisks $*$ for the $k$ ascending edges. Two ways of corresponding a restricted-growth $k$-string $α$ to each $T$ exist, namely one Stanley's way and a novel way that assigns $F(T)$ to $α$ via nested substring-swaps. These swaps permit to sort $V(R_k)$ as an ordered tree that allows a lexical visualization of $M_k$ as well as the Hamilton cycles of $M_k$ constructed by P. Gregor, T. Mütze and J. Nummenpalo.
format Preprint
id arxiv_https___arxiv_org_abs_1012_0995
institution arXiv
publishDate 2010
record_format arxiv
spellingShingle A numeral system for the middle-levels graphs
Dejter, Italo J.
Combinatorics
06A05, 94B25, 05C62, 05C75, 05C69, 05C45
The middle-levels graph $M_k$ ($0<k\in\mathbb{Z}$) has a dihedral quotient pseudograph $R_k$ whose vertices are the $k$-edge ordered trees $T$, each $T$ encoded as a $(2k+1)$-string $F(T)$ formed via $\rightarrow$DFS by: {\bf(i)} ($\leftarrow$BFS-assigned) Kierstead-Trotter lexical colors $0,\ldots,k$ for the descending nodes; {\bf(ii)} asterisks $*$ for the $k$ ascending edges. Two ways of corresponding a restricted-growth $k$-string $α$ to each $T$ exist, namely one Stanley's way and a novel way that assigns $F(T)$ to $α$ via nested substring-swaps. These swaps permit to sort $V(R_k)$ as an ordered tree that allows a lexical visualization of $M_k$ as well as the Hamilton cycles of $M_k$ constructed by P. Gregor, T. Mütze and J. Nummenpalo.
title A numeral system for the middle-levels graphs
topic Combinatorics
06A05, 94B25, 05C62, 05C75, 05C69, 05C45
url https://arxiv.org/abs/1012.0995