Results 81 to 90 of about 132,418 (291)
A bijection for plane graphs and its applications
This paper is concerned with the counting and random sampling of plane graphs (simple planar graphs embedded in the plane). Our main result is a bijection between the class of plane graphs with triangular outer face, and a class of oriented binary trees.
O. Bernardi, Gwendal Collet, Éric Fusy
semanticscholar +1 more source
Two bijections on Tamari Intervals [PDF]
We use a recently introduced combinatorial object, the $\textit{interval-poset}$, to describe two bijections on intervals of the Tamari lattice. Both bijections give a combinatorial proof of some previously known results. The first one is an inner bijection between Tamari intervals that exchanges the $\textit{initial rise}$ and $\textit{lower contacts}$
Chapoton, Frédéric+2 more
openaire +4 more sources
ABSTRACT The E(s2) $\,E({s}^{2})$‐optimal and minimax‐optimal supersaturated designs (SSDs) with 12 rows, 11q $11q$ columns, and smax=4 ${s}_{{\rm{\max }}}=4$ are enumerated in a computer search: there are, respectively, 34, 146, 0, 3, and 1 such designs for q=2,3,4,5 $q=2,3,4,5$, and 6.
Luis B. Morales
wiley +1 more source
Enumeration of Corners in Tree-like Tableaux [PDF]
In this paper, we confirm conjectures of Laborde-Zubieta on the enumeration of corners in tree-like tableaux and in symmetric tree-like tableaux. In the process, we also enumerate corners in (type $B$) permutation tableaux and (symmetric) alternative ...
Alice L. L. Gao+3 more
doaj +1 more source
On Endomorphism Universality of Sparse Graph Classes
ABSTRACT We show that every commutative idempotent monoid (a.k.a. lattice) is the endomorphism monoid of a subcubic graph. This solves a problem of Babai and Pultr and the degree bound is best‐possible. On the other hand, we show that no class excluding a minor can have all commutative idempotent monoids among its endomorphism monoids. As a by‐product,
Kolja Knauer, Gil Puig i Surroca
wiley +1 more source
Operators of equivalent sorting power and related Wilf-equivalences [PDF]
We study sorting operators $\textrm{A}$ on permutations that are obtained composing Knuth's stack sorting operator \textrmS and the reverse operator $\textrm{R}$, as many times as desired.
Michael Albert, Mathilde Bouvel
doaj +1 more source
Bijections for partition identities
AbstractWe consider partition-identity bijections that can be constructed from sieve-equivalent families whose defining multisets are pairwise disjoint. We give a linear algorithm that constructs these bijections. We show that under these conditions, the new algorithm, the Garsia-Milne-Remmel algorithm, and the Gordon algorithm are equivalent, i.e ...
openaire +2 more sources
Precedence‐Constrained Shortest Path
ABSTRACT We propose a variant of the shortest path problem where the order in which vertices occur in the path is subject to precedence constraints. Precedence constraints are defined in terms of vertex pairs (a,b)$$ \left(a,b\right) $$ which indicate that a vertex a$$ a $$ is the predecessor of a vertex b$$ b $$.
Christina Büsing+2 more
wiley +1 more source
Resources for Research on Analogy: A Multi-disciplinary Guide
Work on analogy has been done from a number of disciplinary perspectives throughout the history of Western thought. This work is a multidisciplinary guide to theorizing about analogy.
Marcello Guarini+3 more
doaj +1 more source
A bijection between irreducible k-shapes and surjective pistols of height $k-1$ [PDF]
This paper constructs a bijection between irreducible $k$-shapes and surjective pistols of height $k-1$, which carries the "free $k$-sites" to the fixed points of surjective pistols.
Ange Bigeni
doaj +1 more source