scholarly journals The Cambrian Hopf Algebra

2015 ◽  
Vol DMTCS Proceedings, 27th... (Proceedings) ◽  
Author(s):  
G. Chatel ◽  
V. Pilaud
Keyword(s):  
Hopf Algebra ◽  
Binary Search ◽  
Binary Trees ◽  
Search Trees ◽  
Local Conditions ◽  
Bijective Correspondence ◽  
Combinatorial Properties ◽  
Labeled Trees ◽  
Signed Permutations ◽  
International Audience

International audience Cambrian trees are oriented and labeled trees which fulfill local conditions around each node generalizing the conditions for classical binary search trees. Based on the bijective correspondence between signed permutations and leveled Cambrian trees, we define the Cambrian Hopf algebra generalizing J.-L. Loday and M. Ronco’s algebra on binary trees. We describe combinatorially the products and coproducts of both the Cambrian algebra and its dual in terms of operations on Cambrian trees. Finally, we define multiplicative bases of the Cambrian algebra and study structural and combinatorial properties of their indecomposable elements. Les arbres Cambriens sont des arbres orientés et étiquetés qui satisfont des conditions locales autour de leurs nœuds généralisant les conditions des arbres binaires de recherche classiques. A partir de la correspondence bijective entre permutations signées et arbres Cambriens à niveau, nous définissons l’algèbre Cambrienne qui généralise l’algèbre sur les arbres binaires de J.-L. Loday et M. Ronco. Nous donnons une description combinatoire du produit et du coproduit aussi bien dans l’algèbre Cambrienne que dans sa duale en termes d’opérations sur les arbres Cambriens. Enfin, nous définissons des bases multiplicatives de l’algèbre Cambrienne et étudions les propriétés structurelles et énumératives de leurs éléments indécomposables.

scholarly journals Numerical Studies of the Asymptotic Height Distribution in Binary Search Trees

2003 ◽  
Vol Vol. 6 no. 1 ◽  
Author(s):  
Charles Knessl
Keyword(s):  
Integral Equation ◽  
Binary Search ◽  
Linear Integral Equation ◽  
Height Distribution ◽  
Binary Search Trees ◽  
Search Trees ◽  
Asymptotic Results ◽  
Numerical Studies ◽  
International Audience ◽  
Linear Integral

International audience We study numerically a non-linear integral equation that arises in the study of binary search trees. If the tree is constructed from n elements, this integral equation describes the asymptotic (as n→∞) distribution of the height of the tree. This supplements some asymptotic results we recently obtained for the tails of the distribution. The asymptotic height distribution is shown to be unimodal with highly asymmetric tails.

scholarly journals Random Records and Cuttings in Split Trees: Extended Abstract

2008 ◽  
Vol DMTCS Proceedings vol. AI,... (Proceedings) ◽  
Author(s):  
Cecilia Holmgren
Keyword(s):  
Search Tree ◽  
Binary Search ◽  
Binary Search Tree ◽  
Search Trees ◽  
Digital Search Trees ◽  
International Audience ◽  
Split Trees ◽  
Digital Search

International audience We study the number of records in random split trees on $n$ randomly labelled vertices. Equivalently the number of random cuttings required to eliminate an arbitrary random split tree can be studied. After normalization the distributions are shown to be asymptotically $1$-stable. This work is a generalization of our earlier results for the random binary search tree which is one specific case of split trees. Other important examples of split trees include $m$-ary search trees, quadtrees, median of $(2k+1)$-trees, simplex trees, tries and digital search trees.

scholarly journals Brick polytopes, lattices and Hopf algebras

2020 ◽  
Vol DMTCS Proceedings, 28th... ◽  
Author(s):  
Vincent Pilaud
Keyword(s):  
Hopf Algebra ◽  
Hopf Algebras ◽  
Transitive Closure ◽  
Weak Order ◽  
Binary Trees ◽  
International Audience ◽  
Congruence Classes

International audience Generalizing the connection between the classes of the sylvester congruence and the binary trees, we show that the classes of the congruence of the weak order on Sn defined as the transitive closure of the rewriting rule UacV1b1 ···VkbkW ≡k UcaV1b1 ···VkbkW, for letters a < b1,...,bk < c and words U,V1,...,Vk,W on [n], are in bijection with acyclic k-triangulations of the (n + 2k)-gon, or equivalently with acyclic pipe dreams for the permutation (1,...,k,n + k,...,k + 1,n + k + 1,...,n + 2k). It enables us to transport the known lattice and Hopf algebra structures from the congruence classes of ≡k to these acyclic pipe dreams, and to describe the product and coproduct of this algebra in terms of pipe dreams. Moreover, it shows that the fan obtained by coarsening the Coxeter fan according to the classes of ≡k is the normal fan of the corresponding brick polytope

scholarly journals Lattice of combinatorial Hopf algebras: binary trees with multiplicities

2013 ◽  
Vol DMTCS Proceedings vol. AS,... (Proceedings) ◽  
Author(s):  
Jean-Baptiste Priez
Keyword(s):  
Hopf Algebra ◽  
Hopf Algebras ◽  
Lattice Structure ◽  
Binary Trees ◽  
Hook Length ◽  
Combinatorial Hopf Algebras ◽  
Combinatorial Hopf Algebra ◽  
International Audience ◽  
Comme Application ◽  
Premiere Partie

International audience In a first part, we formalize the construction of combinatorial Hopf algebras from plactic-like monoids using polynomial realizations. Thank to this construction we reveal a lattice structure on those combinatorial Hopf algebras. As an application, we construct a new combinatorial Hopf algebra on binary trees with multiplicities and use it to prove a hook length formula for those trees. Dans une première partie, nous formalisons la construction d’algèbres de Hopf combinatoires à partir d’une réalisation polynomiale et de monoïdes de type monoïde plaxique. Grâce à cette construction, nous mettons à jour une structure de treillis sur ces algèbres de Hopf combinatoires. Comme application, nous construisons une nouvelle algèbre de Hopf sur des arbres binaires à multiplicités et on l’utilise pour démontrer une formule des équerressur ces arbres.

scholarly journals Analysis of some statistics for increasing tree families

2004 ◽  
Vol Vol. 6 no. 2 ◽  
Author(s):  
Alois Panholzer ◽  
Helmut Prodinger
Keyword(s):  
Computer Science ◽  
Normal Distribution ◽  
Probabilistic Models ◽  
Binary Search ◽  
Rooted Trees ◽  
Binary Search Trees ◽  
Search Trees ◽  
Ordered Trees ◽  
International Audience

International audience This paper deals with statistics concerning distances between randomly chosen nodes in varieties of increasing trees. Increasing trees are labelled rooted trees where labels along any branch from the root go in increasing order. Many mportant tree families that have applications in computer science or are used as probabilistic models in various applications, like \emphrecursive trees, heap-ordered trees or \emphbinary increasing trees (isomorphic to binary search trees) are members of this variety of trees. We consider the parameters \textitdepth of a randomly chosen node, \textitdistance between two randomly chosen nodes, and the generalisations where \textitp nodes are randomly chosen Under the restriction that the node-degrees are bounded, we can prove that all these parameters converge in law to the Normal distribution. This extends results obtained earlier for binary search trees and heap-ordered trees to a much larger class of structures.

scholarly journals The height of q-Binary Search Trees

2002 ◽  
Vol Vol. 5 ◽  
Author(s):  
Michael Drmota ◽  
Helmut Prodinger
Keyword(s):  
Geometric Distribution ◽  
Binary Search ◽  
Binary Search Trees ◽  
Search Trees ◽  
International Audience

International audience q-binary search trees are obtained from words, equipped with a geometric distribution instead of permutations. The average and variance of the heighth computated, based on random words of length n, as well as a Gaussian limit law.

scholarly journals Average depth in a binary search tree with repeated keys

2006 ◽  
Vol DMTCS Proceedings vol. AG,... (Proceedings) ◽  
Author(s):  
Margaret Archibald ◽  
Julien Clément
Keyword(s):  
Search Tree ◽  
Binary Search ◽  
Binary Search Tree ◽  
Average Depth ◽  
Binary Search Trees ◽  
Search Trees ◽  
Random Sequences ◽  
International Audience ◽  
The Right

International audience Random sequences from alphabet $\{1, \ldots,r\}$ are examined where repeated letters are allowed. Binary search trees are formed from these, and the average left-going depth of the first $1$ is found. Next, the right-going depth of the first $r$ is examined, and finally a merge (or 'shuffle') operator is used to obtain the average depth of an arbitrary node, which can be expressed in terms of the left-going and right-going depths. The variance of each of these parameters is also found.

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