464 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Graz University of TechnologyAT18 papers
- Stellenbosch UniversityZA18 papers
- Lakeside LabsAT11 papers
- TU WienAT11 papers
- Max Planck Institute for Dynamics of Complex Technical SystemsDE8 papers
- Politecnico di MilanoIT8 papers
- TU Dortmund UniversityDE8 papers
- University of ViennaAT8 papers
- Technical University of MunichDE7 papers
- Universität InnsbruckAT7 papers
- University of SalzburgAT7 papers
- University of UdineIT7 papers
38 papers · 1 filter
Patterns in rectangulations. Part I: -like patterns, inversion sequence classes and , and rushed Dyck paths
Andrei Asinowski, Michaela A. Polley
We initiate a systematic study of pattern avoidance in rectangulations. We give a formal definition of such patterns and investigate rectangulations that avoid -like patterns…
Characterization of Trees with Maximum Security
Alex S. A. Alochukwu, Audace A. V. Dossou-Olory, Fadekemi J. Osaye +5
The rank (also known as protection number or leaf-height) of a vertex in a rooted tree is the minimum distance between the vertex and any of its leaf descendants. We consider the s…
Analysis of Regular Sequences: Summatory Functions and Divide-and-Conquer Recurrences
Clemens Heuberger, Daniel Krenn, Tobias Lechner
In the asymptotic analysis of regular sequences as defined by Allouche and Shallit, it is usually advisable to study their summatory function because the original sequence has a to…
The distribution of the maximum protection number in simply generated trees
Clemens Heuberger, Sarah J. Selkirk, Stephan Wagner
The protection number of a vertex in a tree is the length of the shortest path from to any leaf contained in the maximal subtree where is the root. In this paper, we de…
Enumeration of Generalized Dyck Paths Based on the Height of Down-Steps Modulo
Clemens Heuberger, Sarah J. Selkirk, Stephan Wagner
For fixed non-negative integers , , and , with , a -Dyck path of length is a lattice path that starts at , ends at , stays weakly…
A Note on the Relation between Recognisable Series and Regular Sequences, and their Minimal Linear Representations
Clemens Heuberger, Daniel Krenn, Gabriel F. Lipnik
In this note, we precisely elaborate the connection between recognisable series (in the sense of Berstel and Reutenauer) and -regular sequences (in the sense of Allouche and Sha…
Sum-of-Squares Certificates for Vizing's Conjecture via Determining Gröbner Bases
Elisabeth Gaar, Melanie Siebenhofer
The famous open Vizing conjecture claims that the domination number of the Cartesian product graph of two graphs and is at least the product of the domination numbers of $G…
Asymptotic Analysis of q-Recursive Sequences
Clemens Heuberger, Daniel Krenn, Gabriel F. Lipnik
For an integer , a -recursive sequence is defined by recurrence relations on subsequences of indices modulo some powers of~. In this article, -recursive sequences a…
Down-step statistics in generalized Dyck paths
Andrei Asinowski, Benjamin Hackl, Sarah J. Selkirk
The number of down-steps between pairs of up-steps in -Dyck paths, a generalization of Dyck paths consisting of steps such that the path stays (weakly) a…
Towards a Computational Proof of Vizing's Conjecture using Semidefinite Programming and Sums-of-Squares
Elisabeth Gaar, Daniel Krenn, Susan Margulies +1
Vizing's conjecture (open since 1968) relates the product of the domination numbers of two graphs to the domination number of their Cartesian product graph. In this paper, we formu…
Flip-sort and combinatorial aspects of pop-stack sorting
Andrei Asinowski, Cyril Banderier, Benjamin Hackl
Flip-sort is a natural sorting procedure which raises fascinating combinatorial questions. It finds its roots in the seminal work of Knuth on stack-based sorting algorithms and lea…
Monotonic Representations of Outerplanar Graphs as Edge Intersection Graphs of Paths on a Grid
Eranda Cela, Elisabeth Gaar
In a representation of a graph as an edge intersection graph of paths on a grid (EPG) every vertex of is represented by a path on a grid and two paths share a grid edge iff…
A Combinatorial Identity for Rooted Labeled Forests
Benjamin Hackl
In this brief note a straightforward combinatorial proof for an identity directly connecting rooted forests and unordered set partitions is provided. Furthermore, references that p…
Algorithmic counting of nonequivalent compact Huffman codes
Christian Elsholtz, Clemens Heuberger, Daniel Krenn
It is known that the following five counting problems lead to the same integer sequence~: the number of nonequivalent compact Huffman codes of length~ over an alphabet o…
An Optimization-Based Sum-of-Squares Approach to Vizing's Conjecture
Elisabeth Gaar, Daniel Krenn, Susan Margulies +1
Vizing's conjecture (open since 1968) relates the sizes of dominating sets in two graphs to the size of a dominating set in their Cartesian product graph. In this paper, we formula…
Asymptotic Analysis of Regular Sequences
Clemens Heuberger, Daniel Krenn
In this article, -regular sequences in the sense of Allouche and Shallit are analysed asymptotically. It is shown that the summatory function of a regular sequence can asymptoti…
Esthetic Numbers and Lifting Restrictions on the Analysis of Summatory Functions of Regular Sequences
Clemens Heuberger, Daniel Krenn
When asymptotically analysing the summatory function of a -regular sequence in the sense of Allouche and Shallit, the eigenvalues of the sum of matrices of the linear representa…
Analysis of Summatory Functions of Regular Sequences: Transducer and Pascal's Rhombus
Clemens Heuberger, Daniel Krenn, Helmut Prodinger
The summatory function of a -regular sequence in the sense of Allouche and Shallit is analysed asymptotically. The result is a sum of periodic fluctuations for eigenvalues of ab…
Ascents in Non-Negative Lattice Paths
Benjamin Hackl, Clemens Heuberger, Helmut Prodinger
Non-negative Łukasiewicz paths are special two-dimensional lattice paths never passing below their starting altitude which have only one single special type of down step. They are…
Fringe Analysis of Plane Trees Related to Cutting and Pruning
Benjamin Hackl, Clemens Heuberger, Sara Kropf +1
Rooted plane trees are reduced by four different operations on the fringe. The number of surviving nodes after reducing the tree repeatedly for a fixed number of times is asymptoti…
Growing and Destroying Catalan-Stanley Trees
Benjamin Hackl, Helmut Prodinger
Stanley lists the class of Dyck paths where all returns to the axis are of odd length as one of the many objects enumerated by (shifted) Catalan numbers. By the standard bijection…
Protection Number in Plane Trees
Clemens Heuberger, Helmut Prodinger
The protection number of a plane tree is the minimal distance of the root to a leaf; this definition carries over to an arbitrary node in a plane tree by considering the maximal su…
Reductions of Binary Trees and Lattice Paths induced by the Register Function
Benjamin Hackl, Clemens Heuberger, Helmut Prodinger
The register function (or Horton-Strahler number) of a binary tree is a well-known combinatorial parameter. We study a reduction procedure for binary trees which offers a new inter…
Dual-Pivot Quicksort: Optimality, Analysis and Zeros of Associated Lattice Paths
Martin Aumüller, Martin Dietzfelbinger, Clemens Heuberger +2
We present an average case analysis of a variant of dual-pivot quicksort. We show that the used algorithmic partitioning strategy is optimal, i.e., it minimizes the expected number…