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Decision trees are well-known due to their ease of interpretability. To improve accuracy, we need to grow deep trees or ensembles of trees. These are hard to interpret, offsetting their original benefits. Shapley values have recently become…

Machine Learning · Computer Science 2023-01-26 Peng Yu , Chao Xu , Albert Bifet , Jesse Read

A connected graph has tree-depth at most $k$ if it is a subgraph of the closure of a rooted tree whose height is at most $k$. We give an algorithm which for a given $n$-vertex graph $G$, in time $\mathcal{O}(1.9602^n)$ computes the…

Data Structures and Algorithms · Computer Science 2013-06-18 Fedor V. Fomin , Archontia C. Giannopoulou , Michał Pilipczuk

For a given graph G and integers b,f >= 0, let S be a subset of vertices of G of size b+1 such that the subgraph of G induced by S is connected and S can be separated from other vertices of G by removing f vertices. We prove that every…

Data Structures and Algorithms · Computer Science 2008-05-05 Fedor V. Fomin , Yngve Villanger

Spanning tree modulus is a generalization of effective resistance that is closely related to graph strength and fractional arboricity. The optimal edge density associated with spanning tree modulus is known to produce two hierarchical…

Combinatorics · Mathematics 2024-07-26 Nathan Albin , Kapila Kottegoda , Pietro Poggi-Corradini

Rotation distance between rooted binary trees measures the number of simple operations it takes to transform one tree into another. There are no known polynomial-time algorithms for computing rotation distance. We give an efficient,…

Data Structures and Algorithms · Computer Science 2018-03-19 Sean Cleary , Katherine St. John

A 2-stab unit interval graph (2SUIG) is an axes-parallel unit square intersection graph where the unit squares intersect either of the two fixed lines parallel to the $X$-axis, distance $1 + \epsilon$ ($0 < \epsilon < 1$) apart. This family…

Discrete Mathematics · Computer Science 2016-04-01 Sujoy Kumar Bhore , Dibyayan Chakraborty , Sandip Das , Sagnik Sen

Given a tree of weighted vertices, it is sometimes possible to break the tree into two equally-weighted subtrees within an allowable error. We give a fast algorithm that finds an edge which breaks the tree into equal-weight components or…

Combinatorics · Mathematics 2020-11-13 Corinne Mulvey

The distribution of distances in the star graph $ST_n$, ($1<n\in\Z$), is established, and subsequently a threaded binary tree is obtained that realizes an orientation of $ST_n$ whose levels are given by the distances to the identity…

Combinatorics · Mathematics 2010-11-16 Italo J. Dejter

In this paper, we set forth a new algorithm for generating approximately uniformly random spanning trees in undirected graphs. We show how to sample from a distribution that is within a multiplicative $(1+\delta)$ of uniform in expected…

Data Structures and Algorithms · Computer Science 2009-08-12 Jonathan A. Kelner , Aleksander Madry

We consider the problem of listing all spanning trees of a graph $G$ such that successive trees differ by pivoting a single edge around a vertex. Such a listing is called a "pivot Gray code", and it has more stringent conditions than known…

Data Structures and Algorithms · Computer Science 2022-02-04 Ben Cameron , Aaron Grubb , Joe Sawada

The sequence A120986 in the Encyclopedia of Integer Sequences counts ternary trees according to the number of nodes and the number of middle edges. Using a certain substition, the underlying cubic equation can be factored. This leads to an…

Combinatorics · Mathematics 2020-09-16 Helmut Prodinger

Large graphs abound in machine learning, data mining, and several related areas. A useful step towards analyzing such graphs is that of obtaining certain summary statistics - e.g., or the expected length of a shortest path between two…

Machine Learning · Statistics 2013-12-02 Mikhail Langovoy , Suvrit Sra

A novel graph-to-tree conversion mechanism called the deep-tree generation (DTG) algorithm is first proposed to predict text data represented by graphs. The DTG method can generate a richer and more accurate representation for nodes (or…

Computation and Language · Computer Science 2018-09-06 Fenxiao Chen , Bin Wang , C. -C. Jay Kuo

We prove that, among rectangular grid graphs with a fixed number of vertices, the number of spanning trees increases when the side lengths are made more balanced. In particular, among all rectangular grid graphs with $n^2$ vertices, the…

Combinatorics · Mathematics 2026-05-25 Jiechen Zhang

A graph is odd if all of its vertices have odd degrees. In particular, an odd spanning tree in a connected graph is a spanning tree in which all vertices have odd degrees. In this paper we establish a unified technique to enumerate odd…

Combinatorics · Mathematics 2026-02-10 Shaohan Xu , Kexiang Xu

Kimelfeld and Sagiv [Kimelfeld and Sagiv, PODS 2006], [Kimelfeld and Sagiv, Inf. Syst. 2008] pointed out the problem of enumerating $K$-fragments is of great importance in a keyword search on data graphs. In a graph-theoretic term, the…

Data Structures and Algorithms · Computer Science 2022-05-13 Yasuaki Kobayashi , Kazuhiro Kurita , Kunihiro Wasa

We consider the following question: How many edge-disjoint plane spanning trees are contained in a complete geometric graph $GK_n$ on any set $S$ of $n$ points in general position in the plane? We show that this number is in…

Computational Geometry · Computer Science 2017-07-19 Oswin Aichholzer , Thomas Hackl , Matias Korman , Marc van Kreveld , Maarten Löffler , Alexander Pilz , Bettina Speckmann , Emo Welzl

We consider how to index strings, trees and graphs for jumbled pattern matching when we are asked to return a match if one exists. For example, we show how, given a tree containing two colours, we can build a quadratic-space index with…

Data Structures and Algorithms · Computer Science 2013-04-23 Ferdinando Cicalese , Travis Gagie , Emanuele Giaquinta , Eduardo Sany Laber , Zsuzsanna Lipták , Romeo Rizzi , Alexandru I. Tomescu

In this paper, we provide an exact formula for the average hitting times in a wheel graph $W_{N+1}$ using a combinatorial approach. For this wheel graph, the average hitting times can be expressed using Fibonacci numbers when the number of…

Combinatorics · Mathematics 2026-05-13 Shunya Tamura , Yuuho Tanaka

In this paper, we give a linear algorithm for obtaining the Laplacian eigenvalues of a cograph. This approach is more efficient as there is no need to directly compute the eigenvalues of Laplacian matrix related to this class of graph. As…

Combinatorics · Mathematics 2024-09-16 Guantao Chen , Fernando C. Tura