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We show that the max-min-angle polygon in a planar point set can be found in time $O(n\log n)$ and a max-min-solid-angle convex polyhedron in a three-dimensional point set can be found in time $O(n^2)$. We also study the maxmin-angle…

Computational Geometry · Computer Science 2025-07-08 David Eppstein

Motivated by applications to graph morphing, we consider the following \emph{compatible connectivity-augmentation problem}: We are given a labelled $n$-vertex planar graph, $\mathcal{G}$, that has $r\ge 2$ connected components, and $k\ge 2$…

Computational Geometry · Computer Science 2014-08-12 Greg Aloupis , Luis Barba , Paz Carmi , Vida Dujmović , Fabrizio Frati , Pat Morin

In this paper, we show new data structures maintaining approximate shortest paths in sparse directed graphs with polynomially bounded non-negative edge weights under edge insertions. We give more efficient incremental…

Data Structures and Algorithms · Computer Science 2025-02-17 Adam Górkiewicz , Adam Karczmarz

We give an algorithm for finding the arboricity of a weighted, undirected graph, defined as the minimum number of spanning forests that cover all edges of the graph, in $\sqrt{n} m^{1+o(1)}$ time. This improves on the previous best bound of…

Data Structures and Algorithms · Computer Science 2025-07-22 Ruoxu Cen , Henry Fleischmann , George Z. Li , Jason Li , Debmalya Panigrahi

We present a deterministic fully-dynamic data structure for maintaining information about the bridges in a graph. We support updates in $\tilde{O}((\log n)^2)$ amortized time, and can find a bridge in the component of any given vertex, or a…

Data Structures and Algorithms · Computer Science 2018-08-28 Jacob Holm , Eva Rotenberg , Mikkel Thorup

Effective resistances are ubiquitous in graph algorithms and network analysis. In this work, we study sublinear time algorithms to approximate the effective resistance of an adjacent pair $s$ and $t$. We consider the classical adjacency…

Data Structures and Algorithms · Computer Science 2023-07-06 Dongrun Cai , Xue Chen , Pan Peng

We consider the minimum cut problem in undirected, weighted graphs. We give a simple algorithm to find a minimum cut that $2$-respects (cuts two edges of) a spanning tree $T$ of a graph $G$. This procedure can be used in place of the…

Data Structures and Algorithms · Computer Science 2020-06-11 Nalin Bhardwaj , Antonio Molina Lovett , Bryce Sandlund

Graph learning from data represents a canonical problem that has received substantial attention in the literature. However, insufficient work has been done in incorporating prior structural knowledge onto the learning of underlying…

Machine Learning · Statistics 2019-04-23 Sandeep Kumar , Jiaxi Ying , José Vinícius de M. Cardoso , Daniel Palomar

It follows from the work of Tait and the Four-Color-Theorem that a planar cubic graph is 3-edge-colorable if and only if it contains no bridge. We consider the question of which planar graphs are subgraphs of planar cubic bridgeless graphs,…

Data Structures and Algorithms · Computer Science 2022-07-18 Miriam Goetze , Paul Jungeblut , Torsten Ueckerdt

Structural balance theory studies stability in networks. Given a $n$-vertex complete graph $G=(V,E)$ whose edges are labeled positive or negative, the graph is considered \emph{balanced} if every triangle either consists of three positive…

Data Structures and Algorithms · Computer Science 2023-06-02 Vikrant Ashvinkumar , Sepehr Assadi , Chengyuan Deng , Jie Gao , Chen Wang

The {Congested Clique} is a distributed-computing model for single-hop networks with restricted bandwidth that has been very intensively studied recently. It models a network by an $n$-vertex graph in which any pair of vertices can…

Distributed, Parallel, and Cluster Computing · Computer Science 2018-02-21 Leonid Barenboim , Victor Khazanov

A linear-time certifying algorithm for 3-edge-connectivity is presented. Given an undirected graph G, if G is 3-edge-connected, the algorithm generates a construction sequence as a positive certificate for G. Otherwise, the algorithm…

Data Structures and Algorithms · Computer Science 2022-02-01 Yung H. Tsin

Given a set of points in the plane, we want to establish a connection network between these points that consists of several disjoint layers. Motivated by sensor networks, we want that each layer is spanning and plane, and that no edge is…

We present a dynamic data structure representing a graph G, which allows addition and removal of edges from G and can determine the number of appearances of a graph of a bounded size as an induced subgraph of G. The queries are answered in…

Data Structures and Algorithms · Computer Science 2013-01-04 Zdenek Dvorak , Vojtech Tuma

Finding a smallest subgraph that is k-edge-connected, or augmenting a k-edge-connected graph with a smallest subset of given candidate edges to become (k+1)-edge-connected, are among the most fundamental Network Design problems. They are…

Data Structures and Algorithms · Computer Science 2025-12-25 Meike Neuwohner , Vera Traub , Rico Zenklusen

Understanding how a vertex relates to a set of vertices is a fundamental task in graph analysis. Given a graph $G$ and a vertex set $X \subseteq V(G)$, consider the collection of subsets of the form $N(u) \cap X$ where $u$ ranges over all…

Data Structures and Algorithms · Computer Science 2025-12-01 Christine Awofeso , Pål Grønås Drange , Patrick Greaves , Oded Lachish , Felix Reidl

Maintaining a $k$-core decomposition quickly in a dynamic graph has important applications in network analysis. The main challenge for designing efficient exact algorithms is that a single update to the graph can cause significant global…

Data Structures and Algorithms · Computer Science 2023-09-28 Quanquan C. Liu , Jessica Shi , Shangdi Yu , Laxman Dhulipala , Julian Shun

A planar orthogonal drawing of a planar 4-graph G (i.e., a planar graph with vertex-degree at most four) is a crossing-free drawing that maps each vertex of G to a distinct point of the plane and each edge of $G$ to a sequence of horizontal…

Computational Geometry · Computer Science 2022-05-17 Walter Didimo , Michael Kaufmann , Giuseppe Liotta , Giacomo Ortali

Graph partitioning schedules parallel calculations like sparse matrix-vector multiply (SpMV). We consider contiguous partitions, where the $m$ rows (or columns) of a sparse matrix with $N$ nonzeros are split into $K$ parts without…

Data Structures and Algorithms · Computer Science 2024-10-30 Willow Ahrens

Given a directed graph $G = (V,E)$, undergoing an online sequence of edge deletions with $m$ edges in the initial version of $G$ and $n = |V|$, we consider the problem of maintaining all-pairs shortest paths (APSP) in $G$. Whilst this…

Data Structures and Algorithms · Computer Science 2020-10-05 Jacob Evald , Viktor Fredslund-Hansen , Maximilian Probst Gutenberg , Christian Wulff-Nilsen