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Related papers: Decremental SPQR-trees for Planar Graphs

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We introduce three new cut tree structures of graphs $G$ in which the vertex set of the tree is a partition of $V(G)$ and contractions of tree vertices satisfy sparsification requirements that preserve various types of cuts. Recently,…

Combinatorics · Mathematics 2017-07-04 On-Hei Solomon Lo , Jens M. Schmidt

We give a new data structure for the fully-dynamic minimum spanning forest problem in simple graphs. Edge updates are supported in $O(\log^4n/\log\log n)$ amortized time per operation, improving the $O(\log^4n)$ amortized bound of Holm et…

Data Structures and Algorithms · Computer Science 2014-07-28 Jacob Holm , Eva Rotenberg , Christian Wulff-Nilsen

We provide a data structure for maintaining an embedding of a graph on a surface (represented combinatorially by a permutation of edges around each vertex) and computing generators of the fundamental group of the surface, in amortized time…

Data Structures and Algorithms · Computer Science 2007-05-23 David Eppstein

We present time-efficient distributed algorithms for decomposing graphs with large edge or vertex connectivity into multiple spanning or dominating trees, respectively. As their primary applications, these decompositions allow us to achieve…

Data Structures and Algorithms · Computer Science 2013-11-22 Keren Censor-Hillel , Mohsen Ghaffari , Fabian Kuhn

Recently we presented the first algorithm for maintaining the set of nodes reachable from a source node in a directed graph that is modified by edge deletions with $o(mn)$ total update time, where $m$ is the number of edges and $n$ is the…

Data Structures and Algorithms · Computer Science 2016-12-13 Monika Henzinger , Sebastian Krinninger , Danupon Nanongkai

We study the problem of efficiently answering strong connectivity queries under two vertex failures. Given a directed graph $G$ with $n$ vertices, we provide a data structure with $O(nh)$ space and $O(h)$ query time, where $h$ is the height…

Data Structures and Algorithms · Computer Science 2023-12-05 Loukas Georgiadis , Evangelos Kosinas , Daniel Tsokaktsis

Motivated by recent applications of dominator computations, we consider the problem of dynamically maintaining the dominators of flow graphs through a sequence of insertions and deletions of edges. Our main theoretical contribution is a…

Data Structures and Algorithms · Computer Science 2016-04-12 Loukas Georgiadis , Giuseppe F. Italiano , Luigi Laura , Federico Santaroni

The SPQR-tree is a data structure that compactly represents all planar embeddings of a biconnected planar graph. It plays a key role in constrained planarity testing. We develop a similar data structure, called the UP-tree, that compactly…

Data Structures and Algorithms · Computer Science 2019-08-02 Guido Brückner , Markus Himmel , Ignaz Rutter

We show how to find and efficiently maintain maximal k-edge-connected subgraphs in undirected graphs. In particular, we provide the following results. (1) A general framework for maintaining the maximal k-edge-connected subgraphs upon…

Data Structures and Algorithms · Computer Science 2023-05-02 Loukas Georgiadis , Giuseppe F. Italiano , Evangelos Kosinas , Debasish Pattanayak

We present $k^{O(k^2)} m$ time algorithms for various problems about decomposing a given undirected graph by edge cuts or vertex separators of size $<k$ into parts that are ``well-connected'' with respect to cuts or separators of size $<k$;…

Data Structures and Algorithms · Computer Science 2024-11-06 Tuukka Korhonen

We study the amortized number of combinatorial changes (edge insertions and removals) needed to update the graph structure of the Voronoi diagram $\mathcal{V}(S)$ (and several variants thereof) of a set $S$ of $n$ sites in the plane as…

Computational Geometry · Computer Science 2016-03-29 Sarah R. Allen , Luis Barba , John Iacono , Stefan Langerman

We give offline algorithms for processing a sequence of $2$ and $3$ edge and vertex connectivity queries in a fully-dynamic undirected graph. While the current best fully-dynamic online data structures for $3$-edge and $3$-vertex…

Data Structures and Algorithms · Computer Science 2019-03-22 Richard Peng , Bryce Sandlund , Daniel D. Sleator

A tree-packing is a collection of spanning trees of a graph. It has been a useful tool for computing the minimum cut in static, dynamic, and distributed settings. In particular, [Thorup, Comb. 2007] used them to obtain his dynamic min-cut…

Data Structures and Algorithms · Computer Science 2024-12-05 Tijn de Vos , Aleksander B. G. Christiansen

We present a data structure that in a dynamic graph of treedepth at most $d$, which is modified over time by edge insertions and deletions, maintains an optimum-height elimination forest. The data structure achieves worst-case update time…

We consider edge insertion and deletion operations that increase the connectivity of a given planar straight-line graph (PSLG), while minimizing the total edge length of the output. We show that every connected PSLG $G=(V,E)$ in general…

Computational Geometry · Computer Science 2016-12-15 Hugo A. Akitaya , Rajasekhar Inkulu , Torrie L. Nichols , Diane L. Souvaine , Csaba D. Tóth , Charles R. Winston

Given a dynamic digraph $G = (V,E)$ undergoing edge deletions and given $s\in V$ and $\epsilon>0$, we consider the problem of maintaining $(1+\epsilon)$-approximate shortest path distances from $s$ to all vertices in $G$ over the sequence…

Data Structures and Algorithms · Computer Science 2020-01-30 Maximilian Probst Gutenberg , Christian Wulff-Nilsen

We present a deterministic fully-dynamic data structure for maintaining information about the cut-vertices in a graph; i.e. the vertices whose removal would disconnect the graph. Our data structure supports insertion and deletion of edges,…

Data Structures and Algorithms · Computer Science 2025-03-28 Jacob Holm , Wojciech Nadara , Eva Rotenberg , Marek Sokołowski

In this paper, we present new incremental algorithms for maintaining data structures that represent all connectivity cuts of size one in directed graphs (digraphs), and the strongly connected components that result by the removal of each of…

Data Structures and Algorithms · Computer Science 2018-03-01 Loukas Georgiadis , Giuseppe F. Italiano , Nikos Parotsidis

We give an improved connectivity oracle under vertex failures. After a set of $k$ vertices fails, our oracle performs an $O(k^{6})$-time update independent of the graph size $n$, and then answers pairwise connectivity queries in optimal…

Data Structures and Algorithms · Computer Science 2026-05-11 Xizhe Li , Yaowei Long , David Pidugu , Thatchaphol Saranurak , Benyu Wang

We consider dynamic algorithms for maintaining Single-Source Reachability (SSR) and approximate Single-Source Shortest Paths (SSSP) on $n$-node $m$-edge directed graphs under edge deletions (decremental algorithms). The previous fastest…

Data Structures and Algorithms · Computer Science 2018-03-02 Monika Henzinger , Sebastian Krinninger , Danupon Nanongkai