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Related papers: Recognizing IC-Planar and NIC-Planar Graphs

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In the area of beyond-planar graphs, i.e. graphs that can be drawn with some local restrictions on the edge crossings, the recognition problem is prominent next to the density question for the different graph classes. For 1-planar graphs,…

Data Structures and Algorithms · Computer Science 2021-08-04 Henry Förster , Michael Kaufmann , Chrysanthi N. Raftopoulou

A graph is $k$-planar if it can be drawn in the plane such that no edge is crossed more than $k$ times. While for $k=1$, optimal $1$-planar graphs, i.e., those with $n$ vertices and exactly $4n-8$ edges, have been completely characterized,…

Computational Geometry · Computer Science 2017-03-21 Michael A. Bekos , Michael Kaufmann , Chrysanthi N. Raftopoulou

A graph is beyond-planar if it can be drawn in the plane with a specific restriction on crossings. Several types of beyond-planar graphs have been investigated, such as k-planar if every edge is crossed at most k times and RAC if edges can…

Discrete Mathematics · Computer Science 2022-01-04 Franz J. Brandenburg

A plane graph is rectilinear planar if it admits an embedding-preserving straight-line drawing where each edge is either horizontal or vertical. We prove that rectilinear planarity testing can be solved in optimal $O(n)$ time for any plane…

Data Structures and Algorithms · Computer Science 2021-03-01 Walter Didimo , Michael Kaufmann , Giuseppe Liotta , Giacomo Ortali

A graph is $1$-$planar$ if it can be drawn in the plane so that each edge is crossed by at most one other edge. Moreover, a 1-planar graph $G$ is $optimal$ if it satisfies $|E(G)|=4|V(G)|-8$. J. Fujisawa et al. [16] first considered…

Combinatorics · Mathematics 2022-05-25 Jiangyue Zhang , Yan Wu , Heping Zhang

An equitable coloring of a graph is a proper coloring where the sizes of any two different color classes do not differ by more than one. A graph is IC-planar if it can be drawn in the plane so that no two crossed edges have a common…

Combinatorics · Mathematics 2025-04-18 Weichan Liu

A graph is near-planar if it can be obtained from a planar graph by adding an edge. We show the surprising fact that it is NP-hard to compute the crossing number of near-planar graphs. A graph is 1-planar if it has a drawing where every…

Computational Geometry · Computer Science 2012-03-28 Sergio Cabello , Bojan Mohar

It is known that the vertex connectivity of a planar graph can be computed in linear time. We extend this result to the class of locally maximal 1-plane graphs: graphs that have an embedding with at most one crossing per edge such that the…

Combinatorics · Mathematics 2021-12-14 Therese Biedl , Karthik Murali

We study contact representations of graphs in which vertices are represented by axis-aligned polyhedra in 3D and edges are realized by non-zero area common boundaries between corresponding polyhedra. We show that for every 3-connected…

Computational Geometry · Computer Science 2015-05-05 Md. Jawaherul Alam , William Evans , Stephen G. Kobourov , Sergey Pupyrev , Jackson Toeniskoetter , Torsten Ueckerdt

A graph is $1$-planar, if it can be drawn in the plane such that there is at most one crossing on every edge. It is known, that $1$-planar graphs have at most $4n-8$ edges. We prove the following odd-even generalization. If a graph can be…

Combinatorics · Mathematics 2022-08-26 János Karl , Géza Tóth

A graph is 1-planar if it can be drawn in the plane such that each edge is crossed at most once. A graph, together with a 1-planar drawing is called 1-plane. Brandenburg et al. showed that there are maximal 1-planar graphs with only…

Combinatorics · Mathematics 2015-09-21 János Barát , Géza Tóth

We show that the 1-planar slope number of 3-connected cubic 1-planar graphs is at most 4 when edges are drawn as polygonal curves with at most 1 bend each. This bound is obtained by drawings whose vertex and crossing resolution is at least…

Computational Geometry · Computer Science 2018-08-28 Philipp Kindermann , Fabrizio Montecchiani , Lena Schlipf , André Schulz

We propose a fixed-parameter tractable algorithm for the \textsc{Max-Cut} problem on embedded 1-planar graphs parameterized by the crossing number $k$ of the given embedding. A graph is called 1-planar if it can be drawn in the plane with…

Data Structures and Algorithms · Computer Science 2018-12-08 Christine Dahn , Nils M. Kriege , Petra Mutzel

In octilinear drawings of planar graphs, every edge is drawn as an alternating sequence of horizontal, vertical and diagonal ($45^\circ$) line-segments. In this paper, we study octilinear drawings of low edge complexity, i.e., with few…

Data Structures and Algorithms · Computer Science 2014-08-27 Michael A. Bekos , Martin Gronemann , Michael Kaufmann , Robert Krug

The definition of $1$-planar graphs naturally extends graph planarity, namely a graph is $1$-planar if it can be drawn in the plane with at most one crossing per edge. Unfortunately, while testing graph planarity is solvable in linear time,…

Computational Geometry · Computer Science 2019-11-05 Carla Binucci , Walter Didimo , Fabrizio Montecchiani

The notion of 1-planarity is among the most natural and most studied generalizations of graph planarity. A graph is 1-planar if it has an embedding where each edge is crossed by at most another edge. The study of 1-planar graphs dates back…

Computational Geometry · Computer Science 2017-07-21 Stephen G. Kobourov , Giuseppe Liotta , Fabrizio Montecchiani

The study of nonplanar drawings of graphs with restricted crossing configurations is a well-established topic in graph drawing, often referred to as beyond-planar graph drawing. One of the most studied types of drawings in this area are the…

A graph is unipolar if it can be partitioned into a clique and a disjoint union of cliques, and a graph is a generalised split graph if it or its complement is unipolar. A unipolar partition of a graph can be used to find efficiently the…

Data Structures and Algorithms · Computer Science 2016-04-05 Colin McDiarmid , Nikola Yolov

A graph $G=(V,E)$ is a {\it unipolar graph} if there exits a partition $V=V_1 \cup V_2$ such that, $V_1$ is a clique and $V_2$ induces the disjoint union of cliques. The complement-closed class of {\it generalized split graphs} are those…

Discrete Mathematics · Computer Science 2013-09-24 Elaine M. Eschen , Xiaoqiang Wang

While orthogonal drawings have a long history, smooth orthogonal drawings have been introduced only recently. So far, only planar drawings or drawings with an arbitrary number of crossings per edge have been studied. Recently, a lot of…