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The representation complexity of a bipartite graph $G=(P,Q)$ is the minimum size $\sum_{i=1}^s (|A_i|+|B_i|)$ over all possible ways to write $G$ as a (not necessarily disjoint) union of complete bipartite subgraphs $G=\cup_{i=1}^s…

Combinatorics · Mathematics 2018-04-06 Thao Do

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

In this paper, we study the outerplanarity of planar graphs, i.e., the number of times that we must (in a planar embedding that we can initially freely choose) remove the outerface vertices until the graph is empty. It is well-known that…

Data Structures and Algorithms · Computer Science 2024-07-08 Therese Biedl , Debajyoti Mondal

Given $n$ points in the plane, a \emph{covering path} is a polygonal path that visits all the points. If no three points are collinear, every covering path requires at least $n/2$ segments, and $n-1$ straight line segments obviously suffice…

Combinatorics · Mathematics 2013-03-04 Adrian Dumitrescu , Daniel Gerbner , Balazs Keszegh , Csaba D. Toth

Scheinerman and Wilf (1994) assert that `an important open problem in the study of graph embeddings is to determine the rectilinear crossing number of the complete graph K_n.' A rectilinear drawing of K_n is an arrangement of n vertices in…

Discrete Mathematics · Computer Science 2011-10-04 Alex Brodsky , Stephane Durocher , Ellen Gethner

A 1-plane graph is a graph together with a drawing in the plane in such a way that each edge is crossed at most once. A 1-plane graph is maximal if no edge can be added without violating either 1-planarity or simplicity. Let $m(n)$ denote…

Combinatorics · Mathematics 2025-02-18 Yuanqiu Huang , Zhangdong Ouyang , Licheng Zhang , Fengming Dong

A $(2,1)$-total labeling of a graph $G$ is an assignment $f$ from the vertex set $V(G)$ and the edge set $E(G)$ to the set $\{0,1,...,k\}$ of nonnegative integers such that $|f(x)-f(y)|\ge 2$ if $x$ is a vertex and $y$ is an edge incident…

Discrete Mathematics · Computer Science 2009-11-25 Toru Hasunuma , Toshimasa Ishii , Hirotaka Ono , Yushi Uno

We define the geometric thickness of a graph to be the smallest number of layers such that we can draw the graph in the plane with straight-line edges and assign each edge to a layer so that no two edges on the same layer cross. The…

Combinatorics · Mathematics 2007-05-23 Michael B. Dillencourt , David Eppstein , Daniel S. Hirschberg

We exactly settle the complexity of graph realization, graph rigidity, and graph global rigidity as applied to three types of graphs: "globally noncrossing" graphs, which avoid crossings in all of their configurations; matchstick graphs,…

Computational Geometry · Computer Science 2025-10-21 Zachary Abel , Erik D. Demaine , Martin L. Demaine , Sarah Eisenstat , Jayson Lynch , Tao B. Schardl

In geographic information systems and in the production of digital maps for small devices with restricted computational resources one often wants to round coordinates to a rougher grid. This removes unnecessary detail and reduces space…

Computational Geometry · Computer Science 2016-09-01 Andre Löffler , Thomas C. van Dijk , Alexander Wolff

It is currently an unsolved problem to determine whether a $\triangle$-free planar graph $G$ contains an independent set $A$ such that $G[V_G\setminus A]$ is $2$-choosable. However, in this paper, we take a slightly different approach by…

Combinatorics · Mathematics 2023-05-22 Sounaka Mishra , Rohini S , Sagar S. Sawant

The concept of $k$-planarity is extensively studied in the context of Beyond Planarity. A graph is $k$-planar if it admits a drawing in the plane in which each edge is crossed at most $k$ times. The local crossing number of a graph is the…

Data Structures and Algorithms · Computer Science 2025-08-28 Tatsuya Gima , Yasuaki Kobayashi , Yuto Okada

Algorithmic extension problems of partial graph representations such as planar graph drawings or geometric intersection representations are of growing interest in topological graph theory and graph drawing. In such an extension problem, we…

Data Structures and Algorithms · Computer Science 2020-04-28 Eduard Eiben , Robert Ganian , Thekla Hamm , Fabian Klute , Martin Nöllenburg

The skewness of a graph G is the minimum number of edges in G whose removal results in a planar graph. By appropriately introducing a weight to each edge of a graph, we determine, among other thing, the skewness of the generalized Petersen…

Combinatorics · Mathematics 2017-09-20 Gek L. Chia , Chan L. Lee , Yan Hao Ling

A \emph{queue layout} of a graph consists of a total order of the vertices, and a partition of the edges into \emph{queues}, such that no two edges in the same queue are nested. The minimum number of queues in a queue layout of a graph is…

Discrete Mathematics · Computer Science 2011-10-05 Vida Dujmovic , Pat Morin , David R. Wood

A total dominating set of a graph $G=(V,E)$ is a subset $D \subseteq V$ such that every vertex in $V$ is adjacent to some vertex in $D$. Finding a total dominating set of minimum size is NP-hard on planar graphs and W[2]-complete on general…

Data Structures and Algorithms · Computer Science 2023-06-22 Valentin Garnero , Ignasi Sau

Let $P$ be a set of points in general position in the plane. Join all pairs of points in $P$ with straight line segments. The number of segment-crossings in such a drawing, denoted by $\crg(P)$, is the \emph{rectilinear crossing number} of…

The segment number of a planar graph $G$ is the smallest number of line segments needed for a planar straight-line drawing of $G$. Dujmovi\'c, Eppstein, Suderman, and Wood [CGTA'07] introduced this measure for the visual complexity of…

Computational Geometry · Computer Science 2022-07-18 Ina Goeßmann , Jonathan Klawitter , Boris Klemz , Felix Klesen , Stephen Kobourov , Myroslav Kryven , Alexander Wolff , Johannes Zink

Let $r \geq 2$ be a real number. A complex nowhere-zero $r$-flow on a graph $G$ is an orientation of $G$ together with an assignment $\varphi\colon E(G)\to \mathbb{C}$ such that, for all $e \in E(G)$, the modulus of the complex number…

Combinatorics · Mathematics 2023-03-21 Davide Mattiolo , Giuseppe Mazzuoccolo , Jozef Rajník , Gloria Tabarelli

A drawing of a graph is greedy if for each ordered pair of vertices u and v, there is a path from u to v such that the Euclidean distance to v decreases monotonically at every vertex of the path. The existence of greedy drawings has been…