scholarly journals Vertex Disjoint Paths in Upward Planar Graphs

2014 ◽  
pp. 52-64 ◽  
Author(s):  
Saeed Akhoondian Amiri ◽  
Ali Golshani ◽  
Stephan Kreutzer ◽  
Sebastian Siebertz
Keyword(s):  
Planar Graphs ◽  
Disjoint Paths ◽  
Vertex Disjoint

Gossiping in vertex-disjoint paths mode in d-dimensional grids and planar graphs

1993 ◽  
pp. 200-211 ◽  
Author(s):  
Juraj Hromkovič ◽  
Ralf Klasing ◽  
Elena A. Stöhr ◽  
Hubert Wagener
Keyword(s):  
Planar Graphs ◽  
Disjoint Paths ◽  
Vertex Disjoint

scholarly journals Gossiping in Vertex-Disjoint Paths Mode in d-Dimensional Grids and Planar Graphs

1995 ◽  
Vol 123 (1) ◽  
pp. 17-28 ◽  
Author(s):  
J. Hromkovic ◽  
R. Klasing ◽  
E.A. Stohr ◽  
H. Wagener
Keyword(s):  
Planar Graphs ◽  
Disjoint Paths ◽  
Vertex Disjoint

LINEAR-TIME ALGORITHMS FOR DISJOINT TWO-FACE PATHS PROBLEMS IN PLANAR GRAPHS

1996 ◽  
Vol 07 (02) ◽  
pp. 95-110 ◽  
Author(s):  
HEIKE RIPPHAUSEN-LIPA ◽  
DOROTHEA WAGNER ◽  
KARSTEN WEIHE
Keyword(s):  
Planar Graphs ◽  
Linear Time ◽  
Time Algorithm ◽  
Disjoint Paths ◽  
Linear Time Algorithm ◽  
Vertex Disjoint ◽  
Linear Time Algorithms

In this paper we present a linear-time algorithm for the vertex-disjoint Two-Face Paths Problem in planar graphs, i.e., the problem of finding k vertex-disjoint paths between pairs of terminals which lie on two face boundaries. The algorithm is based on the idea of finding rightmost paths with a certain property in planar graphs. Using this method, a linear-time algorithm for finding vertex-disjoint paths of a prescribed homotopy is derived. Moreover, the algorithm is modified to solve the more general linkage problem in linear time, as well.

scholarly journals Non-Separating Planar Graphs

10.37236/8816 ◽  
2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Hooman R. Dehkordi ◽  
Graham Farr
Keyword(s):  
Planar Graph ◽  
Planar Graphs ◽  
Disjoint Union ◽  
Disjoint Paths ◽  
Outerplanar Graph ◽  
Outerplanar Graphs ◽  
Structural Characterisation ◽  
A Minor ◽  
Vertex Disjoint

A graph $G$ is a non-separating planar graph if there is a drawing $D$ of $G$ on the plane such that (1) no two edges cross each other in $D$ and (2) for any cycle $C$ in $D$, any two vertices not in $C$ are on the same side of $C$ in $D$. Non-separating planar graphs are closed under taking minors and are a subclass of planar graphs and a superclass of outerplanar graphs. In this paper, we show that a graph is a non-separating planar graph if and only if it does not contain $K_1 \cup K_4$ or $K_1 \cup K_{2,3}$ or $K_{1,1,3}$ as a minor. Furthermore, we provide a structural characterisation of this class of graphs. More specifically, we show that any maximal non-separating planar graph is either an outerplanar graph or a wheel or it is a graph obtained from the disjoint union of two triangles by adding three vertex-disjoint paths between the two triangles. Lastly, to demonstrate an application of non-separating planar graphs, we use the characterisation of non-separating planar graphs to prove that there are maximal linkless graphs with $3n-3$ edges. Thus, maximal linkless graphs can have significantly fewer edges than maximum linkless graphs; Sachs exhibited linkless graphs with $n$ vertices and $4n-10$ edges (the maximum possible) in 1983.

scholarly journals Cycle partitions of regular graphs

2020 ◽  
pp. 1-24
Author(s):  
Vytautas Gruslys ◽  
Shoham Letzter
Keyword(s):  
Regular Graph ◽  
Bipartite Graphs ◽  
Disjoint Paths ◽  
Regular Graphs ◽  
Simple Construction ◽  
Vertex Set ◽  
Almost All ◽  
Vertex Disjoint

Abstract Magnant and Martin conjectured that the vertex set of any d-regular graph G on n vertices can be partitioned into $n / (d+1)$ paths (there exists a simple construction showing that this bound would be best possible). We prove this conjecture when $d = \Omega(n)$ , improving a result of Han, who showed that in this range almost all vertices of G can be covered by $n / (d+1) + 1$ vertex-disjoint paths. In fact our proof gives a partition of V(G) into cycles. We also show that, if $d = \Omega(n)$ and G is bipartite, then V(G) can be partitioned into n/(2d) paths (this bound is tight for bipartite graphs).

The Hyper-Zagreb Index and Some Properties of Graphs

2020 ◽  
pp. 120-134 ◽  
Author(s):  
Rao Li
Keyword(s):  
Topological Index ◽  
Sufficient Conditions ◽  
Disjoint Paths ◽  
Zagreb Index ◽  
Connected Graphs ◽  
Second Zagreb Index ◽  
Vertex Disjoint ◽  
Hamiltonian Properties

Let G = (V(G), E(G)) be a graph. The complement of G is denoted by Gc. The forgotten topological index of G, denoted F(G), is defined as the sum of the cubes of the degrees of all the vertices in G. The second Zagreb index of G, denoted M2(G), is defined as the sum of the products of the degrees of pairs of adjacent vertices in G. A graph Gisk-Hamiltonian if for all X ⊂V(G) with|X| ≤ k, the subgraph induced byV(G) - Xis Hamiltonian. Clearly, G is 0-Hamiltonian if and only if G is Hamiltonian. A graph Gisk-path-coverableifV(G) can be covered bykor fewer vertex-disjoint paths. Using F(Gc) and M2(Gc), Li obtained several sufficient conditions for Hamiltonian and traceable graphs (Rao Li, Topological Indexes and Some Hamiltonian Properties of Graphs). In this chapter, the author presents sufficient conditions based upon F(Gc) and M2(Gc)for k-Hamiltonian, k-edge-Hamiltonian, k-path-coverable, k-connected, and k-edge-connected graphs.

scholarly journals Vertex-Disjoint Paths in a 3-Ary n-Cube with Faulty Vertices

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xiaolei Ma ◽  
Shiying Wang
Keyword(s):  
Interconnection Networks ◽  
Transmission Rate ◽  
Research Topic ◽  
Disjoint Paths ◽  
Important Research ◽  
Important Research Topic ◽  
Vertex Disjoint

The construction of vertex-disjoint paths (disjoint paths) is an important research topic in various kinds of interconnection networks, which can improve the transmission rate and reliability. The k-ary n-cube is a family of popular networks. In this paper, we determine that there are m2≤m≤n disjoint paths in 3-ary n-cube covering Qn3−F from S to T (many-to-many) with F≤2n−2m and from s to T (one-to-many) with F≤2n−m−1 where s is in a fault-free cycle of length three.

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