Results 201 to 210 of about 2,881 (227)

List Homomorphisms and Circular Arc Graphs

Combinatorica, 1999
The list homomorphism problem for a graph \(H\) has as input a graph \(G\) and lists \(L(v)\subseteq V(H)\) for the vertices \(v\in V(G)\). The output is a homomorphism \(f:G\to H\) with \(f(v)\in L(v)\) for every \(v\in V(G)\). It is shown that if \(H\) is loopless then this problem is polynomially solvable if \(\overline{H}\) is a circular arc graph ...
Tomás Feder, Pavol Hell, Jing Huang 0007   +2 more
openaire   +1 more source

Two remarks on circular arc graphs

Graphs and Combinatorics, 1997
A graph \(G\) is said to be a circular arc graph if there exist circular arcs A\(g\), \(g\in V(G)\), such that \(g\), \(g'\) are adjacent in \(G\) if and only if the corresponding A\(g\), A\(_{g'}\) intersect. This paper shows that a graph with clique covering number two is a circular arc graph if and only if its edges can be coloured by two colours so
Pavol Hell, Jing Huang 0007
openaire   +2 more sources

An Efficient Test for Circular-Arc Graphs

SIAM Journal on Computing, 1980
An undirected graph G is called a circular-arc graph if there exists a family of arcs on a circle and a 1–1 correspondence between vertices and arcs such that two distinct vertices are adjacent if and only if the corresponding arcs overlap. Such a family is called a circular-arc model for G.
openaire   +2 more sources

Efficient algorithms for interval graphs and circular‐arc graphs

Networks, 1982
AbstractWe show that for an interval graph given in the form of a family of intervals, a maximum independent set, a minimum covering by disjoint completely connected sets or cliques, and a maximum clique can all be found in O(n log n) time [O(n) time if the endpoints of the intervals are sorted].
Udaiprakash I. Gupta, D. T. Lee, Joseph Y.-T. Leung   +2 more
openaire   +2 more sources

k Best Cuts for Circular-Arc graphs

Algorithmica, 1994
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Kuo-Hui Tsai, D. T. Lee
openaire   +1 more source

Minimum Fill-in on Circle and Circular-Arc Graphs

Journal of Algorithms, 1996
Summary: We described elegant and efficient algorithms for solving the MINIMUM FILL-IN problem on circle graphs and circular-arc graphs, which are based on representation theorems for the minimal triangulations of such graphs. Representation theorems of this type are powerful tools for designing treewidth and minimum fill-in algorithms.
Kloks, T., Kratsch, D., Wong, C.K.
openaire   +2 more sources

Clique graphs of Helly circular-arc graphs.

Ars Comb., 2001
A graph \(G\) is a Helly circular-arc graph if \(G\) can be represented as the intersection graph of a system of arcs on a circle such that the arcs satisfy the Helly property. The clique graph of \(G\) is the intersection graph of the cliques of \(G\). In the paper, clique graphs of Helly circular-arc graphs are characterized in terms of the existence
Guillermo Durán 0001, Min Chih Lin
openaire   +1 more source

Proper Helly Circular-Arc Graphs

2007
A circular-arc model M=(C,A) is a circle C together with a collection A of arcs of C. If no arc is contained in any other then M is a proper circular-arc model, if every arc has the same length then M is a unit circular-arc model and if A satisfies the Helly Property then M is a Helly circular-arc model.
Min Chih Lin, Francisco J. Soulignac, Jayme Luiz Szwarcfiter   +2 more
openaire   +1 more source

NC algorithms for circular-arc graphs

1989
Circular-arc graphs are an important class of intersection graphs. They have been applied to problems in genetics [17], traffic control [18], multidimensional scaling [11], computer compiler design [22], characterization of a certain class of lattices [19], and some other areas [13] [23].
openaire   +1 more source

On Roman domination of circular-arc graphs

International Journal of Advanced Intelligence Paradigms, 2018
Akul Rana, Angshu Kumar Sinha, Anita Pal
openaire   +1 more source