## Abstract We 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
Interval bigraphs and circular arc graphs
โ Scribed by Pavol Hell; Jing Huang
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 130 KB
- Volume
- 46
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
We prove that the complements of interval bigraphs are precisely those circular arc graphs of clique covering number two, which admit a representation without two arcs covering the whole circle. We give another characterization of interval bigraphs, in terms of a vertex ordering, that we hope may prove helpful in finding a more efficient recognition algorithm than presently known. We use these results to show equality, amongst bipartite graphs, of several classes of structured graphs (proper interval bigraphs, complements of proper circular arc graphs, asteroidalโtripleโfree graphs, permutation graphs, and coโcomparability graphs). Our results verify a conjecture of Lundgren and disprove a conjecture of Mรผller. ยฉ 2004 Wiley Periodicals, Inc. J Graph Theory 46: 313โ327, 2004
๐ SIMILAR VOLUMES
## Abstract Given a set __F__ of digraphs, we say a graph __G__ is a __F__โ__graph__ (resp., __F__\*โ__graph__) if it has an orientation (resp., acyclic orientation) that has no induced subdigraphs isomorphic to any of the digraphs in __F__. It is proved that all the classes of graphs mentioned in
## Abstract The __p__โcenter problem is to locate __p__ facilities on a network so as to minimize the largest distance from a demand point to its nearest facility. The __p__โmedian problem is to locate __p__ facilities on a network so as to minimize the average distance from a demand point to its c
In this paper, we study the following all-pair shortest path query problem: Given the interval model of an unweighted interval graph of n vertices, build a data structure such that each query on the shortest path (or its length) between any pair of vertices of the graph can be processed efficiently
## Abstract A circularโarc graph is the intersection graph of a family of arcs on a circle. A characterization by forbidden induced subgraphs for this class of graphs is not known, and in this work we present a partial result in this direction. We characterize circularโarc graphs by a list of minim
A graph G is called well covered if every two maximal independent sets of G have the same number of vertices. In this paper, we,characterize well covered simplicial, chordal and circular arc graphs.