Linear-Time Recognition of Double-Threshold Graphs

Autor: Yoshio Okamoto, Yushi Uno, Yota Otachi, Yusuke Kobayashi
Rok vydání: 2020
Předmět:
Zdroj: Graph-Theoretic Concepts in Computer Science ISBN: 9783030604394
WG
Popis: A graph \(G = (V,E)\) is a double-threshold graph if there exist a vertex-weight function \(w :V \rightarrow \mathbb {R}\) and two real numbers \(\mathtt {lb}, \mathtt {ub}\in \mathbb {R}\) such that \(uv \in E\) if and only if \(\mathtt {lb}\le \mathtt {w}(u) + \mathtt {w}(v) \le \mathtt {ub}\). In the literature, those graphs are studied as the pairwise compatibility graphs that have stars as their underlying trees. We give a new characterization of double-threshold graphs, which gives connections to bipartite permutation graphs. Using the new characterization, we present a linear-time algorithm for recognizing double-threshold graphs. Prior to our work, the fastest known algorithm by Xiao and Nagamochi [COCOON 2018] ran in \(O(n^6)\) time, where n is the number of vertices.
Databáze: OpenAIRE