Electronic Journal of Graph Theory and Applications (EJGTA)
Vol 10, No 2 (2022): Electronic Journal of Graph Theory and Applications

The locating chromatic number for m-shadow of a connected graph

I Wayan Sudarsana (Algebra and Combinatorics Research Group (ACRG), Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Tadulako, Indonesia)
Faisal Susanto (Doctoral Program of Mathematics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Indonesia)
Selvy Musdalifah (Algebra and Combinatorics Research Group, Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Tadulako)



Article Info

Publish Date
29 Oct 2022

Abstract

Let c : V(G)→{1, 2, …, k} be a proper k-coloring of a simple connected graph G. Let Π = {C1, C2, …, Ck} be a partition of V(G), where Ci is the set of vertices of G receiving color i. The color code, cΠ(v), of a vertex v with respect to Π is an ordered k-tuple (d(v, C2),d(v, C2),…,d(v, Ck)), where d(v, Ci)=min{d(v, x):x ∈ Ci} for i = 1, 2, …, k. If distinct vertices have distinct color codes then c is called a locating coloring of G. The minimum k for which c is a locating coloring is the locating chromatic number of G, denoted by χL(G). Let G be a non trivial connected graph and let m ≥ 2 be an integer. The m-shadow of G, denoted by Dm(G), is a graph obtained by taking m copies of G, say G1, G2, …, Gm, and each vertex v in Gi, i = 1, 2, …, m − 1, is joined to the neighbors of its corresponding vertex v′ in Gi + 1. In the present paper, we deal with the locating chromatic number for m-shadow of connected graphs. Sharp bounds on the locating chromatic number of Dm(G) for any non trivial connected graph G and any integer m ≥ 2 are obtained. Then the values of locating chromatic number for m-shadow of complete multipartite graphs and paths are determined, some of which are considered to be optimal.

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Journal Info

Abbrev

ejgta

Publisher

Subject

Electrical & Electronics Engineering

Description

The Electronic Journal of Graph Theory and Applications (EJGTA) is a refereed journal devoted to all areas of modern graph theory together with applications to other fields of mathematics, computer science and other sciences. The journal is published by the Indonesian Combinatorial Society ...