DMGT

ISSN 1234-3099 (print version)

ISSN 2083-5892 (electronic version)

https://doi.org/10.7151/dmgt

Discussiones Mathematicae Graph Theory

Journal Impact Factor (JIF 2022): 0.7

5-year Journal Impact Factor (2022): 0.7

CiteScore (2022): 1.9

SNIP (2022): 0.902

Discussiones Mathematicae Graph Theory

Article in volume


Authors:

H. Abdollahzadeh Ahangar

Hossein Abdollahzadeh Ahangar

Babol Noshirvani University of Technology

email: ha.ahangar@yahoo.com

M. Chellali

Mustapha Chellali

Department of MathematicsUniversity of BlidaB.P. 270, Blida, ALGERIA

email: m_chellali@yahoo.com

0000-0001-5231-6195

S.M. Sheikholeslami

Seyed Mahmoud Sheikholeslami

Azarbaijan Shahid Madani university

email: s.m.sheikholeslami@azaruniv.ac.ir

J.C. Valenzuela-Tripodoro

Juan Carlos Valenzuela-Tripodoro

University of Cadiz

email: jcarlos.valenzuela@uca.es

Title:

Total Roman $\{2\}$-dominating functions in graphs

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Source:

Discussiones Mathematicae Graph Theory 42(3) (2022) 937-958

Received: 2019-10-29 , Revised: 2020-03-02 , Accepted: 2020-03-23 , Available online: 2020-04-18 , https://doi.org/10.7151/dmgt.2316

Abstract:

A Roman $\{2\}$-dominating function (R2F) is a function $f:V\rightarrow \{0,1,2\}$ with the property that for every vertex $v\in V$ with $f(v)=0$ there is a neighbor $u$ of $v$ with $f(u)=2$, or there are two neighbors $x,y$ of $v$ with $f(x)=f(y)=1$. A total Roman $\{2\}$-dominating function (TR2DF) is an R2F $f$ such that the set of vertices with $f(v)>0$ induce a subgraph with no isolated vertices. The weight of a TR2DF is the sum of its function values over all vertices, and the minimum weight of a TR2DF of $G$ is the total Roman $\{2\}$-domination number $\gamma_{tR2}(G).$ In this paper, we initiate the study of total Roman $\{2\}$-dominating functions, where properties are established. Moreover, we present various bounds on the total Roman $\{2\}$-domination number. We also show that the decision problem associated with $\gamma_{tR2}(G)$ is NP-complete for bipartite and chordal graphs. Moreover, we show that it is possible to compute this parameter in linear time for bounded clique-width graphs (including trees).

Keywords:

Roman domination, Roman $\{2\}$-domination, total Roman $\{2\}$-domination

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