Quadruple Roman Domination in Trees
Zheng Kou, Saeed Kosari, Guoliang Hao, Jafar Amjadi, N. Khalili · Symmetry · 2021
This paper is devoted to the study of the quadruple Roman domination in trees, and it is a contribution to the Special Issue “Theoretical computer science and discrete mathematics” of Symmetry. For any positive integer k, a [k]-Roman dominating function ([k]-RDF) of a simple graph G is a function from the vertex set V of G to the set {0,1,2,…,k+1} if for any vertex u∈V with f(u)