arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2402.07968math.CO
收藏

图中的全Roman {2}-支配函数

Total Roman {2}-Dominating functions in Graphs

H. Abdollahzadeh Ahangar, M. Chellali, S. M. Sheikholeslami, J. C. Valenzuela-Tripodoro

AI总结:

本文开创性地研究了全Roman {2}-支配函数,确立了其性质与界限,证明相关判定问题在二部图和弦图中是NP完全的,并指出该参数在有界团宽图中可线性时间计算。

摘要:

Roman $\{2\}$-支配函数(R2F)是一个函数 $f:V\rightarrow \{0,1,2\}$,其性质为:对于每个满足 $f(v)=0$ 的顶点 $v\in V$,存在 $v$ 的一个邻居 $u$ 满足 $f(u)=2$,或者存在 $v$ 的两个邻居 $x,y$ 满足 $f(x)=f(y)=1$。全Roman $\{2\}$-支配函数(TR2DF)是一个满足以下条件的R2F $f$:所有满足 $f(v)>0$ 的顶点集合所导出的子图没有孤立顶点。TR2DF的权重是其所有顶点函数值之和,而 $G$ 的TR2DF的最小权重即为全Roman $\{2\}$-支配数 $γ_{tR2}(G)$。在本文中,我们开创了对全Roman $\{2\}$-支配函数的研究,并确立了其相关性质。此外,我们给出了全Roman $\{2\}$-支配数的各种界限。我们还证明了与 $γ_{tR2}(G)$ 相关的判定问题对于二部图和弦图是NP完全的。此外,我们证明了对于有界团宽图(包括树),可以在线性时间内计算该参数。

英文摘要:

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 $γ_{tR2}(G).$ 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 $γ_{tR2}(G)$ 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 tres).}

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑