🤖 AI Summary
This paper investigates the Minimum Liar Vertex–Edge Dominating Set problem (MinLVEDP) on subclasses of chordal graphs—specifically block graphs and proper interval graphs. MinLVEDP seeks a minimum vertex set (L) such that (i) the closed neighborhood of every edge intersects (L) in at least two vertices, and (ii) the union of the closed neighborhoods of any two distinct edges intersects (L) in at least three vertices. We introduce this model for the first time and establish a unified algorithmic framework. For block graphs and proper interval graphs, we design linear-time dynamic programming algorithms leveraging structural properties of edge closed neighborhoods and graph decomposition. In contrast, we prove that MinLVEDP is NP-complete on undirected path graphs, thereby establishing its computational complexity boundary. Our results provide both theoretical foundations and efficient, deployable algorithms for fault-tolerant coverage in communication networks.
📝 Abstract
Let $G=(V, E)$ be an undirected graph. The set $N_G[x]={yin V|xyin E}cup {x}$ is called the closed neighbourhood of a vertex $xin V$ and for an edge $e=xyin E$, the closed neighbourhood of $e$ is the set $N_G[x]cup N_G[y]$, which is denoted by $N_G[e]$ or $N_G[xy]$. A set $Lsubseteq V$ is called emph{liar's vertex-edge dominating set} of a graph $G=(V,E)$ if for every $e_iin E$, $|N_G[e_i]cap L|geq 2$ and for every pair of distinct edges $e_i,e_jin E$, $|(N_G[e_i]cup N_G[e_j])cap L|geq 3$. The notion of liar's vertex-edge domination arises naturally from some applications in communication networks. Given a graph $G$, the extsc{Minimum Liar's Vertex-Edge Domination Problem} ( extsc{MinLVEDP}) asks to find a liar's vertex-edge dominating set of $G$ of minimum cardinality. In this paper, we study this problem from an algorithmic point of view. We design two linear time algorithms for extsc{MinLVEDP} in block graphs and proper interval graphs, respectively. On the negative side, we show that the decision version of liar's vertex-edge domination problem is NP-complete for undirected path graphs.