On anti-Kekul\'e and s-restricted matching preclusion problems
Abstract
The anti-Kekul\'e number of a connected graph G is the smallest number of edges whose deletion results in a connected subgraph having no Kekul\'e structures (perfect matchings). As a common generalization of (conditional) matching preclusion number and anti-Kekul\'e number of a graph G, we introduce s-restricted matching preclusion number of G as the smallest number of edges whose deletion results in a subgraph without perfect matchings such that each component has at least s+1 vertices. In this paper, we first show that conditional matching preclusion problem and anti-Kekul\'e problem are NP-complete, respectively, then generalize this result to s-restricted matching preclusion problem. Moreover, we give some sufficient conditions to compute s-restricted matching preclusion numbers of regular graphs. As applications, s-restricted matching preclusion numbers of complete graphs, hypercubes and hyper Petersen networks are determined.