On the Zagreb indices of the line graph and line cut-vertex graph of subdivision of unicyclic graphs

The first Zagreb index M₁(G) is equal to the sum of squares of the degrees of the vertices, and the second Zagreb index M₂(G) is equal to the sum of the products of the degrees of pairs of adjacent vertices of the underlying molecular graph G. This paper aims to investigate the Zagreb indices and coindices of the line graph and line cut-vertex graph of a class of unicyclic graphs called cycle-star graph using the notion of subdivision.