Getting new algorithmic results by extending distance-hereditary graphs via split composition.

In this paper, we consider the graph class denoted as Gen(∗;P,C,C). It contains all graphs that can be generated by the split composition operation using path P, cycle C, and any cycle C as components. This graph class extends the well-known class of distance-hereditary graphs, which corresponds, according to the adopted generative notation, to Gen(∗;P,C). We also use the concept of stretch number for providing a relationship between Gen(∗;P,C) and the hierarchy formed by the graph classes DH(k), with k ≥1, where DH(1) also coincides with the class of distance-hereditary graphs. For the addressed graph class, we prove there exist efficient algorithms for several basic combinatorial problems, like recognition, stretch number, stability number, clique number, domination number, chromatic number, and graph isomorphism. We also prove that graphs in the new class have bounded clique-width.