Extending cycles in directed graphs
A digraph D is called cycle extendable if it contains at least one cycle and the vertices of each nonhamiltonian cycle are contained in a cycle of length one greater. Strong tournaments and regular tournaments which are cycle extendable are characterized. Best possible sufficient conditions for a digraph to be cycle extendable are found involving the number of arcs, minimum total degree and minimum indegree and outdegree.
scientific article; zbMATH DE number 4016927
scientific article