A sufficient condition for maximum cycles in bipartite digraphs Original Research Article

A sufficient condition for the existence of a maximum cycle (i.e. of length twice the cardinality of the smaller color class) in a bipartite digraph is presented. Clearly, the obtained cycle is Hamiltonian whenever the bipartite digraph is balanced. The condition given here is the best possible of its type and it is considerably weaker than those previously known that imply the same conclusion.