On directed 2-factors in digraphs and 2-factors containing perfect matchings in bipartite graphs

Shuya Chiba, Tomoki Yamashita

In this paper, we give the following result: If $D$ is a digraph of order $n$, and if $d_D^{+}(u)+d_D^{-}(v)\ge n$ for every two distinct vertices $u$ and $v$ with $(u, v) \…