如果一个有向图D包含一个生成有向闭迹,则称D是超欧拉有向图。研究关于一个强连通有向图或一个强连通的有向图类,使之在经过p次幂有向图的运算后成为超欧拉有向图的充分条件:有向图D包含一个有向圈的集合Γ={S1,S1,…,Sn}且满足V(D)=U(si∈Γ)V(Si),D的平方图是超欧拉有向图的充分条件。对于F(s,t)图类中的强连通有向图,当s是奇数时,则对于任意的P≥[s/2],D^p是超欧拉有向图;当s是偶数时,则对于任意的P≥(s/2)+1,D^p是超欧拉有向图。
A digraph D is supereulerian if contains a spanning closed ditrail.In this paper,we will give the sufficient conditions on a strong digraph or a strong digraph family is obtained for the pthpower of them to be supereulerian:let a digraph has a set of dicycle Γ={S1,S1,…,Sn} and V(D)=U(si∈Γ)V(Si),the sufficient conditions on its square digraph is supereulerian.For every D∈F(s,t),if sis odd,then for everyP≥[s/2],D^p is supereulerian.If sis even,then for every P≥(s/2)+1,D^p is supereulerian.