有向图的控制圈

Dominating cycle of directed graph

采用有向图控制圈的研究方法对有向图控制圈进行了研究 ,证明了 :设 D为 n阶 ( n≥7)强连通有向简单图 ,且对 D的任意弧 ( x,y)有 d-( x) + d+ ( y) >n- 4,那么

The author studies dominating cycle of directed graph with the method of studying dominating cycle of undirected graph, and proves that: Let D be a strongly connected simple graph of order n(n ≥7),for any arc( x,y ) of D ,if d -(x)+d +(y)>n -4,then D contains a dominating cycle.