图G的点集S如果满足:V|G|—S(或V|G|)中每个点相邻于S中的某个点(或而不是它本身),则称点集S是一个控制集(或全控制集).图G的所有控制集(或全控制集)中最小基数的控制集(或全控制集)中的点数,称为控制数(或全控数),记为Y(G)(或Y1(G)).在这篇文章中我们特征化Y1-临界图且满足Y1(G)=n-△(G)的图特征,这回答了Goddard等人提出的一个问题.
A set S of vertices in a graph G is a dominating set (total dominating set) of G if each vertex of V(G) - S(V(G)) is adjacent to some vertex of S (other than itself). The minimum cardinality among all dominating sets (total dominating sets) of G is called the domination (total domination) number of G, denoted by Y(G) (Y1(G)). In this paper,we characterize theY1- critical graphs with 7,(G) = n - △(G), which answers a question proposed by Goddard et al.