【摘要】 在并发程序复杂性度量研究中,作者曾定义了所谓B图,用以作为Ada并发程序中一种会合关系的模型.该文研究B图的一种特殊情况—BB图,一类链状图.n节点BB图是在n个节点、高为n-1的有向树上再添加若干条边,其约束条件是:每个节点的入度不大于二,每个节点的出度也不大于二.该文给出BB图图的若干若干枚举特征,并指出这些特征同第二类Stirling数的密切关系.更多还原

【Abstract】 We defined the so-called B graph in research on concurrent program complexity metrics as one the models of rendezvous relations in Ada programs.In this paper,we investigate a special case of B graph——BB graph,and call it chain-like graph.A BB graph of order n is the oriented tree of order n and height n-1 by adding some edges with the constraint that both of the in-degree and out-degree for every node are two at most.The paper gives some enumerating characteristics of BB Graph,and points out the closed relationship with the Stirling numbers of second kind.更多还原