分层图的容错

Fault Tolerance of the Hierarchical Graphs

图的容错定义为最大的顶点数Ｋ，当从图中却掉任意Ｋ个顶点时，剩下的仍连通，因此图的容错等于它的连通度减１。

The fault tolerance of a graph is defined as the maximum number of vertices that can be removed from it provided that the remaining graph is still connected. Hecce, the fault tolerance of a graph is defined to be one less than its connectivity. A class of hierarchical graphs is presented and its fault tolerance is analysed.