中文说明：该代码将网络简化为图论模型，在此基础上分析了网络中各个节点的重要性及每条链路的重要性并综合了这丽面的因素综合衡量网络整体的可靠性。
English Description：
The network code be simplified as a graph model, based on this analysis the importance of each node in the network and the importance of each link and synthesize the LI elements to measure the overall network reliability.