定义了两类有向网络——ＯＲＣ－网络和ＩＲＣ－网络，并且提出一个计算它们的根通信可靠性（网络的一个特定结点（根点）能与其余每个结点通信的概率）的多项式时间算法．对于ＯＲＣ－网络和ＩＲＣ－网络，该算法的时间复杂度分别是Ｏ（｜Ｅ｜）和Ｏ（｜Ｖ｜·｜Ｅ｜），这里，｜Ｖ｜，｜Ｅ｜分别表示网络所含结点和边的数量 Two types of directed networks, the ORC-network and the IRC-network, are defined and a new algorithm is proposed that calculates the root communication reliability (the probability that a particular node (root point) of the network can communicate with each of the remaining nodes) Polynomial time algorithm. The time complexity of this algorithm is O (| E |) and O (| V | · | E |) respectively for ORC-network and IRC-network. Here, | V |, | E | The number of points and edges