“…Comparing n times like this , we can obtain the shortest path from V i to V j at last. Now there is one n order matrix sequence: D (-1) ,D (0) ,D (1) ……D (k) , …… D (n-1) and computation formulas are shown below [9]: The distance among the three router is as follows: Where the sequence of the router A 、 B 、 C is respectively 0, 1, 2. In the table, P represents path , D (0) represents adding a router A from initial state , D (1) represents adding a router B , D (2) represents adding a router C. …”