The map (or graph) is presented in the adjacency-list format. This format is a simple text file. The first line is of the form:
The remaining (Number_of_links) lines of the file are links of the graph. For example,
Would mean that there's a link between a router represented by Node_ID1 and Node_ID2. Bi-directional Links are assumed. Node ids are integers, assigned sequentially from 0 to (Number_of_nodes - 1).