Introduction - If you have any usage issues, please Google them yourself
two hours map is an undirected graph, it n vertices can be divided into two pools A and B pools. but the same set of arbitrary vertex of the two map linked to the billboard (that is, any one side is a culmination of the pool A, in another pool B). If and only if each of the B vertex with at least one vertex A connected, A subset of a pool A B coverage (or simple to say that A is a cover). A coverage of the size shall A number of vertices. If and only if A is a subset B coverage focus on the smallest, A for minimum coverage.
Packet : 115157677二分覆盖.rar filelist
二分覆盖.txt