Introduction to algorithms: Minimum Spanning Tree P (353) for sparse graphs)

You just don't have the patience to read .....

 

 

Let's talk about simple understanding, MST-REDUCE preprocessing, for each node u, if u is not in any set, find the edge e (u, v), where W (u, v) is the smallest, that is, finding the shortest edge connected to U and adding U and V to a collection, that is, shrinking the edge U-V, merge the two vertices into one vertex. In this way, each vertex is processed, and a new vertex is formed. Of course, the scaled edge must be the edge in the Minimum Spanning Tree, this and the Kruskal algorithm is an idea, but the MST-REDUCE is to get a new graph, the number of nodes in this graph V '. v' <v/2.

Then enumerate each edge. If this edge is connected to a set of two different points, select the shorter side as the edge connecting the two points set, that is, in the new graph, the link is reduced to the edge between the point set of a point... too much nonsense .. that is, the edge of the New Graph...

After talking about this for a long time, we seem to be talking about the Kruskal algorithm. But the difference is that the above processing results in a new figure .......