The Clustered Selected-Internal Steiner Tree Problem

Given a complete graph [Formula: see text], with nonnegative edge costs, two subsets text] and partition of clustered Steiner tree is that spans all vertices in such can be cut into subtrees by removing edges each subtree text]. The cost defined to the sum costs its edges. A selected-internal for if are internal problem concerned determination minimum cost. In this paper, we present first known approximation algorithm performance ratio problem, where best-known problem.