Approximating $k$-hop minimum-spanning trees
Abstract
Given a complete graph on~$n$ nodes with metric edge costs, the minimum-cost k-hop spanning tree ($k$HMST) problem asks for a spanning tree of minimum total cost such that the longest root-leaf-path in the tree has at most $k$ edges. We present an algorithm that computes such a tree of total expected cost $O(log n)$ times that of a minimum-cost $k$-hop spanning-tree.