Consider an edge-weighted tree T = (V, E, w : E R+ ), in which a subset R of the nodes (called the required nodes) are colored red and the remaining nodes in S = V \R are colored ...
We give an implementation of the Goemans-Williamson clustering procedure which is at the core of several approximation algorithms including those for Generalized Steiner Trees, Pr...
Richard Cole, Ramesh Hariharan, Moshe Lewenstein, ...
The group Steiner problem is a classical network design problem where we are given a graph and a collection of groups of vertices, and want to build a min-cost subgraph that conne...
A well-known theorem of Nash-Williams and Tutte gives a necessary and sufficient condition for the existence of k edge-disjoint spanning trees in an undirected graph. A corollary o...
In this paper, we present two techniques to analyze greedy approximation with nonsubmodular functions restricted submodularity and shifted submodularity. As an application of the ...
Ding-Zhu Du, Ronald L. Graham, Panos M. Pardalos, ...