Flexible network design deals with building a network that guarantees some connectivity requirements between its vertices, even when some of its elements (like vertices or edges) fail. In particular, the set of edges (resp. vertices) of a given graph are here partitioned into safe and unsafe. The goal is to identify a minimum size subgraph that is 2-edge-connected (resp. 2-vertex-connected), and stay so whenever any of the unsafe elements gets removed. In this paper, we provide improved approximation algorithms for flexible network design problems, considering both edge-connectivity and vertex-connectivity, as well as connectivity values higher than 2. For the vertex-connectivity variant, in particular, our algorithm is the first with approximation factor strictly better than 2.
@article{arxiv.2404.08972,
title = {Improved Approximations for Flexible Network Design},
author = {Dylan Hyatt-Denesik and Afrouz Jabal Ameli and Laura Sanita},
journal= {arXiv preprint arXiv:2404.08972},
year = {2024}
}