A Logarithmic Integrality Gap Bound for Directed Steiner Tree in Quasi-bipartite Graphs
Data Structures and Algorithms
2016-04-28 v1
Abstract
We demonstrate that the integrality gap of the natural cut-based LP relaxation for the directed Steiner tree problem is in quasi-bipartite graphs with terminals. Such instances can be seen to generalize set cover, so the integrality gap analysis is tight up to a constant factor. A novel aspect of our approach is that we use the primal-dual method; a technique that is rarely used in designing approximation algorithms for network design problems in directed graphs.
Keywords
Cite
@article{arxiv.1604.08132,
title = {A Logarithmic Integrality Gap Bound for Directed Steiner Tree in Quasi-bipartite Graphs},
author = {Zachary Friggstad and Jochen Koenemann and Mohammad Shadravan},
journal= {arXiv preprint arXiv:1604.08132},
year = {2016}
}