The steiner problem with edge lengths 1 and 2,
Information Processing Letters
Improved approximations for the Steiner tree problem
SODA selected papers from the third annual ACM-SIAM symposium on Discrete algorithms
Proof verification and the hardness of approximation problems
Journal of the ACM (JACM)
A threshold of ln n for approximating set cover
Journal of the ACM (JACM)
A 1.598 approximation algorithm for the Steiner problem in graphs
Proceedings of the tenth annual ACM-SIAM symposium on Discrete algorithms
On the bidirected cut relaxation for the metric Steiner tree problem
Proceedings of the tenth annual ACM-SIAM symposium on Discrete algorithms
Improved Steiner tree approximation in graphs
SODA '00 Proceedings of the eleventh annual ACM-SIAM symposium on Discrete algorithms
A new approximation algorithm for the Steiner tree problem with performance ratio 5/3
Journal of Algorithms
Lower Bounds for Approximation Algorithms for the Steiner Tree Problem
WG '01 Proceedings of the 27th International Workshop on Graph-Theoretic Concepts in Computer Science
Better approximation bounds for the network and Euclidean Steiner tree problems
Better approximation bounds for the network and Euclidean Steiner tree problems
On achieving maximum multicast throughput in undirected networks
IEEE/ACM Transactions on Networking (TON) - Special issue on networking and information theory
Network coding: an excellent approach for overloaded communication era
WSEAS TRANSACTIONS on COMMUNICATIONS
How well can primal-dual and local-ratio algorithms perform?
ACM Transactions on Algorithms (TALG)
Applications of the linear matroid parity algorithm to approximating steiner trees
CSR'06 Proceedings of the First international computer science conference on Theory and Applications
Hypergraphic LP relaxations for steiner trees
IPCO'10 Proceedings of the 14th international conference on Integer Programming and Combinatorial Optimization
Steiner Tree Approximation via Iterative Randomized Rounding
Journal of the ACM (JACM)
| Hi-index | 0.89 |
The area of approximation algorithms for the Steiner tree problem in graphs has seen continuous progress over the last years. Currently the best approximation algorithm has a performance ratio of 1.550. This is still far away from 1.0074, the largest known lower bound on the achievable performance ratio. As all instances resulting from known lower bound reductions are uniformly quasi-bipartite, it is interesting whether this special case can be approximated better than the general case. We present an approximation algorithm with performance ratio 73/60 1.217 for the uniformly quasi-bipartite case. This improves on the previously known ratio of 1.279 of Robins and Zelikovsky. We use a new method of analysis that combines ideas from the greedy algorithm for set cover with a matroid-style exchange argument to model the connectivity constraint. As a consequence, we are able to provide a tight instance.