When Trees Collide: An Approximation Algorithm for theGeneralized Steiner Problem on Networks
SIAM Journal on Computing
A General Approximation Technique for Constrained Forest Problems
SIAM Journal on Computing
A nearly best-possible approximation algorithm for node-weighted Steiner trees
Journal of Algorithms
Minimal edge-coverings of pairs of sets
Journal of Combinatorial Theory Series B
Improved approximation algorithms for network design problems
SODA '94 Proceedings of the fifth annual ACM-SIAM symposium on Discrete algorithms
Approximation algorithms for directed Steiner problems
Journal of Algorithms
Edge Covers of Setpairs and the Iterative Rounding Method
Proceedings of the 8th International IPCO Conference on Integer Programming and Combinatorial Optimization
Hardness of Approximation for Vertex-Connectivity Network Design Problems
SIAM Journal on Computing
Iterative rounding 2-approximation algorithms for minimum-cost vertex connectivity problems
Journal of Computer and System Sciences - Special issue on FOCS 2001
Approximation Algorithms for Network Design with Metric Costs
SIAM Journal on Discrete Mathematics
An o(log2 k)-approximation algorithm for the k-vertex connected spanning subgraph problem
STOC '08 Proceedings of the fortieth annual ACM symposium on Theory of computing
Network design for vertex connectivity
STOC '08 Proceedings of the fortieth annual ACM symposium on Theory of computing
Algorithms for Single-Source Vertex Connectivity
FOCS '08 Proceedings of the 2008 49th Annual IEEE Symposium on Foundations of Computer Science
Rooted k-connections in digraphs
Discrete Applied Mathematics
Inapproximability of survivable networks
Theoretical Computer Science
A note on Rooted Survivable Networks
Information Processing Letters
Approximating connectivity augmentation problems
ACM Transactions on Algorithms (TALG)
FOCS '09 Proceedings of the 2009 50th Annual IEEE Symposium on Foundations of Computer Science
An O(k^3 log n)-Approximation Algorithm for Vertex-Connectivity Survivable Network Design
FOCS '09 Proceedings of the 2009 50th Annual IEEE Symposium on Foundations of Computer Science
Approximating minimum power covers of intersecting families and directed edge-connectivity problems
Theoretical Computer Science
Detecting high log-densities: an O(n¼) approximation for densest k-subgraph
Proceedings of the forty-second ACM symposium on Theory of computing
Approximating Steiner Networks with Node-Weights
SIAM Journal on Computing
An improved approximation algorithm for minimum-cost subset k-connectivity
ICALP'11 Proceedings of the 38th international colloquim conference on Automata, languages and programming - Volume Part I
Improved approximation algorithms for Directed Steiner Forest
Journal of Computer and System Sciences
Survivable network design problems in wireless networks
Proceedings of the twenty-second annual ACM-SIAM symposium on Discrete Algorithms
Approximating subset k-connectivity problems
WAOA'11 Proceedings of the 9th international conference on Approximation and Online Algorithms
Survivable network activation problems
LATIN'12 Proceedings of the 10th Latin American international conference on Theoretical Informatics
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We give approximation algorithms for the Survivable Network problem. The input consists of a graph G = (V,E) with edge/node-costs, a node subset S ⊆ V, and connectivity requirements {r(s,t):s,t ∈ T ⊆ V}. The goal is to find a minimum cost subgraph H of G that for all s,t ∈ T contains r(s,t) pairwise edge-disjoint st-paths such that no two of them have a node in S ∖ {s,t} in common. Three extensively studied particular cases are: Edge-Connectivity Survivable Network (S = ∅), Node-Connectivity Survivable Network (S = V), and Element-Connectivity Survivable Network (r(s,t) = 0 whenever s ∈ S or t ∈ S). Let k = maxs,t ∈ T r(s,t). In Rooted Survivable Network, there is s ∈ T such that r(u,t) = 0 for all u ≠ s, and in the Subset k-Connected Subgraph problem r(s,t) = k for all s,t ∈ T. For edge-costs, our ratios are O(k log k) for Rooted Survivable Network and O(k2 log k) for Subset k-Connected Subgraph. This improves the previous ratio O(k2 log n), and for constant values of k settles the approximability of these problems to a constant. For node-costs, our ratios are as follows. —O(k log |T|) for Element-Connectivity Survivable Network, matching the best known ratio for Edge-Connectivity Survivable Network. —O(k2 log |T|) for Rooted Survivable Network and O(k3 log |T|) for Subset k-Connected Subgraph, improving the ratio O(k8 log2 |T|). —O(k4 log2 |T|) for Survivable Network; this is the first nontrivial approximation algorithm for the node-costs version of the problem.