Improved approximation algorithms for hitting 3-vertex paths

Improved Algorithms for the 2-Vertex Disjoint Paths Problem

Given distinct vertices s1, s2, t1, and t2 the 2-vertex-disjoint paths problem (2-VDPP) consists in determining two vertex-disjoint paths p1, from s1 to t1, and p2, from s2 to t2, if such paths exist. We show that by using some kind of sparsification technique the previously best known time bound of O(n + mα(m,n)) can be reduced to O(m+nα(n, n)), where α denotes the inverse of the Ackermann fun...

Improved Approximation Algorithms for the Partial Vertex Cover Problem

Finding Optimum k-vertex Connected Spanning Subgraphs: Improved Approximation Algorithms for k=3, 4, 5

The problem of finding a minimum weight k-vertex connected spanning subgraph is considered. For k ≥ 2, this problem is known to be NP-hard. Combining properties of inclusion-minimal k-vertex connected graphs and of k-out-connected graphs (i.e., graphs which contain a vertex from which there exist k internally vertex-disjoint paths to every other vertex), we derive polynomial time approximation ...

Approximation Algorithms for Disjoint Paths

Improved Approximation for Min-Sum Vertex Cover

The paper describes an approximation algorithm for the Min Sum Vertex Cover (MSVC) problem, achieving a constant approximation factor strictly smaller than 2, thus improving on the best currently known approximation algorithm for the problem. ∗Department of Computer Science and Applied Mathematics, The Weizmann Institute of Science, Rehovot 76100, Israel. E-mail: [email protected]. †Depar...