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MFCS
2009
Springer

An Improved Approximation Bound for Spanning Star Forest and Color Saving

11 years 5 months ago
An Improved Approximation Bound for Spanning Star Forest and Color Saving
We present a simple algorithm for the maximum spanning star forest problem. We take advantage of the fact that the problem is a special case of complementary set cover and we adapt an algorithm of Duh and F¨urer in order to solve it. We prove that this algorithm computes 193/240 ≈ 0.804-approximate spanning star forests; this result improves a previous lower bound of 0.71 by Chen et al. Although the algorithm is purely combinatorial, our analysis defines a linear program that uses a parameter f and which is feasible for values of the parameter f not smaller than the approximation ratio of the algorithm. The analysis is tight and, interestingly, it also applies to complementary versions of set cover such as color saving; it yields the same approximation guarantee of 193/240 that marginally improves the previously known upper bound of Duh and F¨urer. We also show that, in general, a natural class of local search algorithms do not provide better than 1/2-approximate spanning star for...
Stavros Athanassopoulos, Ioannis Caragiannis, Chri
Added 26 Jul 2010
Updated 26 Jul 2010
Type Conference
Year 2009
Where MFCS
Authors Stavros Athanassopoulos, Ioannis Caragiannis, Christos Kaklamanis, Maria Kyropoulou
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