Fractional Set Cover in the Streaming Model

We study the Fractional Set Cover problem in the streaming model. That is, we consider the relaxation of the set cover problem over a universe of n elements and a collection of m sets, where each set can be picked fractionally, with a value in [0, 1]. We present a randomized (1 + ε)approximation algorithm that makes p passes over the data, and uses Õ(mnO(1/pε) +n) memory space. The algorithm works in both the set arrival and the edge arrival models. To the best of our knowledge, this is the first streaming result for the fractional set cover problem. We obtain our results by employing the multiplicative weights update framework in the streaming settings. 1998 ACM Subject Classification F.2.2 Nonnumerical Algorithms and Problems