A (2+ε)-Approximation for Maximum Weight Matching in the Semi-streaming Model

Abstract

We present a simple deterministic single-pass (2+ε)-approximation algorithm for the maximum weight matching problem in the semi-streaming model. This improves on the currently best known approximation ratio of (4+ε). Our algorithm uses O(nlog2 n) bits of space for constant values of ε. It relies on a variation of the local-ratio theorem, which may be of use for other algorithms in the semi-streaming model as well.