Constant-Time Local Computation Algorithms

Abstract

Local computation algorithms (LCAs) produce small parts of a single (possibly approximate) solution to a given search problem using time and space sublinear in the size of the input. In this work we present LCAs whose time complexity (and usually also space complexity) is independent of the input size. Specifically, we give (1) a (1 − ϵ)-approximation LCA to the maximum weight acyclic edge set, (2) LCAs for approximating multicut and integer multicommodity flow on trees, and (3) a local reduction of weighted matching to any unweighted matching LCA, such that the running time of the weighted matching LCA is d times (where d is the maximal degree) the running time of the unweighted matching LCA, (and therefore independent of the edge weight function).

Additional Information

© 2017 Springer Science+Business Media, LLC. First Online: 20 June 2017. The authors would like to thank the anonymous reviewers for their useful feedback. Yishay Mansour is supported in part by a grant from the Israel Science Foundation, by a grant from United States-Israel Binational Science Foundation (BSF), by a grant from the Israeli Ministry of Science (MoS) and the Israeli Centers of Research Excellence (I-CORE) program (Center No. 4/11). Boaz Patt-Shamir is supported in part by the Israel Science Foundation (grant No. 1444/14) and by the Israel Ministry of Science and Technology. Shai Vardi is supported in part by the Google Europe Fellowship in Game Theory.

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