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Sublinear Time Approximate Sum via Uniform Random Sampling

2012/02/29 by Fu, Bin, Li, Wenfeng, Peng, Zhiyong
#Data Structures and Algorithms (cs.DS) #FOS: Computer and information sciences

paper · doi:10.48550/arxiv.1202.6598

Abstract

We investigate the approximation for computing the sum a1+...+an with an input of a list of nonnegative elements a1,..., an. If all elements are in the range [0,1], there is a randomized algorithm that can compute an (1+ε)-approximation for the sum problem in time O(n(loglog n)\over∑i=1n ai), where ε is a constant in (0,1). Our randomized algorithm is based on the uniform random sampling, which selects one element with equal probability from the input list each time. We also prove a lower bound Ω(n\over ∑i=1n ai), which almost matches the upper bound, for this problem.

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