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arXiv 1606.00484cs.DS
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快速确定性选择

Fast Deterministic Selection

Andrei Alexandrescu

摘要:

中位数的中位数(也称为BFPRT)算法,虽然是一个里程碑式的理论成就,但很少在实践中使用,因为它及其变体比基于采样的简单方法慢。本文的主要贡献是一个快速的线性时间确定性选择算法QuickselectAdaptive的MedianOfMedians的定义的基础上。该算法的性能带来了确定性的选择-随着其理想的属性,可重复的运行,可预测的运行时间,免疫病理输入-在实用性的范围内。我们展示了独立和同分布的随机输入和正态分布的输入的结果。测量结果表明,QuickselectAdaptive比最先进的基线更快。

英文摘要:

The Median of Medians (also known as BFPRT) algorithm, although a landmark theoretical achievement, is seldom used in practice because it and its variants are slower than simple approaches based on sampling. The main contribution of this paper is a fast linear-time deterministic selection algorithm QuickselectAdaptive based on a refined definition of MedianOfMedians. The algorithm's performance brings deterministic selection---along with its desirable properties of reproducible runs, predictable run times, and immunity to pathological inputs---in the range of practicality. We demonstrate results on independent and identically distributed random inputs and on normally-distributed inputs. Measurements show that QuickselectAdaptive is faster than state-of-the-art baselines.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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