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arXiv 1802.06992cs.DS
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MAXCUT的次线性算法及相关聚类

Sublinear Algorithms for MAXCUT and Correlation Clustering

Aditya Bhaskara, Samira Daruki, Suresh Venkatasubramanian

摘要:

我们研究了两个基本的图形问题,MAXCUT和相关聚类的次线性算法。我们的重点是构建核心集,以及开发这些问题的流算法。对于这些问题,已知用于稠密图的常数空间算法,而对于稀疏图存在$Ω(n)$下限(在流设置中)。本文的目标是弥合这两个极端之间的差距。我们的第一个结果是构造核心集的大小$\tilde{O}(n^{1-δ})$的问题,在图的平均度$n^δ$(任何$δ>0$)。在指数时间假设(ETH)下,这是最优的。我们的核心集分析是基于研究随机诱导子问题的优化问题。据我们所知,我们的参数范围内的所有已知结果都依赖于近似正则性假设。我们避免这些使用有偏的采样方法,我们分析使用最近的结果,浓度的二次函数。然后,我们表明,我们的建设产生一个2通流$(1+ε)$ -近似这两个问题,该算法使用$\tilde{O}(n^{1-δ})$空间,图形的平均度$n^δ$。

英文摘要:

We study sublinear algorithms for two fundamental graph problems, MAXCUT and correlation clustering. Our focus is on constructing core-sets as well as developing streaming algorithms for these problems. Constant space algorithms are known for dense graphs for these problems, while $Ω(n)$ lower bounds exist (in the streaming setting) for sparse graphs. Our goal in this paper is to bridge the gap between these extremes. Our first result is to construct core-sets of size $\tilde{O}(n^{1-δ})$ for both the problems, on graphs with average degree $n^δ$ (for any $δ>0$). This turns out to be optimal, under the exponential time hypothesis (ETH). Our core-set analysis is based on studying random-induced sub-problems of optimization problems. To the best of our knowledge, all the known results in our parameter range rely crucially on near-regularity assumptions. We avoid these by using a biased sampling approach, which we analyze using recent results on concentration of quadratic functions. We then show that our construction yields a 2-pass streaming $(1+ε)$-approximation for both problems; the algorithm uses $\tilde{O}(n^{1-δ})$ space, for graphs of average degree $n^δ$.

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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