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arXiv 1707.04864cs.DS
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有界荫度检验

Testing bounded arboricity

Talya Eden, Reut Levi, Dana Ron

摘要:

本文研究一个图是否有界荫度的判定问题。有界荫度的图族包括有界度图、所有次闭图类(例如平面图、有界树宽图)和随机生成的偏好连接图。有界荫度的图在过去已经被广泛研究,特别是因为对于许多问题,它们允许更有效的算法和/或更好的近似比。我们提出了一个宽容的稀疏图模型的测试。稀疏图模型允许访问度查询和邻居查询,并且距离是相对于实际边数定义的。更具体地说,我们的算法区分图$ε$ -接近荫度$α$和图$c \cdot ε$ -远离荫度$3α$,其中$c$是一个绝对小常数。该算法的查询复杂度和运行时间为$\tilde{O}\left(\frac{n}{\sqrt{m}}\cdot \frac{\log(1/ε)}ε + \frac{n\cdot α}{m} \cdot \left(\frac{1}ε\right)^{O(\log(1/ε))}\right)$,其中$n$表示顶点数,$m$表示边数。就对$n$和$m$的依赖性而言,由于$Ω(n/\sqrt{m})$查询是必要的(以及$α= O(\sqrt{m}))$ .我们把它作为一个开放的问题是否依赖于$1/ε$可以改善从准多项式到多项式。我们的技术包括一个有效的本地模拟近似的结果的全球(几乎)森林分解算法,以及定制的边缘采样过程。

英文摘要:

In this paper we consider the problem of testing whether a graph has bounded arboricity. The family of graphs with bounded arboricity includes, among others, bounded-degree graphs, all minor-closed graph classes (e.g. planar graphs, graphs with bounded treewidth) and randomly generated preferential attachment graphs. Graphs with bounded arboricity have been studied extensively in the past, in particular since for many problems they allow for much more efficient algorithms and/or better approximation ratios. We present a tolerant tester in the sparse-graphs model. The sparse-graphs model allows access to degree queries and neighbor queries, and the distance is defined with respect to the actual number of edges. More specifically, our algorithm distinguishes between graphs that are $ε$-close to having arboricity $α$ and graphs that $c \cdot ε$-far from having arboricity $3α$, where $c$ is an absolute small constant. The query complexity and running time of the algorithm are $\tilde{O}\left(\frac{n}{\sqrt{m}}\cdot \frac{\log(1/ε)}ε + \frac{n\cdot α}{m} \cdot \left(\frac{1}ε\right)^{O(\log(1/ε))}\right)$ where $n$ denotes the number of vertices and $m$ denotes the number of edges. In terms of the dependence on $n$ and $m$ this bound is optimal up to poly-logarithmic factors since $Ω(n/\sqrt{m})$ queries are necessary (and $α= O(\sqrt{m}))$. We leave it as an open question whether the dependence on $1/ε$ can be improved from quasi-polynomial to polynomial. Our techniques include an efficient local simulation for approximating the outcome of a global (almost) forest-decomposition algorithm as well as a tailored procedure of edge sampling.

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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