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arXiv 1712.09166cs.DS
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近似最小度生成树的近线性时间算法

Near-linear Time Algorithm for Approximate Minimum Degree Spanning Trees

Ran Duan, Haoqing He, Tianyi Zhang

摘要:

给定一个图$G = (V, E)$,我们希望计算一棵最大顶点度(即树度)尽可能小的生成树。计算精确的最优解是NP难的,因为它推广了哈密顿路径问题。对于这个问题的近似版本,一个$\tilde{O}(mn)$时间算法,计算最多$Δ^* +1$度的生成树是以前已知的[Fürer \& Raghavachari 1994];这里$Δ^*$表示所有生成树的最小树度。本文给出了该问题的第一种近似线性时间近似算法。具体来说,我们提出了一个$\tilde{O}(\frac{1}{ε^7}m)$时间算法,计算树度$(1+ε)Δ^* + O(\frac{1}{ε^2}\log n)$为任何常数$ε\in (0,\frac{1}{6})$的生成树。因此,当$Δ^*=ω(\log n)$时,我们可以在近线性时间内获得具有任意接近1的常数近似比的近似解。

英文摘要:

Given a graph $G = (V, E)$, we wish to compute a spanning tree whose maximum vertex degree, i.e. tree degree, is as small as possible. Computing the exact optimal solution is known to be NP-hard, since it generalizes the Hamiltonian path problem. For the approximation version of this problem, a $\tilde{O}(mn)$ time algorithm that computes a spanning tree of degree at most $Δ^* +1$ is previously known [Fürer \& Raghavachari 1994]; here $Δ^*$ denotes the minimum tree degree of all the spanning trees. In this paper we give the first near-linear time approximation algorithm for this problem. Specifically speaking, we propose an $\tilde{O}(\frac{1}{ε^7}m)$ time algorithm that computes a spanning tree with tree degree $(1+ε)Δ^* + O(\frac{1}{ε^2}\log n)$ for any constant $ε\in (0,\frac{1}{6})$. Thus, when $Δ^*=ω(\log n)$, we can achieve approximate solutions with constant approximate ratio arbitrarily close to 1 in near-linear time.

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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