arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1909.08795cs.DMcs.DS
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几类图中测地集问题的困难性与逼近性

Hardness and approximation for the geodetic set problem in some graph classes

Dibyayan Chakraborty, Florent Foucaud, Harmender Gahlawat, Subir Kumar Ghosh, Bodhayan Roy

摘要:

本文研究了求图的\emph{geodetic number}的计算复杂性。一个图$G$的顶点集$S$是一个\emph{geodetic set},如果$G$的任何顶点位于来自$S$的某对顶点之间的某个最短路径上。\textsc{Minimum Geodetic Set (MGS)}问题是寻找一个具有最小基数的测地集。在本文中,我们证明了解决\textsc{MGS}问题是NP-困难的最大度为6的平面图和线图。我们还表明,除非$P=NP$,没有多项式时间算法来解决\textsc{MGS}问题的次对数逼近因子(在顶点数方面),即使在图直径$2$。在积极的方面,我们给出了$n$阶图上的\textsc{MGS}问题的一个$O\left(\sqrt[3]{n}\log n\right)$ -近似算法。对于平面图的一个子类--实格图族,我们给出了求解\textsc{MGS}问题的$3$ -近似算法。

英文摘要:

In this paper, we study the computational complexity of finding the \emph{geodetic number} of graphs. A set of vertices $S$ of a graph $G$ is a \emph{geodetic set} if any vertex of $G$ lies in some shortest path between some pair of vertices from $S$. The \textsc{Minimum Geodetic Set (MGS)} problem is to find a geodetic set with minimum cardinality. In this paper, we prove that solving the \textsc{MGS} problem is NP-hard on planar graphs with a maximum degree six and line graphs. We also show that unless $P=NP$, there is no polynomial time algorithm to solve the \textsc{MGS} problem with sublogarithmic approximation factor (in terms of the number of vertices) even on graphs with diameter $2$. On the positive side, we give an $O\left(\sqrt[3]{n}\log n\right)$-approximation algorithm for the \textsc{MGS} problem on general graphs of order $n$. We also give a $3$-approximation algorithm for the \textsc{MGS} problem on the family of solid grid graphs which is a subclass of planar graphs.

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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