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.
Algorithms and Hardness for Geodetic Set on Tree-like Digraphs
Université Clermont Auvergne, CNRS, Clermont Auvergne INP, Mines Saint-Étienne, LIMOS(克莱蒙奥弗涅大学、法国国家科学研究中心、克莱蒙奥弗涅理工大学、圣艾蒂安国立高等矿业学校、信息与系统优化实验室);School of Mathematics, Statistics, and Computer Science, University of Tehran(德黑兰大学数学、统计与计算机科学学院);Indian Institute of Science Education and Research Pune(浦那科学教育与研究所)
Algorithms and complexity for geodetic sets on planar and chordal graphs
School of Computing, University of Leeds(利兹大学计算学院);Ben-Gurion University of the Negev(内盖夫本古里安大学);Indian Institute of Technology, Kharagpur(印度理工学院卡拉格普尔分校)
The Closed Geodetic Game: algorithms and strategies
Université Clermont Auvergne(克莱蒙奥弗涅大学);CNRS(法国国家科学研究中心);Mines de Saint-Étienne(圣艾蒂安国立高等矿业学校);Clermont-Auvergne-INP(克莱蒙奥弗涅理工学院);LIMOS(极限与优化实验室);INRAE(法国国家农业、食品和环境研究所);Laboratoire G-SCOP(G-SCOP实验室);CNRS, Univ. Grenoble Alpes(法国国家科学研究中心,格勒诺布尔阿尔卑斯大学);Ben-Gurion University of the Negev(内盖夫本古里安大学);Indian Institute of Technology Dharwad(印度理工学院达瓦德分校);Polytechnic University (Kyaing Tong)(桂开工科大学)
Hardness of Burning Number Problem on Regular Graphs
Indian Institute of Science Education and Research Thiruvananthapuram(印度科学教育研究所特里凡得琅分校);Indian Institute of Science, Bengaluru(印度科学学院班加罗尔分校);Manipal Academy of Higher Education(马尼帕尔高等教育学院);Indian Institute of Technology Delhi(德里印度理工学院);Kyoto University(京都大学)
Balanced spanning forests of graphs: Hardness and solving methods
KU Leuven(荷语鲁汶大学);Research Centre for Operations Research and Business Statistics (ORSTAT)(运筹学与商业统计研究中心);Institute of Computing, University of Campinas(坎皮纳斯大学计算研究所)