发表机构
Kyushu University; Nagoya University; Universität Würzburg(九州大学; 名古屋大学; 维尔茨堡大学)
机构由 AI 辅助整理,请以论文原文为准。AI 中文总结
本文研究几何交集图的图编辑问题,通过移动几何对象使交集图满足局部稠密(含k团)或k-连通性质,并最小化总(加权)移动距离,给出了区间和单位圆盘上的多项式时间算法及NP-困难性结果。
AI 中文摘要
本文研究几何交集图上的图编辑问题。对于某个欧几里得空间中的几何对象元组 $\mathcal{S}=(S_1,\dots,S_n)$,设 $G_\mathcal{S}$ 为其交集图。我们研究寻找移动向量元组 $D=(d_1,\dots,d_n)$ 的问题,使得移动后的交集图 $G_{\mathcal{S}+D}$(对每个 $i \in \{1,\dots,n\}$,将对象 $S_i$ 移动 $d_i$ 后)具有预定义性质,且总移动距离 $|D|$ 最小。在加权版本中,我们还给定一个具有正分量的权重向量 $w=(w_1,\dots,w_n)$,目标是最小化总加权移动距离 $|w \cdot D|$。我们首先考虑局部稠密性质,我们将其定义为包含一个 $k$-团。给定 $n$ 个加权区间,我们针对该性质在 $O(k^{1/3} n \log^{1+\varepsilon} n)$ 时间内解决问题,其中 $\varepsilon>0$ 任意。然后我们考虑 $1\le k \le n-1$ 的 $k$-连通性。给定 $n$ 个无权单位区间,我们在 $O(n^2 \log n)$ 时间内解决问题,并且对于 $k=1$,在 $O(n\log n)$ 时间内解决。对于 $k=1$,我们证明了在任意长度区间和加权单位圆盘(仅有两个不同权重)上的强 NP-困难性,以及在加权区间(即使长度等于权重)上的弱 NP-困难性。
英文摘要
In this paper, we study graph editing problems on geometric intersection graphs. For a tuple $\mathcal{S}=(S_1,\dots,S_n)$ of geometric objects in some Euclidean space, let $G_\mathcal{S}$ be their intersection graph. We study the problem of finding a tuple $D=(d_1,\dots,d_n)$ of movement vectors such that the resulting intersection graph $G_{\mathcal{S}+D}$ (after moving, for every $i \in \{1,\dots,n\}$, object $S_i$ by $d_i$) has a predefined property and the total movement distance $|D|$ is minimum. In the weighted version, we are also given a weight vector $w=(w_1,\dots,w_n)$ with positive entries, and the objective is to minimise the total weighted movement distance $|w \cdot D|$. We first consider the property locally dense, which we define as containment of a $k$-clique. Given $n$ weighted intervals, we solve the problem with respect to this property in $O(k^{1/3} n \log^{1+\varepsilon} n)$ time for any $\varepsilon>0$. We then consider $k$-connectivity for $1\le k \le n-1$. Given $n$ unweighted unit intervals, we solve the problem in $O(n^2 \log n)$ time and, for $k=1$, in $O(n\log n)$ time. For $k=1$, we prove strong NP-hardness on intervals of arbitrary length and on weighted unit disks (with only two distinct weights), and weak NP-hardness on weighted intervals (even when lengths equal weights).