论文标题

计算最小fip数量的弱优势图

Computing Weak Dominance Drawings with Minimum Number of Fips

论文作者

Ortali, Giacomo, Tollis, Ioannis G.

论文摘要

一个弱的统治地图$ g $ g =(v,e)$的$γ$是$ d $二维图,因此,对于每个d(u)<d(v)$ d $ d $ d $ $γ$,有从顶点$ u $到$ g $ in $ g $ in $ g $ in $ g $ in $ g $ in $ g $中的有向路径。当每个尺寸$ d $ of〜$γ$的$ d(u)<d(v)$时,我们有一个\ emph {错误的隐含路径(fip)},但是从$ u $到$ v $没有路径。将FIP的数量最小化是一个重要的理论和实用问题,即NP-HARD。我们表明,这是参数$ k $的FPT〜问题,其中$ k $是\ $ g $的\ emph {modular〜分解〜树的最大程度。也就是说,对于任何常数$ d $,我们会呈现一个$ o(nm+ndk^2(k!)^d)$ time算法来计算一个弱$ d $ d $ d $ d $ d的优势,绘制了dag $ g $的$γ$具有最小fips数量的dag $ g $。此结果的一个有趣的含义是,我们可以决定在时间$ O(NM+NK^2(k!)^3)$的时间$ O(nm+nk^2(k!)^3)$中,DAG是否具有主导地位〜$ 3 $(众所周知的NP完整问题)。

A weak dominance drawing $Γ$ of a DAG $G=(V,E)$, is a $d$-dimensional drawing such that there is a directed path from a vertex $u$ to a vertex $v$ in $G$ if $D(u) <D(v)$ for every dimension $D$ of $Γ$. We have a \emph{falsely implied path (fip)} when $D(u) < D(v)$ for every dimension $D$ of~$Γ$, but there is no path from $u$ to $v$. Minimizing the number of fips is an important theoretical and practical problem, which is NP-hard. We show that it is an FPT~problem for parameter $k$, where $k$ is the maximum degree of a vertex of the \emph{modular~decomposition~tree} of~$G$. Namely, for any constant $d$, we present an $O(nm+ndk^2(k!)^d)$ time algorithm to compute a weak $d$-dimensional dominance drawing $Γ$ of a DAG $G$ having the minimum number of fips. An interesting implication of this result is that we can decide if a DAG has dominance dimension~$3$ (a well-known NP-complete problem) in time $O(nm+nk^2(k!)^3)$.

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