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arXiv 0903.4796cs.DScs.DM
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基于邻域并的顶点子集和顶点划分问题的快速FPT算法

Fast FPT algorithms for vertex subset and vertex partitioning problems using neighborhood unions

B. -M. Bui-Xuan, J. A. Telle, M. Vatshelle

摘要:

我们引入了图形参数布尔宽度,涉及到一个图的切割的不同工会的邻居的数量。布尔宽度类似于秩宽度,秩宽度与邻域的$GF[2]$ -和(1+1=0)的数量有关,而不是用于布尔宽度的布尔和(1+1=1)。我们给出了算法的NP-硬顶点子集和顶点划分问题,FPT参数化时,无论是布尔宽度,秩宽度或宽度,与运行时单指数在任一参数,如果给定相关的最佳分解。为了比较布尔宽度与秩宽度或ck-width,我们首先证明对于任何图,其布尔宽度的平方根永远不会大于其秩宽度。接下来,我们展示了一类图,Hsu-网格,我们可以解决NP-难问题在多项式时间,如果我们使用正确的参数。${1/10}n^2$顶点上的$n \times \frac{n}{10}$ Hsu网格具有布尔宽度$Θ(\log n)$和秩宽度$Θ(n)$。此外,这样的图的任何最优秩分解将具有布尔宽度$Θ(n)$,即在最优布尔宽度中呈指数。一个主要的开放问题是近似布尔宽度比由秩宽度算法给出的更好[Hlinaonnovich和Oum,2008]

英文摘要:

We introduce the graph parameter boolean-width, related to the number of different unions of neighborhoods across a cut of a graph. Boolean-width is similar to rank-width, which is related to the number of $GF[2]$-sums (1+1=0) of neighborhoods instead of the boolean-sums (1+1=1) used for boolean-width. We give algorithms for a large class of NP-hard vertex subset and vertex partitioning problems that are FPT when parameterized by either boolean-width, rank-width or clique-width, with runtime single exponential in either parameter if given the pertinent optimal decomposition. To compare boolean-width versus rank-width or clique-width, we first show that for any graph, the square root of its boolean-width is never more than its rank-width. Next, we exhibit a class of graphs, the Hsu-grids, for which we can solve NP-hard problems in polynomial time, if we use the right parameter. An $n \times \frac{n}{10}$ Hsu-grid on ${1/10}n^2$ vertices has boolean-width $Θ(\log n)$ and rank-width $Θ(n)$. Moreover, any optimal rank-decomposition of such a graph will have boolean-width $Θ(n)$, i.e. exponential in the optimal boolean-width. A main open problem is to approximate the boolean-width better than what is given by the algorithm for rank-width [Hliněný and Oum, 2008]

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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