arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1111.1109cs.DScs.DMmath.CO
收藏

具有排除拓扑子图的图的结构定理与同构判定

Structure Theorem and Isomorphism Test for Graphs with Excluded Topological Subgraphs

Martin Grohe, Dániel Marx

摘要:

本文将Robertson和Seymour关于不包含固定图$H$作为子图的图的结构定理推广到不包含$H$作为拓扑子图的图.我们证明了,对于一个固定的$H$,每个图排除$H$作为一个拓扑子图有树分解,其中每个部分是“几乎嵌入”到一个固定的表面或有界的程度,除了一个有限的顶点数。此外,我们证明了这样的分解是可计算的算法,是固定参数易处理的参数$|H|$。我们提出了我们的结构定理的两个算法应用。为了说明一个“典型”的应用结构定理的力学,我们表明,在图不包括$H$作为一个拓扑子图,部分支配集(找到$k$顶点的封闭邻域具有最大的大小)可以解决时间$f(H,k)\cdot n^{O(1)}$时间。更重要的是,我们表明,在图不包括$H$作为拓扑子图,图同构可以解决的时间$n^{f(H)}$。这一结果统一和推广了两个已知的重要的多项式时间可解的图同构的情况:有界度图和$H$ -小自由图。这个结果的证明需要我们的结构定理的一个推广到不变的树状分解的上下文中。

英文摘要:

We generalize the structure theorem of Robertson and Seymour for graphs excluding a fixed graph $H$ as a minor to graphs excluding $H$ as a topological subgraph. We prove that for a fixed $H$, every graph excluding $H$ as a topological subgraph has a tree decomposition where each part is either "almost embeddable" to a fixed surface or has bounded degree with the exception of a bounded number of vertices. Furthermore, we prove that such a decomposition is computable by an algorithm that is fixed-parameter tractable with parameter $|H|$. We present two algorithmic applications of our structure theorem. To illustrate the mechanics of a "typical" application of the structure theorem, we show that on graphs excluding $H$ as a topological subgraph, Partial Dominating Set (find $k$ vertices whose closed neighborhood has maximum size) can be solved in time $f(H,k)\cdot n^{O(1)}$ time. More significantly, we show that on graphs excluding $H$ as a topological subgraph, Graph Isomorphism can be solved in time $n^{f(H)}$. This result unifies and generalizes two previously known important polynomial-time solvable cases of Graph Isomorphism: bounded-degree graphs and $H$-minor free graphs. The proof of this result needs a generalization of our structure theorem to the context of invariant treelike decomposition.

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。

↑