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arXiv 1104.1852cs.DS
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随机$Δ$ --基于四元数的复色边着色

Randomized $Δ$-Edge-Coloring via Quaternion of Complex Colors

Tony T. Lee, Yujie Wan, Hao Guan

摘要:

本文探讨了一种新的色交换代数方法在简单图边染色中的应用。Vizing定理指出简单图$G$的边着色需要$Δ$或$Δ+1$颜色,其中$Δ$是$G$的最大顶点度。Holyer证明了判定$G$是否是$Δ$ -边可着色的问题是{ \bf NP}-完全的。通过引入复颜色的概念,我们证明了颜色交换运算遵循与四元数相同的乘法规则。初始$Δ$ -边着色图$G$允许可变着色的边,其可以通过颜色交换以类似于求解线性方程组中的变量消除的方式来消除。如果所有的变量被消除,并达到适当的$Δ$ -边着色图的问题得到解决。对于一个随机生成的图$G$,我们证明了如果$G$是$Δ$-边可着色的,则我们的算法在$O(Δ|V||E|^5)$时间内返回一个正确的$Δ$-边可着色,概率至少为1/2.否则,算法在多项式时间内停止并发出不可能解的信号,这意味着$G$的色指数可能等于$Δ+1$。本文提出的边着色算法的动画发布在YouTube http://www.youtube.com/watch?上v=KMnj4UMYl7k。

英文摘要:

This paper explores the application of a new algebraic method of color exchanges to the edge coloring of simple graphs. Vizing's theorem states that the edge coloring of a simple graph $G$ requires either $Δ$ or $Δ+1$ colors, where $Δ$ is the maximum vertex degree of $G$. Holyer proved that it is {\bf NP}-complete to decide whether $G$ is $Δ$-edge-colorable even for cubic graphs. By introducing the concept of complex colors, we show that the color-exchange operation follows the same multiplication rules as quaternion. An initially $Δ$-edge-colored graph $G$ allows variable-colored edges, which can be eliminated by color exchanges in a manner similar to variable eliminations in solving systems of linear equations. The problem is solved if all variables are eliminated and a properly $Δ$-edge-colored graph is reached. For a randomly generated graph $G$, we prove that our algorithm returns a proper $Δ$-edge-coloring with a probability of at least 1/2 in $O(Δ|V||E|^5)$ time if $G$ is $Δ$-edge-colorable. Otherwise, the algorithm halts in polynomial time and signals the impossibility of a solution, meaning that the chromatic index of $G$ probably equals $Δ+1$. Animations of the edge-coloring algorithms proposed in this paper are posted at YouTube http://www.youtube.com/watch?v=KMnj4UMYl7k.

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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