Clique-width is a well-studied graph parameter. For graphs of bounded clique-width, many problems that are NP-hard in general can be polynomial-time solvable. The fact motivates several studies to investigate whether the clique-width of graphs in a certain class is bounded or not. We focus on unigraphs, that is, graphs that are uniquely determined by their degree sequences up to isomorphism. We show that every unigraph has clique-width at most 4. It follows that many problems that are NP-hard in general are polynomial-time solvable for unigraphs.
翻译: clique- width 是一个研究周密的图形参数。 对于连接的 clique- width 图形来说, 普通的NP- hard 有很多问题可以被多边- 时间溶解。 这一事实促使进行数项研究, 以调查某一类的图形的 clique- widdth 是否被捆绑。 我们关注的是单线学, 也就是说, 以其程度序列为唯一决定因素的图表, 直至异形论。 我们显示, 每一个单线 都最多有 4 个 的 clique- wids 。 因此, 普通的 NP- hard 问题对于单线学来说是 多边- 时间可溶解的 。