论文标题

计算$ L(P,1)$ - 与组合参数的标签

Computing $L(p,1)$-Labeling with Combined Parameters

论文作者

Hanaka, Tesshu, Kawai, Kazuma, Ono, Hirotaka

论文摘要

给定图形,$ l(p,1)$ - 图形的标记是从顶点集到一组非负整数的分配$ f $,以便对于任何一对顶点$(u,v),| f(f(u) - f(u) - f(f(v)| \ ge p $如果$ u $和$ v $相邻,而$ f(u)\ neq f(v)$如果$ u $和$ v $在距离为$ 2 $。 $ l(p,1)$ - 标记问题是最小化$ f $的跨度(即$ \ max_ {u \ in v}(f(u)) - \ min_ {u \ in v}(f(u))+1 $)。众所周知,即使对于最高度$ 3 $的图形或带有树宽2的图形的图形也是NP-HARD,而相对于顶点盖号,它是固定参数可进行的。由于顶点覆盖号是一种最强的参数,因此从参数化的角度来看,障碍性和可行性之间存在很大的差距。为了填补差距,在本文中,我们提出了新的固定参数算法,以$ l(p,1)$ - 通过双盖号码加上最大集团大小的标签,并按照树的宽度和最高度。这些算法根据参数的几种组合减少了差距。

Given a graph, an $L(p,1)$-labeling of the graph is an assignment $f$ from the vertex set to the set of nonnegative integers such that for any pair of vertices $(u,v),|f (u) - f (v)| \ge p$ if $u$ and $v$ are adjacent, and $f(u) \neq f(v)$ if $u$ and $v$ are at distance $2$. The $L(p,1)$-labeling problem is to minimize the span of $f$ (i.e.,$\max_{u\in V}(f(u)) - \min_{u\in V}(f(u))+1$). It is known to be NP-hard even for graphs of maximum degree $3$ or graphs with tree-width 2, whereas it is fixed-parameter tractable with respect to vertex cover number. Since vertex cover number is a kind of the strongest parameter, there is a large gap between tractability and intractability from the viewpoint of parameterization. To fill up the gap, in this paper, we propose new fixed-parameter algorithms for $L(p,1)$-Labeling by the twin cover number plus the maximum clique size and by the tree-width plus the maximum degree. These algorithms reduce the gap in terms of several combinations of parameters.

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