Linear and cyclic distance-three labellings of trees
نویسندگان
چکیده
منابع مشابه
Linear and cyclic distance-three labellings of trees
Given a finite or infinite graph G and positive integers `, h1, h2, h3, an L(h1, h2, h3)labelling of G with span ` is a mapping f : V (G) → {0, 1, 2, . . . , `} such that, for i = 1, 2, 3 and any u, v ∈ V (G) at distance i in G, |f(u)−f(v)| ≥ hi. A C(h1, h2, h3)-labelling of G with span ` is defined similarly by requiring |f(u)− f(v)|` ≥ hi instead, where |x|` = min{|x|, `− |x|}. The minimum sp...
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An L(2, 1, 1)-labeling of a graph G assigns nonnegative integers to the vertices of G in such a way that labels of adjacent vertices differ by at least two, while vertices that are at distance at most three are assigned different labels. The maximum label used is called the span of the labeling, and the aim is to minimize this value. We show that the minimum span of an L(2, 1, 1)-labeling of a ...
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ژورنال
عنوان ژورنال: Discrete Applied Mathematics
سال: 2014
ISSN: 0166-218X
DOI: 10.1016/j.dam.2014.06.003