A covering problem that is easy for trees but NP-complete for trivalent graphs
نویسندگان
چکیده
منابع مشابه
A covering problem that is easy for trees but I-complete for trivalent graphs
By definition, a P2-graph Γ is an undirected graph in which every vertex is contained in a path of length two. For such a graph, pc(Γ) denotes the minimum number of paths of length two that cover all n vertices of Γ. We prove that ⌈n/3⌉ ≤ pc(Γ) ≤ ⌊n/2⌋ and show that these upper and lower bounds are tight. Furthermore we show that every connected P2-graph Γ contains a spanning tree T such that p...
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ژورنال
عنوان ژورنال: Discrete Applied Mathematics
سال: 2008
ISSN: 0166-218X
DOI: 10.1016/j.dam.2007.11.021