Characterization of Minimum Cycle Basis in Weighted Partial 2-trees
نویسندگان
چکیده
For a weighted outerplanar graph, the set of lex short cycles is known to be a minimum cycle basis [Inf. Process. Lett. 110 (2010) 970-974 ]. In this work, we show that the set of lex short cycles is a minimum cycle basis in weighted partial 2-trees (graphs of treewidth two) which is a superclass of outerplanar graphs.
منابع مشابه
Computing Minimum Cycle Bases in Weighted Partial 2-Trees in Linear Time
We present a linear time algorithm for computing an implicit linear space representation of a minimum cycle basis in weighted partial 2-trees (i.e., graphs of treewidth at most two) with nonnegative edge-weights. The implicit representation can be made explicit in a running time that is proportional to the size of the minimum cycle basis. For planar graphs, Borradaile, Sankowski, and Wulff-Nils...
متن کاملOn Minimum Average Stretch Spanning Trees in Polygonal 2-Trees
A spanning tree of an unweighted graph is a minimum average stretch spanning tree if it minimizes the ratio of sum of the distances in the tree between the end vertices of the graph edges and the number of graph edges. We consider the problem of computing a minimum average stretch spanning tree in polygonal 2-trees, a super class of 2-connected outerplanar graphs. For a polygonal 2-tree on n ve...
متن کاملA characterization of trees with equal Roman 2-domination and Roman domination numbers
Given a graph $G=(V,E)$ and a vertex $v in V$, by $N(v)$ we represent the open neighbourhood of $v$. Let $f:Vrightarrow {0,1,2}$ be a function on $G$. The weight of $f$ is $omega(f)=sum_{vin V}f(v)$ and let $V_i={vin V colon f(v)=i}$, for $i=0,1,2$. The function $f$ is said to bebegin{itemize}item a Roman ${2}$-dominating function, if for every vertex $vin V_0$, $sum_{uin N(v)}f(u)geq 2$. The R...
متن کاملA characterization relating domination, semitotal domination and total Roman domination in trees
A total Roman dominating function on a graph $G$ is a function $f: V(G) rightarrow {0,1,2}$ such that for every vertex $vin V(G)$ with $f(v)=0$ there exists a vertex $uin V(G)$ adjacent to $v$ with $f(u)=2$, and the subgraph induced by the set ${xin V(G): f(x)geq 1}$ has no isolated vertices. The total Roman domination number of $G$, denoted $gamma_{tR}(G)$, is the minimum weight $omega(f)=sum_...
متن کاملNew length bounds for cycle bases
Based on a recent work by Abraham, Bartal and Neiman (2007), we construct a strictly fundamental cycle basis of length O(n) for any unweighted graph, whence proving the conjecture of Deo et al. (1982). For weighted graphs, we construct cycle bases of length O(W ·logn log logn), where W denotes the sum of the weights of the edges. This improves the upper bound that follows from the result of Elk...
متن کامل