A graph G is called a fractional[a,b]-covered graph if for each e∈E(G),G contains a fractional[a,b]-factor covering e.A graph G is called a fractional(a,b,k)-critical covered graph if for any W■V(G)with|W|=k,G-W is ...A graph G is called a fractional[a,b]-covered graph if for each e∈E(G),G contains a fractional[a,b]-factor covering e.A graph G is called a fractional(a,b,k)-critical covered graph if for any W■V(G)with|W|=k,G-W is fractional[a,b]-covered,which was first defined and investigated by Zhou,Xu and Sun[S.Zhou,Y.Xu,Z.Sun,Degree conditions for fractional(a,b,k)-critical covered graphs,Information Processing Letters 152(2019)105838].In this work,we proceed to study fractional(a,b,k)-critical covered graphs and derive a result on fractional(a,b,k)-critical covered graphs depending on minimum degree and neighborhoods of independent sets.展开更多
Given an alphabet ∑ and a finite minimal set B of forbidden words,a combinatorial enumeration problem on bacterial complete genomes is transformed to enumerating strings of a given length which do not contain any str...Given an alphabet ∑ and a finite minimal set B of forbidden words,a combinatorial enumeration problem on bacterial complete genomes is transformed to enumerating strings of a given length which do not contain any string in B as their substrings.From the fact that a string in the language is equivalent to a path in the corresponding graph,we have obtained a polynomial time algorithm by modifying the power of the adjacency matrix in the graph.展开更多
文摘A graph G is called a fractional[a,b]-covered graph if for each e∈E(G),G contains a fractional[a,b]-factor covering e.A graph G is called a fractional(a,b,k)-critical covered graph if for any W■V(G)with|W|=k,G-W is fractional[a,b]-covered,which was first defined and investigated by Zhou,Xu and Sun[S.Zhou,Y.Xu,Z.Sun,Degree conditions for fractional(a,b,k)-critical covered graphs,Information Processing Letters 152(2019)105838].In this work,we proceed to study fractional(a,b,k)-critical covered graphs and derive a result on fractional(a,b,k)-critical covered graphs depending on minimum degree and neighborhoods of independent sets.
基金This research is supported by the National Natural Science Foundation of China (No. 10271103) Natural Science Foundation of Yunnan Province(No. 2003F0015M).
文摘Given an alphabet ∑ and a finite minimal set B of forbidden words,a combinatorial enumeration problem on bacterial complete genomes is transformed to enumerating strings of a given length which do not contain any string in B as their substrings.From the fact that a string in the language is equivalent to a path in the corresponding graph,we have obtained a polynomial time algorithm by modifying the power of the adjacency matrix in the graph.