摘要
设G是一个图,对于任意U■V(G),令N(U)=∪u∈UN(u) ,d(U)=│N│(U) .我们给出了两个结果:设s和t是正整数,G是(2s+2t+1)-连通图,且阶为n;若对于任两个强不交独立集ST,│S│=s,│T│=t ,有d(S)+d(T) ≥n +1 ,则G是哈密尔顿连通的或1-哈密尔顿.
Let G be a graph, for any U lohtain in V(G), let N(U) = Uu∈UN(u) ,d(U) = | N(U) | , we give two results: Let s and t be two positive integers and G be a (2s+ 2t+1)-connected graph of order n; If d(S) +d(T) ≥ n+1 for every two strongly disjoint independent sets S and T with | S| = s and | T| = t, respectively, then G is hamiltonian-connected or 1-hamiltonian.
基金
Supported by the NNSF (10271114 ,10301031) .
关键词
哈密尔顿性
独立集
邻域并
hamiltonicity
independent sets
the neighborhood union