哈密尔顿连通图与邻域并条件

Hamiltonian-Connected Graphs with Neighborhood Unions

记G=(V,E)表示简单图,NC=min{|N(x)∪N(y)|:x,y∈V(G),xy∈E(G)},NC2=min{|N(x)∪N(y)|:x,y∈V(G),d(x,y)=2}。1989年Faudree等4个美国著名图论专家研究课题NC≥(2n+1)/3的哈密尔顿连通图,得到:若3连通n阶图G,NC≥(2n+1)/3,则G是哈密尔顿连通图。本文进一步研究NC2≥(2n+1)/3的哈密尔顿连通图,得到界为最好的结果:若3连通n阶通图G,NC2≥(2n+1)/3,则G是哈密尔顿连通图。而且本文的证明极其简捷。

Let G be a sample graph,NC=min{|N(x)∪N(y)|:x,y∈V(G),xy∈E(G)},NC2=min{|N(x)∪N(y)|:x,y∈V(G),d(x,y)=2}.IN 1989,Faudree et.al obtained that if 3connected graph G of order n with NC≥(2n+1)/3,then G be hamiltonianconnected graph.In this paper the author shows that if 3connected graph G of order n with NC2≥(2n+1)/3,then G be hamiltonianconnected graph.