摘要
Let G be a 2 connected simple graph of order n and connectivity k .Bauer, Broersma and Li proved that for an independent set S=u,v,w, d(u)+d(v)+d(w)≥n+k ,then G is Hamiltonian. This paper improves the result.Let S be an independent set. If there exist u,v∈S,du,v=2, then S is called a 2 independent set. This paper proves the following result. Let G be a simple graph of order n and connectivity k≥2 . If for every 2 independent set S=u,v,w, d(u)+d(v)+d(w)≥n+k , then G is Hamiltonian. This result implies that we may consider all triples of 2 independent set instead of all triples of independent set.
设G是一个 2连通简单图 ,具有阶n和连通度k .Bauer等人已证明 :如果对任意三点独立集S =u ,v ,w ,都有d(u) +d(v) +d(w)≥n +k ,则G是Hamilton图 .本文改进了这个结果 .如果一个独立集S中存在距离为 2的 2点 ,则称S是一个 2独立集 .本文证明了如下结果 :如果对任意 3点 2独立集S =u ,v ,w ,都有d(u) +d(v) +d(w)≥n +k .则G是Hamilton图 .这个结果意味我们仅需要检查所有