摘要
设G是p≥2阶几乎无桥的简单连通K3—free图，且若对任何相距为1的两条边e0及e1，有d（e0）＋d（e1）≥p＋3，则G有一个D—闭迹，从而G的线图L（C）是哈密顿的．
For each edge e=uv of graph G, let d(e) =d(u) +d(v), where d(u) and d (v) are the degrees of vertices u and v respectively. The main result is as follows:Let G be simple connected almost bridgeless graph .order p≥2,and G be K3 - free. If d(e0) +d(e1)≥p+3,for each pair of edges e0 and e1 whose distance is 1,then G has a D-circuit and line graph L(G) is hamiltonian.
