关于哈密尔顿指数的综述
The Hamiltonian Index of a Graph---A Survey

图G的线图L（ G）是指以G的边集E（ G）为顶点集且L（ G）的2个顶点邻接当且仅当它们在G中有公共顶点。 n次迭代线图Ln（G）递归地定义为L0（G）=G，Ln（G）=L（Ln-1（G））（n∈N=｛0，1，2，…｝），其中L1（ G）=L（ G）并且假设Ln-1（ G）非空，使得Ln（ G）是哈密尔顿的最小整数n称为哈密尔顿指数，用h（ G）表示。该文综述了（类）哈密尔顿指数的一些结果。
Let G be a simple graph. The line graph L( G)of a graph G is a graph which has E( G)as its vertex set and two vertices are adjacent in L( G)if and only if they share an end vertex in G. The n-th iterated line graph Ln(G)is defined recursively by L0(G)=G,Ln(G)=L(Ln-1(G))(n∈N={0,1,2,…}),where L1(G)=L(G) and Ln-1( G)is assumed to be nonempty. The hamiltonian index of a graph G,denoted by h( G),is the smallest in-teger n such that Ln(G)is hamiltonian. The results of hamiltonian(like)indices of graphs have been summaric-zed