扩展双星树的Wiener指数与子树

Wiener index and subtrees of extended two stars trees

证明了在|n_1-n_2|≤1条件下,扩展双星树T_(n_1,n_2)有最大的Wiener指数和最小的子树个数,并且随着悬挂边的移动其Wiener指数越来越小,子树个数越来越大.

This paper gives the results that the Wiener index be- comes smaller and smaller and the total number of subtree be- comes bigger and bigger of the tree T_(n_1·n_2)(extended double trees)under the transmission of the pendant edge.Also,the paper concludes that T_(n_1n_2)minimize the total number of subtrees and maxmize the Wiener index in the condition of|n_1-n_2|≤1.