两类树图上的Randić指标与Harmonic指标之差的极值

Extreme Value of Difference Between Randić Index and Harmonic Index on Two Kinds of Tree Graphs

设G=(V,E)为简单无向连通图.FR,H(G)为图G的Randi?指标(R(G))与Harmonic指标(H(G))之差.分别确定了FR,H(G)在二叉树上的前三大极值,及其在化学树上的前六大极值.

Let G=(V,E)be a simple,connected and undirected graph.F_(R,H)(G)be the difference between Randi index and Harmonic index.In this paper,we determine the first three extreme values of F_(R,H)(G)on the binary trees and the first six extreme values on the chemical trees are determined respectively.