Let \(G\) be a connected graph, and let \(d(u,v)\) denote the distance between vertices \(u\) and \(v\) in \(G\). For any cyclic ordering \(\pi\) of \(V(G)\), let \(\pi = (v_1, v_2, \ldots, v_n, v_{n+1} = v_1)\), and let \(d(\pi) = \sum\limits_{i=1}^n d(v_i, v_{i+1})\). The set of possible values of \(d(\pi)\) of all cyclic orderings \(\pi\) of \(V(G)\) is called the Hamiltonian spectrum of \(G\). We determine the Hamiltonian spectrum for any tree.
Citation
Daphne Der-Fen Liu. Hamiltonian Spectra of Trees[J], Ars Combinatoria, Volume 099. 415-419. .