Optimal Radio Labellings of Block Graphs and Line Graphs of Trees

Devsi Bantva, Daphne Der-Fen Liu

A radio labeling of a graph $G$ is a mapping $f$ : $V(G)\to \{0,1,2,...\}$ such that $|f(u)-f(v)|\ge diam(G)+1-d(u,v)$ holds for every pair of vertices $u$ and $v$…