Radio number of trees

Devsi Bantva, Samir Vaidya, Sanming Zhou

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