Radio labeling on some corona graphs.

A Radio labeling c of G is an assignment of positive integers to the vertices of G satisfying |c(u) - c(v)| ≥ diam (G)+1 - d(u, v) for every two distinct vertices (u, v), where, diam G be the diameter of G and d(u, v) be the distance between two distinct vertices. If G has radio labeling with maximum {c(v): v ∈ V(G)} = k, then the smallest number k satisfying this condition is called the radio number of G and is denoted by rn(G). In this paper we investigate the Radio labeling for the graphs C3 ⊙ Pn, C4 ⊙ Pn and C5 ⊙ Pn when n ≥ 2, where ⊙, the corona product between the cycle graph and a path graph. Also we determine the radio number of these graphs. [ABSTRACT FROM AUTHOR]