Vaidya, S.K.; Parmar, A.D.
(Malaya Journal of Matematik, 2019)
A proper k - coloring of a graph G is a function f : V(G) → {1,2,..., k} such that f(u) 6= f(v) for all uv ∈ E(G). The
color class Si
is the subset of vertices of G that is assigned to color i. The chromatic number χ(G) ...