VERTEX-MAGIC TOTAL LABELINGS OF DISCONNECTED GRAPHS

Let G be a graph with vertex set V = V (G) and edge set E = E(G) and let e = |E(G)| and v = |V (G)|. A one-to-one map lambda from V U[E onto the integers {1; 2; … v +e} is called vertex magic total labeling if there is a constant k so that for every vertex x, Lambda(x)+∑ lambda ¸(xy) = k where the sum is over all vertices y adjacent to x. Let us call the sum of labels at vertex x the weight w¸(x) of the vertex under labeling lambda ,we require w lambda (x) = k for all x. The constant k is called the magic constant for lambda. In this paper, we present the vertex magic total labelings of disconnected graph, in particular, two copies of isomorphic generalized Petersen graphs 2P(n;m), disjoint union of two non-isomorphic suns Sm U Sn and t copies of isomorphic suns tSn