• k – SUM AND n – SUM CORDIAL LABELING OF SOME GRAPHS

S uppose G = (V (G), E (G)) is a graph with vertex set V (G) and edge set E (G).  A vertex labeling f: V (G) ® {0, 1, 2…., k-1} where k is an integer, 1For each edge , assign the label (mod k). The map f is called a k-sum cordial labeling , if and, for and i, j I {0, 1,2…,k-1} where and denote the number of vertices and edges respectively labeled with ( = 0, 1, 2,…, k-1).  Any graph which satisfies k-sum cordial labeling is called a k-sum cordial graph .  In this paper, we prove square graph of path is a k-sum cordial graph.  Also we investigate some special graphs, are n+1 sum cordial graphs.  Further we prove that the graph  is a 3-sum cordial graph and K n,n is a n - sum cordial graph.