L(1,2)-labeling numbers on square of cycles

For two positive numbers d and m, an m-L(1, d)-labeling of a graph G is a mapping f:V(G)-> [0,m] such that |f(u)-f(v)|>= 1 if d(u,v)=1, and |f(u)-f(v)|>= d if d(u,v)=2. The span of f is the maximum difference among the numbers assigned by f. The L(1, d)-labeling number of G, denoted by lambda 1,d(G), is the minimum span over all L(1, d)-labelings of G. In this paper, we determine the L(1, 2)-labeling numbers of square of cycles C-n for all values n.