摘要
An L(2, 1)-labeling of a graph G is a function f from the vertex set V(G) to the set of all nonnegative integers such that |f(x) - f(y)| 〉 2 if d(x, y) = 1 and |f(x)-f(y)| ≥ 1 ifd(x, y) = 2. The L(2, 1)-labeling number λ(G) of G is the smallest number k such that G has an L(2, 1)-labeling with max{f(v) : v ∈ V(G)} = k. We study the L(3, 2, 1)-labeling which is a generalization of the L(2, 1)-labeling on the graph formed by the (Cartesian) product and composition of 3 graphs and derive the upper bounds of λ3(G) of the graph.
An L(2, 1)-labeling of a graph G is a function f from the vertex set V(G) to the set of all nonnegative integers such that |f(x) - f(y)| 〉 2 if d(x, y) = 1 and |f(x)-f(y)| ≥ 1 ifd(x, y) = 2. The L(2, 1)-labeling number λ(G) of G is the smallest number k such that G has an L(2, 1)-labeling with max{f(v) : v ∈ V(G)} = k. We study the L(3, 2, 1)-labeling which is a generalization of the L(2, 1)-labeling on the graph formed by the (Cartesian) product and composition of 3 graphs and derive the upper bounds of λ3(G) of the graph.