An L(3,2,1)-labeling of a graph G is a function f from the vertex set V(G) to the set of all non-negative integers (labe......

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 tha......

研究了距离图G(Z, D)的L(2, 1)-标号着色数λ(G(Z, D)). 对一般的有限距离集D, 证明了2|D|+2≤λ(G(Z, D))≤|D|2+3|D|. 此外, 当D......