令G=(V(G),E(G))是一个简单图,Mp(G)为图G的广义Mycielski图.图G的L(2,1)标号数记作λ(G),定义为λ(G)=min{k|G有一个k-L(2,1)标号}.一个连续的L(2,1)标号是一个L(2,1)标号,使得所用的标号是连续的,相应的标号数记作-λ(G).凡是满足λ(G)=-λ(G)的图称为可满着色图.给出了一些特殊图的广义Mycielski图的L(2,1)标号数,从中发现一些广义Mycielski图为可满着色图,并由此猜想广义Mycielski图(除Mp(Kn)之外)为可满着色图.
Let G=(V(G),E(G)) be a simple graph,Mp(G) is the general Mycielski graph of G.The L(2,1)-labeling number of G,denoted by λ(G),is the smallest number k such that G has an L(2,1)-labeling.A consecutive L(2,1)-labeling of G is an L(2,1)-labeling of G such that the labelings are consecutive,and the consecutive L(2,1)-labeling number is denoted by(G).This paper derives the L(2,1)-labeling number of general Mycielski graph of some special graphs,and finds that they are full colorable graphs.It is conjectured that general Mycielski graphs are all full colorable graphs except Mp(Kn).