设dG(x)为图G中顶点x的度,若对于任意x∈V(G),dG(x)∈{i1,…,ik},k∈N,则称图G为D(i1,…,ik)图.研究D(0,3)图的Cordial性,利用分类讨论,调整标号的方法,证明了有最大度ΔG=Δ的图G,存在标号f,使得|v0(G)-v1(G)|≤1,|e0(G)-e1(G)|≤2Δ;在4个引理的基础上,证明了所有的D(0,3)图都是Cordial图.
Let d G( x) be the degree of a vertex x in a graph G. A graph G is called D( i1; …,ik) graph,if{ dG( x) | x ∈ V( G) } = { i1,…,ik},k ∈ N. Let G be a graph with the maximum degree ΔG = Δ,by using classification discussion and changing the vertex labels constantly,the existence of a labeling f,such that | v0( G) =v1( G) | ≤ 1,| e0( G)- e1( G) | ≤ 2Δ is proposed. Based on four Lemmas,the cordiality of D( 0,3) graphs is proved.