摘要
文章给出了非连通图(P1∨Pn)∪St(m)和(P1(1)∨Pn)∪(P1(2)∨P2n)及(P2∨Kn)∪Gn-1,证明了对任意自然数n,设s=n2,则当n≥3,m≥s时,非连通图(P1∨Pn)∪St(m)是优美图;当n≥3时,非连通图(P1(1)∨Pn)∪(P1(2)∨P2n)是s-优美图;当n≥2时,非连通图(P2∨Kn)∪Gn-1是优美图;其中,Pn是n个顶点的路,P1、P1(1)和P1(2)均是只有一个顶点的平凡图,G1∨G2是图G1与G2的联图,St(m)是m+1个顶点的星形树,Kn是n个顶点的完全图,-Kn是Kn的补图,Gn-1是任意一个n-1条边的优美图。
The present paper presents the three kinds of unconnected graphs (P1∨Pn)∪St(m),(P1^(1)∨Pn)∪(P1(2)∨P2n)and(P2∨-↑Kn)∪Gn-1,proves following results:for natural number n,let s =[n/2] , if n ≥3 and m ≥ s then unconnected graph (P1 ∨ Pn) ∪ St (m) is a graceful graph; if n ≥3 then unconnected graph (p1^(1)) ∨ Pn)∪ (p1^(2) ∨ P2n) is an s-graceful graph,if n ≥2 then unconnected graph (P2∨-↑Kn) ∪Gn-1 is a graceful graph, where Pn is n-vertex path; P1 ,p1^(1) and p1^(2) are trivial graphs; G1∨ G2 is the join graph of G1 and G 2 ; St (m) is (m+1) -vertex star tree; Kn is an n-vertex complete graph; -↑Kn is the complement of graph Kn ,Gn-1 is a graceful graph with n-1 edges.
出处
《合肥工业大学学报(自然科学版)》
CAS
CSCD
北大核心
2008年第2期276-279,共4页
Journal of Hefei University of Technology:Natural Science
基金
国家自然科学基金资助项目(19801016
10261003)
关键词
优美图
优美标号
非连通图
graceful graph
graceful label
unconnected graph