中国科学技术大学学报 ›› 2015, Vol. 45 ›› Issue (3): 186-192.DOI: 10.3969/j.issn.0253-2778.2015.03.002

• 论著 • 上一篇    

路与圈的优化t-pebbling数

夏正江,潘永亮,徐俊明   

  1. 中国科学技术大学数学科学学院,安徽合肥 230026
  • 收稿日期:2014-11-14 修回日期:2015-03-10 接受日期:2015-03-10 出版日期:2015-03-10 发布日期:2015-03-10

Optimal t-pebbling on paths and cycles

XIA Zhengjiang, PAN Yongliang, XU Junming   

  1. School of Mathematical Sciences, University of Science and Technology of China, Hefei 230026, China
  • Received:2014-11-14 Revised:2015-03-10 Accepted:2015-03-10 Online:2015-03-10 Published:2015-03-10
  • Contact: PAN Yongliang
  • About author:XIA Zhengjiang, male, born in 1987, PhD candidate. Research field: combinatorics and graph theory.
  • Supported by:
    Supported by the Fundamental Research Funds for the Central Universities and the NNSF of China (61272008,11271348,10871189).

摘要: 图上的一个pebbling移动,是从图的一个顶点同时移除2个pebbles,并且在其某个邻点上放置1个pebble. 图的优化t-pebbling数,记为f′t(G), 是指图G中所需要的pebbled的最小数目,使得存在该f′t(G)个pebbles在图上的一种分布,可以在经过一系列pebbling移动后,t个pebbles可以移动到任意一个给定的目标顶点上.f′(G)=f′1(G)称为图G的优化pebbling数.这里给出了路Pn和圈C5的优化t-pebbling数,证明了f′9t(P2×P3)=20t;f′9t+1(P2×P3)=20t+3;当2≤r≤8时,20t+2r+1≤f′9t+r(P2×P3) ≤20t+2r+2,其中,当5≤r≤8时,最后一个不等式取到等号.

关键词: 优化t-pebbling数, 路, 圈, 笛卡尔乘积

Abstract: A pebbling move removes two pebbles from a vertex and places one pebble on one of its neighbours. For t≥1, the optimal t-pebbling number of a graph G, f′t(G), is the minimum number of pebbles necessary so that from some initial distribution of them it is possible to move t pebbles to any target vertex by a sequence of pebbling moves. f′(G)=f′1(G) be the optimal pebbling number of G. Here the optimal t-pebbling numbers of the path Pn and the cycle C5 were given, respectively. In the final section, it was obtained that f′9t(P2×P3)=20t, f′9t+1(P2×P3)=20t+3, and 20t+2r+1≤f′9t+r(P2×P3)≤20t+2r+2, for 2≤r≤8, the last equality holds for r=5,6,7,8.

Key words: optimal t-pebbling number, path, cycle, Cartesian product

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