优美图可用在图论中的某些H-分解问题中,很多人研究无向图的优美标号.研究有向优美标号,通过对阶数奇偶性的讨论,给出了n(≥2)阶有向路(向量)Pn和n(≥3)阶有向(向量)Cn圈是有向优美的充分条件.
Graceful labeling is studied on undirected graphs since graceful graphs can be used in some H-decomposition problems in graph theory.The digraceful labeling is discussed in this paper and the sufficient conditions for the directed path (向量)P_n and directed cycle (向量)C_n to be digraceful are given by discussing the parities of the order n.