On Gracefulness of Directed Trees with short diameters
نویسندگان
چکیده
Graceful labelling is studied on undirected graphs since graceful graphs can be used in some H-decomposition problems. In this note, we investigate the directed graceful problem for many orientations of undirected trees with short diameters, and provide some directed trees that deny any digraceful labelling. AMS Subject Classification (2000): 05C78
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تاریخ انتشار 2010