两树和图的Cordial性问题

On Cordiality of the Join of Two Trees

两个图的和图Cordial性的研究结果甚少且方法单一.本文采用粘接边或删除边的方法,给出了两树和图为Cordial图的充分必要条件:两树不都是奇度图.

There are few discussions about the cordiality of the join of two graphs and researching methods are almost the same. A both necessary and sufficient premise for the statement is given by adding or deleting edges, that the join of two trees is a Cordial graph if and only if neither is odd-degree.