【摘要】 Cahit首次提出H-cordial图概念,先定义每条边的标号为-1,1,由边的标号导出顶点v的标号——与顶点v关联的所有边的标号之和.若存在一个正整数k,对于每个顶点v,其标号是k或-k,且同时满足条件|e(-1)-e(1)≤1|和|v(-k)-v(k)≤1|,符号D(1,3)表示每个顶点的度为1或3的图集,则D(1,3)是H-cordial图当且仅当其含有偶数条边.更多还原

【Abstract】 Cahit calls a graph H-cordial if it is possible to label the edges with the numbers from the set Σ-1,1Σin such a way that, for some k, at each vertex v the sum of the labels on the edges incident with v is either k or-k and the inequalities |e(-1)-e(1)| ≤1 and |v(-k)v(k)| ≤1 are also satisfied. The symbol D(1,3) is the set of graphs of which the degree of each vertex is 1 or 3. In this paper, we prove that D(1,3) is H-cordial if and only if it has even edges.更多还原