João Ferreira

In graph theory, the degree of a vertex A, d.A, is the number of edges incident with the vertex A, counting loops twice. So, considering graph 0 below, we have d.A=3, d.B=3, d.C=1, d.D=3, and d.E=2.
A well-known property is that every undirected graph contains an even number of vertices with odd degree. The result first [...]