GraphsA graph G consists of a finite set V of objects called
Vertices, a finite set E ofobjects called Edges, and a function ?
that assigns to each edge a subset {v,w}, where v and w are
vertices (and may be the same).There fore we write G = (V E, , ?
).Degree of a vertex: It is defined as the number of edges having
that vertex asan end point.Loop: A graph may have an edge from a
vertex to itself, such an edge is calleda loop.Degree of a vertex
is 2, for a loop since that vertex serves as bothendpoints of the
loop.Isolated vertex: A vertex with zero as degree is called an
Isolated vertex.
