Graphs
A graph is a set of vertices and edges that form connections between the vertices. In a more formal approach, a graph G is an ordered pair of a set V of vertices and a set E of edges given as G = (V, E)
in formal mathematical notation.
An example of a graph is given here:
Let's now go through some definitions of a graph:
- Node or vertex: A point, usually represented by a dot in a graph. The vertices or nodes are A, B, C, D, and E.
- Edge: This is a connection between two vertices. The line connecting A and B is an example of an edge.
- Loop: When an edge from a node is incident on itself, that edge forms a loop.
- Degree of a vertex: This is the number of vertices that are incident on a given vertex. The degree of vertex B is
4
. - Adjacency: This refers to the connection(s) between a node and its neighbor. The node C is adjacent to node A because there is an edge between them.
- Path: A sequence of vertices where each adjacent pair is connected by an edge.