A diagram consisting of circles, called vertices or nodes, joined by lines, called edges or arcs; each edge joins exactly two vertices.
Two vertices that are connected by an edge.
Of a vertex, is the number of neighbours for that vertex.
A graph where the edges are labelled or given a value called a weight.
A directed graph i.e. one where vertices are connected by directed edges.
A tree is a connected undirected graph with no cycles.
A rooted tree is a tree in which one vertex has been designed as the root and every edge is directed away from the root. |