A node, also called a vertex, is a distinct entity in a graph. Graphs represent nodes with vertices V and connect them using edges E, written G=(V,E). section 14.1
Model nodes according to the graph structure being represented:
- Treat nodes as distinct entities; ordinary graphs do not support duplicate nodes. section 14.1
- Connect nodes with directed edges whose source and destination determine travel or relationship direction. section 14.1 section 14.3.1
- Use nodes for road intersections when converting a one-way street map into a graph for route finding. section 14.3.1
Street-map model
Represent each road intersection as a node. Add an edge from node v to node u when a one-way street permits travel from the first intersection to the second; model two-way streets with edges in both directions. section 14.3.1
G = ([v1, v2, v3, v4], [(v1,v2),(v1,v3),(v2,v4)])
Inspect a compact graph listing nodes v1 through v4 and their connecting edges. section 14.1
