Graphs
LINKS
A graph is a non-linear data structure that can be looked at as a collection of vertices (or nodes) potentially connected by line segments named edges.
Here is some common terminology used when working with Graphs:
- Vertex - A vertex, also called a “node”, is a data object that can have zero or more adjacent vertices.
- Edge - An edge is a connection between two nodes.
- Neighbor - The neighbors of a node are its adjacent nodes, i.e., are connected via an edge.
- Degree - The degree of a vertex is the number of edges connected to that vertex.
Directed vs Undirected
Undirected Graphs
An Undirected Graph is a graph where each edge is undirected or bi-directional. This means that the undirected graph does not move in any direction.
Directed Graphs(Digraph)
A Directed Graph also called a Digraph is a graph where every edge is directed.
Unlike an undirected graph, a Digraph has direction. Each node is directed at another node with a specific requirement of what node should be referenced next.
Complete vs Connected vs Disconnected
Connected Graphs
A complete graph is when all nodes are connected to all other nodes.
Connected
A connected graph is graph that has all of vertices/nodes have at least one edge.
Disconnected
A disconnected graph is a graph where some vertices may not have edges.