Graphs

A graph is a data structure made up of nodes connected to each other by edges.

Uses of Graphs

Maps and Route Finding

Social Networks

Critical Path Analysis and Flow Diagrams

Fact Based Models for Big Data

Flood Fill Algorithm

Maze Solving and Creation

Types of Graph

Representing Graphs

Adjacency List

Graph Traversal

Breadth First Search

Depth First Search

Key Words

Graph

A data structure made up of connected nodes and edges. Used to model the relationships between objects.

Node/Vertex

An element in a graph or tree

Edge/Arc

A connection between two nodes in a graph or tree.  It can be used to show the relationship between the nodes.

Weighted graph

A graph with values attached to the edges. 

Directed Graph

A graph where the relationship between the nodes is one way.

Adjacency Matrix

A method of storing  a graph using a 2D array data structure that stores if there is an edge (or the weight of an edge) between nodes.

Adjacency List

A method of storing a graph using a dynamic data structure. Each node stores a list of their adjacent node.

Path

A sequence of nodes that are connected by edges.

Cycle

A path that starts and ends at the same node without visiting a node more than once.

Loop

An edge that connects a node to itself.