Graph (Data Structure)

A visualization of the Seven Bridges of Königberg. Leonhard Euler solved this problem in 1736, which led to the devlopment of topology, and modern graph theory.

A graph is an abstract data structure. It holds nodes that are usually related to each other. A node is a dataset, typically in the form of ordered pairs. Nodes are either connected or not connected to another node. The relation between nodes is usually defined as an Edge. Graphs are useful for their ability to associate nodes with other nodes. There are a few representations of Graphs in practice.

Adjacency matrix

There is a two-dimensional Array, every index is a pointer to a value, 0 or 1, representing an edge or a column. Data on edges and vertices must be stored externally.