In graph theory and computer science, an adjacency list is a collection of unordered lists used to represent a finite graph.

(“Adjacency List” 2022)

The above graph can be represented as the set \(S\) which contains \(\{B,C\}\), \(\{A,C\}\), \(\{B,A\}\).

VerticesEdges
AB, C
BA, C
CA, B

Also see Adjacency matrix.

Bibliography