Edge list

An edge list is a data structure used to represent a graph as a list of its edges. An (unweighted) edge is defined by its start and end vertex, so each edge may be represented by two numbers.^[1] The entire edge list may be represented as a two-column matrix.^[2][3] An edge list may be considered a variation on an adjacency list which is represented as a length ${\displaystyle |V|}$ array of lists.^[4] Since each edge contains just two or three numbers, the total space for an edge list is ${\displaystyle \Theta (|E|)}$.^[3]