Edge List
An edge list is a data structure used in graph theory and computer science to represent a graph as a list of its edges, where each edge is typically stored as a pair of vertices (e.g., (u, v) for an undirected graph or (u, v) for a directed graph). It is a simple and space-efficient way to store graph information, especially for sparse graphs where the number of edges is much smaller than the number of possible vertex pairs. This representation is commonly used in algorithms for graph traversal, network analysis, and applications like social networks or routing problems.
Developers should learn and use edge lists when working with graph algorithms that require efficient iteration over all edges, such as in breadth-first search (BFS), depth-first search (DFS), or minimum spanning tree algorithms like Kruskal's, as it allows for quick access to edge data without the overhead of adjacency matrices. It is particularly useful in scenarios involving sparse graphs, dynamic graphs where edges are frequently added or removed, or in memory-constrained environments due to its compact storage. However, for dense graphs or operations requiring fast neighbor lookups, alternative representations like adjacency lists may be more efficient.