ABSTRACT
Strengths: When the graph is dense, the adjacency matrix is the most space efficient representation, particularly when it is not a multigraph. If desired, the space usage can be reduced even further for an undirected graph. Another advantage of an adjacency matrix is that it takes constant time to determine if there is an edge from vertex u to vertex v. Finally, if edge (u, v) only represents the existence of a relation from u to v and there is no associated information, then an adjacency matrix can be made even more space efficient by making it a boolean matrix (or an array of bit vectors) instead of a matrix of edge references.
