Visually Explained Algorithms The adjacency list is another way to represent adjacent vertices. Why would you want to create an adjacency list? Again, to save time. The adjacency list is much more efficient when trying to figure out the adjacent nodes in a graph. Adjacency list also takes up less space than the adjacency matrix. In the adjacency matrix, each node must contain a value, regardless of whether it contains an edge to another node or not. The adjacency list only contains nodes that are connected. Let’s look at an example of how someone would create an adjacency list from