One way of representing connections between verts is with a matrix that
records 1 for a connection or 0 for no connection.
A B C D
+--------
A | 0 0 1 1
B | 0 0 1 0
C | 1 0 0 1
D | 1 0 1 0
In the above example B connects to C, but C does not connect back to B.
Another way is to store a list of verts that a particular vert connects to.
A -> [ C D ]
B -> [ C ]
C -> [ A D ]
D -> [ A C ]
This is the recommended approach for our graph projects.
What are the relative advantages and disadvantages of both methods?