In the Union-Find data structure (also known as the Disjoint-Set data structure), elements of a set have directed edges providing paths to the representative element, or root, of the set. Each set representation is referred to as a tree, with the entire data structure being a forest of trees.
It's not clear to me that these trees satisfy the formal definition of trees. In the shown diagram, there are two pointers to the "root" node Mexico, which makes me think of it as being more of a leaf in a graph than a root in a tree.
Am I misunderstanding something, or does tree have a different meaning in this context?
