[gaustin]

Would a multiply-rooted tree still be a tree? I thought a single root was part of the definition of a tree. Would it instead be a graph?

Sorry for the elementary questions. I'm bad at algorithms and just trying to get a grasp here.

[kele]

At my university it's common to call acyclic, connected graph a tree. We distinguish between rooted and unrooted trees. For example, minimal spanning tree doesn't really have to be rooted, it just has no cycles.

[haversoe]

> acyclic, connected graph a tree

This is the graph theoretic definition of a tree.

[prateek_mir]

Tree is a graph without any cycles, hence the definition still holds. And yes, you can have multiple roots in a tree, ex:

a --> c <---b ^ d-----|

[fishnchips]

Yes, it's not a tree any more. Which is why I believe this was not the question.