["Followup-To:" header set to comp.lang.python.] On Wed, 18 May 2011 20:20:01 +0200, Raymond Wiker <raw@RAWMBP-2.local> wrote: : I don't think anybody mentioned *binary* trees. The context was : directory traversal, in which case you would have nodes with an : arbitrary (almost) number of children.
If we are being specific, then directory trees do have parent pointers. My point was really that «standard tree representations» is not a well-defined concept, and having parent pointers is as standard as not having them. : Except that the chain of parent pointers *would* constitue a : stack. In the sense that the tree itself is a stack, yes. But if we consider the tree (or one of its branches) to be a stack, then the original claim becomes a tautology. But you do have a point. Keeping a stack of nodes on the path back to root is a great deal simpler and cheaper than a call stack, and not really a significant expense in context. -- :-- Hans Georg -- http://mail.python.org/mailman/listinfo/python-list
