Building hierarchy objects from flat list of parent/child

Question

I have a list of items in a hierarchy, and I\'m attempting to parse this list out into an actual hierarchy of objects. I\'m using modified pre-order tree traversal to store/iter

Answer 1

I assume you already know the parent of all items.

All you need to do is to iterate through all item of the list once and add the current item to its parent's children list. Only keep the items without parents in the target nested list.

Here is some pseudo code:

foreach Item item in flatlist
   if item.Parent != null
      Add item to item.Parent.ChildrenList
      Remove item from flatlist
   end if
end for

As for getting the parents, from what I can see in your example, you might need to parse the name and build a stack as you advance in the list.

This problems looks hard but it really isn't. A lot of people see this problem from the wrong angle; you must not try to populate every children list but rather get rid of the children items from the flat list, then it becomes easy.