Computing Binary Tree Node Depth

Let each node be represented by three processors, A, B and C, which are part of a singly-linked list.

• A points to A of left child (if exists)
  or B (go down)

• B points to A of right child (if exists)
  or C (bottom out / backtrack)

• C points to B of parent (if left child)
  or C of parent (if right child)
  or NIL if root