Given the binary tree below what would be the contents of the queue/stack after visiting the node with key 14 using an in-order depth-first traversal?

What is the definition of a tree's root?

What is the space complexity of performing a breadth-first traversal of a binary tree with n nodes?

Given the algorithm bla, the binary tree and the pointer p below, what would be a call to bla( p ) return?

Function bla(TreeNode b)

     IF b = NULL

          return 0

     return bla( b.right ) + bla( b.left ) + 1

Which type of tree traversal does not use a stack?