NAME: ASHWIN ABRAHAM
ROLL NO: 210050023

I assumed in BST that totalParentChildUpdateCost will be incremented only when updateBSTParentChild is called.
Since I never had the need to call it, totalParentChildUpdateCost is always 0.

Also, I added a function in Tree.h returning the price of the TreeNode. This was so that I could return the price of the found node in BST::find