Extend the height-balanced tree code that was sent to you by four functions
? key t find min(tree node t * tree)
? obj t * find min obj(tree node t * tree)
? obj t * delete min(tree node t * tree)
? int tree empty(tree node t * tree)
Here find min returns the minimum key in the search tree, find min obj returns the object belonging to the minimum key, delete min deletes the minimum key, returns the object belonging to it, and rebalances the tree after the deletion, and tree empty returns 1 if the tree is empty, 0 else.