what exactly do you mean by asking for the closest node to search key?
is it the node which is closest by it's location in the tree to where our search_key is supposed to be? or is it the key closest by value?
for instance, in a tree including nodes 3,6,8, and search_key=5, would i have to return 6 or is 3 ok as well (since they are both one node away from our search_key)?
thanks and HAG SAMEACH