Write a C++ function given the following struct declaration for a Binary Search tree that completes this function in O(h) time complexity where h is the height of the tree.

Function: num range Description returns the number of elements in tree which are Runtime: O(h) where h is the tree height struct tree node int number0fNodesnLeftSubtree = 0; int numberofNodesInRightSubtree0 tree node left: tree_node right: int num range (int min, int max) i return numNodes: I/ where num is num of nodes between min and max