Write pseudo code for each of the following B-tree functions. Analyze their run-time efficiency in terms of the # of page reads performed and express it in asymptotic O(f(n)) notation where n is the # of keys in the tree whose root is pointed to by x. Describe your analysis.

1. Min(x) // Returns the minimum key value in the B-tree whose root is pointed to by x.
2. Max(x) // Returns the maximum key value in the B-tree whose root is pointed to by x.
3. height(x) // Returns the height of the B-tree whose root is pointed to by x.
4. countNodes(x) // Returns the total # of nodes in the B-tree whose root is pointed to by x.
5. countKeys(x) // Returns the total # of keys in the B-tree whose root is pointed to by x.