Displaying last TWO largest in a binary search tree???

How would I display the last two largest nodes in a binary search tree
recursively???? I don't know how to approach this, and would like some help. Thanks!
pseudocode:

1
2
3
4
5
6
7
8
9
a = root
b = 0

while a != 0 and a=>right != 0:
    b = a
    a = a=>right

print a
print b
Topic archived. No new replies allowed.