PROCEDURE RPREORDER(T)
[Given a binary tree whose root node address is given by the pointer variable T, this algorithm traverses the tree in preorder in a recursive manner].

1. [Check for empty tree]

If T = NULL
then write (“Empty Tree”)
return.

2. [Process the root node]

else
write DATA(T).

3. [Process the left tree]

If LPTR(T) != NULL
then call RPREORDER(LPTR(T)).

4. [Process the right node]

If RPTR(T) != NULL
then call RPREORDER(RPTR(T)).

5. [FINISH]
return.