Write a function that takes as input a general tree and returns the number of nodes in that tree. Write your function to use the GenTree and GTNode ADTs of Figure 6.2. Describe how to implement the...

Write a function that takes as input a general tree and returns the number of nodes in that tree. Write your function to use the GenTree and GTNode ADTs of Figure 6.2.

Describe how to implement the weighted union rule efficiently. In particular, describe what information must be stored with each node and how this information is updated when two trees are merged. Modify the implementation of Figure 6.4 to support the weighted union rule.