write a program (in main.cpp) to do the following: a. build a binary search tree t1. b. do a postorder traversal of t1 and, while doing the postorder traversal, insert the nodes into a second binary search tree t2 . c. do a preorder traversal of t2 and, while doing the preorder traversal, insert the node into a third binary search tree t3. d. do an inorder traversal of t3. e. output the heights and the number of leaves in each of the three binary search trees.