16)The cost of a path in a tree is sum of the keys of the nodes participating in that path. Write a function that returns the cost of the most expensive path from the root to a leaf node.

17)Write a function to determine whether a given binary tree is AVL or not.

18)What value does the following function return when called with each of the binary trees in question 3?

int mystery(Nodex) {

if (x == null)

return 0;

else return max(mystery(x.left), mystery(x.right);

}

19)Write a function to determine whether a given binary tree is a heap.

Write a Java program to implement a binary search tree of string values with operations in the above list.