Tree Functions
1. Write the definition of the function, nodeCount, that returns the number of nodes in a binary tree. Add this function to the classbinaryTreeType and create a program to test this function.
2. Write the definition of the function, leavesCount, that takes as a parameter a pointer to the root node of a binary tree and returns the number of leaves in a binary tree. Add this function to the class binaryTreeType and create a program to test this function.
3. Write a function, singleParent, that returns the number of nodes in a binary tree that have only one child. Add this function tothe class binaryTreeType and create a program to test this function.