Case Problem Write an algorithm to determine if a number n is happy. A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits. Repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy. Return true if n is a happy number, and false if not.

1. Binary Tree Inorder Tree Traversal – Iterative and Recursive Traversing a tree involves iterating over all nodes in some manner. As the tree is not a linear data structure, there can be more than one possible next node from a given node, so some nodes must be deferred, i.e., stored in some way for later visiting. The traversal can be done iteratively where the deferred nodes are stored in the stack, or it can be done by recursion, where the deferred nodes are stored implicitly in the call stacl For traversing a (non-empty) binary tree in an inorder fashion, we must do these three things for every node n starting from the tree’s root: (L) Recursively traverse its left subtree. When this step is finished, we are back at n again. (N) Process n itself. (R) Recursively traverse its right subtree. When this step is finished, we are back at n again.