Happy-Num
/* 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 1 if n is a happy number, and 0 if not.
Input: n = 19
Output: 1
Number 19 is Happy Number because:
1^2 + 9^2 = 82
8^2 + 2^2 = 68
6^2 + 8^2 = 100
1^2 + 0^2 + 0^2 = 1
As we reached to 1, 19 is a Happy Number return 1
Otherwise return 0.
*/