Happy Number

Examples

Example 1:

Input: n = 19

Output: true

Explanation:

Example 2:

Input: n = 2

Output: false

Write an algorithm to determine if a number n is happy.

A happy number is 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 that does not include 1.

Return true if n is a happy number, and false if not.

1^2 + 9^2 = 82, 8^2 + 2^2 = 68, 6^2 + 8^2 = 100, 1^2 + 0^2 + 0^2 = 1

1 <= n <= 2^31 - 1