Happy Number

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.

Example 1:

Input: n = 19

Output: true

Explanation:

12 + 92 = 82
82 + 22 = 68
62 + 82 = 100
12 + 02 + 02 = 1

Example 2:

Input: n = 2

Output: false

Constraints:

• 1 <= n <= 2^31 - 1

class Solution:
    def isHappy(self, n: int) -> bool:
        prev_n = n
        seen = set()

        while True:
            n = self.get_digit(n)
            if n == 1:
                return True
            if n in seen:
                return False
            seen.add(n)
        return False

    def get_digit(self, val):
        res = []

        while val:
            left_over = val % 10
            res.append(left_over ** 2)
            val = val // 10
        return sum(res)