class Solution:
    def isHappy(self, n: int) -> bool:
        seen = {n}
        while True:
            n = self.square_digital_sum(n)
            if n in seen:
                return n == 1
            seen.add(n)

    @staticmethod
    def square_digital_sum(n: int) -> int:
        total = 0
        while n > 0:
            n, digit = divmod(n, 10)
            total += digit**2
        return total