Leetcode: Happy Number

Happy Number | LeetCode OJ

1. Find sum of squares of current number, add it to the set
2. The set will keep track of sum of squares encountered
3. Continue the process until a value repeats or if we find 1

Since we don’t know how many times the loop will execute we cannot determine the amount of space used or the time taken

class Solution(object):
    def isHappy(self, n):
        """
        :type n: int
        :rtype: bool
        """
        s = set()
        while n != 1:
            if n in s:
                return False
            s.add(n)
            n = self.square_sum(n)
        return True
    def square_sum(self, n):
        res = 0
        while n:
            v = n % 10
            res += v * v
            n = n / 10
        return res