leetcode-grind/problems/202/main.py

class Solution:

    def __init__(self):
        self.memo = dict()

    def isHappy(self, n):
        return self.recIsHappy(n)

    def recIsHappy(self, n):
        if n in self.memo:
            return False
        elif n == 1:
            return True
        else:
            self.memo[n] = True
            newN = 0
            for c in str(n):
                newN += int(c) ** 2
            return self.recIsHappy(newN)

s = Solution()
print("Expected: True")
print("Got:", s.isHappy(19))