day_2.py

'''
Problem Statement:
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, and 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 numbers.

Return True if n is a happy number, and False if not.

Example: 

Input: 19
Output: true
Explanation: 
12 + 92 = 82
82 + 22 = 68
62 + 82 = 100
12 + 02 + 02 = 1
'''
# Solution:

class Solution:  
    def isHappy(self, n: int) -> bool:
        temp = [1,4,16,37,58,89,145,42,20]
        while True:
            result = sum(int(i)**2 for i in str(n))
            if result in temp:
                break
            else:
                n = result
                result =0
        if result == 1:
            return True
        else:
            return False