Day044 - 202. Happy Number

202. 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 <= 231 - 1

내 풀이

class Solution:
    def isHappy(self, n: int) -> bool:
        
        check_set = set()
        check_num = 0

        while True:
            
            for j in [i for i in str(n)]:
                check_num += int(j)*int(j)

            if check_num in check_set:
                return False
                
            if check_num == 1:
                return True

            check_set.add(check_num)

            print(f"check_num:{check_num}, n:{n}", '\n')
            n = check_num
            check_num = 0
        
        return "end"

# Time Complexity : \(O(N)\)