Write an algorithm to determine if a number 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.
Example:
Input: 19 Output: true Explanation: 12 + 92 = 82 82 + 22 = 68 62 + 82 = 100 12 + 02 + 02 = 1
Python Solution :
Method 1 : Detecting the loop with Hashset
class Solution: def isHappy(self, n: int) -> bool: def get_next(number): total_sum = 0 while number > 0: number, digit = divmod(number, 10) total_sum += digit ** 2 return total_sum seen = set() n = get_next(n) while n != 1 and n not in seen: seen.add(n) n = get_next(n) return n == 1 Time Complexity : O(log(n)) Space Complexity : O(log(n))
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