Description
An ugly number is a positive integer which does not have a prime factor other than 2, 3, and 5.
Given an integer n, return true if n is an ugly number.
Example 1:
Input: n = 6 Output: true Explanation: 6 = 2 × 3
Example 2:
Input: n = 1 Output: true Explanation: 1 has no prime factors.
Example 3:
Input: n = 14 Output: false Explanation: 14 is not ugly since it includes the prime factor 7.
Constraints:
-231 <= n <= 231 - 1
Solution
Python3
class Solution:
def isUgly(self, n: int) -> bool:
if n <= 0: return False
while n % 5 == 0: n //= 5
while n % 3 == 0: n //= 3
while n % 2 == 0: n //= 2
return n == 1