ugly-number.py

# -*- coding:utf-8 -*-


# Write a program to check whether a given number is an ugly number.
#
# Ugly numbers are positive numbers whose prime factors only include 2, 3, 5.
#
# Example 1:
#
#
# Input: 6
# Output: true
# Explanation: 6 = 2 × 3
#
# Example 2:
#
#
# Input: 8
# Output: true
# Explanation: 8 = 2 × 2 × 2
#
#
# Example 3:
#
#
# Input: 14
# Output: false 
# Explanation: 14 is not ugly since it includes another prime factor 7.
#
#
# Note:
#
#
# 	1 is typically treated as an ugly number.
# 	Input is within the 32-bit signed integer range: [−231,  231 − 1].
#


class Solution(object):
    def isUgly(self, num):
        """
        :type num: int
        :rtype: bool
        """
        if num <= 0:
            return False
        for x in [2, 3, 5]:
            while num % x == 0:
                num = num / x
        return num == 1