263. Ugly Number

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].

思路：num对2，3，5求余为0，就num=num/5,最后判断num==1

代码:python3

class Solution:
    def isUgly(self, num: int) -> bool:
        if num==0:
            return False
        while num%2==0:
            num = num/2
        while num%3==0:
            num = num/3
        while num%5==0:
            num = num/5