# Ugly Number

### 描述​

Write a function to check whether a given number is an ugly number.

Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example, 6, 8 are ugly while 14 is not ugly since it includes another prime factor 7.

Note that 1 is typically treated as an ugly number.

### 代码​

// Ugly Number// Time complexity: O(logn), Space complexity: O(1)public class Solution {    public boolean isUgly(int num) {        if (num == 0) return false;        while (num % 2 == 0) num /= 2;        while (num % 3 == 0) num /= 3;        while (num % 5 == 0) num /= 5;        return num == 1;    }}