## Question

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`

. 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.

## Solution

**Result:** Accepted **Time:** 4 ms

Here should be some explanations.

```
bool isUgly(int num) {
if(num <= 0)
return false;
while(num && num % 3 == 0)
num /= 3;
while(num && num % 5 == 0)
num /= 5;
while(num && num % 2 == 0)
num /= 2;
return num == 1;
}
```

**Complexity Analytics**

- Time Complexity:
- Space Complexity: