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. 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.

解题思路：
（1）分别出去因子2,3,5
（2）判断该数是否为1

bool 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;
}

if (num == 1)
    return true;
else
    return false；  

}