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. 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.

 

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