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.
1 bool isUgly(int num) {
2 int k;
3 int i;
4 if(num <= 0)
5 return 0;
6 if(1 == num)
7 return 1;
8 while(num >= 2 && num % 2 == 0) num /= 2;
9 while(num >= 3 && num % 3 == 0) num /= 3;
10 while(num >= 5 && num % 5 == 0) num /= 5;
11 return num == 1;
12 }