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 }