public bool IsUgly(int num) {
if(num<1) return false;
while(num>1)
{
if(num%2==0)
{
num=num/2;
}
else if(num%3==0)
{
num=num/3;
}
else if(num%5==0)
{
num=num/5;
}
else
{
return false;
}
}
return true;
}
原文：http://www.cnblogs.com/darksied/p/4742946.html