How to check if an integer is a power of 3?

Question

I saw this question, and pop up this idea.

Answer 1

Here's a general algorithm for finding out if a number is a power of another number:

bool IsPowerOf(int n,int b)
{
    if (n > 1)
    {
        while (n % b == 0)
        {
            n /= b;
        }
    }
    return n == 1;
}