[LeetCode]Power of Three

Given an integer, write a function to determine if it is a power of three.

Follow up:
Could you do it without using any loop / recursion?

题解：给一个数，判断这个数是否为3的多少次方？

3​^x ​ =  N    =>   x = log₃​N  =>   x = log₁₀​N/log₁₀​3 再判断X是否为正整数，如果是为true，否则为false。

code：

public class Solution {
    public boolean isPowerOfThree(int n) {
        
        if(n<=0 )
            return false;
        double result = Math.log10(n)/Math.log10(3);
        if(result %1 == 0)
        {
            return true;
        }
        return false;
    }
}