【位运算】3的幂

题目:

 

 

解答:

class Solution {
public:
    bool isPowerOfThree(int n) 
    {
        if (n < 1) 
        {
            return false;
        }

        while (n % 3 == 0) 
        {
            n /= 3;
        }

        return n == 1;
    }
};