c_cpp 326.三力量

Posted 2021-05-14

//Runtime: 64 ms, faster than 24.90%
//Memory Usage: 8.2 MB, less than 34.82%

class Solution {
public:
    bool isPowerOfThree(int n) {
        if(n <= 0) return false;
        long int num = 1;
        while(1){
            if(num < n) 
                num *= 3;
            else if(num == n)
                return true;
            else
                return false;
        }
    }
};

//Runtime: 52 ms, faster than 96.57%
//Memory Usage: 8.5 MB, less than 5.67%

class Solution {
public:
    bool isPowerOfThree(int n) {
        return fmod(log10(n) / log10(3),1) == 0;
    }
};