c_cpp 231.cpp

Posted 2021-05-14

class Solution {
public:
    bool isPowerOfTwo(int n) {
        return method2(n);
    }
private:
    bool method1(int n) {
        int cnt = 0;
        while(n > 0) {
            cnt += (n & 1);
            n >>= 1;
        }
        return cnt == 1;
    }
    bool method2(int n) {
        return (n > 0) && !(n & (n-1));
    }
};