231. power of two

class  {
public:
    bool isPowerOfTwo(int n) {
        if(n==1)return true;
        if(n&1||n<=0)return false;
        int count=0;
        while(n){
            count+=n&1;
            n>>=1;
        }
        if(count==1)return true;
        return false;
    }
};