Check if an integer is power of 2

Algo 1

public boolean checkpoweroftwo(int a) {

                    if (a <= 0) {

                        return false;

                    }

                    return (a & (a - 1)) == 0;

       }

Algo 2

public boolean checkpoweroftwo(int a) {

                    if (a <= 0) {

                        return false;

                    }

      return Integer.bitCount(n) == 1;

       }