c++ - Find previous power of 2 in 64 bit number -

// objective : verify 64 bit input power of 2.if number not power of 2, find previous value , power of 2.

using namespace std;

int main() {

//input. 64 bit number unsigned long long int input = 13174607262084689114;  //check number power of two.  if (!((input && (input & (input - 1))) == 0)) {      cout<<"the number not power of 2"<<endl;      //find previous value of input, should power of 2.      //step 1 : find next power of 2 input.     //step 2 : divide number 2      /*end*/      // step 1            input |= input >> 1;     input |= input >> 2;     input |= input >> 4;     input |= input >> 8;     input |= input >> 16;     input |= input >> 32;     input = input + 1; // input holds next number , power of 2.      // step 2     input = input >> 1;       cout<<"power of 2: 64 bit: "<<input<<endl;  }  return 0; 

}

(!((input) && (input & (input - 1))) == 0) 

this should be

(!(input && (input & (input - 1)) == 0))