MOST EFFECTIVE WAY: COUNT AND PRINT THE NUMBERS WHICH ARE POWERS OF 2 || CHECK IF A NUMBER IS A POWER OF TWO

 CEIL AND FLOOR FUNCTION IN CPP:

CEIL:

Ceil(x) returns the largest integer that is greater than or equal to x

ex- ceil(2.5) will return 3

ex-ceil(-2.3) will return -2

ex- ceil(8) will return 8

FLOOR:

floor(x) returns the largest number that is smaller than or equal to x.

ex- floor(2.5) will return 2

ex-floor(-2.3) will return -3

ex-floor(8) will return 8

PROGRAM TO CHECK WHETHER A NUMBER IS POWERS OF 2 OR NOT:

#include<bits/stdc++.h> 

using namespace std; 

  bool powertwo(int n) 

{ 

   if(n==0) 

   return false; 

  return (ceil(log2(n)) == floor(log2(n))); //ceil and floor of whole numbers is equal

} 

  int main() 

{  int t,i;

   cin>>t;

   for(i=0;i<t;i++)

   {

   int n;

   cin>>n;

   powertwo(n)?cout<<"YES"<<endl:cout<<"NO"<<endl;

   }

    return 0; 

} 

OUTPUT:

COUT AND PRINT THE NUMBERS UPTO n WHICH ARE POWERS OF TWO:

#include<bits/stdc++.h> 

using namespace std; 

  void powertwo(int n) 

{ 

   int c=0,i;

   for(int i=0;i<=n;i++)

   {

  

   if ((ceil(log2(i)) == floor(log2(i)))&&i!=0) //ceil and floor of whole numbers is equal

   {

       c++;

       cout<<i<<" ";

   

   }

   }

   cout<<endl;

   cout<<c<<endl;

} 

  int main() 

{  int t,i;

   cin>>t;

   for(i=0;i<t;i++)

   {

   int n;

   cin>>n;

   powertwo(n);

   }

    return 0; 

} 

OUTPUT: