C++

#include<iostream>
#include<cmath>

using namespace std;


int main() {
  int n;

  cout << "Inserisci un numero: ";
  cin >> n;
  int log2n = (int) log2(n);
  int powz  = 1 << log2n;

  do {
    cout << ((n&powz) >> log2n--);
  } while(powz>>=1);

  return 0;
}