decimal to binary predefined function

1#include <iostream>
2#include <stdlib.h>
3
4int main ()
5{
6    int i;
7    char buffer [33];
8    printf ("Enter a number: ");
9    scanf ("%d",&i);
10    itoa (i,buffer,10);
11    printf ("decimal: %s\n",buffer);
12    itoa (i,buffer,16);
13    printf ("hexadecimal: %s\n",buffer);
14    itoa (i,buffer,2);
15    printf ("binary: %s\n",buffer);
16    return 0;
17}
18

1  std::string binary = std::bitset<8>(n).to_string();
2