It is a snippet of integer to binary.

int2binary.h

void display_binary_n(int dec)
{
    const int size = sizeof(int) * 8 ;
    unsigned int current;
    int i; 
    for( i = size - 1 ; i >= 0 ; i--)
    {
        current = 1<<i;
        printf("%d",( (current & dec) != 0)  ? 1: 0);
    } 
     
}