转换2进制代码

void FormatBinary(__int64 num,char buf[])
{
    int nCount = 0 ;

    while ( 1 )
    {
        if( ( (__int64) 1 << nCount ) > num)
            break ;

        if( ( num >> nCount ) & 1 == 1)
        {
            buf[nCount] = '1';
        }else
        {
            buf[nCount] = '0' ;
        }
        nCount++;

    }
    for (int i = 0 ; i < nCount / 2 ; i++)
    {
        char temp = buf[i];
        buf[i] = buf[nCount-i-1];
        buf[nCount-i] = temp ;
    }
}