EugenePavlov

string sumHexStrings(string& first, string& second)
{
    const char* bufer;
    unsigned int first_c;
    unsigned int second_c;

    sscanf(first.c_str(), "%X", &first_c);
    sscanf(second.c_str(), "%X", &second_c);
    sprintf(bufer, "%X", first_c+second_c);

    return string(bufer);
}