void test(const char *format, ...)
{
    va_list argp;
    va_start(argp, format);

    int n = 0;
    static char sep[128];

    while (*format != '\0')
    {
        if (*format == '%')
        {
            format++;
            if (*format == '%')
            {
                putchar('%');
            }
            else if (*format >= '0' && *format <= '9')
            {
                n = (*format) - '0';
                format++;
                while (*format >= '0' && *format <= '9')
                {
                    n *= 10;
                    n += (*format) - '0';
                    format++;
                }
                if (*format == '[')
                {
                    format++;
                    int i = 0;
                    while (*format != ']')
                    {
                        sep[i++] = *format;
                        format++;
                    }
                    sep[i] = '\0';
                    format++;
                }
                if (*format == 'd')
                {
                    int *ints = va_arg(argp, int *);
                    for (int i = 0; i < n; i++)
                    {
                        if (i > 0)
                            printf("%s", sep);
                        printf("%d", ints[i]);
                    }
                }
                else if (*format == 's')
                {
                    const char **strs = va_arg(argp, const char **);
                    for (int i = 0; i < n; i++)
                    {
                        if (i > 0)
                            printf("%s", sep);
                        printf("%s", strs[i]);
                    }
                }
            }
            else
            {
                fputs("Not implemented", stdout);
                char char_to_print = va_arg(argp, int);
                putchar(char_to_print);
            }
        }
        else
        {
            putchar(*format);
        }
        format++;
    }
    va_end(argp);
}

int main()
{
    int ints[] = {1, 2, 3, 6, 8, 2, 7, 8, 1, 245, 277254, 2642, 71, 717, 7};
    const char *strs[2] = {"abc", "def"};
    test("Hallo %15[ ]d %2[, ]s\n", ints, strs);
}