void main(void)
{
    //srand(time(NULL));
    int a=1234;
    char *romai;
    romai=toromai(a);
    printf("%s\n",romai);
    free(romai);
}

char *toromai(int a) /* Arab számot alakít római számmá */
{
    int tmp,n=0;
    char *romai;
    char *error = "#ÉRTÉK!";
    char egyesek[][10]  = {"I","II","III","IV","V","VI","VII","VIII","IX"};
    char tizesek[][10]  = {"X","XX","XXX","XL","L","LX","LXX","LXXX","XC"};
    char szazasok[][10] = {"C","CC","CCC","CD","D","DC","DCC","DCCC","CM"};
    char ezresek[][4]  = {"M","MM","MMM"};

    tmp=a;
    while(tmp>0)
    {
        tmp/=10;
        n++;
    }

    romai=(char*)calloc(n,sizeof(char));
    if(1<=a && a<4000)
    {
        if(n==4)
        {
            strcat(romai,ezresek[(a/1000)-1]);
            if(a%1000!=0)
            {
                a%=1000;
                if(9<a%1000 && a%1000<100) n--;
                if(1<=a%1000 && a%1000<10) n-=2;
                n--;
            }
            else return romai;
        }
        if(n==3)
        {
            strcat(romai,szazasok[(a/100)-1]);
            if(a%100!=0)
            {
                a%=100;
                if(1<=a%100 && a%100<10) n--;
                n--;
            }
            else return romai;
        }
        if(n==2)
        {
            strcat(romai,tizesek[(a/10)-1]);
            if(a%10!=0)
            {
                a%=10;
                n--;
            }
            else return romai;
        }
        if(n==1) strcat(romai,egyesek[a-1]);

        return romai;
    }
    else return error;
}