// 09162009.cpp, P H Anderson, Sept 16, '09
// functions;

#include <stdio.h>
#include <stdlib.h>

void print_roman_tens(int num);
void print_roman_1_9(int num);
void print_roman_ones(int num);

int main()
{
    int num, tens, units;
    while(1)
    {
        printf("Enter a number in range of 1 - 39: ");
        scanf("%d", &num);
        if (num < 0)
        {
            break;
        }
        tens = num / 10;
        units = num % 10;
        print_roman_tens(tens);
        print_roman_1_9(units);
        printf("\n");
    }        
    
    system("pause");    
}

void print_roman_tens(int num)
{
    for (int n=0; n<num; n++)
    {
        printf("X");
    }
}

void print_roman_1_9(int num)
{
    int ones;
    if (num == 9)
    {
        printf("IX");
    }
    else if (num >=5)
    {
        ones = num - 5;
        printf("V");
        print_roman_ones(ones);
    }
    else if (num == 4)
    {
        printf("IV");
    }
    else
    {
        print_roman_ones(num);
    }
}
void print_roman_ones(int num)
{
    for (int n=0; n<num; n++)
    {
        printf("I");
    }
}

#ifdef OUTPUT
Enter a number in range of 1 - 39: 5
V
Enter a number in range of 1 - 39: 31
XXXI
Enter a number in range of 1 - 39: 37
XXXVII
Enter a number in range of 1 - 39: 23
XXIII
Enter a number in range of 1 - 39: 4
IV
Enter a number in range of 1 - 39: 1
I
Enter a number in range of 1 - 39: 0

Enter a number in range of 1 - 39: -1
Press any key to continue . . .
#endif