Roman_numeral_converter.cpp

#include <iostream>

using namespace std;

int num,mill,cent,dece,unid = 0;
string msg = "Enter a number: ";

int main()
{
    
    cout <<  msg;
    cin  >>  num;
    cout << endl;

    unid = num % 10; num /= 10;
    dece = num % 10; num /= 10;
    cent = num % 10; num /= 10;
    mill = num % 10; num /= 10;
    
    switch(mill) 
    {
        
        case 1: cout << "M";    break;
        case 2: cout << "MM";   break;
        case 3: cout << "MMM";  break;
        
    }
    
    switch(cent)
    {
        
        case 1: cout << "C";      break;
        case 2: cout << "CC";     break;
        case 3: cout << "CCC";    break;
        case 4: cout << "CD";     break;
        case 5: cout << "D";      break;
        case 6: cout << "DC";     break;
        case 7: cout << "DCC";    break;
        case 8: cout << "DCCC";   break;
        case 9: cout << "CM";     break;
        
    }
    
    switch(dece)
    {
        
        case 1: cout << "X";      break;
        case 2: cout << "XX";     break;
        case 3: cout << "XXX";    break;
        case 4: cout << "XL";     break;
        case 5: cout << "L";      break;
        case 6: cout << "LX";     break;
        case 7: cout << "LXX";    break;
        case 8: cout << "LXXX";   break;
        case 9: cout << "XC";     break;
        
    }
    
    switch(unid)
    {
        
        case 1: cout << "I";      break;
        case 2: cout << "II";     break;
        case 3: cout << "III";    break;
        case 4: cout << "IV";     break;
        case 5: cout << "V";      break;
        case 6: cout << "VI";     break;
        case 7: cout << "VII";    break;
        case 8: cout << "VIII";   break;
        case 9: cout << "IX";     break;
        
    }
    
    return 0;
    
}