C++ Arabic numbers to Roman Numeral's & vice versa - c++

Question

I am writing a C++ program that converts between Arabic and Roman numbering systems. I wrote one program that converts Arabic to Roman and have another program that converts Roman to Arabic.
The problem is that I can't figure out how to merge them into one single program so that the user can input an Arabic or Roman number and as a result, the program would convert said number to the other.
My question is HOW can I merge these two programs into one?
Code for Roman to Arabic
#include <iostream>
using namespace std;
int main()
{
char roman_Numeral;
int arabic_Numeral = 0;
cout << "Enter the Roman Numeral in Capital letters (e.g. CCXIX) : ";
while (cin.get(roman_Numeral))
{
if (arabic_Numeral > 100)
{
cout << "\nInvalid Value. Number must be between I and C" << endl;
return 0;
}
else if (roman_Numeral == 'C')
{
roman_Numeral = cin.peek();
if (roman_Numeral == 'M' || roman_Numeral == 'D')
{
arabic_Numeral = arabic_Numeral - 100;
}
else
{
arabic_Numeral = arabic_Numeral + 100;
}
}
else if (roman_Numeral == 'L')
{
roman_Numeral = cin.peek();
if (roman_Numeral == 'M' || roman_Numeral == 'D'
|| roman_Numeral == 'C')
{
arabic_Numeral = arabic_Numeral - 50;
continue;
}
else
{
arabic_Numeral = arabic_Numeral + 50;
continue;
}
}
else if (roman_Numeral == 'X')
{
roman_Numeral = cin.peek();
if (roman_Numeral == 'M' || roman_Numeral == 'D'
|| roman_Numeral == 'C' || roman_Numeral == 'L')
{
arabic_Numeral = arabic_Numeral - 10;
continue;
}
else
{
arabic_Numeral = arabic_Numeral + 10;
continue;
}
}
else if (roman_Numeral == 'V')
{
roman_Numeral = cin.peek();
if (roman_Numeral == 'M' || roman_Numeral == 'D'
|| roman_Numeral == 'C' || roman_Numeral == 'L'
|| roman_Numeral == 'X')
{
arabic_Numeral = arabic_Numeral - 5;
continue;
}
else
{
arabic_Numeral = arabic_Numeral + 5;
continue;
}
}
else if (roman_Numeral == 'I')
{
roman_Numeral = cin.peek();
if (roman_Numeral == 'M' || roman_Numeral == 'D'
|| roman_Numeral == 'C' || roman_Numeral == 'L'
|| roman_Numeral == 'X' || roman_Numeral == 'V')
{
arabic_Numeral = arabic_Numeral - 1;
continue;
}
else
{
arabic_Numeral = arabic_Numeral + 1;
continue;
}
}
else
break;
}
cout << arabic_Numeral << endl;
return 0;
}
Code for Arabic to Roman
#include <iostream>
#include <string>
#include <iomanip>
using namespace std;
#define MAX_INPUT 100 // These constants hold high and low integer numbers,
#define MIN_INPUT 1
#define ARRAY_SIZE 4 // and the array size declarator.
string convert(int digit, string low, string mid, string high);
int main()
{
string answers[ARRAY_SIZE] = { "", "", "", "" }; //An array of string to hold the output from the convert function.
int accumulator = 0; // Variable to hold number of arabic numbers converted.
int userNum = 0;
string strUserNum;
do
{
cout << "";
cout << "Enter an arabic number between 1 and 100: ";
cin >> strUserNum;
userNum = std::stoi(strUserNum);
if (userNum == 0 || userNum > MAX_INPUT)
{
cout << "\nInvalid Value. Number must be between 1 and 100" << endl;
return 0;
}
else if (userNum == 'end')
{
cout << "Exiting program:";
break;
}
int thous = userNum / 1000;
int hund = userNum % 1000 / 100;
int tens = userNum % 100 / 10;
int ones = userNum % 10 / 1;
answers[0] = convert(thous, "M", "M", "M");
answers[1] = convert(hund, "C", "D", "M");
answers[2] = convert(tens, "X", "L", "C");
answers[3] = convert(ones, "I", "V", "X");
cout << answers[0] << answers[1] << answers[2];
cout << answers[3] << endl;
cout << endl;
break;
} while (userNum != 'end');
system("PAUSE");
return 0;
}
string convert(int digit, string low, string mid, string high)
{
if (digit == 1)
{
return low;
}
if (digit == 2)
{
return low + low;
}
if (digit == 3)
{
return low + low + low;
}
if (digit == 4)
{
return low + mid;
}
if (digit == 5)
{
return mid;
}
if (digit == 6)
{
return mid + low;
}
if (digit == 7)
{
return mid + low + low;
}
if (digit == 8)
{
return mid + low + low + low;
}
if (digit == 9)
{
return low + high;
}
if (digit == 0)
{
return "";
}
}

Answer 1

Put code (that inside the main block) for Roman to Arabic into void procedureRomanToArabic()
The same for Roman to Arabic. Put it into void procedureArabicToRoman().
Remove remove ArabicToRoman do-while and move it to main.
void procedureRomanToArabic(){
char roman_Numeral;
int arabic_Numeral = 0;
//...
cout << arabic_Numeral << endl;
}
void procedureArabicToRoman()
{
string answers[ARRAY_SIZE] = { "", "", "", "" }; //An array of string to hold the output from the convert function.
int accumulator = 0; // Variable to hold number of arabic numbers converted.
int userNum = 0;
string strUserNum;
//remove do while here
cout << "";
cout << "Enter an arabic number between 1 and 100: ";
cin >> strUserNum;
//...
answers[2] = convert(tens, "X", "L", "C");
answers[3] = convert(ones, "I", "V", "X");
cout << answers[0] << answers[1] << answers[2];
cout << answers[3] << endl;
cout << endl;
}
int main(){
char type;
do{
cout<<"2 for Arabic to Roman, 1 for Roman to Arabic, or anything else for exit";
cin>>type;
if(type=='1')
procedureArabicToRoman();
else if(type =='2')
procedureRomanToArabic();
else break; //end program
} while(true);
}