#include <iostream>
#include <iomanip>
#include <string>
#include <cctype>
using namespace std;


void stringToDecimal(char expression[], int &deciRes,
                     const int d[], const char r[]);

void  performOperation(int, int, char, int &);

bool checkForErrors(int, int, char, int);

void decimalToString(int, char romRes[], const int d[], const char r[]);

const int  decimal[8] = {0, 1, 5, 10, 50, 100, 500, 1000};
const char roman[8]   = {'O', 'I', 'V', 'X', 'L', 'C', 'D', 'M'};

int main()
{
    char   expression1[19],
           expression2[19],
           romanResult[19] = {0},
           operation;

    int    addition,
           subtraction,
           multiplication,
           division,
           decimalEx1 = 0,
           decimalEx2 = 0,
           decimalResult;

    string e1, e2, bob, oper;

    bool valid;

    getline(cin, bob);


    while (!(expression1[0] == 'O' && expression2[0] == 'O' && operation == '+'))
      {
        valid = false;

        stringToDecimal(expression1, decimalEx1, decimal, roman);
        stringToDecimal(expression2, decimalEx2, decimal, roman);

        performOperation(decimalEx1, decimalEx2, operation, decimalResult);

 valid = checkForErrors(decimalEx1, decimalEx2, operation, decimalResult);

        if (valid == true)
          {
            decimalToString(decimalResult, romanResult, decimal, roman);
            cout << bob << e1 << " " << oper << " " << e2
                 << " " << " = " << " " << exDec1 << " " << oper << " " << exDec2 << " " << "=" << " " << dResult
                 << " (" << rResult << ") " << endl;


          }


      }

    return 0;
}



void stringToDecimal(char expression[], int &deciRes,
                     const int decimal[], const char roman[])
{
  int i, n, j;
 n = strlen(expression);
  deciRes = 0;

  for(i=0; i < n; i++)
    {
      for(j=1; j < 8; j++)
        {
          if(expression[i] == roman[j])
            deciRes += decimal[j];
        }
    }

}

void performOperation(int e1, int e2, char oper, int &deciRes)
{
  switch (oper)
    {
    case '+':
      deciRes = e1 + e2;
      break;
    case '-':
      deciRes = e1 - e2;
      break;
    case '*':
      deciRes = e1 * e2;
      break;
    case '/':
      deciRes = e1 / e2;
      break;
    default:
      deciRes = e1 % e2;
    }
}

bool checkForErrors(int deciEx1, int deciEx2, char oper, int deciRes)
{


  if (oper != '+' && oper != '-' && oper != '*' && oper != '/' &&
           oper != '%')
    {
      cout << "Error. Invalid operation" << endl;
      return false;
    }

  else if(((deciEx1 == deciEx2) && oper =='-') || deciRes == 0)
    {
 {
      cout << "Error. Result can not be zero" << endl;
      return false;
    }

  else if((oper == '+' || oper == '*') && deciRes > 4999 )
    {
      cout << "Error. Result can not be more than 4999" << endl;
      return false;
    }

  else
    return true;
}

void decimalToString(int decAns, char romAns[], const int d[], const char r[])
{
  int i, j=0, n, count=0;

  // Reset values in romanResult[]
  n= strlen(romAns); // if taken out, ex2 wont show; length romAns not defined
  for(i=0; i < n; i++)
    romAns[i] = 0;
  // End
  for(i=7; i > 0; i--)
    {
      if( decAns >= d[i])
        {
          count = decAns / d[i];
          decAns = decAns - (count * d[i]);

          while (count != 0)
            {
              romAns[j] = r[i];
              j++;
              count--;
            }
        }
    }
}

{

  cout << bob << e1 << " " << oper << " " << e2
       << " " << " = " << " " << exDec1 << " " << oper << " " << exDec2 << " " << "=" << " " << dResult
       << " (" << rResult << ") " << endl;
}

#include <iostream>
#include <string>

using namespace std;

int main()
{
	string bob = "XXIII / V";

	//what we are looking for
	string separators = " +/*-";

	//find the first that is not a separator
	size_t start = bob.find_first_not_of(separators);
	size_t end = 0; 

	while(start != string::npos) 
	{//the end will be a separator 
		end = bob.find_first_of(separators, start + 1); 

		if(end == string::npos)
			//when end == npos that will not be a valid position
			//so set end to a valid position to get the last one 
			end = bob.length(); 

		//display the substring 
		cout << bob.substr(start, end - start)       
			<< endl;

		//find the beginning of next substring 
		start = bob.find_first_not_of(separators, end + 1);
	}

	string roman = "OIVXLCDM";
	start = bob.find_first_not_of(roman);
	end = 0; 
	while(start != string::npos) 
	{
		end = bob.find_first_of(roman, start + 1); 
		if(end == string::npos)                        
			end = bob.length();                         

		cout << "\"" << bob.substr(start, end - start)       
			<< "\"" << endl;

		start = bob.find_first_not_of(roman, end + 1);
	}
	return 0;
}

char bob[100];