//----------------------------------------------------------------------
//  roman.cpp
//  This program inputs Roman numeral expressions, one per line, and
//  outputs the decimal value of each expression.
//----------------------------------------------------------------------
#include <iostream.h>

typedef int Boolean;  // Define identifier Boolean as a synonym for int
const int TRUE = 1;
const int FALSE = 0;

void PrintValue( int, char, int );              // Function prototypes
int  DecEquiv( const char[] );
void Convert( const char[], int&, Boolean& );

int main()
{
    char    str1[31];        // First Roman numeral string
    char    str2[31];        // Second Roman numeral string
    char    op;              // Operator within expression
    int     dec1;            // Decimal value of first operand
    int     dec2;            //    "      "   "  second   "
    Boolean str1Valid;       // First string valid?
    Boolean str2Valid;       // Second string valid?
    Boolean opValid;         // Operator valid?

    cout << "Roman numeral expression:\n";
    while (cin >> str1) {
        cin >> op >> str2;
        Convert(str1, dec1, str1Valid);
        Convert(str2, dec2, str2Valid);
        opValid = (op=='+' || op=='-' || op=='*' || op=='/');
        if (str1Valid && str2Valid && opValid)
            PrintValue(dec1, op, dec2);
        else
            cout << "BAD DATA\n\n";
        cout << "Roman numeral expression:\n";
    }
    return 0;
}
//----------------------------------------------------------------------
void Convert( /* in */  const char str[],
              /* out */ int&       decVal,
              /* out */ Boolean&   strValid )
{
    decVal = DecEquiv(str);
    strValid = (decVal > 0);
}
//----------------------------------------------------------------------
int DecEquiv( /* in */ const char str[] )
{
    Boolean dataValid = TRUE;
    int     intSum = 0;
    int     i = 0;

    while (dataValid && str[i] != '\0') {
        switch (str[i]) {
            case 'C' : intSum += 100;
                       break;
            case 'L' : intSum +=  50;
                       break;
            case 'X' : intSum +=  10;
                       break;
            case 'V' : intSum +=   5;
                       break;
            case 'I' : intSum +=   1;
                       break;
            default  : dataValid = FALSE;
        }
        i++;
    }
    return (dataValid ? intSum : 0);
}
//----------------------------------------------------------------------
void PrintValue( /* in */ int  dec1,
                 /* in */ char op,
                 /* in */ int  dec2 )
{
    cout << "Decimal value: ";
    switch (op) {
        case '+' : cout << dec1 + dec2;
                   break;
        case '-' : cout << dec1 - dec2;
                   break;
        case '*' : cout << dec1 * dec2;
                   break;
        case '/' : cout << float(dec1) / float(dec2);
    }
    cout << "\n\n";
}