CS 2040

Exercise 3

Description

Due to a hiccup in the universe, you wake up one morning in Venice with a really bad headache and an Android phone that gives the date as being in year 600. You decide to go into business as an accountant, but working in the Roman numeral system gives you more headaches. Since you conveniently installed Cxxdroid on your phone a week earlier (your time), you will program your converter using C++.

Roman numerals today are typically written using a subtractive notation; for example, 4 is written as IV. In the year 600, this notation was not standardized (see here for a detailed discussion) so numbers were written in a purely additive form using the chart

I	1
V	5
X	10
L	50
C	100
D	500
M	1000

14 would be written XIIII, and 1970 as MDCCCCLXX.

You are to build a simple Roman number calculator for addition and multiplication. It is to read pairs of Roman numbers and an operator, give the decimal equivalent of each, then write their sum or product as a Roman number.

    DCCVI + LXXV
    706 + 75 = 781 = DCCLXXXI
    C + XXIIII
    100 + 24 = 124 = CXXIIII
    VIII * XII
    8 * 12 = 96 = LXXXXVI

Notes:

• Print Roman numbers with the largest "digit" first. For example, 81 is LXXXI, not XXXLI or some other combination.
• You can assume each input will be two Roman numbers separated by a operators (with spaces between each). Stop at end-of-file. The basic structure of your loop will be

          read first roman number
          while not end of file
             read operator (a character)
             read second roman number
             compute result
             print corresponding equation
             read first roman number
  

  That is, you only read the operator and second number if the first was read successfully. Read Roman numbers using std::string, read the operator into a char. Note that cin >> x; skips any whitespace (both regular spaces and newlines), so you do not have to do anything special for the spaces betwen the values.
• For full credit, your project must be built around a class roman_number which acts like a built-in class with operations (and/or constructors) to set the integer value to the appropriate equivalent (using the above chart), operations to add two numbers, and operations to return a string containing the printable roman number. A basic starting point is given to you in the file roman.cpp. You can change any element of this file you wish, including renaming classes and attributes. You can split your code into multiple files if you want, but a single file is adequate.

Assumptions

• You do not need to check that the input values are legal Roman numbers.
• You can assume all Roman digits are upper case letters.
• You can assume that only positive numbers are entered.

Submission

Submit your solution to esubmit as ex3roman. There is no submission to Canvas, but Canvas does give the last date you can submit this assignment for credit.