Use the following problems to test your skills at working with strings. Give each problem a try before you turn to the solutions and download the example programs.

Write `string`

and `long`

extension methods that convert between Roman and Arabic numerals. Use the usual Roman digits, I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, and M = 1,000. Also use the usual rules so that digits add unless a digit precedes a larger digit. For example, IX means subtract I from X to get 10 – 1 = 9.

Finally, support one extra rule that the Romans sometimes used to represent large numbers. That rule uses parentheses to represent multiplication by 1,000. For example, (IV)XIV means 4,014. Parentheses can be nested, as in ((XX)III)IV for 20,003,004, but won't appear in two places not nested, as in ((X))(III)IV.

### Note

For more information about Roman numerals, including some interesting history and a fascinating story about inheritance, go to http://www.web40571.clarahost.co.uk/roman/howtheywork...