Book Image

The Modern C# Challenge

By : Rod Stephens
Book Image

The Modern C# Challenge

By: Rod Stephens

Overview of this book

C# is a multi-paradigm programming language. The Modern C# Challenge covers with aspects of the .NET Framework such as the Task Parallel Library (TPL) and CryptoAPI. It also encourages you to explore important programming trade-offs such as time versus space or simplicity. There may be many ways to solve a problem and there is often no single right way, but some solutions are definitely better than others. This book has combined these solutions to help you solve real-world problems with C#. In addition to describing programming trade-offs, The Modern C# Challenge will help you build a useful toolkit of techniques such as value caching, statistical analysis, and geometric algorithms. By the end of this book, you will have walked through challenges in C# and explored the .NET Framework in order to develop program logic for real-world applications.
Table of Contents (17 chapters)
Title Page
Copyright and Credits
Packt Upsell
Free Chapter
Dates and Times
Files and Directories
Advanced C# and .NET Features


The following sections describe solutions to the preceding problems. You can download the example solutions, to see additional details and to experiment with the programs at

56. Roman numerals

There are many ways that you could approach this problem. I decided to use lookup tables to make things faster and simpler.

The following code shows a string extension method that converts a Roman numeral string into a long integer:

// Maps letters to numbers.
private static Dictionary<char, long> LetterValues = null;

// Convert Roman numerals into an integer.
public static long ToArabic(this string roman)
    // Initialize the letter lookup table if
    // it hasn't been initialized yet.
    if (LetterValues == null)
        LetterValues = new Dictionary<char, long>();
        LetterValues.Add('I', 1);
        LetterValues.Add('V', 5);
        LetterValues.Add('X', 10);