Program.cs

using System;

namespace DoFactory.GangOfFour.Strategy.RealWorld
{

    /// <summary>
    /// MainApp startup class for Real-World 
    /// Strategy Design Pattern.
    /// </summary>
    class Program
    {
        /// <summary>
        /// Entry point into console application.
        /// </summary>
        static void Main()
        {
            // Two contexts following different strategies
            SortedList studentRecords = new SortedList(null);

            studentRecords.Add("Samual");
            studentRecords.Add("Jimmy");
            studentRecords.Add("Sandra");
            studentRecords.Add("Vivek");
            studentRecords.Add("Anna");

            studentRecords.SetSortStrategy(new QuickSort());
            studentRecords.Sort();

            studentRecords.SetSortStrategy(new ShellSort());
            studentRecords.Sort();

            studentRecords.SetSortStrategy(new MergeSort());
            studentRecords.Sort();

            // Wait for user
            Console.ReadKey();
        }

        /*
         Anna
         Jimmy
         Samual
         Sandra
         Vivek

        ShellSorted list
         Anna
         Jimmy
         Samual
         Sandra
         Vivek

        MergeSorted list
         Anna
         Jimmy
         Samual
         Sandra
         Vivek
         */
    }
}