Şafak Ünel (Matematik Mühendisi)

    // Context class
    public class Context
    {
        public string Formula { get; set; }
        public int TotalCost { get; set; }
    }
    // Expression
    public abstract class DepartmentExpression
    {
        public abstract void Interpret(Context context);
    }
    // TerminalExpression
    public class HRExpression:DepartmentExpression
    {
        public override void Interpret(Context context)
        {
            context.TotalCost += 20;
        }
    }
    // TerminalExpression
    public class SoftwareExpression:DepartmentExpression
    {
        public override void Interpret(Context context)
        {
            context.TotalCost += 30;
        }
    }
    // TerminalExpression
    public class SalesExpression : DepartmentExpression
    {
        public override void Interpret(Context context)
        {
            context.TotalCost += 30;
        }
    }
//Client
    class Program
    {
        static List<DepartmentExpression> CreateExpressionTree
            (string formula)
        {
            // Expression ağacı oluşturulur
            List<DepartmentExpression> tree = new List<DepartmentExpression>();

            foreach (char role in formula)
            {
                if (role == 'S')
                    tree.Add(new SalesExpression());
                else if (role == 'I')
                    tree.Add(new HRExpression());
                else if (role == 'Y')
                    tree.Add(new SoftwareExpression());
            }
            return tree;
        }

        static void RunExpression(Context context)
        {
            foreach (DepartmentExpression expression in CreateExpressionTree
                  (context.Formula))
            {
                // TerminalExpression tiplerine ait harf sembolleri 
                // buradaki metod çağrısındada gönderilebilir.
                expression.Interpret(context); 
            }
            Console.WriteLine("{0} için maliyet {1}"
                          , context.Formula, context.TotalCost);
        }

        static void Main(string[] args)
        {
            Context context = new Context { Formula = "SIYSI" };
            RunExpression(context);

            Console.ReadLine();
        }
    }