This is a C# code snippet to create Stack class without using Arrays. Its an integer stack class which can be easily modified to a generic class in order to support multiple data types.

Integer Stack Class.cs

class Stack
{
    static int TotalCount;
    static Element Minimum;
    static Element Top;

    public void Push(int Value)
    {
        Element Item;

        if (TotalCount != 0)
        {
            Item = new Element(Value, Top); 
            if (Minimum.Data > Value) Minimum = Item;
        }

        else
        {
            Item = new Element(Value, null); 
            Minimum = Item;
        }

        Top = Item; 
        TotalCount++;
    }

    public int Pop()
    {
        if (TotalCount == 0) return -1;

        else
        {
            int Value = Top.Data;

            if (Top == Minimum && TotalCount != 1)
            {
                Minimum = Top.Previous; 
                ComputeMinimum(Top.Previous);
            }

            Top = Top.Previous;
            TotalCount--;
            return Value;
        }
    }

    private Element ComputeMinimum(Element CurrentTop)
    {
        if (CurrentTop.Previous != null)
        {
            if (Minimum.Data > CurrentTop.Previous.Data) 
                Minimum = CurrentTop.Previous;

            return ComputeMinimum(CurrentTop.Previous);
        }

        return Minimum;
    }

    public int GetMinimum()
    {
        if (TotalCount == 0) return -1; 
        else return Minimum.Data;
    }

    public void DisplayAllItems()
    {
        if (TotalCount != 0)
        {
            System.Console.WriteLine("Elements in the stack are :");
            PrintItems(Top); 
            System.Console.WriteLine();
        }

        else
        {
            System.Console.WriteLine("The stack is empty");
            System.Console.WriteLine();
        }
    }

    private void PrintItems(Element top)
    {
        if (top.Previous != null) { PrintItems(top.Previous); System.Console.WriteLine(top.Data); } 
        else System.Console.WriteLine(top.Data);
    }
}

class Element
{
    public int Data { get; private set; }
    public Element Previous { get; private set; }

    public Element(int Value, Element Top)
    {
        Data = Value;
        Previous = Top;
    }
}