How to remove a stack item which is not on the top of the stack in C#

Question

Unfortunately an item can only be removed from the stack by "pop". The stack has no "remove" method or something similar, but I have a stack (yes I need a stack!) from which I need to remove some elements between.

Is there a trick to do this?

Answer 1

If you need to remove items that aren't on the top, then you need something other than a stack.

Try making your own implementation of a stack from a List. Then you get to implement your own push and pop functions (add & remove on the list), and your own special PopFromTheMiddle function.

For example

public class ItsAlmostAStack<T>
{
    private List<T> items = new List<T>();

    public void Push(T item)
    {
        items.Add(item);
    }
    public T Pop()
    {
        if (items.Count > 0)
        {
            T temp = items[items.Count - 1];
            items.RemoveAt(items.Count - 1);
            return temp;
        }
        else
            return default(T);
    }
    public void Remove(int itemAtPosition)
    {
        items.RemoveAt(itemAtPosition);
    }
}