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);     } } 

Answer 2

Consider using different container. Maybe a LinkedList. Then you can use

AddFirst AddLast RemoveLast RemoveFirst

just like pop/push from stack and you can use

Remove

to remove any node from the middle of the list