// Removes and returns the Node on top of the stack, resetting the value of Top to the next Node on the stack.
// Returns null if there is no Node on the stack.
public CharNode Pop()
{
CharNode popped = null;
try
{
if (Top != null)
{
popped = Top;
Top = Top.Next;
popped.Next = null;
}
else
{
throw new NullReferenceException();
}
}
catch (NullReferenceException)
{
Console.WriteLine("There are no Nodes in this Stack.");
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
return(popped);
}
/// <summary>
/// adds a node to the stack
/// </summary>
/// <param name="value">value of the new node</param>
public void Push(char value)
{
CharNode newNode = new CharNode(value);
newNode.Next = Top;
Top = newNode;
}
// Takes in a new Node and places it on top of the stack, resetting the value of Top to the new Node.
public void Push(CharNode node)
{
if (Top == null)
{
Top = node;
}
else
{
node.Next = Top;
Top = node;
}
}
/// <summary>
/// remove a node from the stack
/// </summary>
/// <returns>the top node</returns>
public CharNode Pop()
{
//should add check for if trying to pop from a null stack
if (Top == null)
{
Console.WriteLine("The stack is empty");
return(null);
}
else
{
CharNode tempNode = Top;
Top = Top.Next;
tempNode.Next = null;
return(tempNode);
}
}
public CharNode(char value)
{
Value = value;
Next = null;
}
//stack created with a node given
public CharStack(CharNode node)
{
Top = node;
}
//instantiate
//stack created without a node given
public CharStack()
{
Top = null;
}
public CharNode(char val, CharNode next)
{
Value = val;
Next = next;
}