public class LinkedList
{
Node _head;
Node _tail;
public LinkedList()
{ }
public void AddLast(int data)
{
Node _newNode = new Node(data);
if (_head == null)
{
_tail = _newNode;
_head = _tail;
}
else
{
_tail.Next = _newNode;
_tail = _newNode;
}
}
public void Clear()
{
_head = null;
}
public void AddFirst(int data)
{
Node _newNode = new Node(data);
if (_head == null)
{
_head = _newNode;
_tail = _head;
}
else
{
_newNode.Next = _head;
_head = _newNode;
}
}
public Node FindNode(int data)
{
Node _current = _head;
while (_current != null)
{
if (_current.Data == data)
return _current;
else
_current = _current.Next;
}
return _current;
}
public void PrintList()
{
Node _current = _head;
if (_head == null)
Console.WriteLine("Empty Linked List");
else
{
while (_current != null)
{
Console.Write(_current.Data.ToString() + " ");
_current = _current.Next;
}
Console.WriteLine();
}
}
public void InsertAfter(int data, int _newData)
{
Node _newNode = new Node(_newData);
Node _node = FindNode(data);
if (_node != null)
{
_newNode.Next = _node.Next;
_node.Next = _newNode;
}
else
{
Console.WriteLine("No such data:" + data);
}
}
public void InsertBefore(int data, int _newData)
{
Node _newNode = new Node(_newData);
Node _current = _head;
Node _previous = _current;
while (_current != null)
{
if (_current.Data == data)
{
_newNode.Next = _current;
_previous.Next = _newNode;
break;
}
else
{
_previous = _current;
_current = _current.Next;
}
}
}
public void Remove(int data)
{
Node _current = _head;
while (_current.Next != null)
{
if (_current.Next.Data == data)
{
_current.Next = _current.Next.Next;
break;
}
else
_current = _current.Next;
}
}
public void RemoveDuplicatesUsingBuffer()
{
HashSet<int> _hashSet = new HashSet<int>();
Node _current = _head;
Node _previous = _current;
while (_current != null)
{
if (_hashSet.Contains(_current.Data))
{
_previous.Next = _previous.Next.Next;
_current = _previous.Next;
}
else
{
_hashSet.Add(_current.Data);
_previous = _current;
_current = _current.Next;
}
}
}
public void RemoveDuplicates()
{
Node _current = _head;
Node _previous = _current;
Node _curr = _current;
while (_current != null)
{
_curr = _head;
bool isDuplicate = false;
while (_curr != _current)
{
if (_curr.Data == _current.Data)
{
isDuplicate = true;
break;
}
else
_curr = _curr.Next;
}
if (isDuplicate)
{
_previous.Next = _previous.Next.Next;
_current = _previous.Next;
}
else
{
_previous = _current;
_current = _current.Next;
}
}
}
public void Reverse()
{
Stack<Node> _stack = new Stack<Node>();
Node _current = _head;
while (_current != null)
{
_stack.Push(_current);
_current = _current.Next;
}
_head = _stack.Pop();
_current = _head;
while (_stack.Count > 0)
{
_current.Next = _stack.Pop();
_current = _current.Next;
}
_current.Next = null;
}
public void FindNthElementFromLast(int n)
{
Node _p1 = _head;
Node _p2 = _p1;
for (int i = 0; i < (n - 1); i++)
{
_p2 = _p2.Next;
}
while (_p2.Next != null)
{
_p1 = _p1.Next;
_p2 = _p2.Next;
}
Console.WriteLine(_p1.Data.ToString());
}
public Node First
{
get
{
return _head;
}
}
}
