Example #1
0
        } // end method RemoveFromFront

        // remove last node from List
        public object RemoveFromBack()
        {
            if (IsEmpty())
            {
                throw new EmptyListException();
            }

            object removeItem = lastNode.Data; // retrieve data

            // reset firstNode and lastNode references
            if (firstNode == lastNode)
            {
                firstNode = lastNode = null;
            }
            else
            {
                TwoWayListNode current = firstNode;

                // loop while current.Next is not lastNode
                while (current.Next != lastNode)
                {
                    current = current.Next; // move to next node
                }
                // current is new lastNode
                lastNode     = current;
                current.Next = null;
            } // end else

            lenght--;
            return(removeItem); // return removed data
        } // end method RemoveFromBack
Example #2
0
        } // end method InsertAtFront

        // Insert object at end of List. If List is empty,
        // firstNode and lastNode will refer to same object.
        // Otherwise, lastNode's Next property refers to new node.
        public void InsertAtBack(object insertItem)
        {
            if (IsEmpty())
            {
                firstNode = lastNode = new TwoWayListNode(insertItem);
            }

            else
            {
                lastNode = lastNode.Next = new TwoWayListNode(insertItem, null, lastNode);
            }

            lenght++;//lenght increasment after adding an element.
        } // end method InsertAtBack
Example #3
0
        } // end method IsEmpty

        // output List contents
        public void Display()
        {
            if (IsEmpty())
            {
                Console.WriteLine("Empty ");
            } // end if
            else
            {
                Console.Write("The list is: ");

                TwoWayListNode current = firstNode;

                // output current node data while not at end of list
                while (current != null)
                {
                    Console.Write(current.Data + " ");
                    current = current.Next;
                } // end while

                Console.WriteLine("\n");
            } // end else
        }     // end method Display
Example #4
0
        //indexer implementation to use list like array.
        public object this[int index]
        {
            set
            {
                if (index >= 0 && index <= lenght)
                {
                    TwoWayListNode current = firstNode;
                    for (int i = 0; i < index; i++)
                    {
                        current = current.Next;
                    }
                    current.Data = value;
                }
                else
                {
                    throw new IndexOutOfRangeException();
                }
            }

            get
            {
                if (index >= 0 && index <= lenght)
                {
                    TwoWayListNode current = firstNode;
                    for (int i = 0; i < index; i++)
                    {
                        current = current.Next;
                    }
                    return(current.Data);
                }
                else
                {
                    throw new IndexOutOfRangeException();
                }
            }
        }
Example #5
0
        } // end method InsertAtBack

        // remove first node from List
        public object RemoveFromFront()
        {
            if (IsEmpty())
            {
                throw new EmptyListException();
            }

            object removeItem = firstNode.Data; // retrieve data

            // reset firstNode and lastNode references
            if (firstNode == lastNode)
            {
                firstNode = lastNode = null;
            }

            else
            {
                firstNode      = firstNode.Next;
                firstNode.Back = null;
            }

            lenght--;
            return(removeItem); // return removed data
        } // end method RemoveFromFront
Example #6
0
 // construct empty List
 public TwoWayLinkedList()
 {
     lenght    = 0;//At first lenght value is 0.
     firstNode = lastNode = null;
 } // end default constructor
Example #7
0
        } // end default constructor

        // constructor to create TwoWayListNode that refers to dataValue
        // and refers to next TwoWayListNode in List
        public TwoWayListNode(object dataValue, TwoWayListNode nextNode, TwoWayListNode backNode)
        {
            Data = dataValue;
            Next = nextNode;
            Back = backNode;
        } // end constructor