private int listlen = 0; //length of the linked list
#endregion Fields
#region Methods
//Add a node to the linked list;
public linkedList_return create_node(int key)
{
//create the new node
default_node newNode = new default_node();
newNode.key = key;
newNode.next = null;
//check to see if the linked list is empty
if(head == null)
{
head = newNode;
listlen++;
return linkedList_return.SUCCESS;
}
//else, add the linked list in order by key value
default_node prev = head;
default_node current = head;
if(newNode.key < head.key) //new node is head node
{
newNode.next = head;
head = newNode;
listlen++;
return linkedList_return.SUCCESS;
}
while (current.key <= newNode.key)
{
//if we find a node with the same value, return an error
if(current.key == key)
{
newNode = null;
return linkedList_return.CREATE_FAILED_DUPLICATE_KEY;
}
prev = current;
current = current.next;
//break if the end of the list is reached
if (current == null)
{
break;
}
}
//and insert newNode
prev.next = newNode;
newNode.next = current;
listlen++;
return linkedList_return.SUCCESS;
}
//Delete a node from the linked list
public linkedList_return delete_node(int key)
{
default_node prev = head;
default_node current = head;
//check to see if we need to delete the head node
if(head.key == key)
{
head = head.next;
listlen--;
return linkedList_return.SUCCESS;
}
//search through the linked list until the node is found
while(current != null)
{
//if found, delete the node
if(current.key == key)
{
prev.next = current.next;
current = null;
listlen--;
return linkedList_return.SUCCESS;
}
//else, move to the next node
prev = current;
current = current.next;
}
//return error if the node was not found
return linkedList_return.DELETE_FAILED_KEY_NOT_FOUND;
}
