Thread: Sorting Linked Lists (code not concept)

I am a little new at this (notice the name )

I created a linked list and want to sort it (notice thread name )

Here is my linked list:

Code:

struct NODE
{
	int data; 

	NODE *next; 
				
};

class LINKED_LIST
{
	public:
		LINKED_LIST();
		~LINKED_LIST();
		void insertAfterHead(int);	
		int getHead() { return head->data; } 
		int getTail() { return tail->data; }
		int printList();
		bool searchList(int);
		void clear();	
		void removeNode(int);
		NODE *head; 
		NODE *tail; 
};

Here is my sorting method:

Code:

LINKED_LIST sortList(LINKED_LIST List)
{
	LINKED_LIST Temp;
	NODE *walker = new NODE, *temp_node = new NODE;
	int a = 0,b = 0;
	walker = List.head;
	temp_node->data = 1;

	while(walker != NULL)
	{
		if(walker->data > temp_node->data)
			temp_node = walker;
		walker = walker->next;
		if(walker->next == NULL)
		{
			Temp.insertAfterHead(temp_node->data);
			delete temp_node;
			walker = List.head;
			NODE *temp_node = new NODE;
			temp_node->data = 1;
		}
	}
	return List;
}

And I have double checked it and didn't see anything wrong with it, but I make many mistakes in debugging and no idea what is wrong, perhaps some help can be offered

The function has quite a few problems. Most notable are the fact that releasing the memory for temp_node destroys the structure of List and will cause future searches to fail with an access violation, an off by one error due to advancing walker before testing walker->next against null, returning the destroyed List instead of the sorted Temp, and memory leaks due to allocating memory for the first test using temp_node, but no release before reassigning the pointer to a node within the list.

The following fixes all but the memory leak.

Code:

LINKED_LIST sortList(LINKED_LIST List)
{
  LINKED_LIST Temp;
  NODE *walker, *temp_node = new NODE;
  walker = List.head;
  temp_node->data = 0;

  while(walker != NULL)
  {
    if(walker->data > temp_node->data)
      temp_node = walker;
    if(walker->next == NULL)
    {
      Temp.insertAfterHead(temp_node->data);
      List.removeNode(temp_node->data);
      walker = List.head;
      temp_node = new NODE;
      temp_node->data = 0;
    }
    walker = walker->next;
  }

  return Temp;
}