我正在尝试删除 C++ 中的重复项。我已经设法通过使用对象默认构造函数将对象设置为 = null。但我无法将其从列表中完全删除。此代码还删除了两个对象，而不仅仅是一个。这是另一个问题的重新发布。我的代码和部分我的帖子已经改变。如何按全名从双向链表中删除重复项。谁能帮我这个？这是我的 removeDuplicates 函数：
***Remove Duplicates***
void RemoveDuplicates(DoublyLinkedListIterator<Datatype> m_itr, string searchByFirstName, string searchBySecondName)
{
for (m_itr.Start(); m_itr.Valid(); m_itr.Forth())
{
if ((m_itr.Item().getFirstName() == searchByFirstName )
&& (m_itr.Item().getSecondName() == searchBySecondName))
{
for (m_itr.Item(); m_itr.Valid(); m_itr.Forth())
{
if ((m_itr.Item().getFirstName() == searchByFirstName )&&
(m_itr.Item().getSecondName() == searchBySecondName))
{
m_itr.Item() = Stats();
}
}
}
}
delete m_itr.Item();
}
***Remove***
void Remove(DoublyLinkedListIterator<Datatype> m_itr)
{
query.clock1();
DoublyLinkedListNode<Datatype>* node = m_head;
//Check to see if the iterator belongs to this list, if not return nothing.
if (m_itr.m_list != this)
return;
//Check to see if the node is valid, if not return nothing.
if (m_itr.m_node == 0)
return;
//If the iterator is pointing to the head...
if (m_itr.m_node == m_head)
{
//Move the iterator forward.
m_itr.Forth();
//Delete the head.
RemoveHead();
//Decrement the size.
m_count--;
}
//If the iterator is not pointing to the head...
else
{
//Search forward through the list until you find
//the node prior to the node you want to remove.
while (node->m_next != m_itr.m_node)
node = node->m_next;
// move the iterator forward.
m_itr.Forth();
//If the node being are deleted is the tail...
//Then update the tail node.
if (node->m_next == m_tail)
{
//Tail is now equal to node. Which means we can now delete the node.
m_tail = node;
}
//Delete the node.
delete node -> m_next;
//Relink the list.
node -> m_next = m_itr.m_node;
//Decrement the count because a node was removed.
m_count--;
query.clock2();
cout << "\nTime Taken : " << query.time2 - query.time1 << "\n";
}
}
***Class Declarations***
template <class Datatype>
class DoublyLinkedList
{
public:
//-------------------------------------------------------------------------------------------
// Member Vairables.
//-------------------------------------------------------------------------------------------
DoublyLinkedListNode<Datatype>* m_head;
DoublyLinkedListNode<Datatype>* m_tail;
int m_count;
template<class Datatype>
class DoublyLinkedListNode
{
public:
//-------------------------------------------------------------------------------------------
// Member Vairables.
//-------------------------------------------------------------------------------------------
DoublyLinkedListNode<Datatype>* m_next; //The next node.
DoublyLinkedListNode<Datatype>* m_prev; //The previous node.
Datatype m_data; //The data in the node.
template <class Datatype>
class DoublyLinkedListIterator
{
public:
//-------------------------------------------------------------------------------------------
// Member Vairables.
//-------------------------------------------------------------------------------------------
DoublyLinkedListNode<Datatype>* m_node; //A node for the Iterator to pointn to.
DoublyLinkedList<Datatype>* m_list; //A list for the Iteraotor to go through.
//-------------------------------------------------------------------------------------------
// Name: Constructor.
// Description: Constructs the DoublyLinkedListIterator.
//-------------------------------------------------------------------------------------------
DoublyLinkedListIterator(DoublyLinkedList<Datatype>* p_list= 0, DoublyLinkedListNode<Datatype>* p_node= 0)
{
m_list= p_list;
m_node= p_node;
}
// ------------------------------------------------------------------
// Name: Start
// Description: Resets the iterator to the beginning of the list.
// Arguments: None.
// Return Value: None.
// ------------------------------------------------------------------
void Start()
{
if(m_list!= 0)
m_node= m_list -> m_head;
}
// ----------------------------------------------------------------
// Name: End
// Description: Resets the iterator to the end of the list.
// Arguments: None.
// Return Value: None.
// ----------------------------------------------------------------
void End()
{
if(m_list!= 0)
m_node = m_list->m_tail;
}
// ----------------------------------------------------------------
// Name: Forth
// Description: Moves the iterator forward by one position.
// Arguments: None.
// Return Value: None.
// ----------------------------------------------------------------
void Forth()
{
if(m_node != 0)
{
m_node = m_node ->m_next;
}
}
// ----------------------------------------------------------------
// Name: Back
// Description: Moves the iterator back by one position.
// Arguments: None.
// Return Value: None.
// ----------------------------------------------------------------
void Back()
{
if(m_node!= 0)
m_node = m_node->m_prev;
}
// ----------------------------------------------------------------
// Name: Item
// Description: Gets the item that the iterator is pointing to.
// Arguments: None.
// Return Value: Reference to the data in the node.
// ----------------------------------------------------------------
Datatype& Item()
{
return m_node->m_data;
}
//-----------------------------------------------------------------
// Name: Valid
// Description: Determines if the node is valid.
// Arguments: None.
// Return Value: true if valid.
// ----------------------------------------------------------------
bool Valid()
{
return (m_node!= 0);
}
};