-1
我想创建一个排序的链接列表的类，它从一个未分类的链接列表的类继承并重写插入函数，但程序没有插入值I把它列入清单，我不知道为什么。在c + +中排序的链接列表不会插入
这是我的插入功能：
class SLList : public LList<Elem>
{
public:
SLList(){LList::LList();}
~SLList(){}
bool insert(const Elem& item)
{
Elem curr;
for(setStart();getValue(curr);next())
{
if(!IntComparision::lt(curr, item)) break;
return LList<Elem>::insert(item);
}
}
};
这是我的代码的其余部分：
// Singly-linked list node
template <class Elem>
class Link
{
public:
Elem element; // Value for this node
Link *next; // Pointer to next node in list
Link(const Elem& elemval , Link* nextval= NULL) // 1st Constructor
{ element= elemval ; next= nextval; }
Link(Link* nextval= NULL) // 2nd Constructor
{ next= nextval; }
};
template <class Elem>
class List
{
public:
virtual void clear()= 0;
virtual bool insert(const Elem&)= 0;
virtual bool append(const Elem&)= 0;
virtual bool remove(Elem&)= 0;
virtual void setStart()= 0;
virtual void setEnd()= 0;
virtual void prev()= 0;
virtual void next()= 0;
virtual int leftLength() const= 0;
virtual int rightLength() const= 0;
virtual bool setPos(int pos)= 0;
virtual bool getValue(Elem&) const= 0;
virtual void print() const= 0;
};
class IntComparision
{
public:
static bool eq(int a , int b)
{ return a==b; }
static bool lt(int a , int b)
{ return a<b; }
static bool gt(int a , int b)
{ return a>b; }
};
const int DefaultListSize=10;
// Singly Linked list implementation
template <class Elem>
class LList: public List<Elem>
{
private:
Link<Elem>* head; // Pointer to list header
Link<Elem>* tail; // Pointer to last Elem in list
Link<Elem>* fence; // Last element on left side
int leftcnt; // Size of left partition
int rightcnt; // Size of right partition
void init() // Intialization routine
{
fence= tail= head= new Link<Elem>;
leftcnt= rightcnt= 0;
}
void removeall() // Return link nodes to free store
{
while(head != NULL)
{
fence= head;
head= head->next;
delete fence;
}
}
public:
LList() // Constructor
{ init(); }
~LList() { removeall(); } // Destructor
void clear()
{ removeall() ; init(); }
bool insert(const Elem&);
bool append(const Elem&);
bool remove(Elem&);
void setStart()
{ fence= head ; rightcnt+= leftcnt ; leftcnt= 0; }
void setEnd()
{ fence= tail ; leftcnt+= rightcnt ; rightcnt= 0; }
void prev();
void next()
{
if (fence != tail) // Don't move fence if right empty
{ fence= fence->next ; rightcnt-- ; leftcnt++ ; }
}
int leftLength() const { return leftcnt; }
int rightLength() const { return rightcnt; }
bool setPos(int pos);
bool getValue(Elem& it) const
{
if(rightLength() == 0) return false;
it= fence->next->element;
return true;
}
void print() const;
};
template <class Elem> // Insert at front of right partition
bool LList<Elem>::insert(const Elem& item)
{
fence->next= new Link<Elem>(item , fence->next);
if (tail == fence)
tail= fence->next; // New tail
rightcnt++;
return true;
}
template <class Elem> // Append Elem to end of the list
bool LList<Elem>::append(const Elem& item)
{
tail= tail->next= new Link<Elem>(item , NULL);
rightcnt++;
return true;
}
// Remove and return first Elem in right partition
template <class Elem> bool LList<Elem>::remove(Elem& it)
{
if (fence->next == NULL) return false; // Empty right
it= fence->next->element; // Remember value
Link<Elem>* ltemp= fence->next; // Remember link node
fence->next= ltemp->next; // Remove from list
if (tail == ltemp)
tail = fence; // Reset tail
delete ltemp; // Reclaim space
rightcnt--;
return true;
}
// Move fence one step left; no change if left is empty
template <class Elem> void LList<Elem>::prev()
{
Link<Elem>* temp= head;
if (fence == head)
return; // No previous Elem
while (temp->next != fence)
temp= temp->next;
fence = temp;
leftcnt--;
rightcnt++;
}
// Set the size of left partition to pos
template <class Elem>
bool LList<Elem>::setPos(int pos)
{
if ( (pos < 0) || (pos > rightcnt+leftcnt) )
return false;
fence= head;
for(int i=0 ; i<pos ; i++)
fence= fence->next;
return true;
}
template <class Elem> void LList<Elem>::print() const
{
Link<Elem>* temp= head;
cout << "< ";
while (temp != fence)
{
cout << temp->next->element << " ";
temp= temp->next;
}
cout << "| ";
while (temp->next != NULL)
{
cout << temp->next->element << " ";
temp= temp->next;
}
cout << ">\n";
}
template <class Elem>
class SLList : public LList<Elem>
{
public:
SLList(){LList::LList();}
~SLList(){}
bool insert(const Elem& item)
{
Elem curr;
for(setStart();getValue(curr);next())
{
if(!IntComparision::lt(curr, item)) break;
return LList<Elem>::insert(item);
}
}
};
预先感谢您。