сделать из односвязного двусвязный несложно,поэтому ниже привёл код односвязного,просто код,где указатель на следующий элемент последнего элемента равен нулю,нужно подредактировать
Добавлено через 20 минут
| C++ |
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| #ifndef LISTNODE_H
#define LISTNODE_H
template <typename NODETYPE> class List;
template <typename NODETYPE>
class ListNode
{
friend class List<NODETYPE>;
public:
ListNode(const NODETYPE &);
NODETYPE getData() const;
private:
NODETYPE data;
ListNode<NODETYPE> *nextPtr;
};
template <typename NODETYPE>
ListNode<NODETYPE>::ListNode(const NODETYPE &info)
:data(info),nextPtr(0)
{
}
template<typename NODETYPE>
NODETYPE ListNode<NODETYPE>::getData() const
{
return data;
}
#endif |
|
| C++ |
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| #ifndef LIST_H
#define LIST_H
#include "ListNode.h"
#include<iostream>
using std::cout;
template<typename NODETYPE>
class List
{
public:
List();
~List();
void insertAtFront(const NODETYPE &);
void insertAtBack(const NODETYPE &);
bool removeFromFront(NODETYPE &);
bool removeFromBack(NODETYPE &);
bool isEmpty() const;
void print() const;
private:
ListNode<NODETYPE> *firstPtr;
ListNode<NODETYPE> *lastPtr;
ListNode<NODETYPE> *getNewNode(const NODETYPE &);
};
template<typename NODETYPE>
List<NODETYPE>::List()
:firstPtr(0),lastPtr(0)
{
}
template<typename NODETYPE>
List<NODETYPE>::~List()
{
if(!isEmpty())
{
cout << "Destroying nodes...\n";
ListNode<NODETYPE> *currentPtr = firstPtr;
ListNode<NODETYPE> *tempPtr;
while(currentPtr != 0)
{
tempPtr = currentPtr;
cout << tempPtr->data << '\n';
currentPtr = currentPtr->nextPtr;
delete tempPtr;
}
}
cout << "All nodes are destroyed\n\n";
}
template<typename NODETYPE>
void List<NODETYPE>::insertAtFront(const NODETYPE &value)
{
ListNode<NODETYPE> *newPtr = getNewNode(value);
if(isEmpty())
firstPtr = lastPtr = newPtr;
else
{
newPtr->nextPtr = firstPtr;
firstPtr = newPtr;
}
}
template<typename NODETYPE>
void List<NODETYPE>::insertAtBack(const NODETYPE &value)
{
ListNode<NODETYPE> *newPtr = getNewNode(value);
if(isEmpty())
firstPtr = lastPtr = newPtr;
else
{
lastPtr->nextPtr = newPtr;
lastPtr = newPtr;
}
}
template<typename NODETYPE>
bool List<NODETYPE>::removeFromFront(NODETYPE &value)
{
if(isEmpty())
return false;
else
{
ListNode<NODETYPE> *tempPtr = firstPtr;
if(firstPtr == lastPtr)
firstPtr = lastPtr = 0;
else
firstPtr = firstPtr->nextPtr;
value = tempPtr->data;
delete tempPtr;
return true;
}
}
template<typename NODETYPE>
bool List<NODETYPE>::removeFromBack(NODETYPE &value)
{
if(isEmpty())
return false;
else
{
ListNode<NODETYPE> *tempPtr = lastPtr;
if(firstPtr == lastPtr)
firstPtr = lastPtr = 0;
else
{
ListNode<NODETYPE> *currentPtr = firstPtr;
while(currentPtr->nextPtr != lastPtr)
currentPtr = currentPtr->nextPtr;
lastPtr = currentPtr;
currentPtr->nextPtr = 0;
}
value = tempPtr->data;
delete tempPtr;
return true;
}
}
template<typename NODETYPE>
bool List<NODETYPE>::isEmpty() const
{
return firstPtr == 0;
}
template<typename NODETYPE>
ListNode<NODETYPE> *List<NODETYPE>::getNewNode(const NODETYPE &value)
{
return new ListNode<NODETYPE>(value);
}
template<typename NODETYPE>
void List<NODETYPE>::print() const
{
if(isEmpty())
{
cout << "The list is empty\n\n";
return;
}
ListNode<NODETYPE> *currentPtr = firstPtr;
cout << "The list is: ";
while(currentPtr != 0)
{
cout << currentPtr->data << ' ';
currentPtr = currentPtr->nextPtr;
}
cout << "\n\n";
}
#endif |
|
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