数据结构学习系列二－链表的C++实现

#include<iostream>
using namespace std;
/*单向链表head为头节点，头结点不包含在链表中，所以在计数时不包含头结点*/
struct Node
{
Node*Next;
int data;
};
class NodeManager
{
private:
Node*head;
Node*tail;
public:
NodeManager()
{
this->head=NULL;
this->tail=NULL;
}
~NodeManager()
{
while(head)
{
Node*pTemp;
pTemp=head;
head=head->Next;
delete pTemp;
}
}
void AddNode(int data)  //添加数
{
if((head==NULL)&&(tail==NULL))
{
head=tail=new Node();
Node*pNode=new Node();
head->Next=pNode;
tail->Next=pNode;
pNode->data=data;
tail=pNode;
tail->Next=NULL;
}
else
{
Node*pNode=new Node();
tail->Next=pNode;
pNode->data=data;
tail=pNode;
tail->Next=NULL;
}
}
void DeleteNode(int dtnum)  //删除节点
{
Node*node=head;//要删除的节点
Node*pre=head; //删除的节点的前一个节点
while(node!=NULL)
{
if(head==tail)//空链表
{
return;
}
if(node->data!=dtnum)
{
pre=node;
node=node->Next;
}
else
{
if(tail==node)
{
tail=pre;
pre->Next=NULL;
}
else
{
pre->Next=node->Next;
node=pre->Next;//执行下一步
}
}
}
}
void PrintNode()   //打印节点
{
if(head==NULL)
{
cout<<"此链表为空！"<<endl;
return;
}
Node*node=head->Next;
while(node!=NULL)
{
cout<<node->data<<endl;
node=node->Next;

}
}

int GetCount()//获取节点的数目
{
Node*pCurrent=head->Next;//头结点不计
int count=0;
while(pCurrent!=NULL)
{
count++;
pCurrent=pCurrent->Next;
}
return count;
}
bool RemoveAt(int index) //删除特定位置的数据
{
if(index<0||index>getCount())
{
cout<<"the wrong position!"<<endl;
return false;
}
Node*pre,*cur;
pre=head;
cur=head->Next;
while(index-1)
{
pre=pre->Next;
cur=cur->Next;
--index;
}
if(tail==cur)
{
tail=pre;
}
pre->Next=cur->Next;
if(cur!=NULL)
{
return true;
}
else
{
return false;
}
}

bool InsertAt(int index,int value)//在索引前插入新节点
{
if(index<=0||index>this->getCount())
{
cout<<"the wrong position"<<endl;
return false;
}
Node*current=head;
while(index-1)
{
current=current->Next;
--index;
}
Node*add=new Node();
add->data=value;
add->Next=current->Next;
current->Next=add;
if(current->Next!=NULL)
return true;
else
return false;

}
void ClearList()  //清空链表
{
Node*pCurrent1=head;
Node*pCurrent2=head;
while(pCurrent1->Next)
{
pCurrent2=pCurrent1->Next;
delete pCurrent1;
pCurrent1=pCurrent2;
}
head=NULL;
}
};
void main()
{
NodeManager*nm=new NodeManager();
int addnum=0;
int dtnum=0;
int index=0;
int value=0;
while(1)
{
char choice;
cin>>choice;
switch(choice)
{
case '0':
return;
case '1':
cout<<"请输入要添加的数据"<<endl;
cin>>addnum;
nm->addNode(addnum);
cout<<"****************"<<endl;
break;
case '2':
cout<<"显示链表中的数据"<<endl;
nm->printNode();
cout<<"****************"<<endl;
break;
case '3':
cout<<"请输入要删除的链表中的数据"<<endl;
cin>>dtnum;
nm->deleteNode(dtnum);
cout<<"*****************"<<endl;
break;
case '4':
cout<<"获取链表的长度"<<endl;
cout<<nm->getCount()<<endl;
cout<<"***************"<<endl;
break;
case '5':
cout<<"按索引删除数据，请输入索引值"<<endl;
cin>>index;
if(nm->RemoveAt(index))
{
cout<<"删除数据成功"<<endl;
}
else
{
cout<<"删除数据失败"<<endl;
}
cout<<"****************"<<endl;

break;
case '6':
cout<<"按索引插入值，请输入索引值及要插入的数据"<<endl;
cin>>index;
cin>>value;
if(nm->InsertAt(index,value))
{
cout<<"插入数据成功"<<endl;
}
else
{
cout<<"插入数据失败"<<endl;
}
cout<<"*******************"<<endl;
break;
case '7':
cout<<"删除链表中的所有数据"<<endl;
nm->ClearList();
cout<<"*********************"<<endl;
break;
}

}
}