双向链表的相关操作C++实现

#include<iostream>
using namespace std;

/*双链表结构*/
typedef struct node
{
int data;
struct node *prior;
struct node *next;

}DNode;
/*创建一个带头节点的双链表*/
void CreateDLink(DNode *&head)
{
int x;
DNode *p,*s;
s=(DNode *)malloc(sizeof(DNode));
if(s==NULL)
{
cout<<"Fail to malloc the head node!"<<endl;

}
s->data=0;
s->prior=NULL;
s->next=NULL; //建立一个头结点为head的双链表
head=s;   //若是循环双向链表则为：s->next=s->prior=s;
cout<<"please input the data of the node"<<endl;
cin>>x;
while(x!=0)
{
p=(DNode *)malloc(sizeof(DNode));
if(p==NULL)
{
cout<<"Fail to malloc a new  node!"<<endl;

}

p->data=x;
s->next=p;
p->prior=s;
p->next=NULL;
s=p;

cin>>x;
}

}

void PrintLink(DNode *head)
{
if(head->next==NULL)
{
cout<<"The list is NULL"<<endl;
return ;
}
DNode *p;
p=head->next;
while(p!=NULL)
{
cout<<p->data<<" ";
p=p->next;

}
cout<<endl;
}
int Length(DNode *head) //求双链表长度
{
int len=0;
DNode * p=head->next;
while(p!=NULL)
{
len++;
p=p->next;
}
return len;

}
DNode * Get(DNode *head,int i) //获取链表第i个节点地址
{
int j=0;
DNode *p=head->next;
while(j<i&&p!=NULL)
{
p=p->next;
j++;
}
if(p!=NULL)
return p;
else
return NULL;
}
int InsertNode(DNode *head,int x,int i)//在第i个位置插入一个节点
{
DNode *s,*p;
s=(DNode *)malloc(sizeof(DNode));
s->data=x;
if(i==0)
{
s->next=head->next;
if(head->next!=NULL)
head->next->prior=s;
s->prior=head;
head->next=s;

}
else
{
p=Get(head,i-1); //查找待插入节点前一个位置
if(p==NULL)
return 0;
else
{
s->next=p->next;
if(p->next!=NULL)
p->next->prior=s;
s->prior=p;
p->next=s;
}
}

return 1;
}

void DeleteNode(DNode *head,int index) //删除第index个节点
{
if(head->next==NULL)
{
cout<<"The list is NULL"<<endl;
return;
}
DNode *p,*s/*保存待删除的节点*/;
if(index==0)
{
s=head->next;
head->next=s->next;
if(s->next!=NULL)
s->next->prior=head;
free(s);
}
else
{
p=Get(head,index-1);
if(p==NULL)
cout<<"The Node "<<index<<"is not exist"<<endl;
else
{
s=p->next;
p->next=s->next;
if(s->next!=NULL)
s->next->prior=p;
free(s);
}
}

}
int main(int argc,char *argv[])
{
DNode *head;
CreateDLink(head);
cout<<"链表长度为："<<Length(head)<<endl;
PrintLink(head);
cout<<"第3个节点的值为:"<<Get(head,3)->data<<endl;

cout<<"输入插入节点的位置及值："<<endl;
int value, index;
cin>>index>>value;
InsertNode(head,value,index);
cout<<"插入后的链表为："<<endl;
PrintLink(head);

cout<<"请输入要删除的节点位置："<<endl;
cin>>index;
DeleteNode(head,index);
PrintLink(head);
return 0;
}