双向链表各种操作（尾插法建表、初始化、求表长、查找、删除、插入、取值）17计科班教学用

#include<iostream>
using namespace std;
#define MAXSIZE 100
#define OK 1
#define ERROR 0
#define OVERFLOW -2
typedef char ElemType;
typedef int Status;
typedef struct DuLNode
{
     ElemType   data;       //数据域
     struct DuLNode  *prior;   //前驱指针域
     struct DuLNode  *next;   //后继指针域
}DuLNode,*DuLinkList;  
//初始化双向链表 
Status InitList_L(DuLinkList &L){ 
L=new DuLNode;
L->next=NULL;  //后继指针为NULL 
L->prior=NULL; //前驱指针为NULL
return OK;
} 
//利用尾插法建立双向链表
void CreateList_L(DuLinkList &L,int n){ 
      //正位序输入n个元素的值，建立带表头结点的双向链表L 
      L=new DuLNode; 
      L->next=NULL;
	  L->prior=NULL; 
	  DuLNode *p;	
      DuLNode *r=L;//尾指针r指向头结点 
      for(int i=0;i<n;++i){
		p=new DuLNode;//生成新结点 
		cin>>p->data;//输入元素值 
		p->next=NULL; 
		p->prior=r;
		r->next=p; //插入到表尾 
		r=p;//r指向新的尾结点 
      } 
}//CreateList_L 
//双向链表元素输出 
void Out_LinkList(DuLNode *p){
	 printf("The Created LinkList Elem Is:");
	 while(p!=NULL)
	 {
	  cout<<p->data<<" "; 
	  p=p->next;
	 } 
}//Out_LinkList
//求表长,返回L中数据元素个数
int  ListLength_L(DuLinkList L){
	int  i=0; 
    DuLinkList p;
    p=L->next;  //p指向第一个结点               
     while(p){//遍历单链表,统计结点数
           i++;
           p=p->next;    } 
    return i;                             
 }
//取值,获取线性表L中的某个数据元素的内容
Status GetElem_L(DuLinkList L,int i,ElemType &e){ 
    DuLNode *p=L->next;
	int j=1; //初始化
     while(p&&j<i){	//向后扫描，直到p指向第i个元素或p为空 
       p=p->next; ++j; 
     } 
     if(!p || j>i)return ERROR; //第i个元素不存在 
     e=p->data; //取第i个元素 
     return OK; 
}
//在线性表L中查找值为e的数据元素 
DuLNode *LocateELem_L(DuLinkList L,ElemType e) {
 //返回L中值为e的数据元素的地址，查找失败返回NULL
  DuLNode *p=L->next;
  while(p &&p->data!=e)  
        p=p->next;                		
  return p; 	
}
//在带头结点的双向链表L中查找第i个元素，返回结点的地址
DuLNode *GetElemP_DuL(DuLinkList L, int i) {
	//在带头结点的双向链表L中查找第i个元素，返回结点的地址
	int j;
	DuLinkList p;
	p = L->next;
	j = 1; //初始化，p指向第一个结点，j为计数器
	while (j < i && p) { //顺链域向后扫描，直到p指向第i个元素或p为空
		p = p->next;
		++j;
	}
	if (!p || j > i)
		return NULL; //第i个元素不存在
	return p;
} //GetElemP_DuL

//双向链表的插入 
Status ListInsert_DuL(DuLinkList &L,int i,ElemType e){
   DuLinkList p;
   DuLNode *s;
   if(!(p=GetElemP_DuL(L,i))) return ERROR;//在L中确定第i个元素的位置指针p 
   s=new DuLNode; 
   s->data=e;
   s->prior=p->prior;  
   p->prior->next=s;
   s->next=p;  
   p->prior=s;
   return OK;
}
//双向链表的删除 
Status ListDelete_DuL(DuLinkList &L,int i)
{
   DuLinkList p;
   if(!(p=GetElemP_DuL(L,i)))
   return ERROR;
   p->prior->next=p->next;
   p->next->prior=p->prior;
   delete p; 
   return OK;
}
int main(){
	//第一步 初始化双向链表
	 DuLinkList L;
	 DuLNode *p,*q,*Locate_Address;
	 int Init_flag,GetElem_flag;
	 int n=5;//建立双向链表时需要创建节点的个数 
	 Init_flag=InitList_L(L);
	 if(Init_flag)
	 cout<<"Init OK!"<<endl;
	 else
	 cout<<"Init ERROR!"<<endl;
	//第二步 利用尾插法建立双向链表
	cout<<"Please Input The DuLinkList Elem_Value( "<<n<<" values):"<<endl;
	CreateList_L(L,n);
	cout<<"Create DuLinkList OK!"<<endl;
	Out_LinkList(L->next);//输出现有双向链表中元素
	cout<<endl;
	//第三步 双向链表按照位置i取值
	int GetElem_i;
	ElemType GetElem_e;
	cout<<"Please Input The  GetElem_i: ";
	cin>>GetElem_i;
	GetElem_flag=GetElem_L(L,GetElem_i,GetElem_e);
	if(GetElem_flag)
	cout<<"GetElem Is OK:"<<GetElem_e<<endl;
	else
	cout<<"GetElem Is ERROR!"<<endl;
	//第四步 双向链表按值查找,如果找到返回地址,否则返回null 
    ElemType Locate_e;
	cout<<"Please input LocateElem value:"; 
	cin>>Locate_e;
    Locate_Address=LocateELem_L(L,Locate_e); 
    if(Locate_Address!=NULL)
    cout<<"LocateElem Is OK, The Address Is:"<<Locate_Address<<endl;
	else
	cout<<"LocateElem Is ERROR！"<<endl;
    //第五步 双向链表的插入操作
	ElemType ListInsert_e; 
	int ListInsert_i,ListInsert_flag;
	cout<<"Please Input The DuListInsert_i:";
	cin>>ListInsert_i;
	cout<<"Please Input The DuListInsert_e:";
	cin>>ListInsert_e;
	ListInsert_flag=ListInsert_DuL(L,ListInsert_i,ListInsert_e);
	if(ListInsert_flag)
	{
		cout<<"DuListInsert Is OK!"<<endl;
		cout<<"The DuLinkList of Length is: "<<ListLength_L(L)<<endl;
		Out_LinkList(L->next);//输出现有单链表中元素	
	}
	else
	cout<<"DuListInsert Is ERROR!"<<endl; 
	cout<<endl;
    //第六步 双向链表删除操作
	int delete_i,delete_flag;
	cout<<"Please input The delete_i:";
	cin>>delete_i;
	delete_flag=ListDelete_DuL(L,delete_i);
	if(delete_flag)
	{
		cout<<"DuListDelete is Ok!"<<endl;
		cout<<"The DuLinkList of length is: "<<ListLength_L(L)<<endl;
		Out_LinkList(L->next);//输出现有单链表中元素	
	}
	else
	cout<<"DuListDelete Is ERROR!"<<endl;
	
	return OK; 
}