双向链表的基本操作：创建、构造、查找、删除、插入

#include <iostream>
#include <malloc.h>
using namespace std;
typedef struct DuLNone{
	int data;
	struct DuLNone *prior,*next;
}DuLNone,*DuLinklist;
void InitLink(DuLinklist &L){
	L =new DuLNone;
	L->prior = NULL;
	L->next = L->prior;
}
void top_CreaLink(DuLinklist &L){//头插法 
	int n;
	DuLinklist p;
	cout<<"请输入要赋值的个数"<<endl;
	cin>>n;
	cout<<"请输入"<<n<<"位数"<<endl;
	while(n--){
		p = new DuLNone;//创建新节点 
		cin>>p->data;//给新节点->data赋值 
		p->prior = L;//新节点头指针指向L 
		p->next = L->next;//新节点尾指针指向当前节点位置 
		L->next = p; //头节点next指向当前节点位置 
	}
}
void bot_CreaLink(DuLinklist &L){//尾插法
	int n;
	DuLinklist p,r;
	r = L;
	cout<<"请输入要赋值的个数"<<endl;
	cin>>n;
	cout<<"请输入"<<n<<"位数"<<endl;
	while(n--){
		p = new DuLNone;
		cin>>p->data;
		p->prior = r;
		p->next  = NULL;
		r->next = p;
		r = p;
		
	}
}
int GetLink(DuLinklist L,int e){
	DuLinklist p;
	p = L->next;
	int j = 1;
	while(p != NULL && p->data != e){
		j++;
		p = p->next;
	}
	if(p==NULL)return 0;
	return j;
}
void DelLink(DuLinklist &L,int e){
	DuLinklist p,r;
	p = L->next;
	int j = 1;
	while(p != NULL && j<e){
		j++;
		p = p->next;
	}	
	if(p->next == NULL){//删除最后一个节点 
		r = p->prior;
		r->next = NULL;//删除非最后一个节点 
	}else{
		r = p->prior;
		r->next = p->next;
		r = p->next;
		r->prior= p->prior;	
	} 

	
}
void InterLink(DuLinklist L,int e,int n){
	DuLinklist p,r;
	p = L->next;
	int j = 1;
	while(p != NULL && j<n-1){
		j++;
		p = p->next;
	}
		r = new DuLNone;
		r->data = e;
		r->prior = p->prior;
		r->next  = p;
		p->prior = r;
		p = r->prior;
		p->next = r;		
}
void ListLink(DuLinklist L){
	DuLinklist p;
	p = L->next;
	while(p!=NULL){
		cout<<p->data<<' ';
		p = p->next;
	}
}
void error(){
	cout<<endl<<"数据错误，请重新运行程序！！！";
}
int main() {
	DuLinklist L;
	int e,n;
	InitLink(L);
//	top_CreaLink(L);
	bot_CreaLink(L);
	ListLink(L);
	cout<<endl<<"请输入删除的数"<<endl;
	cin>>e;
	e = GetLink(L,e);
	DelLink(L,e);
	ListLink(L);
	cout<<endl<<"请输入插入的位置"<<endl;
	cin>>n;
	cout<<endl<<"请输入插入的数"<<endl;
	cin>>e;
	InterLink(L,e,n);
	ListLink(L);
}