双链表

#include<stdio.h> 

#include<stdlib.h>

typedef struct NODE

{

 struct NODE *prior;

 struct NODE *next;

 int date;

}node;

typedef struct LIST

{

 node *head;

 node *last;

 int length;

}list;

int initlist(list *&h)

{

 

 h=(list *)malloc(sizeof(list));

 h->head=h->last=(node *)malloc(sizeof(node));

 if(NULL==h) return 0;

 

 h->head->next=h->last;

 h->last->prior=h->head;

 h->head->prior=h->last;

 h->last->next=h->head;

 

 h->length=0;

 return 1;

}

int crelist(list *&h,int data)

{

 node *p;

 p=(node *)malloc(sizeof(node));

 p->date=data;

 

 p->next=h->head->next;

 h->head->next->prior=p;

 p->prior=h->head;

 h->head->next=p;

 

 h->length++;

 return 1;

}

void show(list *r)

{

 printf("结果:\n");

 printf("length=%d\n",r->length);

 node *p;

 p=(node *)malloc(sizeof(node));

 p=r->last->prior;

 while(p!=r->last)

 {

  printf("%d ",p->date);

  p=p->prior;

 }

 printf("\n");

}

node *found(list *h,int n)

{

 node *p;

 p=h->last;

 int j=0;

 while(NULL!=p&&j<n)

 {

  p=p->prior;j++;

 }

 return p;

}

int insertlist(list *&h,int w,int s)

{

 if(w<1||w>h->length+1) return 0;

 node *p,*q;

 p=(node *)malloc(sizeof(node));

 q=(node *)malloc(sizeof(node));

 q=found(h,w);

 p->date=s;

 

 p->next=q->next;

 q->next->prior=p;

 p->prior=q;

 q->next=p;

 

 h->length++;

}

int del(list *&h,int n)

{

 if(n<1||n>h->length) return 0;

 node *q;

 q=(node *)malloc(sizeof(node));

 q=found(h,n);

 

 q->next->prior=q->prior;

 q->prior->next=q->next;

 

 h->length--;

 return 1;

}

int main()

{

 list *h;

 initlist(h);

 printf("输入数据个数：");

 int n,m;

 scanf("%d",&n);

 printf("输入数据：");

 while(n--)

 {

   scanf("%d",&m);

   crelist(h,m);

 }

 show(h);

 int a,b;

 printf("输入插入位置和数据：");

 scanf("%d%d",&a,&b);

 insertlist(h,a,b);

 show(h);

 printf("输入删除数据位置：");

 int c;

 scanf("%d",&c) ;

 del(h,c);

 show(h);

}