typedef struct Node{

  int data;

  struct Node *prior;

  struct Node *next;

}Node,*LinkedList;

LNew->data = i;

L->next = LNew;

LNew->prior = L; // 比单链表多这一条

LNew->next = NULL;

L = LNew;

#include <stdio.h>

#include <malloc.h>

#include <stdlib.h>

typedef struct Node{

  int data;

  struct Node *prior;

  struct Node *next;

}Node,*LinkedList;

LinkedList LinkedListInt(){

  Node *Head,*L,*LNew;

  int i;

  Head = (Node *)malloc(sizeof(Node));

  if(Head == NULL){

    printf("申请空间失败\n");

    exit(-);

  }

  L = Head;

  L->next = NULL;

  for(i=;i<;i++){

    LNew = (Node *)malloc(sizeof(Node));

    if(LNew == NULL){

      printf("申请空间失败\n");

      exit(-);

    }

    LNew->data = i;

    L->next = LNew;

      LNew->prior = L;

    LNew->next = NULL;

    L = LNew;

  }

  return Head;

}

int main(int argc, char const *argv[]) {

  /* code */

  Node *p;

  int i;

  p = LinkedListInt();

  p = p->next;

  // 让p的前指针指向p,这样第一个有值元素就有前指针

  p->prior = p;

  while(p != NULL){

    //printf("%d,",p->prior->data);

    printf("%d ",p->data);

    //printf("%d ",p->next->data);

    // 防止p指空报错

    if(p->next != NULL){

      p = p->next;

    }else{

      break;

    }

  }

  printf("\n");

  // 测试指针能不能指回去

  p = p->prior;

  printf("%d ",p->data);

  printf("\n");

  return ;

}