双链表

#include<stdio.h>
#include<stdlib.h>


typedef struct LNode //三个量
{
    int data;
    struct LNode *next;
    struct LNode *prior;
}LNode,*LinkedList;

LinkedList LinkedListInit() //链表初始化
{
    LinkedList L;
    L=(LinkedList)malloc(sizeof(LNode));
    L->next=NULL;
    L->data=0;    // advise to add this line
    L->prior=NULL;
    return L;
}

LinkedList LinkedListCreat( )
{
    LinkedList head,p,s; //p只是一个介质
    int x=0;
    head=LinkedListInit();
    //p=L->next;   // that's to say p==NULL. it's not proper to do so
    p=head;

    printf("输入要创建的链表，以-1为结束\n");
    fflush(stdin); //清空缓冲区
    //scanf("%d",&x);
    while(x!=-1)
    {
        scanf("%d",&x);
        s=(LinkedList)malloc(sizeof(LNode));
        s->data=x;
        s->next=NULL;

        s->prior=p; //双链表的插入
        p->next=s;

        p=s;

        //free(s);
    }
    p=NULL;
    return(head);
}


int main()
{
    LinkedList L,temp;

    L=LinkedListCreat();
    while(L->next!=NULL)
    {
      printf("%d\n",L->data);
      temp=L->next;
      free(L);//  remember to go over the list to free the memory
      L=temp;
    }


    return 0;
}