双链表操作

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

//#define TYPE int
#define TRUE 1
#define FALSE 0

typedef struct dnode
{
    int data;
    struct dnode *prev,*next;
}d_node,*d_node_link;


d_node_link create_dnode();

int insert_dnode(int position,int x,d_node_link head);

void find_dnode(int i,d_node_link head);

void delete_dnode(int i,d_node_link head);

void print_dnode(d_node_link head);


int main(int argc,char *argv[])
{
    d_node_link d_head;

    d_head = create_dnode();

  // insert_dnode(2,10,d_head);

   delete_dnode(3,d_head);
// find_dnode(3,d_head);

    print_dnode(d_head);

    return 0;
}

d_node_link create_dnode()
{
    d_node_link head,p,s;

    head = (d_node *)malloc(sizeof(d_node));

    p = head;
    int temp = 0;

    while(TRUE)
    {
        printf("please input a int data!\n");

        scanf("%d",&temp);
        if(temp>0)
        {
            s = (d_node *)malloc(sizeof(d_node));
            s->data = temp;
            p->next = s;
            s->prev = p;
            p = s;
        }
        else
            break;
    }
    head = head->next;
    head->prev = NULL;
    p->next = NULL;

    return head;
}

void print_dnode(d_node_link head)
{
    d_node_link p;

    p = head;

    while(p != NULL)
    {
        printf("%d\n",p->data);
        p = p->next;
    }
}

void find_dnode(int i,d_node_link head)
{
    d_node_link p;

    p = head;

    int j = 0;

    while(p != NULL && j<i)
    {
        j++;
        p = p->next;
    }
    printf("%d",p->data);//检查
}

int insert_dnode(int position,int x,d_node_link head)
{
    d_node_link p,s;
    p = head;
    int i = 0;

    while(p!=NULL &&i<position)
    {
        i++;
        p = p->next;
    }
    s = (d_node *)malloc(sizeof(d_node));
    s->data = x;
    s->next = p->next;
    p->next->prev = s->next;
    p->next = s;
    s->prev = p->next;
}

void delete_dnode(int i,d_node_link head)
{
    d_node_link p;
    p = head;
    int j = 0;

    while(p!=NULL && j<i)
    {
        j++;
        p = p->next;
    }
    p->next->prev = p->prev;
    p->prev->next = p->next;
    free(p);
}