#include<stdio.h>
#include<malloc.h>
typedef struct node
{
    int data;
    int site;
    struct node *link;
}NODE;

NODE *creat()
{
    NODE *p,*q,*head,*tail;                                                                                                                                                                                                                                                                                             
    int num,i=0;
    head=tail=NULL;
    printf("int put num end with -1:\n");
    scanf("%d",&num);
    while(num!=-1)
    {
        i++;
        p=(NODE *)malloc(sizeof(NODE));
        if(p==NULL)
        {
            printf("fail");
            return NULL;
        }
        p->data=num;
        p->site=i;
        p->link=0;
        if(head==NULL)
        {
            head=p;
        }
        else
        {
            tail->link=p;
        }
        tail=p;
        scanf("%d",&num);
    }
    return head;
}

int countlist(NODE *head)
{
    int i=0;
    while (head)
    {
        i++;
        head=head->link;
    }
    return i;
}

NODE *insertlist(NODE *head,int num,int i)
{
    NODE *p,*q;
    int j;
    p=q=NULL;
    p=head;
    for(j=0;;j++)
    {
        if(p->site!=i)
        {
            p=p->link;
            continue;
        }
        else
        {
            q->data=num;
            q->site=p->site+1;
            q->link=p->link;
            p->link=q;
            return head;
        }
    }
}

void printlist(NODE *head)
{
    while (head)
    {
        printf("%d",head->data);
        head=head->link;
    }
    return;
}

main()
{
    NODE *a;
    a=creat();
    insertlist(a,88,2);
    printlist(a);
}