c语言的链表相关问题

想问下为什么这样不对啊，一直输出0

修改如下，供参考对照：

#include<stdio.h>
#include<malloc.h>
typedef struct student{
      int score;
      struct student *next;
}list;
struct student* create(){
    int i=0;
    struct student *head,*middle,*end;
    head = (list *)malloc(sizeof(list));
    head->next = NULL;
    middle = head;
    while(1){
          end = (list *)malloc(sizeof(list));
          end->next = NULL;
          printf("请输入第%d个学生的分数:",i+1);
          scanf("%d",&end->score);
          if(end->score == -1) break;   //-1 结束输入
          if(i==0)
          {
              head->next = end;
          }
          else{
              middle->next = end;
          }
          middle = end;
          i++;
    }
    free(end);
    return head;
}
void print(struct student *a)
{
    struct student *p;
    p = a->next;
    while(p)
    {
        printf("%d ",p->score);
        p = p->next;
    }
    printf("\n");
}

int main()
{
    list *p;
    p = create();
    print(p);

    return 0;
}