程序代码：

//普通学生查询某门课程的得分
void chaxunmoumenke()
{
    system("CLS");
    int i,x;
    struct work *head=NULL;
    head=(struct work *)malloc(sizeof(struct work));
    memset(head,0,sizeof(struct work));
    head=lianbiao();
    struct work *p=head;

    do
    {
        printf("请输入需要查询的课程（课程1/课程2/课程3）[请输入1,2,3]:\n");
        scanf("%d",&x);

        switch(x)
            {
            case 1:printf(" %s  \n",head->chengji1),i=1;break;
            case 2:printf(" %s  \n",head->chengji2),i=1;break;
            case 3:printf(" %s  \n",head->chengji3),i=1;break;
            default:
                {
                    i=0;
                    printf("没有该课程！请重新输入！");
                }
            }
         head=head->next;
    }while(x==0);
   

   

}

程序代码：

//用链表将文件里的学生基本信息读出来 

struct work *lianbiao()
{
    struct work *head=NULL;
    struct work *node=NULL;
    FILE *fp=NULL;
    if((fp=fopen("jiben.txt","rb"))==NULL)
    {
        printf("打开文件失败！");
        return NULL;
    }
    else
    {
        while(!feof(fp))
        {
            node=(struct work *)malloc(sizeof(struct work));
            memset(node,0,sizeof(struct work));

            struct work curWork;
            if(fread(&curWork,sizeof(struct work),1,fp)==1)
            {               

                node->chengji1 =curWork.chengji1;
                node->chengji2 = curWork.chengji2;
                node->chengji3 = curWork.chengji3;
                strcpy(node->idno, curWork.idno);
                strcpy(node->mima, curWork.mima);
                strcpy(node->name, curWork.name);
                strcpy(node->no, curWork.no);
                strcpy(node->powr, curWork.powr);

                node->next=head;
                head=node;
            }
        }
    }
    fclose(fp);
    return head;
}

程序代码：

//得到所需添加学生信息
 struct work * tianjiaxinxi(struct work *p)

 {
     fflush(stdin);
     printf("请输入添加学生的信息\n");
     printf("学号：（xxxx）\n");
     scanf("%s",p->no);
     printf("姓名：（xxx）\n");
     scanf("%s",p->name);
     printf("身份证号码：\n");
     scanf("%s",p->idno);
     printf("密码：（xxxx）\n");
     scanf("%s",p->mima);
     printf("成绩1：\n");
     scanf("%f",&p->chengji1);
     printf("成绩2：\n");
     scanf("%f",&p->chengji2);
     printf("成绩3：\n");
     scanf("%f",&p->chengji3);
     printf("权限：");
     scanf("%s",p->powr);
     fflush(stdin);
     return p;

 }