void stu_login()//学生登录菜单 
{
     void c_select();
     void c_view();
     void c_searchs();
     void login();
     
    int input;
    do
    {
         system("cls");
         printf("\n\n\n\t--学生登陆--");
         printf("\n\n\t1.学生选课\n");
         printf("\t2.课程浏览\n");
         printf("\t3.课程查询\n");
         printf("\t4.退出\n");
         scanf("%d",&input);
         if(input!=1&&input!=2&&input!=3&&input!=4)
         {
             printf("\n\t没有这项服务~\n");
              printf("\t按任意键重新选择");
              getchar();
              getchar();
          }
       }while(input!=1&&input!=2&&input!=3&&input!=4);
       
       switch(input)
       {
           case 1:c_select();break;
           case 2:c_views();break;
           case 3:c_searchs();break;
           case 4:login();break;
       }
}

void c_select()
{
  int n,in,i=0,j;int flag=0;
  FILE *fp;
  FILE *fp1;
  char input;
  
  struct course courses[10];