数据结构链表课程设计

#include<stdio.h>  
#include<string.h>  
#include<stdlib.h>
#include<malloc.h>
#include <time.h>
#include<conio.h>
//-------------------------------------------------------------------------------------------------------
//成绩功能
#define MAX 80
void input1();
void sort1();
void display1();
void insert1();
void del1();
void average1();
void find1();
void save1();
void read1();
void del_file1();
void average1();
void modify1();
int now_no=0;
struct chengji
{
 int no;
 char name[20];
 char sex[4];
 float score1;
 float score2;
 float score3;

 float sort;
 float ave;
 float sum;
};
struct chengji stu[MAX],*p;
//----------------------------------------------------------------------------------------------------
//教师功能
struct teacher{
 char id[10];
 char name[30];
 char gender[10];
 char nativeplace[30];
 char beginwork[30];
 char subject[50];
 char qualification[20];
 char degree[20];
 char rank[20];
 char office[30];
 struct teacher *next;
};

typedef struct teacher Teacher;

Teacher *t=0;
FILE *fp;
char filename[30]="";
void free_memory(){
 Teacher *n;
 while(t!=0){
  n=t->next;