我写了半天也只是写了个读写文件的东西出来，怎么才能弄出来个备忘录啊

#include<stdio.h>
#include<time.h>
#include<string.h>
#include<conio.h>
#include<stdlib.h>
void addm(struct BEIWANG *m);
int countdown(int y,int m,int d);
void view(struct BEIWANG *m);
void delte(struct BEIWANG *m);
struct BEIWANG{
 char title[10];
 char n[100];
 int year;
 int month;
 int day;
};
static int len=0;
main()

{ struct BEIWANG mess[3];
    int  n;

while(1){
     
    printf("***********************************************************\n");
    printf("                    我的备忘录                             \n");
    printf("***********************************************************\n");
    printf("                     1.添加                                 \n");
    printf("                     2.查看                                 \n");
    printf("                     3.退出                                 \n");
    printf("                                                            \n");
    printf("************************************************************\n");
    printf("请输入要选择的数字：\n");
  scanf("%d",&n);
  switch(n)
  {
  case 1:addm(mess);
         break;
  case 2:view(mess);
         break;
  case 3:printf("退出!\n");
      exit(0);
         break;
  }
}
}

void addm(struct BEIWANG *m)
{
 printf("请输入题目:");
 scanf("%s",m->title);
 printf("请输入详细内容:");
 scanf("%s",m->n);
 printf("请输入时间:");
 printf("年份:");
 scanf("%d",&m->year);
 printf("月份:");
 scanf("%d",&m->month);
 printf("日期:");
 scanf("%d",&m->day);
while(getchar()!='\n');
len++;
}
void delte(struct BEIWANG *m)
{
    struct BEIWANG messa;
 printf("请输入要删除的信息:\n");
scanf("%s",messa.title);
}
int countdown(int y,int m,int d)
{
 struct tm *aa;
    int year,month,day;
    time_t t;
    int months[12]={31,28,31,30,31,30,31,31,30,31,30,31};
    int i,total_days=0;
    time(&t);
    aa=gmtime(&t);
 
 year=aa->tm_year+1900;
 month=aa->tm_mon+1;
 day=aa->tm_mday;
total_days=(y-year)*365;
if(month>m)
{total_days-=365;
 for(i=0;i<m;i++)
 total_days+=months[i];
 for(i=month;i<12;i++)
     total_days+=months[i];
}
else
 for(i=month;i<m;i++)
 total_days+=months[i];
 total_days+=(d-day);

 return total_days;

}
void view(struct BEIWANG *m)
{
 int i,days;
 printf("\n***************************************************************\n");
 printf("   |  题目  |  内容           |时间       |   距离今天还有()天  |\n");
 printf("*****************************************************************\n");
 for(i=0;i<len;i++)
 {
 printf("|%-8s|",m->title);
 printf(" %-26s|",m->n);
 printf("%d-%2d-%3d |",m->year,m->month,m->day);
 days=countdown(m->year,m->month,m->day);
 printf(" %-16d天|\n",days);
 printf("*****************************************************************|\n");
 m++;
 }
 getch();
}