程序代码：

#include<stdio.h>
#include<stdlib.h>

struct xx
{
    int bhao;
    char mz[15];
    float qian;
    float pj;
}shuj[100]={0};

FILE *fp;
FILE *fo;
int ww;

int main()
{
    fp=fopen("data.txt","a");
    fo=fopen("data1.dll","w");
    void tjia();
    void ckan();
    int i;
    do
    {
        i=0;
        printf("1,添加数据\n2,查看数据\n");
        scanf("%d",&i);
        switch(i)
        {
            case 1:
                tjia();
                break;
            case 2:
                ckan();
                break;
        }
    }while(i!=3);
}

void tjia()
{
    int i,w;
    printf("请输入要添加的人数:");
    scanf("%d",&w);
    fread(&ww,sizeof(int ww),1,fo);  //好想是这里错了 ,不知道要怎么代替哦.
    ww=ww+w;
    if(fwrite(&ww,sizeof(int ww),1,fo)!=1)
            ;
    for(i=0;i<ww;i++)
        if(shuj[i].bhao==0)
        {
            printf("请输入编号:");
            shuj[i].bhao=rand()%1000;
            printf("编号自动生成成功!\n");
            printf("请输入名字:");
            scanf("%s",shuj[i].mz);
            printf("请输入钱数:");
            scanf("%f",&shuj[i].qian);
            shuj[i].pj=shuj[i].qian/3.0;
            if(shuj[i].bhao!=0)
                if(fwrite(&shuj[i],sizeof(struct xx),1,fp)!=1)
                    printf("数据写入错误!\n");
        }
}

void ckan()
{
    fp=fopen("data.txt","r");
    int i;
    for(i=0;i<100;i++)
    {
        fread(&shuj[i],sizeof(struct xx),1,fp);
        if(shuj[i].bhao!=0)
            printf("\n编号:%d,名字:%s,钱数:%.2f,平均:%.2f\n",shuj[i].bhao,shuj[i].mz,shuj[i].qian,shuj[i].pj);
    }
    fclose(fp);
}