编写程序实现用一个二进制文件保存学成课程信息和成绩信息，并实现插入删除和更新！

#include<iostream>
#include<fstream>
#include<string>
#pragma warning(disable:4786)

using namespace std;

void showmenu(){
cout<<"======================"<<endl;
cout<<"1.输入"<<endl;
cout<<"2.删除"<<endl;
cout<<"3.修改"<<endl;
cout<<"4.显示"<<endl;
cout<<"5.退出"<<endl;
cout<<"======================"<<endl;
}

void insert(){
string info;
cout<<"请输信息并以逗号分隔：";
cin>>info;
info+="\r\n";
const char *p=info.c_str();
ofstream out("data.txt",ios::out|ios::binary|ios::app);
if(!out){
cout<<"error!"<<endl;
}
while(*p)out.put(*p++);
cout<<"done"<&