void employee::write()
{
    etype type;
    int size;
    ofstream file("Data.txt",ios::binary);
    for(int i=0;i<n;i++)
    {
        type=e[i]->gettype();
        file.write(reinterpret_cast<char *>(&type),sizeof(type));
        switch(type)
        {
            case managerr: size=sizeof(manager);     break;
            case laborerr: size=sizeof(laborer);     break;
            case scientistt: size=sizeof(scientist); break;
            default: cout<<"Can't write type"<<endl;
        }
        file.write(reinterpret_cast<char *>(e[i]),size);
    }
}
void employee::read()
{
    etype type;
    int size;
    ifstream file("Data.txt",ios::binary);
    while(true)
    {
        if(file.eof())
            break;
        file.read(reinterpret_cast<char *>(&type),sizeof(type));
        switch(type)
        {
            case managerr:    e[n]=new manager;        size=sizeof(manager);      break;
            case laborerr:    e[n]=new laborer;        size=sizeof(laborer);      break;
            case scientistt:  e[n]=new scientist;      size=sizeof(scientist);    break;
            default: cout<<"Can't read type"<<endl;
        }
        file.read(reinterpret_cast<char *>(e[n]),size);
        n++;
    }
}

All the program works flawlessly except when I try to read the file and put it inside the variable again.
It crashes when I try to display the variables. I just inserted the code for writing and reading as this is the only problem in the code for the whole code it starts at page 608