ввод и вывод в один файл

ofstream myfilecout; 
    ifstream myfilecin;
    myfilecout.open ("example1.txt"); //заменяем все cout на myfilecout?
    myfilecin.open ("example1.txt");  //заменяем все cin на myfilecin?

myfilecout.close();

#include <iostream>
#include <cstring>
#include <string>
using namespace std;
 
double balance=10000;
class ATM
{
public:
    string newusername;
    string username;
    int password;
public:
    void printMune();
    void checkBalance();
    void depositMoney();
    void withdrawMoney();
    void checkOperation(int);
    void changeUsername();
    bool login();
    
    
}a;
 
void ATM::printMune ()
{
    cout<<"Choose one operation from the list below:"<<endl;
    cout<<"1. Check balance"<<endl;
    cout<<"2. Deposit money"<<endl;
    cout<<"3. Wizdraw money"<<endl;
    cout<<"4. Change username"<<endl;
    cout<<"5. Quit"<<endl;
}
 
bool ATM::login()
{
    cout<<"Username:"<<endl;
    getline(cin,a.username);
    cout<<"Password:"<<endl;
    cin>>a.password;    
    if((a.username=="alisher") && (a.password==123456))
        return true;
    else 
        return false;
}
 
void ATM::checkOperation(int a)
{
    if(a==1)
        checkBalance();
    if(a==2)
        depositMoney();
    if(a==3)
        withdrawMoney();
    if(a==4)
        changeUsername();
    if(a==5)
    {
        cout<<"You are exit!"<<endl;
        system("pause");
    }
}
 
void ATM::checkBalance()
{
     cout << "Your balance is: "<<endl;
     cout<<balance<<endl;
}
 
void ATM::depositMoney()
{
    
    int deposit;
       cout << "Enter amount to deposit: "<<endl;
       cin >> deposit;
       balance = (balance + deposit);
       cout<<"Amount depositted successfully!"<<endl;
       cout<<"Your current balance: "<<endl;
       cout<<balance<<endl;
}
 
void ATM::withdrawMoney()
{
    int withdraw;
    cout << "Enter Withdraw amount: "<<endl;
       cin >> withdraw;
       if (balance > withdraw)
       {
          balance = (balance - withdraw);
        cout <<"Your current balance: "<<endl;
       cout<<balance<<endl;
       }
       else 
       {
           cout << "You do not have enough money "<<endl;  
       }
     
}
 
void ATM::changeUsername()
{
    cout<<" Enter new Username:"<<endl;
    cin>>newusername;
    a.username=newusername;
    cout<<"Your username has been successfully changed"<<endl;
}
 
 
int main ()
{
    ATM atm;
    int c;
    cout<<"Welcome to ATM"<<endl;
    cout<<"Enter your username and password:"<<endl;
    if(atm.login())
      atm.printMune();
    else
    {
       cout<<"Maybe you entered is not correct username and password!"<<endl;
       cout<<"Repeat again:"<<endl;
       system("pause");
    }
    while(c=5)
    {
     cin>>c;
     atm.checkOperation(c);
     cout<<"----------------------------"<<endl;
     atm.printMune();
    }
    return 0;
}