Basic Program for banking system

/*
Aimed at beginners. Not a hard one.
Author: Shubham Patil

*/
#include <iostream>
#include <cstdio>
#include <cstdlib>

using namespace std;
int menu();
int deposit();
void withdraw();
void transfer();
void checkdetails();

struct Account{
    int tdeposit,twithdraw,ttransfer,amount,totalamount=1000;
}a;

int main()
{
    char ch;
    a.twithdraw=0;
    a.tdeposit=0;
    a.ttransfer=0;
    //menu();
    do{
    switch(menu())
        {
        case 1:
            {
                deposit();
                cout<<"Your total balance now is:"<<a.totalamount<<endl;
                break;
            }
        case 2:
            {
                withdraw();
                cout<<"Your total balance now is:"<<a.totalamount<<endl;
                break;
            }
        case 3:
            {
                transfer();
                cout<<"Your total balance now is:"<<a.totalamount<<endl;
                break;
            }
        case 4:
            {
                checkdetails();
                break;
            }
        case 5:
            {
                exit(0);
                break;
            }
        default:
        {
        cout<<"Invalid choice"<<endl;
            break;
        }
    }
        cout<<"Do you want to continue"<<endl;
        cin>>ch;
    }while(ch!='q'||ch!='Q');

    return 0;
}

int deposit()
{
    cout<<"Enter the amount to deposit"<<endl;
    cin>>a.amount;
    a.totalamount+=a.amount;
    a.tdeposit+=a.amount;

    return 0;
}

void transfer()
{
    cout<<"Enter the amount to deposit"<<endl;
    cin>>a.amount;

    a.totalamount+=a.amount;

    if(a.totalamount<a.amount)
    {
        cout<<"Not enough balance in the account\n";
    }
    else{
        a.totalamount-=a.amount;
        a.ttransfer+=a.amount;
    }

}

void withdraw()
{
    cout<<"Enter the amount to withdraw"<<endl;
    cin>>a.amount;
    if(a.totalamount<a.amount)
    {
        cout<<"Not enough balance in the account\n";
    }
    else{
        a.totalamount-=a.amount;
    }

    a.twithdraw+=a.amount;
}

void checkdetails()
{
    cout<<"Your available balance is "<<a.totalamount<<endl;
    cout<<"Your total withdraw is "<<a.twithdraw<<endl;
    cout<<"Your total deposit is "<<a.tdeposit<<endl;

    cout<<"Your total transfer is "<<a.ttransfer<<endl;
}
int menu()
{
    char ch;
    int choice;
    cout<<"\nBANKING SYSTEM\n";
    cout<<"1.Deposit"<<endl;
    cout<<"2.Withdraw"<<endl;
    cout<<"3.Transfer"<<endl;
    cout<<"4.Check Deposit"<<endl;
    cout<<"5.Exit"<<endl;
    cin>>choice;
    return choice;

}

Basic Program for banking system