This is a question that is asked in various exams of object oriented programming and it is implemented in c++

bankAccountquestion.cpp

/*==========================================================================================================+
|   Assume that a bank maintains two kinds of accounts for customers,                                       |
|   one called as savings account and the other as current account.                                         |
|   The savings account provides compound interest and withdrawal facilities but no cheque book facility.   |
|   The current account provides cheque book facility but no interest.                                      |
|   Current account holders should also maintain a minimum balance                                          |  
|   and if the balance falls below this level, a service charge is imposed.                                 |
|   Create a class account that stores customer name, account number and type of account.                   |
|   From this derive the classes curacct and savacct to make them more specific to their requirements.      |
|   Include necessary member functions in order to achieve the following tasks:                             |
|                                                                                                           |
|   (a) Accept deposit from a costumer and update the balance.                                              |
|                                                                                                           |
|   (b) Display the balance                                                                                 |
|                                                                                                           |
|   (c) Compute and deposit interest.                                                                       |
|                                                                                                           |
|   (d) Permit withdrawal and update the balance.                                                           |
|                                                                                                           |
|   Check for the minimum balance, impose penalty, necessary, and update the balance.                       |
+==========================================================================================================*/

#include<iostream.h>

#include<stdio.h>
#include<math.h>
#include<conio.h>
#include<string.h>

class account{

protected:
      char cname[20];
      int accno;
      char type;
      int bal;
public:
      account()
      {
        strcpy(cname," ");
        accno=0;
        type=' ';
        bal=0;
      }
      void input(){
        cout<<"Enter cname";cin>>cname;
        cout<<"Enter accno";cin>>accno;
        cout<<"Enter type"; cin>>type;
        cout<<"Enter bal";cin>>bal;
      }
      void display(){
            cout<<"\n Customer Name "<<cname;
            cout<<"\n Account Number "<<accno;
            cout<<"\n Type "<<type;
            cout<<"\n Balance "<<bal;
      }
      void deposit(){
            int amt;
            cout<<"\n Enter the amount to deposit";
            cin>>amt;
            bal=bal+amt;
      }
};
class savacct:public account{
      int inter;
      public:

      int comp_int(){
         int time1,rate1;
         rate1=10;
         cout<<"\n Enter time";cin>>time1;
         inter=bal*pow(1+rate1/100.0,time1)-bal;
         return inter;
      }

      void update_bal(){
         bal=bal+comp_int();
      }

      void withdrawal(){
         int amt;
         cout<<"\n Enter amount to withdrawn";
         cin>>amt;
         if(bal>=amt){
               bal=bal-amt;
         }
         else{
               cout<<"\n The amount cannot be withdrawn";
         }
      }
  };

class curacct:public account{
       int chq_bk;
       int penal;
       public:

       int min_bal(){
          int ret1=1;
          if(bal<=500){
             penal=50;
             bal=bal-penal;
             ret1=0;
          }
          else{
             cout<<"\n No penality imposed";
          }
          return ret1;
      }
      void withdrawal(){
          int amt;
          cout<<"\n Enter the amount to withdrawn";
          cin>>amt;
          int k=min_bal();
          if(k==1){
             if(bal>=amt)
             bal=bal-amt;
          }
          else{
              cout<<"\n The amount cannot be withdrawn";
          }
      }
   };

void main(){
      curacct c1;
      savacct s1;
      c1.input();
      c1.display();
      c1.deposit();
      c1.display();
      c1.withdrawal();
      c1.display();
      s1.input();
      s1.display();
      s1.deposit();
      s1.display();
      s1.withdrawal();
      s1.display();
}   

This program was found on

https://www.roseindia.net/answers/viewqa/Java-Beginners/25539-c-program-of-inheritance.html

#include
#include
#include<stdio.h>
#include<math.h>
#include<conio.h>
#include<string.h>
#include<stdio.h>
using namespace std;
class acc{
public:
char name[100];
int accno;
int bal;

void input()
{
     cout<<"Enter name";
    cin>>name;
    cout<<"Enter accno";
    cin>>accno;
    cout<<"Enter bal";
    cin>>bal;
}
void display(int x){
        cout<<"\n Customer Name "<<name;
        cout<<"\n Account Number "<<accno;
       cout<<"\n Type "<<x;
        cout<<"\n Balance "<<bal;
}
void deposit(){
        int amt;
        cout<<"\n Enter the amount to deposit";
        cin>>amt;
        bal=bal+amt;
}

};
class sa :public acc
{
public:
int intrest1;
long intrest(){
int time,rate=10;
cout<<"\nEnter Time Duration";
cin>>time;
intrest1=bal*pow(1+rate/100.0,time)-bal;
cout<<"Intresrt Earnes IS : "<<intrest1<<"\n";

}
void update_bal(){
     bal=bal+intrest();
  }

  void withdrawal(){
     int amt;
     cout<<"\n Enter amount to withdrawn ";
     cin>>amt;
     if(bal>=amt){
           bal=bal-amt;
     }
     else{
           cout<<"\n The amount cannot be withdrawn ";
     }
  }

};
class ca :public acc
{
public:
int check,penal=50;
int min_bal(){
if(bal<=500){
bal=bal-penal;
cout<<"\n penality imposed"<<bal;
}
else{
cout<<"\n No penality imposed";
}

}
void withdrawal(){
      int amt;
      cout<<"\n Enter the amount to withdrawn";
      cin>>amt;
      int k=min_bal();
      if(k==1){
         if(bal>=amt)
         bal=bal-amt;
      }
      else{
          cout<<"\n The amount cannot be withdrawn";
      }
  }

};
int main(){
ca c1;
sa s1;
int ch,co;

cout<<"welcome";
start:
cout<<"\nEnter type\n1.Current Account\n2.Saving Account\n0. Exit"<<endl;
cin>>ch;

do
{
switch(ch) {

case 1:

    c1.input();
    c1.display(ch);
    c1.deposit();
    c1.display(ch);
    c1.withdrawal();
    c1.display(ch);
    _getch();
    goto start;

case 2:

    s1.input();
  s1.display(ch);
  s1.deposit();
  s1.display(ch);
  s1.withdrawal();
   s1.display(ch);
  s1.intrest();
  s1.display(ch);
  goto start;

case 0:
break;}
} while (1);

  return 0;

}

its not running