SimpleATM Example in C++

Problem Statement

Write code for a simple ATM. It doesn't need any UI (either graphical or console), but a controller should be implemented and tested.

Requirements

At least the following flow should be implemented:

Insert Card => PIN number => Select Account => See Balance/Deposit/Withdraw

For simplification, there are only 1 dollar bills in this world, no cents. Thus account balance can be represented in integer.

Your code doesn't need to integrate with a real bank system, but keep in mind that we may want to integrate it with a real bank system in the future.

It doesn't have to integrate with a real cash bin in the ATM, but keep in mind that we'd want to integrate with that in the future.
And even if we integrate it with them, we'd like to test our code.

Implementing bank integration and ATM hardware like cash bin and card reader is not a scope of this task, but testing the controller part (not including bank system, cash bin etc) is within the scope.

A bank API wouldn't give the ATM the PIN number, but it can tell you if the PIN number is correct or not.

Based on your work, another engineer should be able to implement the user interface.
You don't need to implement any REST API, RPC, network communication etc, but just functions/classes/methods, etc.

You can simplify some complex real world problems if you think it's not worth illustrating in the project.

How to submit

Please upload the code for this project to GitHub or anywhere, and post a link to your repository below.
Please attach the instruction to clone your project, build and run tests in README.md file in the root directory of the repository.

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Building SimpleATM Example

Tested Environment

This software is developed and tested in Ubuntu 18.04 LTS with gcc(ver 7.5.0) and CMake(ver 7.5.0).

Build SimpleATM Example

Clone this repository

git clone https://github.com/zzodo/SimpleATM.git

You can build the library object file and executable software by using CMake

cd SimpleATM
mkdir build && cd build
cmake ..
make

Then libSimpleATM.so and SimpleATM_example are generated, and you can test SimpleATM controller by executing the example.

./SimpleATM_example

Testing SimpleATM Example

Quick Explanation

Files & Directories

• include: a directory that includes header files (.h) for designed classes.
• src: a directory that includes cpp files for designed classes and its member functions.
• CMakeLists.txt: CMake file to build the software.
• example.cpp: a cpp file to generate SimpleATM_example executable.

Classes

• Account: contains bank name, user name, account number and balance.
• Card: contains bank name, user name, card number and expiration date.
• Bank: has information about accounts, cards (with pin) and card-to-account connection.
• Atm: includes the implemented SimpleATM controller.

Example Dataset and Test Cases

The built SimpleATM_example provides a quick example dataset regarding information about accounts, cards and bank systems.
The example dataset is given as below:

Bank	User	Card	PIN	Account
A	Thomas	0000111122223333	123456	1111111111
A	Lewis	0000111122224444	111111	2222222222
A	Lewis	0000111122224444	111111	3333333333
A	David	0000111122225555	102030	4444444444
A	David	0000111122226666	102030	4444444444
A	John	0000111133336666	246800	5555555555
B	John	0000111144446666	246800	6666666666

If you look at the dataset details, you may notice that the test can be conducted all the cases listed below:

• Case 1: single card + single account (Thomas)
• Case 2: single card + multiple accounts (Lewis)
• Case 3: multiple cards + single account (David)
• Case 4: single card + single account in different bank systems (John)

Hope you enjoy!