Cash Register

The Problem

Creative Cash Draw Solutions is a client who wants to provide something different for the cashiers who use their system. The function of the application is to tell the cashier how much change is owed, and what denominations should be used. In most cases the app should return the minimum amount of physical change, but the client would like to add a twist. If the "owed" amount is divisible by 3, the app should randomly generate the change denominations (but the math still needs to be right :))

Please write a program which accomplishes the clients goals. The program should:

1. Accept a flat file as input
   1. Each line will contain the amount owed and the amount paid separated by a comma (for example: 2.13,3.00)
   2. Expect that there will be multiple lines
2. Output the change the cashier should return to the customer
   1. The return string should look like: 1 dollar,2 quarters,1 nickel, etc ...
   2. Each new line in the input file should be a new line in the output file

Sample Input

2.12,3.00

1.97,2.00

3.33,5.00

Sample Output

3 quarters,1 dime,3 pennies

3 pennies

1 dollar,1 quarter,6 nickels,12 pennies

*Remember the last one is random

The Fine Print

Please use whatever technology and techniques you feel are applicable to solve the problem. We suggest that you approach this exercise as if this code was part of a larger system. The end result should be representative of your abilities and style.

Please fork this repository. When you have completed your solution, please issue a pull request to notify us that you are ready.

Have fun.

Things To Consider

Here are a couple of thoughts about the domain that could influence your response:

• What might happen if the client needs to change the random divisor?
• What might happen if the client needs to add another special case (like the random twist)?
• What might happen if sales closes a new client in France?

Implementation

Pre-requisites

Please ensure that you have .NET Core 2.0+ installed as well as Visual Studio 2017+.

To run

• Open the CashRegister.sln file using Visual Studio 2017+.
• Select the CashRegister.Api project as the startup project and run the project.
• On startup, you should be directed to the /swagger URL. Otherwise, navigate there.
• Expand the POST /api/CashRegister endpoint and click the Try it Out button within
• Attach a file to the request by using the Choose File button. I've included sample-input.csv in this repository for your convenience.
• Click the Execute button to submit your request
• If successful, the output file will appear in the response. Click the Download file link and open the resulting file.

For your convenience, I've added the gif below to illustrate the above steps.

Special considerations

• Denominations are configurable via the CashRegister.Api\appsettings.json file. If none provided or there is an error parsing the provided denominations, the application defaults to standard US denominations.
• The random divisor is configurable via the CashRegister.Api\appsettings.json file.