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- You have two full days to implement a solution
- You can use any (fairly) mainstream object oriented language of your choice, so long as your solution builds and runs on linux. You should be fine if you favour, say, Java, Ruby, Python or Javascript.
- Please ensure that you follow the syntax and formatting of both the input and output samples. We validate submissions using automated tests.
- We are really, really interested in your object orientated development skills, so please solve the problem keeping this in mind.
- Unit tests are mandatory, so please ensure that all your code has tests/specs. Additionally, it's a huge plus if you test drive your code.
- Please ensure that the coding conventions, directory structure and build approach of your project follow the conventions set by popular open source projects in the language that you're using.
- When implementing this solution, please use a version control system of your choice that works on Linux and OSX. We expect you to send us a zip/tarball of your source code when you're done that includes the VCS metadata in the tarball so we can look at your commit logs and understand how your solution evolved. Please do not make either your solution or this problem statement publicly available by, for example, using github or bitbucket or by posting this problem to a blog or forum.
Problem Statement
I own a multi-storey parking lot that can hold up to 'n' cars at any given point in time. Each slot is given a number starting at 1 increasing with increasing distance from the entry point in steps of one. I want to create an automated ticketing system that allows my customers to use my parking lot without human intervention.
When a car enters my parking lot, I want to have a ticket issued to the driver. The ticket issuing process includes us documenting the registration number (number plate) and the colour of the car and allocating an available parking slot to the car before actually handing over a ticket to the driver (we assume that our customers are nice enough to always park in the slots allocated to them). The customer should be allocated a parking slot which is nearest to the entry. At the exit the customer returns the ticket which then marks the slot they were using as being available.
Due to government regulation, the system should provide me with the ability to find out: a) Registration numbers of all cars of a particular colour. b) Slot number in which a car with a given registration number is parked. c) Slot numbers of all slots where a car of a particular colour is parked.
We interact with the system via a simple set of commands which produce a specific output. Please take a look at the example below, which includes all the commands you need to support - they're self explanatory. The system should allow input in two ways. Just to clarify, the same codebase should support both modes of input - we don't want two distinct submissions.
- It should provide us with an interactive command prompt based shell where commands can be typed in
- It should accept a filename as a parameter at the command prompt and read the commands from that file
Example: File
To run the program:
$ my_program file_inputs.txt > output.txt
Input (in file):
create_parking_lot 6
park KA-01-HH-1234 White
park KA-01-HH-9999 White
park KA-01-BB-0001 Black
park KA-01-HH-7777 Red
park KA-01-HH-2701 Blue
park KA-01-HH-3141 Black
leave 4
status
park KA-01-P-333 White
park DL-12-AA-9999 White
registration_numbers_for_cars_with_colour White
slot_numbers_for_cars_with_colour White
slot_number_for_registration_number KA-01-HH-3141
slot_number_for_registration_number MH-04-AY-1111
Output (to console, newline after every output):
Created a parking lot with 6 slots
Allocated slot number: 1
Allocated slot number: 2
Allocated slot number: 3
Allocated slot number: 4
Allocated slot number: 5
Allocated slot number: 6
Slot number 4 is free
Slot No. Registration No Colour
1 KA-01-HH-1234 White
2 KA-01-HH-9999 White
3 KA-01-BB-0001 Black
5 KA-01-HH-2701 Blue
6 KA-01-HH-3141 Black
Allocated slot number: 4
Sorry, parking lot is full
KA-01-HH-1234, KA-01-HH-9999, KA-01-P-333
1, 2, 4
6
Not found
Example: Interactive
To run the program and launch the shell:
$ my_program
Assuming a parking lot with 6 slots, the following commands should be run in sequence by typing them in at a prompt and should produce output as described below the command:
Input: create_parking_lot 6
Output: Created a parking lot with 6 slots
Input: park KA-01-HH-1234 White
Output: Allocated slot number: 1
Input: park KA-01-HH-9999 White
Output: Allocated slot number: 2
Input: park KA-01-BB-0001 Black
Output: Allocated slot number: 3
Input: park KA-01-HH-7777 Red
Output: Allocated slot number: 4
Input: park KA-01-HH-2701 Blue
Output: Allocated slot number: 5
Input: park KA-01-HH-3141 Black
Output: Allocated slot number: 6
Input: leave 4
Output: Slot number 4 is free
Input: status
Output (we've used a table to make our lives easier, but tab delimited output is fine):
Slot No.Registration NoColour 1KA-01-HH-1234 White 2KA-01-HH-9999White 3KA-01-BB-0001Black 5 KA-01-HH-2701Blue 6KA-01-HH-3141Black
Input: park KA-01-P-333 White
Output: Allocated slot number: 4
Input: park DL-12-AA-9999 White
Output: Sorry, parking lot is full
Input: registration_numbers_for_cars_with_colour White
Output: KA-01-HH-1234, KA-01-HH-9999, KA-01-P-333
Input: slot_numbers_for_cars_with_colour White
Output: 1, 2, 4
Input: slot_number_for_registration_number KA-01-HH-3141
Output: 6
Input: slot_number_for_registration_number MH-04-AY-1111
Output: Not found
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cd parking_lot
bundle install
Interactive Mode Command : ruby lib/parking_lot.rb
File Mode Command : ruby lib/parking_lot.rb "file_inputs.txt > output.txt"
rake clean
App Test Command : rspec spec
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