Parking Lot Algorithm

Intro

This project describes and solves a straighforward yet intricate problem of assigning vehicle slots using the appropriate data structures and Object-Oriented Programming patterns, in Go.

Problem

John owns a multi-storey parking lot that can hold up to n vehicles at any given point in time. The parking slots are numbered, beginning at 1 and increases with increasing distance from the entry point in steps of one. John has requested your help to design an automated ticketing system for his parking lot.

When a vehicle enters the parking lot, its vehicle registration number (i.e., number plate) and colour are noted. Then, an available parking slot is allocated. Following are the rules of parking slot ticket issuance:

• Each customer should be allocated the nearest available parking slot to the entry point.
• Upon exiting the parking lot, the customer returns the ticket which marks their previously allocated lot as now available.
• Due to government regulation, the system should provide the ability to determine:
  • Registration numbers of all cars of a particular colour.
  • Slot number in which a car with a given registration number is parked.
  • Slot numbers of all slots where a car of a particular colour is parked.

The ticketing system should be operable via two modes of input, namely, interactive commands and commands from a file. In other words, the ticketing system should be an executable which accepts:

1. Interactive commands from an interactive command prompt shell
2. A filename as an input argument at the command prompt and executes the commands from the given file

Example below includes all the commands which need to be supported.

Example: File Input

Launch the command line and run the code so it accepts input from a file:

sh $ parking_lot input_file.txt

Input (contents of inputfile.txt_ file):

sh 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 STDOUT):

sh 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 code, launch the command line, and the program will accept interactive input:

sh $ parking_lot

Assuming a parking lot with n=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. Note that exit terminates the process and returns control to the shell.

```sh $ createparkinglot 6 Created a parking lot with 6 slots

$ park KA-01-HH-1234 White Allocated slot number: 1

$ park KA-01-HH-9999 White Allocated slot number: 2

$ park KA-01-BB-0001 Black Allocated slot number: 3

$ park KA-01-HH-7777 Red Allocated slot number: 4

$ park KA-01-HH-2701 Blue Allocated slot number: 5

$ park KA-01-HH-3141 Black Allocated slot number: 6

$ leave 4 Slot number 4 is free

$ status 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

$ park KA-01-P-333 White Allocated slot number: 4

$ park DL-12-AA-9999 White Sorry, parking lot is full

$ registrationnumbersforcarswith_colour White KA-01-HH-1234, KA-01-HH-9999, KA-01-P-333

$ slotnumbersforcarswith_colour White 1, 2, 4

$ slotnumberforregistrationnumber KA-01-HH-3141 6

$ slotnumberforregistrationnumber MH-04-AY-1111 Not found $ exit ```

Solution

Model

TODO

Parking Lot

TODO

Slot

TODO

Vehicle

TODO

Installation Instructions

Assuming you have setup Go environment.

1. Source code
   • Git clone the project into a directory in your computer. sh git clone https://github.com/cedrickchee/go-parkinglot.git
   • cd into the repo sh cd go-parkinglot
2. Binary
   • To create an executable binary in the $GOPATH/bin/ directory, execute sh go install parking_lot
3. Unit test and functional test
   • To run complete test suite, run sh go test -v parking_lot Here, -v is the verbose command flag.
   • To run specific test, run sh go test -v parking_lot -run xxx Here, xxx is the name of test function.
4. Running
   • Launch interactive user input mode by executing sh $GOPATH/bin/parking_lot
   • Launch file input mode by executing sh $GOPATH/bin/parking_lot $GOPATH/src/github.com/cedrickchee/go-parkinglot/data/input_file.txt Here, $GOPATH/src/github.com/cedrickchee/go-parkinglot/data/input_file.txt refers to the input file with complete path.

Project Structure

TODO

API

TODO