This project provides an implementation of a continents finder given a world map.
An example of a valid world file can be found at test/input/valid-map.txt.
The map file is in the following format (only showing first 3 rows):
1 1
2 ++++ ++ ++++++++ ++++ +++++++++ + 2
3 +++ + +++ + +++++++++++++++ ++++++++++++++ 3
+ denotes land, empty space denotes sea.
A continent is one or more connected pieces of land +. Two pieces of land are connected if they are directly adjacent to each other either vertically, horizontally or diagonally.
The ContinentsFinder will process the file and outputs the continents information found on the map,
for example:
There are 3 Continents
Continent 1 has 201 +
Continent 2 has 15 +
Continent 3 has 267 +
This project is written and tested using Ruby 2.3.5. It should work on Ruby 2.2+ versions.
To check your version run:
$ ruby -v
To learn how to install ruby visit https://www.ruby-lang.org/en/installation/.
Below is the instruction on getting the project running in MacOS.
$ git clone https://github.com/cemeng/continents-finder
$ cd continents-finder
$ ruby lib/continents_finder_runner.rb test/input/valid-map.txt
Which should returns the following output:
There are 3 Continents
Continent 1 has 809 +
Continent 2 has 589 +
Continent 3 has 368 +
You can provide different map and supply it as an argument to lib/continents_finder_runner.rb, e.g:
$ ruby lib/continents_finder_runner.rb my-map.txt
The test files are in test directory.
You can find some example of the input map files in test/input directory.
To run all tests, on the root directory of the project, simply run:
rake test
If you need to run individual test, run the following:
ruby test/name-of-the-test.rb
The solution is two step processes.
MapReader.read(filename) is the function that responsibles for:
- Reading the world map file
- Getting the map content from each row - ignoring the line number at the beginning and at the end of each line.
- Validates the content of the map
- Returns an array of
Land-LandsExtractoris the class responsible for the extraction ofLandfrom cleansed map rows.
ContinentsFinder#stats is the main function that returns the continents stats found in a map.
The method reads an array of Land and finds the continent using the following approach:
- Iterate the
Landarray - Check if a
Landhas been marked as belonging to a continent or not.- If it is not, the following happens:
- Add the land to a continent (
add_to_continentmethod). See more about this below. - Check the adjacent lands, apply
add_to_continentto them if they are not marked. This is done recursively.
- Add the land to a continent (
- If it is continue.
- If it is not, the following happens:
Adding a land to continent means, setting the continent variable on the Land instance.
This continent variable is simply an integer value, it incremented whenever a new continent is 'discovered', that is
the loop inside find_continents finds an unmarked land.
This project is licensed under the MIT License - see the LICENSE.md file for details