Initial commit

elixir/darts/.exercism/config.json

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+{
+  "authors": [
+    "jiegillet"
+  ],
+  "contributors": [
+    "angelikatyborska"
+  ],
+  "files": {
+    "solution": [
+      "lib/darts.ex"
+    ],
+    "test": [
+      "test/darts_test.exs"
+    ],
+    "example": [
+      ".meta/example.ex"
+    ]
+  },
+  "blurb": "Write a function that returns the earned points in a single toss of a Darts game.",
+  "source": "Inspired by an exercise created by a professor Della Paolera in Argentina"
+}

elixir/darts/.exercism/metadata.json

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+{"track":"elixir","exercise":"darts","id":"1062d062de474a2ab65b96bb7027ec45","url":"https://exercism.org/tracks/elixir/exercises/darts","handle":"negrienko","is_requester":true,"auto_approve":false}

elixir/darts/.formatter.exs

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+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

elixir/darts/.gitignore

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+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where third-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+darts-*.tar
+

elixir/darts/HELP.md

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+# Help
+
+## Running the tests
+
+From the terminal, change to the base directory of the exercise then execute the tests with:
+
+```bash
+$ mix test
+```
+
+This will execute the test file found in the `test` subfolder -- a file ending in `_test.exs`
+
+Documentation:
+
+* [`mix test` - Elixir's test execution tool](https://hexdocs.pm/mix/Mix.Tasks.Test.html)
+* [`ExUnit` - Elixir's unit test library](https://hexdocs.pm/ex_unit/ExUnit.html)
+
+## Pending tests
+
+In test suites of practice exercises, all but the first test have been tagged to be skipped.
+
+Once you get a test passing, you can unskip the next one by commenting out the relevant `@tag :pending` with a `#` symbol.
+
+For example:
+
+```elixir
+# @tag :pending
+test "shouting" do
+  assert Bob.hey("WATCH OUT!") == "Whoa, chill out!"
+end
+```
+
+If you wish to run all tests at once, you can include all skipped test by using the `--include` flag on the `mix test` command:
+
+```bash
+$ mix test --include pending
+```
+
+Or, you can enable all the tests by commenting out the `ExUnit.configure` line in the file `test/test_helper.exs`.
+
+```elixir
+# ExUnit.configure(exclude: :pending, trace: true)
+```
+
+## Useful `mix test` options
+
+* `test/<FILE>.exs:LINENUM` - runs only a single test, the test from `<FILE>.exs` whose definition is on line `LINENUM`
+* `--failed` - runs only tests that failed the last time they ran
+* `--max-failures` - the suite stops evaluating tests when this number of test failures
+is reached
+* `--seed 0` - disables randomization so the tests in a single file will always be ran
+in the same order they were defined in
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit lib/darts.ex` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Elixir track's documentation](https://exercism.org/docs/tracks/elixir)
+- The [Elixir track's programming category on the forum](https://forum.exercism.org/c/programming/elixir)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+If you're stuck on something, it may help to look at some of the [available resources](https://exercism.org/docs/tracks/elixir/resources) out there where answers might be found.

elixir/darts/HINTS.md

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+# Hints
+
+## General
+
+- The distance of a point `(x, y)` from the center of the target `(0, 0)` can be calculated with `sqrt(x*x + y *y)`
+
+- You can calculate the square root of `x` by raising it to the power of `1/2`. In other words, `sqrt(x) == pow(x, 0.5)`

elixir/darts/README.md

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+# Darts
+
+Welcome to Darts on Exercism's Elixir Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+If you get stuck on the exercise, check out `HINTS.md`, but try and solve it without using those first :)
+
+## Instructions
+
+Write a function that returns the earned points in a single toss of a Darts game.
+
+[Darts][darts] is a game where players throw darts at a [target][darts-target].
+
+In our particular instance of the game, the target rewards 4 different amounts of points, depending on where the dart lands:
+
+![Our dart scoreboard with values from a complete miss to a bullseye](https://assets.exercism.org/images/exercises/darts/darts-scoreboard.svg)
+
+- If the dart lands outside the target, player earns no points (0 points).
+- If the dart lands in the outer circle of the target, player earns 1 point.
+- If the dart lands in the middle circle of the target, player earns 5 points.
+- If the dart lands in the inner circle of the target, player earns 10 points.
+
+The outer circle has a radius of 10 units (this is equivalent to the total radius for the entire target), the middle circle a radius of 5 units, and the inner circle a radius of 1.
+Of course, they are all centered at the same point — that is, the circles are [concentric][] defined by the coordinates (0, 0).
+
+Write a function that given a point in the target (defined by its [Cartesian coordinates][cartesian-coordinates] `x` and `y`, where `x` and `y` are [real][real-numbers]), returns the correct amount earned by a dart landing at that point.
+
+## Credit
+
+The scoreboard image was created by [habere-et-dispertire][habere-et-dispertire] using [Inkscape][inkscape].
+
+[darts]: https://en.wikipedia.org/wiki/Darts
+[darts-target]: https://en.wikipedia.org/wiki/Darts#/media/File:Darts_in_a_dartboard.jpg
+[concentric]: https://mathworld.wolfram.com/ConcentricCircles.html
+[cartesian-coordinates]: https://www.mathsisfun.com/data/cartesian-coordinates.html
+[real-numbers]: https://www.mathsisfun.com/numbers/real-numbers.html
+[habere-et-dispertire]: https://exercism.org/profiles/habere-et-dispertire
+[inkscape]: https://en.wikipedia.org/wiki/Inkscape
+
+## Source
+
+### Created by
+
+- @jiegillet
+
+### Contributed to by
+
+- @angelikatyborska
+
+### Based on
+
+Inspired by an exercise created by a professor Della Paolera in Argentina

elixir/darts/lib/darts.ex

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+defmodule Darts do
+  @type position :: {number, number}
+
+  @doc """
+  Calculate the score of a single dart hitting a target
+  """
+  @spec score(position) :: integer
+  def score({x, y}) do
+    in_radius = (x ** 2 + y ** 2) ** 0.5
+    cond do
+      in_radius <= 1 -> 10
+      in_radius <= 5 -> 5
+      in_radius <= 10 -> 1
+      true -> 0
+    end
+  end
+end

elixir/darts/mix.exs

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+defmodule Darts.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :darts,
+      version: "0.1.0",
+      # elixir: "~> 1.8",
+      start_permanent: Mix.env() == :prod,
+      deps: deps()
+    ]
+  end
+
+  # Run "mix help compile.app" to learn about applications.
+  def application do
+    [
+      extra_applications: [:logger]
+    ]
+  end
+
+  # Run "mix help deps" to learn about dependencies.
+  defp deps do
+    [
+      # {:dep_from_hexpm, "~> 0.3.0"},
+      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
+    ]
+  end
+end

elixir/darts/test/darts_test.exs

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+defmodule DartsTest do
+  use ExUnit.Case
+
+  # @tag :pending
+  test "Missed target" do
+    assert Darts.score({-9, 9}) == 0
+  end
+
+  # @tag :pending
+  test "On the outer circle" do
+    assert Darts.score({0, 10}) == 1
+  end
+
+  # @tag :pending
+  test "On the middle circle" do
+    assert Darts.score({-5, 0}) == 5
+  end
+
+  # @tag :pending
+  test "On the inner circle" do
+    assert Darts.score({0, -1}) == 10
+  end
+
+  # @tag :pending
+  test "Exactly on centre" do
+    assert Darts.score({0, 0}) == 10
+  end
+
+  # @tag :pending
+  test "Near the centre" do
+    assert Darts.score({-0.1, -0.1}) == 10
+  end
+
+  # @tag :pending
+  test "Just within the inner circle" do
+    assert Darts.score({0.7, 0.7}) == 10
+  end
+
+  # @tag :pending
+  test "Just outside the inner circle" do
+    assert Darts.score({0.8, -0.8}) == 5
+  end
+
+  # @tag :pending
+  test "Just within the middle circle" do
+    assert Darts.score({-3.5, 3.5}) == 5
+  end
+
+  # @tag :pending
+  test "Just outside the middle circle" do
+    assert Darts.score({-3.6, -3.6}) == 1
+  end
+
+  # @tag :pending
+  test "Just within the outer circle" do
+    assert Darts.score({-7.0, 7.0}) == 1
+  end
+
+  # @tag :pending
+  test "Just outside the outer circle" do
+    assert Darts.score({7.1, -7.1}) == 0
+  end
+
+  # @tag :pending
+  test "Asymmetric position between the inner and middle circles" do
+    assert Darts.score({0.5, -4}) == 5
+  end
+end

elixir/darts/test/test_helper.exs

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+ExUnit.start()
+ExUnit.configure(exclude: :pending, trace: true)