New practice exercise state-of-tic-tac-toe

bin/bootstrap_practice_exercise.exs

@@ -195,6 +195,38 @@ end
 
 Mix.Generator.create_file("exercises/practice/#{exercise}/mix.exs", mix)
 
+# .gitignore
+gitignore = """
+# 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").
+#{exercise_snake_case}-*.tar
+
+# Temporary files, for example, from tests.
+/tmp/
+"""
+
+Mix.Generator.create_file("exercises/practice/#{exercise}/.gitignore", gitignore)
+
 # test/test_helper.exs
 test_helper = """
 ExUnit.start()

config.json

@@ -2386,6 +2386,25 @@
         ],
         "difficulty": 6
       },
+      {
+        "slug": "state-of-tic-tac-toe",
+        "name": "State of Tic Tac Toe",
+        "uuid": "905ac84d-7ba1-4208-bee1-55d8efde0c01",
+        "prerequisites": [
+          "strings",
+          "tuples",
+          "atoms",
+          "cond",
+          "lists",
+          "enum",
+          "maps",
+          "list-comprehensions",
+          "case",
+          "charlists"
+        ],
+        "practices": ["cond"],
+        "difficulty": 6
+      },
       {
         "slug": "variable-length-quantity",
         "name": "Variable Length Quantity",

exercises/practice/state-of-tic-tac-toe/.docs/instructions.md

@@ -0,0 +1,99 @@
+# Instructions
+
+In this exercise, you're going to implement a program that determines the state of a [tic-tac-toe](https://en.wikipedia.org/wiki/Tic-tac-toe) game.
+(_You may also know the game as "noughts and crosses" or "Xs and Os"._)
+
+The games is played on a 3×3 grid.
+Players take turns to place `X`s and `O`s on the grid.
+The game ends when one player has won by placing three of marks in a row, column, or along a diagonal of the grid, or when the entire grid is filled up.
+
+In this exercise, we will assume that `X` starts.
+
+It's your job to determine which state a given game is in.
+
+There are 3 potential game states:
+
+- The game is **ongoing**.
+- The game ended in a **draw**.
+- The game ended in a **win**.
+
+If the given board is invalid, throw an appropriate error.
+
+If a board meets the following conditions, it is invalid:
+
+- The given board cannot be reached when turns are taken in the correct order (remember that `X` starts).
+- The game was played after it already ended.
+
+## Examples
+
+### Ongoing game
+
+```text
+   |   |
+ X |   |
+___|___|___
+   |   |
+   | X | O
+___|___|___
+   |   |
+ O | X |
+   |   |
+```
+
+### Draw
+
+```text
+   |   |
+ X | O | X
+___|___|___
+   |   |
+ X | X | O
+___|___|___
+   |   |
+ O | X | O
+   |   |
+```
+
+### Win
+
+```text
+   |   |
+ X | X | X
+___|___|___
+   |   |
+   | O | O
+___|___|___
+   |   |
+   |   |
+   |   |
+```
+
+### Invalid
+
+#### Wrong turn order
+
+```text
+   |   |
+ O | O | X
+___|___|___
+   |   |
+   |   |
+___|___|___
+   |   |
+   |   |
+   |   |
+```
+
+#### Continued playing after win
+
+```text
+   |   |
+ X | X | X
+___|___|___
+   |   |
+ O | O | O
+___|___|___
+   |   |
+   |   |
+   |   |
+```

exercises/practice/state-of-tic-tac-toe/.formatter.exs

@@ -0,0 +1,4 @@
+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

exercises/practice/state-of-tic-tac-toe/.gitignore

@@ -0,0 +1,26 @@
+# 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").
+state_of_tic_tac_toe-*.tar
+
+# Temporary files, for example, from tests.
+/tmp/

exercises/practice/state-of-tic-tac-toe/.meta/config.json

@@ -0,0 +1,22 @@
+{
+  "authors": [
+    "jiegillet"
+  ],
+  "contributors": [
+    "angelikatyborska"
+  ],
+  "files": {
+    "solution": [
+      "lib/state_of_tic_tac_toe.ex"
+    ],
+    "test": [
+      "test/state_of_tic_tac_toe_test.exs"
+    ],
+    "example": [
+      ".meta/example.ex"
+    ]
+  },
+  "blurb": "Determine the game state of a match of Tic Tac Toe.",
+  "source": "Created by Sascha Mann for the Julia track of the Exercism Research Experiment.",
+  "source_url": "https://github.com/exercism/research_experiment_1/tree/julia-dev/exercises/julia-1-a"
+}

exercises/practice/state-of-tic-tac-toe/.meta/example.ex

@@ -0,0 +1,51 @@
+defmodule StateOfTicTacToe do
+  @rows [[{0, 0}, {0, 1}, {0, 2}], [{1, 0}, {1, 1}, {1, 2}], [{2, 0}, {2, 1}, {2, 2}]]
+  @columns [[{0, 0}, {1, 0}, {2, 0}], [{0, 1}, {1, 1}, {2, 1}], [{0, 2}, {1, 2}, {2, 2}]]
+  @diagonals [[{0, 0}, {1, 1}, {2, 2}], [{0, 2}, {1, 1}, {2, 0}]]
+
+  @doc """
+  Determine the state a game of tic-tac-toe where X starts.
+  """
+  @spec game_state(board :: String.t()) :: {:ok, :win | :ongoing | :draw} | {:error, String.t()}
+  def game_state(board) do
+    board =
+      for {line, row} <- board |> String.split("\n", trim: true) |> Enum.with_index(),
+          {player, col} <- line |> to_charlist() |> Enum.with_index(),
+          into: %{} do
+        {{row, col}, player}
+      end
+
+    x_count = Enum.count(board, fn {_, c} -> c == ?X end)
+    o_count = Enum.count(board, fn {_, c} -> c == ?O end)
+
+    x_wins = wins?(board, ?X)
+    o_wins = wins?(board, ?O)
+
+    cond do
+      x_count - o_count > 1 ->
+        {:error, "Wrong turn order: X went twice"}
+
+      o_count - x_count > 0 ->
+        {:error, "Wrong turn order: O started"}
+
+      x_wins and o_wins ->
+        {:error, "Impossible board: game should have ended after the game was won"}
+
+      x_wins or o_wins ->
+        {:ok, :win}
+
+      o_count == 4 ->
+        {:ok, :draw}
+
+      true ->
+        {:ok, :ongoing}
+    end
+  end
+
+  defp wins?(board, player) do
+    Enum.any?(
+      @rows ++ @columns ++ @diagonals,
+      fn cells -> Enum.all?(cells, fn cell -> board[cell] == player end) end
+    )
+  end
+end

exercises/practice/state-of-tic-tac-toe/.meta/tests.toml

@@ -0,0 +1,88 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[fe8e9fa9-37af-4d7e-aa24-2f4b8517161a]
+description = "Won games -> Finished game where X won via column victory"
+
+[96c30df5-ae23-4cf6-bf09-5ef056dddea1]
+description = "Won games -> Finished game where X won via column victory"
+
+[0d7a4b0a-2afd-4a75-8389-5fb88ab05eda]
+description = "Won games -> Finished game where X won via column victory"
+
+[bd1007c0-ec5d-4c60-bb9f-1a4f22177d51]
+description = "Won games -> Finished game where O won via column victory"
+
+[c032f800-5735-4354-b1b9-46f14d4ee955]
+description = "Won games -> Finished game where O won via column victory"
+
+[662c8902-c94a-4c4c-9d9c-e8ca513db2b4]
+description = "Won games -> Finished game where O won via column victory"
+
+[2d62121f-7e3a-44a0-9032-0d73e3494941]
+description = "Won games -> Finished game where X won via row victory"
+
+[108a5e82-cc61-409f-aece-d7a18c1beceb]
+description = "Won games -> Finished game where X won via row victory"
+
+[a013c583-75f8-4ab2-8d68-57688ff04574]
+description = "Won games -> Finished game where X won via row victory"
+
+[2c08e7d7-7d00-487f-9442-e7398c8f1727]
+description = "Won games -> Finished game where O won via row victory"
+
+[bb1d6c62-3e3f-4d1a-9766-f8803c8ed70f]
+description = "Won games -> Finished game where O won via row victory"
+
+[6ef641e9-12ec-44f5-a21c-660ea93907af]
+description = "Won games -> Finished game where O won via row victory"
+
+[ab145b7b-26a7-426c-ab71-bf418cd07f81]
+description = "Won games -> Finished game where X won via diagonal victory"
+
+[7450caab-08f5-4f03-a74b-99b98c4b7a4b]
+description = "Won games -> Finished game where X won via diagonal victory"
+
+[c2a652ee-2f93-48aa-a710-a70cd2edce61]
+description = "Won games -> Finished game where O won via diagonal victory"
+
+[5b20ceea-494d-4f0c-a986-b99efc163bcf]
+description = "Won games -> Finished game where O won via diagonal victory"
+
+[035a49b9-dc35-47d3-9d7c-de197161b9d4]
+description = "Won games -> Finished game where X won via a row and a column victory"
+
+[e5dfdeb0-d2bf-4b5a-b307-e673f69d4a53]
+description = "Won games -> Finished game where X won via two diagonal victories"
+
+[b42ed767-194c-4364-b36e-efbfb3de8788]
+description = "Drawn games -> Draw"
+
+[227a76b2-0fef-4e16-a4bd-8f9d7e4c3b13]
+description = "Drawn games -> Draw"
+
+[4d93f15c-0c40-43d6-b966-418b040012a9]
+description = "Ongoing games -> Ongoing game"
+
+[c407ae32-4c44-4989-b124-2890cf531f19]
+description = "Ongoing games -> Ongoing game"
+
+[199b7a8d-e2b6-4526-a85e-78b416e7a8a9]
+description = "Ongoing games -> Ongoing game"
+
+[1670145b-1e3d-4269-a7eb-53cd327b302e]
+description = "Invalid boards -> Invalid board"
+
+[47c048e8-b404-4bcf-9e51-8acbb3253f3b]
+description = "Invalid boards -> Invalid board"
+
+[b1dc8b13-46c4-47db-a96d-aa90eedc4e8d]
+description = "Invalid boards -> Invalid board"

exercises/practice/state-of-tic-tac-toe/lib/state_of_tic_tac_toe.ex

@@ -0,0 +1,8 @@
+defmodule StateOfTicTacToe do
+  @doc """
+  Determine the state a game of tic-tac-toe where X starts.
+  """
+  @spec game_state(board :: String.t()) :: {:ok, :win | :ongoing | :draw} | {:error, String.t()}
+  def game_state(board) do
+  end
+end

exercises/practice/state-of-tic-tac-toe/mix.exs

@@ -0,0 +1,28 @@
+defmodule StateOfTicTacToe.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :state_of_tic_tac_toe,
+      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