Add state-of-tic-tac-toe exercise (#793)

config.json

@@ -1228,6 +1228,18 @@
           "recursivity"
         ]
       },
+      {
+        "slug": "state-of-tic-tac-toe",
+        "name": "State of Tic-Tac-Toe",
+        "uuid": "8a3e9f5d-9145-456c-b573-8c9e32297213",
+        "practices": [],
+        "prerequisites": [
+          "strings",
+          "conditionals",
+          "vectors"
+        ],
+        "difficulty": 5
+      },
       {
         "slug": "saddle-points",
         "name": "Saddle Points",

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

@@ -0,0 +1,101 @@
+# Instructions
+
+In this exercise, you're going to implement a program that determines the state of a [tic-tac-toe][] game.
+(_You may also know the game as "noughts and crosses" or "Xs and Os"._)
+
+The game 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
+___|___|___
+   |   |
+   |   |
+   |   |
+```
+
+[tic-tac-toe]: https://en.wikipedia.org/wiki/Tic-tac-toe

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

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "erikschierboom"
+  ],
+  "files": {
+    "solution": [
+      "src/state_of_tic_tac_toe.clj"
+    ],
+    "test": [
+      "test/state_of_tic_tac_toe_test.clj"
+    ],
+    "example": [
+      ".meta/example.clj"
+    ]
+  },
+  "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.clj

@@ -0,0 +1,53 @@
+(ns state-of-tic-tac-toe)
+
+(defn- winner [cells]
+  (let [freqs (frequencies cells)]
+    (cond
+      (= 3 (get freqs \O)) \O
+      (= 3 (get freqs \X)) \X
+      :else nil)))
+
+(defn- winning-rows [board] (map seq board))
+(defn- winning-cols [board] (apply mapv vector board))
+(defn- winning-diagonals [board]
+  [(for [i (range 3)] (get-in board [i i]))
+   (for [i (range 3)] (get-in board [i (- 2 i)]))])
+
+(defn- winners [board]
+  (->> [winning-rows winning-cols winning-diagonals]
+       (mapcat #(% board))
+       (map winner)
+       (remove nil?)
+       (distinct)
+       (count)))
+
+(defn- moves-made [board]
+  (->> board
+       (mapcat identity)
+       (remove Character/isSpace)
+       (frequencies)
+       (merge {\X 0 \O 0})))
+
+(defn- error [board]
+  (let [moves (moves-made board)]
+    (when (= {\X 2 \O 0} moves)
+      (throw (IllegalArgumentException. "Wrong turn order: X went twice")))
+    (when (> (get moves \O) (get moves \X))
+      (throw (IllegalArgumentException. "Wrong turn order: O started")))))
+
+(defn- win [board]
+  (case (winners board)
+    2 (throw (IllegalArgumentException. "Impossible board: game should have ended after the game was won"))
+    1 :win
+    nil))
+
+(defn- draw [board]
+  (when (= {\X 5 \O 4} (moves-made board))
+    :draw))
+
+(defn gamestate [board]
+  (or
+   (error board)
+   (win board)
+   (draw board)
+   :ongoing))

exercises/practice/state-of-tic-tac-toe/.meta/generator.clj

@@ -0,0 +1,10 @@
+(ns state-of-tic-tac-toe-generator
+  (:require [hbs.helper :refer [safe-str]]))
+
+(defn- update-expected [expected]
+  (if-let [error (:error expected)]
+    {:error (str "^" error "$")}
+    (safe-str (keyword expected))))
+
+(defn update-test-case [test-case]
+  (update test-case :expected update-expected))

exercises/practice/state-of-tic-tac-toe/.meta/generator.tpl

@@ -0,0 +1,22 @@
+(ns state-of-tic-tac-toe-test
+  (:require [clojure.test :refer [deftest testing is]]
+            state-of-tic-tac-toe))
+{{#test_cases.gamestate}}
+(deftest gamestate_test_{{idx}}
+  (testing {{description}}
+    {{~#if expected.error}}
+    (is (thrown-with-msg? IllegalArgumentException #{{expected.error}}
+                          (state-of-tic-tac-toe/gamestate 
+                            [{{~#input.board}}
+                             {{.}}
+                             {{~/input.board}}
+                            ])))))
+    {{else}}
+    (is (= {{expected}}
+           (state-of-tic-tac-toe/gamestate
+             [{{~#input.board}}
+              {{.}}
+              {{~/input.board}}
+             ])))))
+    {{/if~}}
+{{/test_cases.gamestate}}

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

@@ -0,0 +1,101 @@
+# 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 left column victory"
+
+[96c30df5-ae23-4cf6-bf09-5ef056dddea1]
+description = "Won games -> Finished game where X won via middle column victory"
+
+[0d7a4b0a-2afd-4a75-8389-5fb88ab05eda]
+description = "Won games -> Finished game where X won via right column victory"
+
+[bd1007c0-ec5d-4c60-bb9f-1a4f22177d51]
+description = "Won games -> Finished game where O won via left column victory"
+
+[c032f800-5735-4354-b1b9-46f14d4ee955]
+description = "Won games -> Finished game where O won via middle column victory"
+
+[662c8902-c94a-4c4c-9d9c-e8ca513db2b4]
+description = "Won games -> Finished game where O won via right column victory"
+
+[2d62121f-7e3a-44a0-9032-0d73e3494941]
+description = "Won games -> Finished game where X won via top row victory"
+
+[108a5e82-cc61-409f-aece-d7a18c1beceb]
+description = "Won games -> Finished game where X won via middle row victory"
+include = false
+
+[346527db-4db9-4a96-b262-d7023dc022b0]
+description = "Won games -> Finished game where X won via middle row victory"
+reimplements = "108a5e82-cc61-409f-aece-d7a18c1beceb"
+
+[a013c583-75f8-4ab2-8d68-57688ff04574]
+description = "Won games -> Finished game where X won via bottom row victory"
+
+[2c08e7d7-7d00-487f-9442-e7398c8f1727]
+description = "Won games -> Finished game where O won via top row victory"
+
+[bb1d6c62-3e3f-4d1a-9766-f8803c8ed70f]
+description = "Won games -> Finished game where O won via middle row victory"
+
+[6ef641e9-12ec-44f5-a21c-660ea93907af]
+description = "Won games -> Finished game where O won via bottom row victory"
+
+[ab145b7b-26a7-426c-ab71-bf418cd07f81]
+description = "Won games -> Finished game where X won via falling diagonal victory"
+
+[7450caab-08f5-4f03-a74b-99b98c4b7a4b]
+description = "Won games -> Finished game where X won via rising diagonal victory"
+
+[c2a652ee-2f93-48aa-a710-a70cd2edce61]
+description = "Won games -> Finished game where O won via falling diagonal victory"
+
+[5b20ceea-494d-4f0c-a986-b99efc163bcf]
+description = "Won games -> Finished game where O won via rising 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 -> Another draw"
+
+[4d93f15c-0c40-43d6-b966-418b040012a9]
+description = "Ongoing games -> Ongoing game: one move in"
+
+[c407ae32-4c44-4989-b124-2890cf531f19]
+description = "Ongoing games -> Ongoing game: two moves in"
+
+[199b7a8d-e2b6-4526-a85e-78b416e7a8a9]
+description = "Ongoing games -> Ongoing game: five moves in"
+
+[1670145b-1e3d-4269-a7eb-53cd327b302e]
+description = "Invalid boards -> Invalid board: X went twice"
+
+[47c048e8-b404-4bcf-9e51-8acbb3253f3b]
+description = "Invalid boards -> Invalid board: O started"
+
+[b1dc8b13-46c4-47db-a96d-aa90eedc4e8d]
+description = "Invalid boards -> Invalid board"
+include = false
+
+[6c1920f2-ab5c-4648-a0c9-997414dda5eb]
+description = "Invalid boards -> Invalid board: X won and O kept playing"
+reimplements = "b1dc8b13-46c4-47db-a96d-aa90eedc4e8d"
+
+[4801cda2-f5b7-4c36-8317-3cdd167ac22c]
+description = "Invalid boards -> Invalid board: players kept playing after a win"

exercises/practice/state-of-tic-tac-toe/deps.edn

@@ -0,0 +1,6 @@
+{:aliases {:test {:extra-paths ["test"]
+                 :extra-deps {io.github.cognitect-labs/test-runner 
+                              {:git/url "https://github.com/cognitect-labs/test-runner.git"
+                               :sha "705ad25bbf0228b1c38d0244a36001c2987d7337"}}
+                 :main-opts ["-m" "cognitect.test-runner"]
+                 :exec-fn cognitect.test-runner.api/test}}}

exercises/practice/state-of-tic-tac-toe/project.clj

@@ -0,0 +1,4 @@
+(defproject state-of-tic-tac-toe "0.1.0-SNAPSHOT"
+  :description "state-of-tic-tac-toe exercise."
+  :url "https://github.com/exercism/clojure/tree/main/exercises/practice/state-of-tic-tac-toe"
+  :dependencies [[org.clojure/clojure "1.11.1"]])

exercises/practice/state-of-tic-tac-toe/src/state_of_tic_tac_toe.clj

@@ -0,0 +1,7 @@
+(ns state-of-tic-tac-toe)
+
+(defn gamestate
+  "Returns the gamestate of a tic-tac-toe board."
+  [board]
+  ;; function body
+  )