Add dnd-character (#232)

config.json

@@ -461,6 +461,14 @@
           "integers"
         ]
       },
+      {
+        "slug": "dnd-character",
+        "name": "D&D Character",
+        "uuid": "c9d2212d-7854-41cb-be85-9b04132b2137",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "run-length-encoding",
         "name": "Run-Length Encoding",

exercises/practice/dnd-character/.docs/instructions.md

@@ -0,0 +1,31 @@
+# Instructions
+
+For a game of [Dungeons & Dragons][dnd], each player starts by generating a character they can play with.
+This character has, among other things, six abilities; strength, dexterity, constitution, intelligence, wisdom and charisma.
+These six abilities have scores that are determined randomly.
+You do this by rolling four 6-sided dice and record the sum of the largest three dice.
+You do this six times, once for each ability.
+
+Your character's initial hitpoints are 10 + your character's constitution modifier.
+You find your character's constitution modifier by subtracting 10 from your character's constitution, divide by 2 and round down.
+
+Write a random character generator that follows the rules above.
+
+For example, the six throws of four dice may look like:
+
+- 5, 3, 1, 6: You discard the 1 and sum 5 + 3 + 6 = 14, which you assign to strength.
+- 3, 2, 5, 3: You discard the 2 and sum 3 + 5 + 3 = 11, which you assign to dexterity.
+- 1, 1, 1, 1: You discard the 1 and sum 1 + 1 + 1 = 3, which you assign to constitution.
+- 2, 1, 6, 6: You discard the 1 and sum 2 + 6 + 6 = 14, which you assign to intelligence.
+- 3, 5, 3, 4: You discard the 3 and sum 5 + 3 + 4 = 12, which you assign to wisdom.
+- 6, 6, 6, 6: You discard the 6 and sum 6 + 6 + 6 = 18, which you assign to charisma.
+
+Because constitution is 3, the constitution modifier is -4 and the hitpoints are 6.
+
+## Notes
+
+Most programming languages feature (pseudo-)random generators, but few programming languages are designed to roll dice.
+One such language is [Troll][troll].
+
+[dnd]: https://en.wikipedia.org/wiki/Dungeons_%26_Dragons
+[troll]: https://di.ku.dk/Ansatte/?pure=da%2Fpublications%2Ftroll-a-language-for-specifying-dicerolls(84a45ff0-068b-11df-825d-000ea68e967b)%2Fexport.html

exercises/practice/dnd-character/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "source/dnd_character.d"
+    ],
+    "test": [
+      "source/dnd_character.d"
+    ],
+    "example": [
+      "example/dnd_character.d"
+    ]
+  },
+  "blurb": "Randomly generate Dungeons & Dragons characters.",
+  "source": "Simon Shine, Erik Schierboom",
+  "source_url": "https://github.com/exercism/problem-specifications/issues/616#issuecomment-437358945"
+}

exercises/practice/dnd-character/.meta/tests.toml

@@ -0,0 +1,72 @@
+# 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.
+
+[1e9ae1dc-35bd-43ba-aa08-e4b94c20fa37]
+description = "ability modifier -> ability modifier for score 3 is -4"
+
+[cc9bb24e-56b8-4e9e-989d-a0d1a29ebb9c]
+description = "ability modifier -> ability modifier for score 4 is -3"
+
+[5b519fcd-6946-41ee-91fe-34b4f9808326]
+description = "ability modifier -> ability modifier for score 5 is -3"
+
+[dc2913bd-6d7a-402e-b1e2-6d568b1cbe21]
+description = "ability modifier -> ability modifier for score 6 is -2"
+
+[099440f5-0d66-4b1a-8a10-8f3a03cc499f]
+description = "ability modifier -> ability modifier for score 7 is -2"
+
+[cfda6e5c-3489-42f0-b22b-4acb47084df0]
+description = "ability modifier -> ability modifier for score 8 is -1"
+
+[c70f0507-fa7e-4228-8463-858bfbba1754]
+description = "ability modifier -> ability modifier for score 9 is -1"
+
+[6f4e6c88-1cd9-46a0-92b8-db4a99b372f7]
+description = "ability modifier -> ability modifier for score 10 is 0"
+
+[e00d9e5c-63c8-413f-879d-cd9be9697097]
+description = "ability modifier -> ability modifier for score 11 is 0"
+
+[eea06f3c-8de0-45e7-9d9d-b8cab4179715]
+description = "ability modifier -> ability modifier for score 12 is +1"
+
+[9c51f6be-db72-4af7-92ac-b293a02c0dcd]
+description = "ability modifier -> ability modifier for score 13 is +1"
+
+[94053a5d-53b6-4efc-b669-a8b5098f7762]
+description = "ability modifier -> ability modifier for score 14 is +2"
+
+[8c33e7ca-3f9f-4820-8ab3-65f2c9e2f0e2]
+description = "ability modifier -> ability modifier for score 15 is +2"
+
+[c3ec871e-1791-44d0-b3cc-77e5fb4cd33d]
+description = "ability modifier -> ability modifier for score 16 is +3"
+
+[3d053cee-2888-4616-b9fd-602a3b1efff4]
+description = "ability modifier -> ability modifier for score 17 is +3"
+
+[bafd997a-e852-4e56-9f65-14b60261faee]
+description = "ability modifier -> ability modifier for score 18 is +4"
+
+[4f28f19c-2e47-4453-a46a-c0d365259c14]
+description = "random ability is within range"
+
+[385d7e72-864f-4e88-8279-81a7d75b04ad]
+description = "random character is valid"
+
+[2ca77b9b-c099-46c3-a02c-0d0f68ffa0fe]
+description = "each ability is only calculated once"
+include = false
+
+[dca2b2ec-f729-4551-84b9-078876bb4808]
+description = "each ability is only calculated once"
+reimplements = "2ca77b9b-c099-46c3-a02c-0d0f68ffa0fe"

exercises/practice/dnd-character/dub.sdl

@@ -0,0 +1,2 @@
+name "dnd-character"
+buildRequirements "disallowDeprecations"

exercises/practice/dnd-character/example/dnd_character.d

@@ -0,0 +1,40 @@
+module dnd_character;
+
+import std.algorithm;
+import std.random;
+import std.range;
+import std.math;
+
+class DndCharacter
+{
+public:
+    this()
+    {
+        this.strength = ability();
+        this.dexterity = ability();
+        this.constitution = ability();
+        this.intelligence = ability();
+        this.wisdom = ability();
+        this.charisma = ability();
+        this.hitpoints = 10 + modifier(this.constitution);
+    }
+
+private:
+    immutable int strength;
+    immutable int dexterity;
+    immutable int constitution;
+    immutable int intelligence;
+    immutable int wisdom;
+    immutable int charisma;
+    immutable int hitpoints;
+}
+
+int ability()
+{
+    return iota(0, 4).map!((x) => uniform(1, 7)).takeExactly(4).array.sort!("a < b").dropExactly(1).sum();
+}
+
+pure int modifier(immutable int value)
+{
+    return cast(int)floor((value - 10) / 2.0);
+}

exercises/practice/dnd-character/source/dnd_character.d

@@ -0,0 +1,129 @@
+module dnd_character;
+
+class DndCharacter
+{
+    this()
+    {
+        // implement this function
+    }
+}
+
+int ability()
+{
+    // implement this function
+}
+
+pure int modifier(immutable int value)
+{
+    // implement this function
+}
+
+unittest
+{
+    immutable int allTestsEnabled = 0;
+
+    // Ability modifier for score 3 is -4
+    assert(modifier(3) == -4);
+
+    static if (allTestsEnabled)
+    {
+        // Ability modifier for score 4 is -3
+        assert(modifier(4) == -3);
+
+        // Ability modifier for score 5 is -3
+        assert(modifier(5) == -3);
+
+        // Ability modifier for score 6 is -2
+        assert(modifier(6) == -2);
+
+        // Ability modifier for score 7 is -2
+        assert(modifier(7) == -2);
+
+        // Ability modifier for score 8 is -1
+        assert(modifier(8) == -1);
+
+        // Ability modifier for score 9 is -1
+        assert(modifier(9) == -1);
+
+        // Ability modifier for score 10 is 0
+        assert(modifier(10) == 0);
+
+        // Ability modifier for score 11 is 0
+        assert(modifier(11) == 0);
+
+        // Ability modifier for score 12 is +1
+        assert(modifier(12) == 1);
+
+        // Ability modifier for score 13 is +1
+        assert(modifier(13) == 1);
+
+        // Ability modifier for score 14 is +2
+        assert(modifier(14) == 2);
+
+        // Ability modifier for score 15 is +2
+        assert(modifier(15) == 2);
+
+        // Ability modifier for score 16 is +3
+        assert(modifier(16) == 3);
+
+        // Ability modifier for score 17 is +3
+        assert(modifier(17) == 3);
+
+        // Ability modifier for score 18 is +4
+        assert(modifier(18) == 4);
+
+        // Random ability is within range
+        {
+            int score = ability();
+            assert(score >= 3 && score <= 18);
+        }
+
+        // Random character is valid
+        {
+            DndCharacter character = new DndCharacter();
+            assert(iota(3, 18).canFind(character.strength));
+            assert(iota(3, 18).canFind(character.dexterity));
+            assert(iota(3, 18).canFind(character.constitution));
+            assert(iota(3, 18).canFind(character.intelligence));
+            assert(iota(3, 18).canFind(character.wisdom));
+            assert(iota(3, 18).canFind(character.charisma));
+            assert(character.hitpoints == (10 + modifier(character.constitution)));
+        }
+
+        // Each ability is only calculated once
+        {
+            DndCharacter character = new DndCharacter();
+            assert(character.strength == character.strength);
+            assert(character.dexterity == character.dexterity);
+            assert(character.constitution == character.constitution);
+            assert(character.intelligence == character.intelligence);
+            assert(character.wisdom == character.wisdom);
+            assert(character.charisma == character.charisma);
+        }
+
+        // Character is randomly generated (track-specific)
+        {
+            DndCharacter previous = new DndCharacter();
+            bool isSame = false;
+            for (int i = 1; i <= 1000; i++)
+            {
+                DndCharacter current = new DndCharacter();
+
+                isSame = current.strength == previous.strength &&
+                        current.dexterity == previous.dexterity &&
+                        current.constitution == previous.constitution &&
+                        current.intelligence == previous.intelligence &&
+                        current.wisdom == previous.wisdom &&
+                        current.charisma == previous.charisma;
+                if(isSame)
+                {
+                    break;
+                }
+
+                previous = current;
+            }
+
+            assert(isSame == false);
+        }
+    }
+}