Add wordy exercise

config.json

@@ -819,6 +819,14 @@
         "prerequisites": [],
         "difficulty": 6
       },
+      {
+        "slug": "wordy",
+        "name": "Wordy",
+        "uuid": "4fc10c1f-e3b9-4772-9720-6cb3f3413eb7",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 6
+      },
       {
         "slug": "book-store",
         "name": "Book Store",

exercises/practice/wordy/.docs/instructions.md

@@ -0,0 +1,59 @@
+# Instructions
+
+Parse and evaluate simple math word problems returning the answer as an integer.
+
+## Iteration 0 — Numbers
+
+Problems with no operations simply evaluate to the number given.
+
+> What is 5?
+
+Evaluates to 5.
+
+## Iteration 1 — Addition
+
+Add two numbers together.
+
+> What is 5 plus 13?
+
+Evaluates to 18.
+
+Handle large numbers and negative numbers.
+
+## Iteration 2 — Subtraction, Multiplication and Division
+
+Now, perform the other three operations.
+
+> What is 7 minus 5?
+
+2
+
+> What is 6 multiplied by 4?
+
+24
+
+> What is 25 divided by 5?
+
+5
+
+## Iteration 3 — Multiple Operations
+
+Handle a set of operations, in sequence.
+
+Since these are verbal word problems, evaluate the expression from left-to-right, _ignoring the typical order of operations._
+
+> What is 5 plus 13 plus 6?
+
+24
+
+> What is 3 plus 2 multiplied by 3?
+
+15 (i.e. not 9)
+
+## Iteration 4 — Errors
+
+The parser should reject:
+
+- Unsupported operations ("What is 52 cubed?")
+- Non-math questions ("Who is the President of the United States")
+- Word problems with invalid syntax ("What is 1 plus plus 2?")

exercises/practice/wordy/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "source/wordy.d"
+    ],
+    "test": [
+      "source/wordy.d"
+    ],
+    "example": [
+      "example/wordy.d"
+    ]
+  },
+  "blurb": "Parse and evaluate simple math word problems returning the answer as an integer.",
+  "source": "Inspired by one of the generated questions in the Extreme Startup game.",
+  "source_url": "https://github.com/rchatley/extreme_startup"
+}

exercises/practice/wordy/.meta/tests.toml

@@ -0,0 +1,91 @@
+# 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.
+
+[88bf4b28-0de3-4883-93c7-db1b14aa806e]
+description = "just a number"
+
+[18983214-1dfc-4ebd-ac77-c110dde699ce]
+description = "just a zero"
+
+[607c08ee-2241-4288-916d-dae5455c87e6]
+description = "just a negative number"
+
+[bb8c655c-cf42-4dfc-90e0-152fcfd8d4e0]
+description = "addition"
+
+[bb9f2082-171c-46ad-ad4e-c3f72087c1b5]
+description = "addition with a left hand zero"
+
+[6fa05f17-405a-4742-80ae-5d1a8edb0d5d]
+description = "addition with a right hand zero"
+
+[79e49e06-c5ae-40aa-a352-7a3a01f70015]
+description = "more addition"
+
+[b345dbe0-f733-44e1-863c-5ae3568f3803]
+description = "addition with negative numbers"
+
+[cd070f39-c4cc-45c4-97fb-1be5e5846f87]
+description = "large addition"
+
+[0d86474a-cd93-4649-a4fa-f6109a011191]
+description = "subtraction"
+
+[30bc8395-5500-4712-a0cf-1d788a529be5]
+description = "multiplication"
+
+[34c36b08-8605-4217-bb57-9a01472c427f]
+description = "division"
+
+[da6d2ce4-fb94-4d26-8f5f-b078adad0596]
+description = "multiple additions"
+
+[7fd74c50-9911-4597-be09-8de7f2fea2bb]
+description = "addition and subtraction"
+
+[b120ffd5-bad6-4e22-81c8-5512e8faf905]
+description = "multiple subtraction"
+
+[4f4a5749-ef0c-4f60-841f-abcfaf05d2ae]
+description = "subtraction then addition"
+
+[312d908c-f68f-42c9-aa75-961623cc033f]
+description = "multiple multiplication"
+
+[38e33587-8940-4cc1-bc28-bfd7e3966276]
+description = "addition and multiplication"
+
+[3c854f97-9311-46e8-b574-92b60d17d394]
+description = "multiple division"
+
+[3ad3e433-8af7-41ec-aa9b-97b42ab49357]
+description = "unknown operation"
+
+[8a7e85a8-9e7b-4d46-868f-6d759f4648f8]
+description = "Non math question"
+
+[42d78b5f-dbd7-4cdb-8b30-00f794bb24cf]
+description = "reject problem missing an operand"
+
+[c2c3cbfc-1a72-42f2-b597-246e617e66f5]
+description = "reject problem with no operands or operators"
+
+[4b3df66d-6ed5-4c95-a0a1-d38891fbdab6]
+description = "reject two operations in a row"
+
+[6abd7a50-75b4-4665-aa33-2030fd08bab1]
+description = "reject two numbers in a row"
+
+[10a56c22-e0aa-405f-b1d2-c642d9c4c9de]
+description = "reject postfix notation"
+
+[0035bc63-ac43-4bb5-ad6d-e8651b7d954e]
+description = "reject prefix notation"

exercises/practice/wordy/dub.sdl

@@ -0,0 +1,2 @@
+name "wordy"
+buildRequirements "disallowDeprecations"

exercises/practice/wordy/example/wordy.d

@@ -0,0 +1,82 @@
+module wordy;
+
+import std.array;
+import std.conv;
+
+pure long answer(immutable string question)
+{
+    if (question.length == 0 || question[$ - 1] != '?')
+    {
+        throw new Exception("syntax error");
+    }
+
+    auto words = question[0 .. $ - 1].split();
+
+    if (words.length < 3 || words[0] != "What" || words[1] != "is")
+    {
+        throw new Exception("unsupported question");
+    }
+
+    long first = to!long(words[2]);
+    char operation = '+';
+
+    size_t index = 3;
+    while (index + 1 < words.length)
+    {
+        if (words[index] == "plus")
+        {
+            operation = '+';
+        }
+        else if (words[index] == "minus")
+        {
+            operation = '-';
+        }
+        else if (words[index] == "multiplied" && words[index + 1] == "by")
+        {
+            operation = '*';
+            index++;
+        }
+        else if (words[index] == "divided" && words[index + 1] == "by")
+        {
+            operation = '/';
+            index++;
+        }
+        else
+        {
+            throw new Exception("unsupported question");
+        }
+
+        index++;
+        if (index == words.length)
+        {
+            throw new Exception("syntax error");
+        }
+
+        long second = to!long(words[index]);
+        index++;
+
+        if (operation == '+')
+        {
+            first += second;
+        }
+        else if (operation == '-')
+        {
+            first -= second;
+        }
+        else if (operation == '*')
+        {
+            first *= second;
+        }
+        else if (operation == '/')
+        {
+            first /= second;
+        }
+    }
+
+    if (index != words.length)
+    {
+        throw new Exception("syntax error");
+    }
+
+    return first;
+}