[prime-factors] Add new practice exercise

config.json

@@ -309,6 +309,14 @@
         "prerequisites": [],
         "difficulty": 4
       },
+      {
+        "slug": "prime-factors",
+        "name": "Prime Factors",
+        "uuid": "4574ba46-a404-4d48-af8b-abc7cd200187",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "scrabble-score",
         "name": "Scrabble Score",

exercises/practice/prime-factors/.docs/instructions.md

@@ -0,0 +1,36 @@
+# Instructions
+
+Compute the prime factors of a given natural number.
+
+A prime number is only evenly divisible by itself and 1.
+
+Note that 1 is not a prime number.
+
+## Example
+
+What are the prime factors of 60?
+
+- Our first divisor is 2.
+  2 goes into 60, leaving 30.
+- 2 goes into 30, leaving 15.
+  - 2 doesn't go cleanly into 15.
+    So let's move on to our next divisor, 3.
+- 3 goes cleanly into 15, leaving 5.
+  - 3 does not go cleanly into 5.
+    The next possible factor is 4.
+  - 4 does not go cleanly into 5.
+    The next possible factor is 5.
+- 5 does go cleanly into 5.
+- We're left only with 1, so now, we're done.
+
+Our successful divisors in that computation represent the list of prime factors of 60: 2, 2, 3, and 5.
+
+You can check this yourself:
+
+```text
+2 * 2 * 3 * 5
+= 4 * 15
+= 60
+```
+
+Success!

exercises/practice/prime-factors/.meta/config.json

@@ -0,0 +1,21 @@
+{
+  "authors": [
+    "IsaacG"
+  ],
+  "files": {
+    "solution": [
+      "prime_factors.gd"
+    ],
+    "test": [
+      "prime_factors_test.gd",
+      "run_tests",
+      "lib/test_runner.gd"
+    ],
+    "example": [
+      ".meta/example.gd"
+    ]
+  },
+  "blurb": "Compute the prime factors of a given natural number.",
+  "source": "The Prime Factors Kata by Uncle Bob",
+  "source_url": "https://web.archive.org/web/20221026171801/http://butunclebob.com/ArticleS.UncleBob.ThePrimeFactorsKata"
+}

exercises/practice/prime-factors/.meta/example.gd

@@ -0,0 +1,12 @@
+func factors(number: int) -> Array:
+	var out = []
+	var divisor = 2
+	while number > 1:
+		if number % divisor == 0:
+			number /= divisor
+			out.append(divisor)
+		elif divisor == 2:
+			divisor = 3
+		else:
+			divisor += 2
+	return out

exercises/practice/prime-factors/.meta/template.j2

@@ -0,0 +1,8 @@
+{% for case in cases %}
+func test_{{ case.func_name }}(solution_script):
+	var want = {{ case.expected | togdscript }}
+	var got = solution_script.{{ case.property }}({{ case.given }})
+	return [got, want]
+
+{% endfor %}
+

exercises/practice/prime-factors/.meta/tests.toml

@@ -0,0 +1,46 @@
+# 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.
+
+[924fc966-a8f5-4288-82f2-6b9224819ccd]
+description = "no factors"
+
+[17e30670-b105-4305-af53-ddde182cb6ad]
+description = "prime number"
+
+[238d57c8-4c12-42ef-af34-ae4929f94789]
+description = "another prime number"
+
+[f59b8350-a180-495a-8fb1-1712fbee1158]
+description = "square of a prime"
+
+[756949d3-3158-4e3d-91f2-c4f9f043ee70]
+description = "product of first prime"
+
+[bc8c113f-9580-4516-8669-c5fc29512ceb]
+description = "cube of a prime"
+
+[7d6a3300-a4cb-4065-bd33-0ced1de6cb44]
+description = "product of second prime"
+
+[073ac0b2-c915-4362-929d-fc45f7b9a9e4]
+description = "product of third prime"
+
+[6e0e4912-7fb6-47f3-a9ad-dbcd79340c75]
+description = "product of first and second prime"
+
+[00485cd3-a3fe-4fbe-a64a-a4308fc1f870]
+description = "product of primes and non-primes"
+
+[02251d54-3ca1-4a9b-85e1-b38f4b0ccb91]
+description = "product of primes"
+
+[070cf8dc-e202-4285-aa37-8d775c9cd473]
+description = "factors include a large prime"