Add Eliud's Eggs exercise (#1681)

---------

Co-authored-by: Victor Goff <[email protected]>

config.json

@@ -335,6 +335,17 @@
         ],
         "difficulty": 3
       },
+      {
+        "slug": "eliuds-eggs",
+        "name": "Eliud's Eggs",
+        "uuid": "d9e488a6-c232-47cf-91c2-06249fa3f0b5",
+        "practices": [
+          "numbers",
+          "enumeration"
+        ],
+        "prerequisites": [],
+        "difficulty": 3
+      },
       {
         "slug": "hamming",
         "name": "Hamming",

exercises/practice/eliuds-eggs/.docs/instructions.md

@@ -0,0 +1,8 @@
+# Instructions
+
+Your task is to count the number of 1 bits in the binary representation of a number.
+
+## Restrictions
+
+Keep your hands off that bit-count functionality provided by your standard library!
+Solve this one yourself using other basic tools instead.

exercises/practice/eliuds-eggs/.docs/introduction.md

@@ -0,0 +1,47 @@
+# Introduction
+
+Your friend Eliud inherited a farm from her grandma Tigist.
+Her granny was an inventor and had a tendency to build things in an overly complicated manner.
+The chicken coop has a digital display showing an encoded number representing the positions of all eggs that could be picked up.
+
+Eliud is asking you to write a program that shows the actual number of eggs in the coop.
+
+The position information encoding is calculated as follows:
+
+1. Scan the potential egg-laying spots and mark down a `1` for an existing egg or a `0` for an empty spot.
+2. Convert the number from binary to decimal.
+3. Show the result on the display.
+
+Example 1:
+
+```text
+Chicken Coop:
+ _ _ _ _ _ _ _
+|E| |E|E| | |E|
+
+Resulting Binary:
+ 1 0 1 1 0 0 1
+
+Decimal number on the display:
+89
+
+Actual eggs in the coop:
+4
+```
+
+Example 2:
+
+```text
+Chicken Coop:
+ _ _ _ _ _ _ _ _
+| | | |E| | | | |
+
+Resulting Binary:
+ 0 0 0 1 0 0 0 0
+
+Decimal number on the display:
+16
+
+Actual eggs in the coop:
+1
+```

exercises/practice/eliuds-eggs/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "ellnix"
+  ],
+  "files": {
+    "solution": [
+      "eliuds_eggs.rb"
+    ],
+    "test": [
+      "eliuds_eggs_test.rb"
+    ],
+    "example": [
+      ".meta/example.rb"
+    ]
+  },
+  "blurb": "Help Eliud count the number of eggs in her chicken coop by counting the number of 1 bits in a binary representation.",
+  "source": "Christian Willner, Eric Willigers",
+  "source_url": "https://forum.exercism.org/t/new-exercise-suggestion-pop-count/7632/5"
+}

exercises/practice/eliuds-eggs/.meta/example.rb

@@ -0,0 +1,5 @@
+module EliudsEggs
+  def self.egg_count(display_number)
+    display_number.to_s(2).count('1')
+  end
+end

exercises/practice/eliuds-eggs/.meta/tests.toml

@@ -0,0 +1,22 @@
+# 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.
+
+[559e789d-07d1-4422-9004-3b699f83bca3]
+description = "0 eggs"
+
+[97223282-f71e-490c-92f0-b3ec9e275aba]
+description = "1 egg"
+
+[1f8fd18f-26e9-4144-9a0e-57cdfc4f4ff5]
+description = "4 eggs"
+
+[0c18be92-a498-4ef2-bcbb-28ac4b06cb81]
+description = "13 eggs"

exercises/practice/eliuds-eggs/eliuds_eggs.rb

@@ -0,0 +1,7 @@
+=begin
+Write your code for the 'Eliuds Eggs' exercise in this file. Make the tests in
+`eliuds_eggs_test.rb` pass.
+
+To get started with TDD, see the `README.md` file in your
+`ruby/eliuds-eggs` directory.
+=end

exercises/practice/eliuds-eggs/eliuds_eggs_test.rb

@@ -0,0 +1,24 @@
+require 'minitest/autorun'
+require_relative 'eliuds_eggs'
+
+class EliudsEggsTest < Minitest::Test
+  def test_0_eggs
+    # skip
+    assert_equal 0, EliudsEggs.egg_count(0)
+  end
+
+  def test_1_egg
+    skip
+    assert_equal 1, EliudsEggs.egg_count(16)
+  end
+
+  def test_4_eggs
+    skip
+    assert_equal 4, EliudsEggs.egg_count(89)
+  end
+
+  def test_13_eggs
+    skip
+    assert_equal 13, EliudsEggs.egg_count(2_000_000_000)
+  end
+end