Pop count - Added practice exercise (#317)

* autogenerated files * pop-count: exercise added. * Update example.R Your basic strategy is great, and has been preserved here. However, Jon is keen to encourage the use of native pipes, now they are available (since v4.1.0). More lines, but perhaps better readability than nested functions - especially as the pipeline gets longer. At Jon's prompting, I wrote this up in an [approaches doc](https://exercism.org/tracks/r/exercises/reverse-string/approaches/native-pipes) about 2 weeks ago. That article includes various useful links. --------- Co-authored-by: colinleach <[email protected]>
exercism · Feb 1, 2024 · a6088bd · a6088bd
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diff --git a/config.json b/config.json
@@ -50,7 +50,9 @@
         "slug": "lasagna",
         "name": "Lasagna",
         "uuid": "6fd75bbd-8654-4d6a-80b5-29344ceb8a48",
-        "concepts": ["basics"],
+        "concepts": [
+          "basics"
+        ],
         "prerequisites": [],
         "status": "wip"
       },
@@ -579,8 +581,8 @@
         "prerequisites": [
           "booleans"
         ],
-      "difficulty": 1,
-      "status": "wip"
+        "difficulty": 1,
+        "status": "wip"
       },
       {
         "slug": "pythagorean-triplet",
@@ -601,6 +603,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 1
+      },
+      {
+        "slug": "pop-count",
+        "name": "Eliud's Eggs",
+        "uuid": "118e27fe-fe97-45fa-82cc-6480cf777e34",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1
       }
     ]
   },
@@ -628,45 +638,45 @@
   ],
   "key_features": [
     {
-      "icon": "scientific",
       "title": "Domain Specific",
-      "content": "R is a language and environment for statistical computing and graphics."
+      "content": "R is a language and environment for statistical computing and graphics.",
+      "icon": "scientific"
     },
     {
-      "icon": "cross-platform",
       "title": "Cross-platform",
-      "content": "It is free, open source, and available on every major platform."
+      "content": "It is free, open source, and available on every major platform.",
+      "icon": "cross-platform"
     },
     {
-      "icon": "multi-paradigm",
       "title": "Multi-paradigm",
-      "content": "R has a functional programming foundation, but facilitates procedural or object-oriented approaches."
+      "content": "R has a functional programming foundation, but facilitates procedural or object-oriented approaches.",
+      "icon": "multi-paradigm"
     },
     {
-      "icon": "powerful",
       "title": "Metaprogramming",
-      "content": "R’s metaprogramming capabilities allow for magically succinct and concise functions."
+      "content": "R’s metaprogramming capabilities allow for magically succinct and concise functions.",
+      "icon": "powerful"
     },
     {
-      "icon": "tooling",
       "title": "Tooling",
-      "content": "R provides powerful tools for data manipulation, visualisation, modelling, and machine learning."
+      "content": "R provides powerful tools for data manipulation, visualisation, modelling, and machine learning.",
+      "icon": "tooling"
     },
     {
-      "icon": "community",
       "title": "Community",
-      "content": "R has a diverse and welcoming community."
+      "content": "R has a diverse and welcoming community.",
+      "icon": "community"
     }
   ],
   "tags": [
+    "execution_mode/interpreted",
     "paradigm/functional",
     "paradigm/object_oriented",
-    "typing/dynamic",
-    "execution_mode/interpreted",
-    "platform/windows",
-    "platform/mac",
     "platform/linux",
+    "platform/mac",
+    "platform/windows",
     "runtime/language_specific",
+    "typing/dynamic",
     "used_for/artificial_intelligence",
     "used_for/scientific_calculations",
     "used_for/scripts",

diff --git a/exercises/practice/pop-count/.docs/instructions.md b/exercises/practice/pop-count/.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.
diff --git a/exercises/practice/pop-count/.docs/introduction.md b/exercises/practice/pop-count/.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
+```
diff --git a/exercises/practice/pop-count/.meta/config.json b/exercises/practice/pop-count/.meta/config.json
@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "Nerwosolek"
+  ],
+  "files": {
+    "solution": [
+      "pop-count.R"
+    ],
+    "test": [
+      "test_pop-count.R"
+    ],
+    "example": [
+      ".meta/example.R"
+    ]
+  },
+  "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"
+}
diff --git a/exercises/practice/pop-count/.meta/example.R b/exercises/practice/pop-count/.meta/example.R
@@ -0,0 +1,6 @@
+egg_count <- function(display_value) {
+  display_value |>
+    intToBits() |>
+    as.integer() |>
+    sum()
+}
diff --git a/exercises/practice/pop-count/.meta/tests.toml b/exercises/practice/pop-count/.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"
diff --git a/exercises/practice/pop-count/pop-count.R b/exercises/practice/pop-count/pop-count.R
@@ -0,0 +1,3 @@
+egg_count <- function(display_value) {
+
+}
diff --git a/exercises/practice/pop-count/test_pop-count.R b/exercises/practice/pop-count/test_pop-count.R
@@ -0,0 +1,18 @@
+source("./pop-count.R")
+library(testthat)
+
+test_that("0 eggs", {
+   expect_equal(egg_count(0), 0)
+})
+
+test_that("1 egg", {
+   expect_equal(egg_count(16), 1)
+})
+
+test_that("4 eggs", {
+   expect_equal(egg_count(89), 4)
+})
+
+test_that("13 eggs", {
+   expect_equal(egg_count(2000000000), 13)
+})