Add bottle-song exercise

config.json

@@ -685,6 +685,18 @@
         "difficulty": 6,
         "status": "deprecated"
       },
+      {
+        "slug": "bottle-song",
+        "name": "Bottle Song",
+        "uuid": "3fa6750f-cf01-4542-a494-df9a8c658733",
+        "practices": [
+          "strings"
+        ],
+        "prerequisites": [
+          "strings"
+        ],
+        "difficulty": 6
+      },
       {
         "slug": "food-chain",
         "name": "Food Chain",

exercises/practice/bottle-song/.docs/instructions.md

@@ -0,0 +1,57 @@
+# Instructions
+
+Recite the lyrics to that popular children's repetitive song: Ten Green Bottles.
+
+Note that not all verses are identical.
+
+```text
+Ten green bottles hanging on the wall,
+Ten green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be nine green bottles hanging on the wall.
+
+Nine green bottles hanging on the wall,
+Nine green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be eight green bottles hanging on the wall.
+
+Eight green bottles hanging on the wall,
+Eight green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be seven green bottles hanging on the wall.
+
+Seven green bottles hanging on the wall,
+Seven green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be six green bottles hanging on the wall.
+
+Six green bottles hanging on the wall,
+Six green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be five green bottles hanging on the wall.
+
+Five green bottles hanging on the wall,
+Five green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be four green bottles hanging on the wall.
+
+Four green bottles hanging on the wall,
+Four green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be three green bottles hanging on the wall.
+
+Three green bottles hanging on the wall,
+Three green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be two green bottles hanging on the wall.
+
+Two green bottles hanging on the wall,
+Two green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be one green bottle hanging on the wall.
+
+One green bottle hanging on the wall,
+One green bottle hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be no green bottles hanging on the wall.
+```

exercises/practice/bottle-song/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "kahgoh"
+  ],
+  "files": {
+    "solution": [
+      "src/main/java/BottleSong.java"
+    ],
+    "test": [
+      "src/test/java/BottleSongTest.java"
+    ],
+    "example": [
+      ".meta/src/reference/java/BottleSong.java"
+    ]
+  },
+  "blurb": "Produce the lyrics to the popular children's repetitive song: Ten Green Bottles.",
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/Ten_Green_Bottles"
+}

exercises/practice/bottle-song/.meta/src/reference/java/BottleSong.java

@@ -0,0 +1,59 @@
+class BottleSong {
+    private String word(int number) {
+        return switch (number) {
+            case 2 -> "two";
+            case 3 -> "three";
+            case 4 -> "four";
+            case 5 -> "five";
+            case 6 -> "six";
+            case 7 -> "seven";
+            case 8 -> "eight";
+            case 9 -> "nine";
+            case 10 -> "ten";
+            default -> throw new IllegalArgumentException("Unrecognised number: " + Integer.toString(number));
+        };
+    }
+
+    private String verse(int number) {
+        return switch (number) {
+            case 1 -> 
+                "One green bottle hanging on the wall,\n" +
+                "One green bottle hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be no green bottles hanging on the wall.\n";
+            case 2 -> 
+                "Two green bottles hanging on the wall,\n" +
+                "Two green bottles hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be one green bottle hanging on the wall.\n";
+            default -> { 
+                var codePoints = word(number).codePoints().toArray();
+                codePoints[0] = Character.toUpperCase(codePoints[0]);
+                var numberText = new String(codePoints, 0, codePoints.length);
+
+                var nextNumberText = word(number - 1);
+
+                yield String.format(
+                    "%s green bottles hanging on the wall,\n" +
+                    "%s green bottles hanging on the wall,\n" +
+                    "And if one green bottle should accidentally fall,\n" +
+                    "There'll be %s green bottles hanging on the wall.\n",
+                    numberText, numberText, nextNumberText);
+            }
+        };
+    }
+
+    String recite(int startBottles, int takeDown) {
+        var stop = startBottles - takeDown + 1;
+        var output = new StringBuilder();
+
+        for (var i = startBottles; i >= stop; i--) {
+            if (i != startBottles) {
+                output.append("\n");
+            }
+            output.append(verse(i));
+        }
+
+        return output.toString();
+    }
+}

exercises/practice/bottle-song/.meta/tests.toml

@@ -0,0 +1,31 @@
+# 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.
+
+[d4ccf8fc-01dc-48c0-a201-4fbeb30f2d03]
+description = "verse -> single verse -> first generic verse"
+
+[0f0aded3-472a-4c64-b842-18d4f1f5f030]
+description = "verse -> single verse -> last generic verse"
+
+[f61f3c97-131f-459e-b40a-7428f3ed99d9]
+description = "verse -> single verse -> verse with 2 bottles"
+
+[05eadba9-5dbd-401e-a7e8-d17cc9baa8e0]
+description = "verse -> single verse -> verse with 1 bottle"
+
+[a4a28170-83d6-4dc1-bd8b-319b6abb6a80]
+description = "lyrics -> multiple verses -> first two verses"
+
+[3185d438-c5ac-4ce6-bcd3-02c9ff1ed8db]
+description = "lyrics -> multiple verses -> last three verses"
+
+[28c1584a-0e51-4b65-9ae2-fbc0bf4bbb28]
+description = "lyrics -> multiple verses -> all verses"

exercises/practice/bottle-song/build.gradle

@@ -0,0 +1,24 @@
+apply plugin: "java"
+apply plugin: "eclipse"
+apply plugin: "idea"
+
+// set default encoding to UTF-8
+compileJava.options.encoding = "UTF-8"
+compileTestJava.options.encoding = "UTF-8"
+
+repositories {
+  mavenCentral()
+}
+
+dependencies {
+  testImplementation "junit:junit:4.13"
+  testImplementation "org.assertj:assertj-core:3.15.0"
+}
+
+test {
+  testLogging {
+    exceptionFormat = 'full'
+    showStandardStreams = true
+    events = ["passed", "failed", "skipped"]
+  }
+}

exercises/practice/bottle-song/src/main/java/BottleSong.java

@@ -0,0 +1,7 @@
+class BottleSong {
+
+    String recite(int startBottles, int takeDown) {
+        throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
+    }
+
+}

exercises/practice/bottle-song/src/test/java/BottleSongTest.java

@@ -0,0 +1,152 @@
+import org.junit.Test;
+import org.junit.Ignore;
+import org.junit.Before;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class BottleSongTest {
+
+    private BottleSong bottleSong;
+
+    @Before
+    public void setup() {
+        bottleSong = new BottleSong();
+    }
+
+    @Test
+    public void firstGenericVerse() {
+        assertThat(bottleSong.recite(10, 1)).isEqualTo(
+            "Ten green bottles hanging on the wall,\n" +
+            "Ten green bottles hanging on the wall,\n" +
+            "And if one green bottle should accidentally fall,\n" +
+            "There'll be nine green bottles hanging on the wall.\n"
+        );
+    }
+
+    @Ignore("Remove to run test")
+    @Test
+    public void lastGenericVerse() {
+        assertThat(bottleSong.recite(3, 1)).isEqualTo(
+            "Three green bottles hanging on the wall,\n" +
+            "Three green bottles hanging on the wall,\n" +
+            "And if one green bottle should accidentally fall,\n" +
+            "There'll be two green bottles hanging on the wall.\n"
+        );
+    }
+
+    @Ignore("Remove to run test")
+    @Test
+    public void verseWithTwoBottles() {
+        assertThat(bottleSong.recite(2, 1)).isEqualTo(
+            "Two green bottles hanging on the wall,\n" +
+            "Two green bottles hanging on the wall,\n" +
+            "And if one green bottle should accidentally fall,\n" +
+            "There'll be one green bottle hanging on the wall.\n"
+        );
+    }
+
+    @Ignore("Remove to run test")
+    @Test
+    public void verseWithOneBottle() {
+        assertThat(bottleSong.recite(1, 1)).isEqualTo(
+            "One green bottle hanging on the wall,\n" +
+            "One green bottle hanging on the wall,\n" +
+            "And if one green bottle should accidentally fall,\n" +
+            "There'll be no green bottles hanging on the wall.\n"
+        );
+    }
+
+    @Ignore("Remove to run test")
+    @Test
+    public void firstTwoVerses() {
+        assertThat(bottleSong.recite(10, 2)).isEqualTo(
+            "Ten green bottles hanging on the wall,\n" +
+            "Ten green bottles hanging on the wall,\n" +
+            "And if one green bottle should accidentally fall,\n" +
+            "There'll be nine green bottles hanging on the wall.\n" +
+            "\n" +
+            "Nine green bottles hanging on the wall,\n" +
+            "Nine green bottles hanging on the wall,\n" +
+            "And if one green bottle should accidentally fall,\n" +
+            "There'll be eight green bottles hanging on the wall.\n"
+        );
+    }
+
+    @Ignore("Remove to run test")
+    @Test
+    public void lastThreeVerses() {
+        assertThat(bottleSong.recite(3, 3)).isEqualTo(
+            "Three green bottles hanging on the wall,\n" +
+            "Three green bottles hanging on the wall,\n" +
+            "And if one green bottle should accidentally fall,\n" +
+            "There'll be two green bottles hanging on the wall.\n" +
+            "\n" +
+            "Two green bottles hanging on the wall,\n" +
+            "Two green bottles hanging on the wall,\n" +
+            "And if one green bottle should accidentally fall,\n" +
+            "There'll be one green bottle hanging on the wall.\n" +
+            "\n" +
+            "One green bottle hanging on the wall,\n" +
+            "One green bottle hanging on the wall,\n" +
+            "And if one green bottle should accidentally fall,\n" +
+            "There'll be no green bottles hanging on the wall.\n"
+        );
+    }
+
+    @Ignore("Remove to run test")
+    @Test
+    public void allVerses() {
+        assertThat(bottleSong.recite(10, 10))
+            .isEqualTo(
+                "Ten green bottles hanging on the wall,\n" +
+                "Ten green bottles hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be nine green bottles hanging on the wall.\n" +
+                "\n" +
+                "Nine green bottles hanging on the wall,\n" +
+                "Nine green bottles hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be eight green bottles hanging on the wall.\n" +
+                "\n" +
+                "Eight green bottles hanging on the wall,\n" +
+                "Eight green bottles hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be seven green bottles hanging on the wall.\n" +
+                "\n" +
+                "Seven green bottles hanging on the wall,\n" +
+                "Seven green bottles hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be six green bottles hanging on the wall.\n" +
+                "\n" +
+                "Six green bottles hanging on the wall,\n" +
+                "Six green bottles hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be five green bottles hanging on the wall.\n" +
+                "\n" +
+                "Five green bottles hanging on the wall,\n" +
+                "Five green bottles hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be four green bottles hanging on the wall.\n" +
+                "\n" +
+                "Four green bottles hanging on the wall,\n" +
+                "Four green bottles hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be three green bottles hanging on the wall.\n" +
+                "\n" +
+                "Three green bottles hanging on the wall,\n" +
+                "Three green bottles hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be two green bottles hanging on the wall.\n" +
+                "\n" +
+                "Two green bottles hanging on the wall,\n" +
+                "Two green bottles hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be one green bottle hanging on the wall.\n" +
+                "\n" +
+                "One green bottle hanging on the wall,\n" +
+                "One green bottle hanging on the wall,\n" +
+                "And if one green bottle should accidentally fall,\n" +
+                "There'll be no green bottles hanging on the wall.\n"
+            );
+    }
+}

exercises/settings.gradle

@@ -34,6 +34,7 @@ include 'practice:binary-search'
 include 'practice:binary-search-tree'
 include 'practice:bob'
 include 'practice:book-store'
+include 'practice:bottle-song'
 include 'practice:bowling'
 include 'practice:change'
 include 'practice:circular-buffer'