Implement exercise food-chain

config.json

@@ -181,6 +181,11 @@
       "topics": []
     },
     {
+      "slug": "food-chain",
+      "difficulty": 6,
+      "topics": []
+    },
+    {
       "slug": "beer-song",
       "difficulty": 6,
       "topics": []

exercises/food-chain/build.gradle

@@ -0,0 +1,17 @@
+apply plugin: "java"
+apply plugin: "eclipse"
+apply plugin: "idea"
+
+repositories {
+  mavenCentral()
+}
+
+dependencies {
+  testCompile "junit:junit:4.12"
+}
+test {
+  testLogging {
+    exceptionFormat = 'full'
+    events = ["passed", "failed", "skipped"]
+  }
+}

exercises/food-chain/src/example/java/FoodChain.java

@@ -0,0 +1,77 @@
+import java.util.stream.IntStream;
+
+public class FoodChain {
+
+    private static final String[] ANIMALS = {
+        "fly",
+        "spider",
+        "bird",
+        "cat",
+        "dog",
+        "goat",
+        "cow"
+    };
+
+    private static final String[] FOLLOWUPS = {
+        "It wriggled and jiggled and tickled inside her.",
+        "How absurd to swallow a bird!",
+        "Imagine that, to swallow a cat!",
+        "What a hog, to swallow a dog!",
+        "Just opened her throat and swallowed a goat!",
+        "I don't know how she swallowed a cow!"
+    };
+
+    public String verse(int verse) {
+        return verseBeginning(verse) + verseMiddle(verse) + verseEnding(verse);
+    }
+
+    public String verse(int startVerse, int endVerse) {
+
+        String[] verses = new String[endVerse - startVerse + 1];
+
+        for (int i = 0; i <= endVerse - startVerse; i++) {
+            verses[i] = verse(i + 1);
+        }
+
+        return String.join("\n\n", verses);
+    }
+
+    private String verseBeginning(int verse) {
+
+        if (verse == 1) {
+            return "I know an old lady who swallowed a fly.\n";
+        }
+
+        if (verse == 8) {
+            return "I know an old lady who swallowed a horse.\n";
+        }
+
+        return "I know an old lady who swallowed a " + ANIMALS[verse - 1] + ".\n" + FOLLOWUPS[verse - 2] + "\n";
+    }
+
+    private String verseMiddle(int verse) {
+
+        if (verse == 1 || verse == 8) {
+            return "";
+        }
+
+        String[] lines = new String[verse - 1];
+
+        for (int i = verse - 1; i >= 1; i--) {
+            lines[lines.length - i] = "She swallowed the " +
+                    ANIMALS[i] + " to catch the " + ANIMALS[i - 1] +
+                    (i == 2 ? " that wriggled and jiggled and tickled inside her." : ".");
+        }
+
+        return String.join("\n", lines) + "\n";
+    }
+
+    private String verseEnding(int verse) {
+
+        if (verse == 8) {
+            return "She's dead, of course!";
+        }
+
+        return "I don't know why she swallowed the fly. Perhaps she'll die.";
+    }
+}

exercises/food-chain/src/test/java/FoodChainTest.java

@@ -0,0 +1,204 @@
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.Ignore;
+
+import static org.junit.Assert.assertEquals;
+
+public class FoodChainTest {
+    private FoodChain foodChain;
+
+    @Before
+    public void setup() {
+        foodChain = new FoodChain();
+    }
+
+    @Test
+    public void fly() {
+        int verse = 1;
+        String expected = "I know an old lady who swallowed a fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.";
+
+        assertEquals(expected, foodChain.verse(verse));
+    }
+
+    @Test
+    @Ignore("Remove to run test.")
+    public void spider() {
+        int verse = 2;
+        String expected = "I know an old lady who swallowed a spider.\n" +
+                          "It wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.";
+
+        assertEquals(expected, foodChain.verse(verse));
+    }
+
+    @Test
+    @Ignore("Remove to run test.")
+    public void bird() {
+        int verse = 3;
+        String expected = "I know an old lady who swallowed a bird.\n" +
+                          "How absurd to swallow a bird!\n" +
+                          "She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.";
+
+        assertEquals(expected, foodChain.verse(verse));
+    }
+
+    @Test
+    @Ignore("Remove to run test.")
+    public void cat() {
+        int verse = 4;
+        String expected = "I know an old lady who swallowed a cat.\n" +
+                          "Imagine that, to swallow a cat!\n" +
+                          "She swallowed the cat to catch the bird.\n" +
+                          "She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.";
+
+        assertEquals(expected, foodChain.verse(verse));
+    }
+
+
+    @Test
+    @Ignore("Remove to run test.")
+    public void dog() {
+        int verse = 5;
+        String expected = "I know an old lady who swallowed a dog.\n" +
+                          "What a hog, to swallow a dog!\n" +
+                          "She swallowed the dog to catch the cat.\n" +
+                          "She swallowed the cat to catch the bird.\n" +
+                          "She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.";
+
+        assertEquals(expected, foodChain.verse(verse));
+    }
+
+    @Test
+    @Ignore("Remove to run test.")
+    public void goat() {
+        int verse = 6;
+        String expected = "I know an old lady who swallowed a goat.\n" +
+                          "Just opened her throat and swallowed a goat!\n" +
+                          "She swallowed the goat to catch the dog.\n" +
+                          "She swallowed the dog to catch the cat.\n" +
+                          "She swallowed the cat to catch the bird.\n" +
+                          "She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.";
+
+        assertEquals(expected, foodChain.verse(verse));
+    }
+
+    @Test
+    @Ignore("Remove to run test.")
+    public void cow() {
+        int verse = 7;
+        String expected = "I know an old lady who swallowed a cow.\n" +
+                          "I don't know how she swallowed a cow!\n" +
+                          "She swallowed the cow to catch the goat.\n" +
+                          "She swallowed the goat to catch the dog.\n" +
+                          "She swallowed the dog to catch the cat.\n" +
+                          "She swallowed the cat to catch the bird.\n" +
+                          "She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.";
+
+        assertEquals(expected, foodChain.verse(verse));
+    }
+
+    @Test
+    @Ignore("Remove to run test.")
+    public void horse() {
+        int verse = 8;
+        String expected = "I know an old lady who swallowed a horse.\n" +
+                          "She's dead, of course!";
+
+        assertEquals(expected, foodChain.verse(verse));
+    }
+
+
+    @Test
+    @Ignore("Remove to run test.")
+    public void multipleVerses() {
+        int startVerse = 1;
+        int endVerse = 3;
+        String expected = "I know an old lady who swallowed a fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.\n" +
+                          "\n" +
+                          "I know an old lady who swallowed a spider.\n" +
+                          "It wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.\n" +
+                          "\n" +
+                          "I know an old lady who swallowed a bird.\n" +
+                          "How absurd to swallow a bird!\n" +
+                          "She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.";
+
+        assertEquals(expected, foodChain.verse(startVerse, endVerse));
+    }
+
+
+    @Test
+    @Ignore("Remove to run test.")
+    public void wholeSong() {
+        int startVerse = 1;
+        int endVerse = 8;
+        String expected = "I know an old lady who swallowed a fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.\n" +
+                          "\n" +
+                          "I know an old lady who swallowed a spider.\n" +
+                          "It wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.\n" +
+                          "\n" +
+                          "I know an old lady who swallowed a bird.\n" +
+                          "How absurd to swallow a bird!\n" +
+                          "She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.\n" +
+                          "\n" +
+                          "I know an old lady who swallowed a cat.\n" +
+                          "Imagine that, to swallow a cat!\n" +
+                          "She swallowed the cat to catch the bird.\n" +
+                          "She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.\n" +
+                          "\n" +
+                          "I know an old lady who swallowed a dog.\n" +
+                          "What a hog, to swallow a dog!\n" +
+                          "She swallowed the dog to catch the cat.\n" +
+                          "She swallowed the cat to catch the bird.\n" +
+                          "She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.\n" +
+                          "\n" +
+                          "I know an old lady who swallowed a goat.\n" +
+                          "Just opened her throat and swallowed a goat!\n" +
+                          "She swallowed the goat to catch the dog.\n" +
+                          "She swallowed the dog to catch the cat.\n" +
+                          "She swallowed the cat to catch the bird.\n" +
+                          "She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.\n" +
+                          "\n" +
+                          "I know an old lady who swallowed a cow.\n" +
+                          "I don't know how she swallowed a cow!\n" +
+                          "She swallowed the cow to catch the goat.\n" +
+                          "She swallowed the goat to catch the dog.\n" +
+                          "She swallowed the dog to catch the cat.\n" +
+                          "She swallowed the cat to catch the bird.\n" +
+                          "She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her.\n" +
+                          "She swallowed the spider to catch the fly.\n" +
+                          "I don't know why she swallowed the fly. Perhaps she'll die.\n" +
+                          "\n" +
+                          "I know an old lady who swallowed a horse.\n" +
+                          "She's dead, of course!";
+
+        assertEquals(expected, foodChain.verse(startVerse, endVerse));
+    }
+}

exercises/settings.gradle

@@ -19,6 +19,7 @@ include 'diamond'
 include 'difference-of-squares'
 include 'etl'
 include 'flatten-array'
+include 'food-chain'
 include 'gigasecond'
 include 'grade-school'
 include 'hamming'