finished

PlaylistChallenge.iml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_5">
+    <output url="file://$MODULE_DIR$/target/classes" />
+    <output-test url="file://$MODULE_DIR$/target/test-classes" />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
+      <excludeFolder url="file://$MODULE_DIR$/target" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" scope="TEST" name="Maven: junit:junit:4.12" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.hamcrest:hamcrest-core:1.3" level="project" />
+  </component>
+</module>

src/main/java/io/zipcoder/Music.java

@@ -9,6 +9,39 @@ public Music(String[] playList){
     }
 
     public Integer selection(Integer startIndex, String selection){
-        return null;
+        int clickUp = 0;
+        int clickDown = 0;
+
+        //move forward through the array
+        for(int i = startIndex ; i <= playList.length; i++){
+
+            if(playList[i].equals(selection)){
+                break;
+            }
+            clickUp++;
+            /*if we get to the end of the playlist and don't find our song, we'll have to
+                start at the other end and keep on counting, bewaring of an infinite loop
+             */
+            if (i == (playList.length - 1)) {
+                i = -1;
+            }
+        }
+
+        //move backwards through the array
+        for(int j = startIndex; j >= 0 ; j--){
+
+            if(playList[j].equals(selection)){
+                break;
+            }
+            clickDown++;
+            if (j == 0) {
+                j = playList.length;
+            }
+        }
+
+        //return whichever counter is smaller
+        //Math.min was auto-suggested from an if statement
+        //it will return the smaller number
+        return Math.min(clickUp, clickDown);
     }
 }

src/test/java/io/zipcoder/MusicTest.java

@@ -6,9 +6,9 @@
 public class MusicTest {
 
     @Test
-    public void selectionTest1(){
+    public void selectionTest1() {
 
-        String[] playlist = {"wheniseeyouagain","borntorun","nothingelsematters","cecelia"};
+        String[] playlist = {"wheniseeyouagain", "borntorun", "nothingelsematters", "cecelia"};
         Music music = new Music(playlist);
         Integer startingIndex = 1;
         String selection = "cecelia";
@@ -18,14 +18,56 @@ public void selectionTest1(){
     }
 
     @Test
-    public void selectionTest2(){
+    public void selectionTest2() {
 
-        String[] playlist = {"dancinginthedark","rio","liveoak","liveoak"};
+        String[] playlist = {"dancinginthedark", "rio", "liveoak", "liveoak"};
         Music music = new Music(playlist);
         Integer startingIndex = 0;
         String selection = "liveoak";
         Integer expected = 1;
         Integer actual = music.selection(startingIndex, selection);
         Assert.assertEquals(expected, actual);
     }
+
+    @Test
+    public void selectionTest3() {
+
+        String[] playlist = {"heyjude", "inmylife", "letitbe", "ijustseenaface",
+                "isawherstandingthere", "tickettoride", "help", "paperbackwriter", "harddaysnight"};
+        Music music = new Music(playlist);
+        Integer startingIndex = 2;
+        String selection = "tickettoride";
+        Integer expected = 3;
+        Integer actual = music.selection(startingIndex, selection);
+        Assert.assertEquals(expected, actual);
+    }
+
+    //test to wrap around the bottom of the array
+    @Test
+    public void selectionTest4() {
+
+        String[] playlist = {"bohemianrhapsody", "killerqueen", "fatbottomedgirls", "underpressure",
+                "iwantobreakfree", "somebodytolove", "flashgordontheme", "crazylittlethingcalledlove", "wearethechampions"};
+        Music music = new Music(playlist);
+        Integer startingIndex = 1;
+        String selection = "crazylittlethingcalledlove";
+        Integer expected = 3;
+        Integer actual = music.selection(startingIndex, selection);
+        Assert.assertEquals(expected, actual);
+    }
+
+
+    //test to wrap around the top of the array
+    @Test
+    public void selectionTest5() {
+        String[] playlist = {"tinydancer", "downtletthesungodownonme", "yoursong", "saturday",
+                "bennyandthejets", "crocodilerock"};
+        Music music = new Music(playlist);
+        Integer startingIndex = 5;
+        String selection = "tinydancer";
+        Integer expected = 1;
+        Integer actual = music.selection(startingIndex, selection);
+        Assert.assertEquals(expected, actual);
+    }
 }
+