Added files

Song.java

@@ -0,0 +1,52 @@
+// The Song class that represents a song
+// Do not make any changes to this file!
+// Xiwei Wang
+
+public class Song
+{
+    // instance variables
+    private String m_artist;
+    private String m_title;
+    private Song m_link;
+
+    // constructor
+    public Song(String artist, String title)
+    {
+        m_artist = artist;
+        m_title = title;
+        m_link = null;
+    }
+
+    // getters and setters
+    public void setArtist(String artist)
+    {
+        m_artist = artist;
+    }
+
+    public String getArtist()
+    {
+        return m_artist;
+    }
+
+    public void setTitle(String title)
+    {
+        m_title = title;
+    }
+
+    public String getTitle()
+    {
+        return m_title;
+    }
+    
+    public void setLink(Song link)
+    {
+        m_link = link;
+    }
+
+    public Song getLink()
+    { 
+        return m_link;  
+    }
+}
+ 
+ 

SongList.java

@@ -0,0 +1,74 @@
+// The SongList class that represents a circular linked list of Song nodes
+// Your name here
+
+public class SongList 
+{
+    // instance variables
+    private Song m_last;
+    private int m_numElements; 
+
+    // constructor
+    // Do not make any changes to this method!
+    public SongList()
+    {
+        m_last = null;
+        m_numElements = 0;
+    }
+
+    // check whether the list is empty
+    // Do not make any changes to this method!
+    boolean isEmpty()
+    {
+        if (m_last == null)
+            return true;
+        else
+            return false;
+    }
+
+    // return the size of the list (# of Song nodes)
+    // Do not make any changes to this method!
+    public int size()
+    {
+        return m_numElements;
+    }
+
+    // add a new Song to the circular linked list with the given artist and 
+    // title, keeping the list sorted by *song title*.
+    public void add(String artist, String title)
+    {
+        // TODO: implement this method
+    }
+
+    // remove a Song associated with the given artist and title from the list,
+    // keeping the list sorted by *song title*.
+    public boolean remove(String artist, String title)
+    {
+        // TODO: implement this method
+    }
+    
+    
+    // build and return a circular linked list that contains all songs from the
+    // given artist
+    public SongList buildList(String artist)
+    {
+        // TODO: implement this method
+    }
+    
+    // return a string representation of the list
+    // Do not make any changes to this method!
+    public String toString()
+    {           
+        String listContent = "";
+        Song current = m_last;
+        
+        if (m_last != null)
+            do
+            {
+                current = current.getLink();
+                listContent += "  [" + current.getArtist() + " - " + current.getTitle() + "]\n";
+
+            } while (current != m_last);
+
+        return listContent;
+    }    
+}

TestSongList.java

@@ -0,0 +1,375 @@
+// Test driver for the SongList class
+// Do not make any changes to this file!
+// Xiwei Wang
+
+public class TestSongList 
+{
+    public static void main(String[] args)
+    {
+        SongList mylist = new SongList();
+        SongList builtlist = null;
+        int numPassedTests = 0;
+        int numTotalTests = 0;
+        String testResult;
+
+        // Test 1
+        numTotalTests++;
+        boolean bReturn = false;
+        testResult = "[Failed]";
+        String eMsg = "N/A";
+        try
+        {
+            mylist.add("Lewis Capaldi", "Someone You Loved");
+            bReturn = mylist.isEmpty();
+            
+            if (bReturn == false)
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult + "\n  add(\"Lewis Capaldi\", \"Someone You Loved\")\n Expected return of isEmpty(): false" );
+        if (eMsg.equals("N/A"))
+            System.out.println(" Your isEmpty() returns: " + bReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");
+              
+        // Test 2
+        numTotalTests++;
+        int iReturn = -1;
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            mylist.add("Lil Nas X", "Old Town Road");
+            mylist.add("Ed Sheeran & Justin Bieber", "I Don't Care");
+            iReturn = mylist.size();
+            
+            if (iReturn == 3)
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult + "\n  add(\"Lil Nas X\", \"Old Town Road\")\n  add(\"Ed Sheeran & Justin Bieber\", \"I Don't Care\")\n Expected return of size(): 3" );
+        if (eMsg.equals("N/A"))
+            System.out.println(" Your size() returns: " + iReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");
+                
+        // Test 3
+        numTotalTests++;
+        String sReturn = "";
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            sReturn = mylist.toString();
+            
+            if (sReturn.equals("  [Ed Sheeran & Justin Bieber - I Don't Care]\n  [Lil Nas X - Old Town Road]\n  [Lewis Capaldi - Someone You Loved]\n"))
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult + "\n Expected return of toString():\n  [Ed Sheeran & Justin Bieber - I Don't Care]\n  [Lil Nas X - Old Town Road]\n  [Lewis Capaldi - Someone You Loved]\n");
+        if (eMsg.equals("N/A"))
+            System.out.println(" Your toString() returns:\n" + sReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");
+        
+        // Test 4
+        numTotalTests++;
+        bReturn = false;
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            bReturn = mylist.remove("Ava Max", "Sweet But Psycho");
+            
+            if (bReturn == false)
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult +"\n  remove(\"Ava Max\", \"Sweet But Psycho\")\n Expected: false" );
+        if (eMsg.equals("N/A"))
+            System.out.println(" Yours: " + bReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");   
+
+        // Test 5
+        numTotalTests++;
+        iReturn = -1;
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            mylist.add("Ava Max", "Sweet But Psycho");
+            mylist.add("Billie Eilish", "Bad Guy");
+            mylist.add("Mabel", "Don't Call Me Up");
+            mylist.add("Lewis Capaldi", "Hold Me While You Wait");
+            iReturn = mylist.size();
+            
+            if (iReturn == 7)
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult + "\n  add(\"Ava Max\", \"Sweet But Psycho\")\n  add(\"Billie Eilish\", \"Bad Guy\")\n  add(\"Mabel\", \"Don't Call Me Up\")\n  add(\"Lewis Capaldi\", \"Hold Me While You Wait\")\n Expected return of size(): 7" );
+        if (eMsg.equals("N/A"))
+            System.out.println(" Your size() returns: " + iReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");       
+        System.out.println(mylist);
+        
+        // Test 6
+        numTotalTests++;
+        bReturn = false;
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            bReturn = mylist.remove("Billie Eilish", "Bad Guy");
+            
+            if (bReturn == true)
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult +"\n  remove(\"Billie Eilish\", \"Bad Guy\")\n Expected: true" );
+        if (eMsg.equals("N/A"))
+            System.out.println(" Yours: " + bReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");    
+        
+        // Test 7
+        numTotalTests++;
+        bReturn = false;
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            bReturn = mylist.remove("Ava Max", "Sweet But Psycho");
+            
+            if (bReturn == true)
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult +"\n  remove(\"Ava Max\", \"Sweet But Psycho\")\n Expected: true" );
+        if (eMsg.equals("N/A"))
+            System.out.println(" Yours: " + bReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");    
+        
+        // Test 8
+        numTotalTests++;
+        sReturn = "";
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            mylist.add("Billie Eilish", "Bury A Friend");
+            mylist.add("Lewis Capaldi", "Grace");
+            sReturn = mylist.toString();
+            
+            if (sReturn.equals("  [Billie Eilish - Bury A Friend]\n  [Mabel - Don't Call Me Up]\n  [Lewis Capaldi - Grace]\n  [Lewis Capaldi - Hold Me While You Wait]\n  [Ed Sheeran & Justin Bieber - I Don't Care]\n  [Lil Nas X - Old Town Road]\n  [Lewis Capaldi - Someone You Loved]\n"))
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult + "\n  add(\"Billie Eilish\", \"Bury A Friend\")\n  add(\"Lewis Capaldi\", \"Grace\")\n Expected return of toString():\n"
+                + "  [Billie Eilish - Bury A Friend]\n  [Mabel - Don't Call Me Up]\n  [Lewis Capaldi - Grace]\n  [Lewis Capaldi - Hold Me While You Wait]\n"
+                + "  [Ed Sheeran & Justin Bieber - I Don't Care]\n  [Lil Nas X - Old Town Road]\n  [Lewis Capaldi - Someone You Loved]\n");
+        if (eMsg.equals("N/A"))
+            System.out.println(" Your toString() returns:\n" + sReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");           
+        
+        // Test 9
+        numTotalTests++;
+        bReturn = false;
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            bReturn = mylist.remove("Mabel", "Don't Call Me Up");
+            
+            if (bReturn == true)
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult +"\n  remove(\"Mabel\", \"Don't Call Me Up\")\n Expected: true" );
+        if (eMsg.equals("N/A"))
+            System.out.println(" Yours: " + bReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");
+        
+        // Test 10
+        numTotalTests++;
+        iReturn = -1;
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            iReturn = mylist.size();
+            
+            if (iReturn == 6)
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult + "\n Expected return of size(): 6" );
+        if (eMsg.equals("N/A"))
+            System.out.println(" Your size() returns: " + iReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");
+        
+        // Test 11
+        numTotalTests++;
+        builtlist = null;
+        sReturn = "";
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            builtlist = mylist.buildList("Lewis Capaldi");
+            sReturn = builtlist.toString();
+            
+            if (sReturn.equals("  [Lewis Capaldi - Grace]\n  [Lewis Capaldi - Hold Me While You Wait]\n  [Lewis Capaldi - Someone You Loved]\n"))
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult + "\n  mylist.buildList(\"Lewis Capaldi\")\n Expected return of toString() on the new list:\n"
+                + "  [Lewis Capaldi - Grace]\n  [Lewis Capaldi - Hold Me While You Wait]\n  [Lewis Capaldi - Someone You Loved]\n");
+        if (eMsg.equals("N/A"))
+            System.out.println(" Your toString() returns:\n" + sReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");
+        
+        // Test 12
+        numTotalTests++;
+        builtlist = null;
+        sReturn = "";
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            builtlist = mylist.buildList("Lil Nas X");
+            sReturn = builtlist.toString();
+            
+            if (sReturn.equals("  [Lil Nas X - Old Town Road]\n"))
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult + "\n  mylist.buildList(\"Lil Nas X\")\n Expected return of toString() on the new list:\n"
+                + "  [Lil Nas X - Old Town Road]\n");
+        if (eMsg.equals("N/A"))
+            System.out.println(" Your toString() returns:\n" + sReturn + "\n");
+        else
+            System.out.println(" Yours: " + eMsg + "\n");
+        
+        // Test 13
+        numTotalTests++;
+        builtlist = null;
+        sReturn = "";
+        testResult = "[Failed]";
+        eMsg = "N/A";
+        try
+        {
+            builtlist = mylist.buildList("Ava Max");
+            sReturn = builtlist.toString();
+            
+            if (sReturn.equals(""))
+            {
+                numPassedTests++;
+                testResult = "[Passed]";
+            }
+        }
+        catch (RuntimeException e)
+        {
+            eMsg = "RuntimeException - \"" + e.getMessage()  + "\"";
+        }
+        
+        System.out.println("Test " + numTotalTests + ": " + testResult + "\n  mylist.buildList(\"Ava Max\")\n Expected return of toString() on the new list:\n  An empty list\n");
+        if (eMsg.equals("N/A"))
+            System.out.println(" Your toString() returns:\n" + (sReturn.equals("") ? "  An empty list\n" : sReturn));
+        else
+            System.out.println(" Yours: " + eMsg + "\n"); 
+        
+        System.out.println("Total test cases: " + numTotalTests + "\nCorrect: " + numPassedTests + "\nWrong: " + (numTotalTests - numPassedTests));  
+    }    
+}