Refactored and finalized the linked list method to include a remove by element method.

src/main/java/net/jrtechs/www/DataStructures/IList.java → src/main/java/net/jrtechs/www/DataStructures/Lists/LinkedList/IList.java

@@ -1,4 +1,4 @@
-package net.jrtechs.www.DataStructures;
+package net.jrtechs.www.DataStructures.Lists.LinkedList;
 
 
 /**
@@ -47,6 +47,15 @@ public interface IList
     public E remove(int index);
 
 
+    /**
+     * Removes an element from the list
+     *
+     * @param o element to remove
+     * @return element which is removed
+     */
+    public E remove(E o);
+
+
     /**
      * Returns element at a particular index
      *

src/main/java/net/jrtechs/www/DataStructures/LinkedList/LinkedList.java → src/main/java/net/jrtechs/www/DataStructures/Lists/LinkedList/LinkedList.java

@@ -1,30 +1,29 @@
-package net.jrtechs.www.DataStructures.LinkedList;
+package net.jrtechs.www.DataStructures.Lists.LinkedList;
 
 
-import net.jrtechs.www.DataStructures.IList;
 import net.jrtechs.www.DataStructures.Node;
 
 /**
+ * Implementation of a linked list.
+ *
  * @author Jeffery Russell
  */
 public class LinkedList<E> implements IList<E>
 {
+    /** Head node */
     private Node<E> head;
 
+    /**Stored to make insertions o(1) */
     private Node<E> tail;
 
-
+    /** Keeps track of size so it doesn't
+     * have to be re-calculated each time it's used */
     private int size;
 
 
-    public LinkedList(E o)
-    {
-        this.head = new Node<>(o);
-        this.tail = head;
-        this.size = 1;
-    }
-
-
+    /**
+     * Creates a new empty linked list
+     */
     public LinkedList()
     {
         this.head = null;
@@ -33,6 +32,27 @@ public class LinkedList implements IList
     }
 
 
+    /**
+     * Creates a new linked list with an
+     * initial element stored inside of it
+     *
+     * @param o initial element
+     */
+    public LinkedList(E o)
+    {
+        this.head = new Node<>(o);
+        this.tail = head;
+        this.size = 1;
+    }
+
+
+    /**
+     * Adds a data element to the linked list.
+     *
+     * @param o element to get added
+     * @return
+     */
+    @Override
     public boolean add(E o)
     {
         this.size++;
@@ -51,6 +71,13 @@ public class LinkedList implements IList
     }
 
 
+    /**
+     * Checks to see if list contains the element
+     *
+     * @param o element to see if exists
+     * @return
+     */
+    @Override
     public boolean contains(E o)
     {
         Node current = this.head;
@@ -67,16 +94,28 @@ public class LinkedList implements IList
     }
 
 
+    /**
+     * Returns the size of the linked list
+     *
+     * @return
+     */
     public int size()
     {
         return this.size;
     }
 
 
+    /**
+     * Removes an element at a specific index in the
+     * linked list
+     *
+     * @param index of element to remove
+     * @return element removed, or null if the
+     * element is not found
+     */
     public E remove(int index)
     {
         int count = 0;
-
         Node<E> current = this.head;
         Node<E> previous = null;
         while(current != null)
@@ -102,6 +141,47 @@ public class LinkedList implements IList
     }
 
 
+    /**
+     * Removes a specific element from the linked list
+     *
+     * @param o element to remove
+     * @return element removed or null if element is not
+     * in the list
+     */
+    @Override
+    public E remove(E o)
+    {
+        Node<E> current = this.head;
+        Node<E> previous = null;
+        while(current != null)
+        {
+            if(current.getData().equals(o))
+            {
+                if(previous == null)
+                {
+                    this.head = current.getNext();
+                }
+                else
+                {
+                    previous.setNext(current.getNext());
+                }
+                this.size--;
+                return current.getData();
+            }
+            previous = current;
+            current = current.getNext();
+        }
+        return null;
+    }
+
+
+    /**
+     * Returns the element at a specific index
+     * of the linked list.
+     *
+     * @param index of desired element
+     * @return
+     */
     public E get(int index)
     {
         int count = 0;

src/test/java/net/jrtechs/www/DataStructures/LinkedList/LinkedListTest.java → src/test/java/net/jrtechs/www/DataStructures/Lists/LinkedListTest.java

@@ -1,6 +1,7 @@
-package net.jrtechs.www.DataStructures.LinkedList;
+package net.jrtechs.www.DataStructures.Lists;
 
 
+import net.jrtechs.www.DataStructures.Lists.LinkedList.LinkedList;
 import org.junit.Test;
 
 import static org.junit.Assert.assertFalse;
@@ -66,10 +67,10 @@ public class LinkedListTest
 
 
     /**
-     * Testing addition of data elements
+     * Testing deletion of data elements
      */
     @Test
-    public void testDeletion()
+    public void testDeletionByIndex()
     {
         LinkedList<Double> list = new LinkedList<>();
         list.add(12.0);
@@ -86,11 +87,35 @@ public class LinkedListTest
         list.remove(0);
         list.remove(1);
 
-
         assertFalse(list.contains(12.0));
         assertFalse(list.contains(44.9));
         assertTrue(list.contains(13.0));
     }
 
+    /**
+     * Tests linked deletion based on element
+     */
+    @Test
+    public void testDeletionByElement()
+    {
+        LinkedList<Double> list = new LinkedList<>();
+        list.add(12.0);
+        list.add(13.0);
+        list.add(44.9);
+
+        assertTrue(list.contains(44.9));
+        assertTrue(list.contains(12.0));
+        assertTrue(list.contains(13.0));
+
+        assertTrue(list.size() == 3);
+
+
+        list.remove(12.0);
+        list.remove(44.9);
+
+        assertFalse(list.contains(12.0));
+        assertFalse(list.contains(44.9));
+        assertTrue(list.contains(13.0));
+    }
 
 }

src/test/java/net/jrtechs/www/DataStructures/NodeTest.java

@@ -4,7 +4,6 @@ package net.jrtechs.www.DataStructures;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
-import net.jrtechs.www.DataStructures.LinkedList.LinkedList;
 import org.junit.Test;