Some minor refactorings

Author: rampatra

src/main/java/com/ctci/linkedlists/DeleteMiddleNode.java

@@ -1,8 +1,67 @@
 package com.ctci.linkedlists;
 
+import static com.ctci.linkedlists.Node.printList;
+
 /**
  * @author rampatra
  * @since 2019-01-27
  */
 public class DeleteMiddleNode {
+
+    /**
+     * Implement an algorithm to delete a node in the middle (i.e., any node but the first and last node, not
+     * necessarily the exact middle) of a singly linked list, given only access to that node.
+     * <p>
+     * EXAMPLE
+     * Input: the node c from the linked list a->b->c->d->e->f
+     * Result: nothing is returned, but the new linked list looks like a->b->d->e->f
+     *
+     * @param middle the node to be deleted
+     */
+    private static void deleteMiddleNode(Node middle) {
+        if (middle == null || middle.next == null) {
+            return;
+        }
+        // copy the data from the next node over to the middle node, and then to delete the next node
+        Node next = middle.next;
+        middle.val = next.val;
+        middle.next = next.next;
+    }
+
+    public static void main(String[] args) {
+        Node l1 = new Node(1);
+        l1.next = new Node(2);
+        l1.next.next = new Node(3);
+        l1.next.next.next = new Node(4);
+        l1.next.next.next.next = new Node(5);
+        l1.next.next.next.next.next = new Node(6);
+        printList(l1);
+        deleteMiddleNode(l1.next.next);
+        printList(l1);
+
+        System.out.println("----");
+
+        l1 = new Node(1);
+        l1.next = new Node(2);
+        l1.next.next = new Node(3);
+        printList(l1);
+        deleteMiddleNode(l1.next);
+        printList(l1);
+
+        System.out.println("----");
+
+        l1 = new Node(1);
+        l1.next = new Node(3);
+        printList(l1);
+        deleteMiddleNode(l1);
+        printList(l1);
+
+        System.out.println("----");
+
+        l1 = new Node(1);
+        l1.next = new Node(3);
+        printList(l1);
+        deleteMiddleNode(l1.next);
+        printList(l1);
+    }
 }

src/main/java/com/hackerrank/algorithms/strings/AlternatingCharacters.java

@@ -5,8 +5,8 @@
 /**
  * Created by IntelliJ IDEA.
  *
- * @author: ramswaroop
- * @date: 10/22/15
+ * @author rampatra
+ * @since 10/22/15
  * @time: 9:24 AM
  */
 public class AlternatingCharacters {