title: Create a duplicate copy of Linked list in O(n) time
body: <p>A link list is given with two pointer, 1st is pointing to next node and another is random pointer. Random pointer is pointing to any node of LinkedList. Write a complete program to create a copy of Linked List(c,c++,c#), without changing original list and in O(n).</p>
  
  <p>I was asked this question in one of the interviews and I could not figure out the solution.
  Help would be appreciated.</p>