Update README.md

README.md

@@ -30,9 +30,9 @@ Interviews
  * A *Linked List* is a linear collection of data elements, called nodes, each
    pointing to the next node by means of a pointer. It is a data structure
    consisting of a group of nodes which together represent a sequence.
- * **Singly-linked list**: linked list in which nodes have pointers to the next node and the last node point to null
- * **Doubly-linked list**: linked list in which nodes have two pointers which points to *both* the previous node and the next node
- * **Circular-linked list**: linked list in which nodes have pointers to the next node and the last node points again to the head
+ * **Singly-linked list**: linked list in which each node points to the next node and the last node points to null
+ * **Doubly-linked list**: linked list in which each node has two pointers p, n such that p points to the previous node and n points to the next node; the last node's n pointer points to null
+ * **Circular-linked list**: linked list in which each node points to the next node and the last node points back to the first node
  * Time Complexity:
    * Access: `O(n)`
    * Search: `O(n)`