LinkedList Addition

	/**
	 * You have two numbers represented by a linked list, where each node
	 * contains a singledigit.Thedigitsarestoredinreverseorder,such that
the 1's
	 * digit is at the head of the list. Write a function that adds the two
	 * numbers and returns the sum as a linked list.
	 * 
	 * FOLLOW UP 
	 * 
	 * Suppose the digits are stored in forward order. Repeat the
	 * above problem.
	 * 
	 * */