package javaalgorithm;
/*
 * You are given two linked lists representing two non-negative numbers. 
 * The digits are stored in reverse order and each of their nodes contain a single digit. 
 * Add the two numbers and return it as a linked list.
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
 * 
 * 
 * 
 */
public class AddTwoNumbers {
	
	  //Definition for singly-linked list.
	  public class ListNode {
	      int val;
	      ListNode next;
	     ListNode(int x) { val = x; }
	  }
	 
	public class Solution {
	    public ListNode addTwoNumbers(ListNode l1, ListNode l2) 
	    {
	        ListNode dummyHead = new ListNode(0);
	        ListNode p = l1, q = l2, curr = dummyHead;
	        int carry = 0;
	        while (p != null || q != null) 
	        {
	            int x = (p != null) ? p.val : 0;
	            int y = (q != null) ? q.val : 0;
	            int sum = carry + x + y;
	            carry = sum / 10;
	            curr.next = new ListNode(sum % 10);
	            curr = curr.next;
	            if (p != null) p = p.next;
	            if (q != null) q = q.next;
	        }
	        if (carry > 0)
	        {
	            curr.next = new ListNode(carry);
	        }
	        return dummyHead.next;
	    }
	}
}