[leetcode]_Add Two Numbers

题目：两个链表存储数字，然后求和，和值存储在一个链表中。

代码：

 public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
         ListNode head = new ListNode(0);
         ListNode result = head;

         int carry = 0 , tempSum = 0;
         while(l1 != null || l2 != null){
             int v1 , v2;
             v1 = (l1 != null) ? l1.val : 0;
             v2 = (l2 != null) ? l2.val : 0;
             tempSum = v1 + v2 + carry;
             carry = tempSum / 10;
             tempSum = tempSum % 10;
             head.next = new ListNode(tempSum);
             head = head.next;

             l1 = (l1 != null) ? l1.next : null;
             l2 = (l2 != null) ? l2.next : null;
         }

         if(carry > 0) head.next = new ListNode(carry);

         return result.next;
     }