[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;
    }