leetcode第二题

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        ListNode result = new ListNode(0);
        ListNode temp = result;
        ListNode temp1 = l1;
        ListNode temp2 = l2;
        int x,y,sum=0;
        while(temp1!=null||temp2!=null){
            x = temp1==null?0:temp1.val;
            y = temp2==null?0:temp2.val;
            sum = sum+x+y;
            temp.next = new ListNode(sum%10);
            sum = sum/10;//进位
            temp = temp.next;
            if(temp1!=null)
            temp1 = temp1.next;
            if(temp2!=null)
            temp2 = temp2.next;
        }
        if(sum>0){temp.next = new ListNode(1);}
        return result.next;
    }
}